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| Happy Life in the Sixties | Jobs - Employee | 2022-08-16 | No Picture |
| Happy Life in the Sixties
Believing it to be true Liu Yue quickly looked at Industrial pallet rack Zhao Jianguo's ears and asked eagerly "Brother Jianguo does it still hurt I didn't mean to" Zhao Jianguo laughed and suddenly turned off the light In the darkness he heard a charming cry in the room You're a big liar a bad man um Ah gently Chapter 131 On the seventh or eighth day of the first lunar month most of the younger generation paid New Year's greetings to their relatives and the uncle's family began to send lanterns and a kind of long fireworks like a rope half a meter long to their nephews and nieces From the tenth day of the first lunar month the children in the village ran around the village with lanterns As soon as they came out there were a group of people each carrying a small lantern in his hand and some holding earthen fireworks and then throwing them into a circle to play The sparks that came out accidentally fell on their clothes which was a small burnt hole They would not go home and play in the middle of the night When the parents found out the next day they could only hold their breath and scold "Coward!"! We'll settle the total account after fifteen This kind of activity will not end until the evening of the fifteenth day of the first lunar month after the lantern festival After the lanterns are scattered on the fifteenth day of the first lunar month parents should insert a candle in every corner of the courtyard to illuminate the courtyard so as to drive away the filth in the courtyard and make the new year clean and bright All the lanterns carried by children should be burned and lanterns will appear in the house when people come except for the big lanterns hanging at the door After the fifteenth day of the first lunar month it means that the New Year is over and the work of the new year will begin Zhao Jianguo is ready to recruit people to develop the hunting ground in his mind and the hot springs found when he sent tigers and grizzly bears back to the mountains and forests and to Pallet rack supplier develop all the resorts for tourism in the Western Hills in the next five years In this way Mingxuan will be able to take over his class after graduation I can also take Liu Yue to play around the world This is he and Zhao Mingxuan has long agreed such as Mingxuan graduation he will help two years to officially retire at this point Zhao Jianguo pit son is not discussed poor Mingxuan just over 21 years old will become a family helmsman When Zhao Jianguo was very busy someone came here to mess with him Zhao Jianguo looked at the shy and timid Sun Xiaoru in front of him He was very speechless It could be said to be a coincidence to meet him once or twice At this time it could not be a coincidence every time With these measures the TV series were all bad Although Zhao Jianguo just started to see Liu Yue long good-looking but this time long Liu Yue meticulous care filial piety to his parents so that he unconsciously fell in love with this kind woman Zhao Jianguo doesn't want to be sorry for Liu Yue and stick to Sun Xiaogu To make Liu Yue sad Bai could not be distressed So when Sun Xiaogu came up again he said clearly "Sun Xiaogu men and women are different You always come to me which has caused me a lot of trouble I hope you can live in peace in the future" Sun Xiaogu was surprised for a moment but then he thought that Zhao Jianguo was not a decent person before It was estimated that he was angry that he had ignored him before There were men in the world who didn't cheat So Pear Flower with Rain cried in a low voice and said in a charming voice "Jianguo I used to like you too but my father was strict and wanted me to marry to the town I couldn't beat my family" Now I am free I really like you as long as I follow you I will not affect your family warehouse rack manufacturer I do not want a name "I don't like you and I won't have anything to do with you You'd better not come to my office again and live a peaceful life Otherwise I'll talk to your family in person" Zhao Jianguo said coldly Although Sun Xiaogu is a beauty but there are many beauties in the world Zhao Jianguo does not want to be penny-wise and pound-foolish so that there is a gap between himself and Liu Yue destroying his happy family Sun Xiaogu looked at the cold Zhao Jianguo is this man's heart made of iron Such a beautiful woman is so wronged that she wants to follow him Shouldn't he be secretly pleased So a little angry asked "Zhao Jianguo you touch your heart I do not have a little heart" "No I'm only interested in my wife Please go out" Zhao Jianguo continued to look at his documents without raising his head Sun Xiaogu was really angry and cried this time "Zhao Jianguo I hate you!" He shouted Then he covered his face and ran out crying As soon as I opened the door I saw Liu Yue at the door and I was even more angry "Humph!" Run away with a sound When Zhao Jianguo heard the noise he looked up and saw that it was Liu Yue He quickly stood up and went over to hug her in He said with a smile "See" Daughter-in-law I am so good do you have any reward Said to Liu Yue's neck Liu Yue looked at the shameless Zhao Jianguo and thought it was funny She was very happy but she pretended to be angry and said "No reward!"! It attracts bees and butterflies every day Zhao Jianguo pretended to be sad and said "Alas I am loyal to my daughter-in-law but my daughter-in-law doesn't believe me I am sad and want to hug her" Liu Yue pinched Zhao Jianguo's face with a reddish face and said with a smile "Your face is getting thicker and thicker" Then he gently kissed Zhao Jianguo on the face "For the sake of your good performance I will reward you" …… Three years later Minghui was admitted to the National University of Defense Technology realizing his first step to become a professional soldier Although Mingxuan university has not graduated but Zhao Jianguo handed over most of the company's business to him this boy is born to be a businessman some ideas practices Zhao Jian thinks that if you change yourself you may not be able to do better than him So Zhao Jianguo was very irresponsible so he became a shopkeeper Every day he went hunting in the mountains fishing in the river and from time to time he took Liu Yue to soak in hot springs and had a lot of fun If he didn't have to make up his mind about something maybe he and Liu Yue would be able to go abroad and travel around the world Zhao Jianguo is carefree In his carefree life Xu Dabiao the director of the Public Security Bureau and Zhang Jiabao the president of the court who took over his father-in-law were so envious that they wished they could beat up the boy They all sighed Among the brothers Zhao Jianguo was the most chicken thief He refused to do public office anyway and did it himself He could retire and visit the mountains and rivers at the age of forty Zhang Jiabao can't see Mingxuan now He used to say that he wanted Mingxuan to be his son-in-law but when Mingxuan abducted his little baby who had just turned sixteen he would scratch his heart and lungs How much he liked Pengxuan before how much he hated it now It's so annoying! omracking.com |
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| What is the difference between N95 and KN95 masks? Can they all be used for medical protection? _ particulate matter | Jobs - Employee | 2022-08-16 | No Picture |
| What is the difference between N95 and KN95 masks? Can they all be used for medical protection? _ particulate matter
Originally published as What's the difference between N95 Medical Full Body Coverall and KN95 masks Can they all be used for medical protection An epidemic has made almost everyone aware of the various standards of masks the most popular of which are N95 and KN95 What is the difference between N95 and KN95 Can these two standard masks be used for first-line medical protection Let's take a look at the answer in this article 1 Is there any difference between KN95 and N95 mask N95 is the certification grade for respirators in the United States and is certified by the National Institute for Occupational Safety and Health (NIOSH) This kind of mask can filter out more than 95% of non-oily particles (aerosols) under the condition of specified airflow (85L/min) so it is named N95 If it can filter more than 99% of particulate matter (aerosol) it is called N99 mask In addition corresponding to N95 KN95 is a mask certified by China's GB2626-2006 Respiratory Protective Equipment Self-priming Filter Particulate Respirator Standard KN95 has the same level of protection as N95 mask but it follows the test standards of different countries KN95 masks follow Chinese standards and N95 mask follow American standards both of which have a protective efficiency of no less than 95% against non-oily particles (sodium chloride particles for experiments) 2 Can KN95 mask be used for first-line protection KN95 respirators and N95 mask include both medical and non-medical types Among them KN95/N95 mask masks with "medical" logo can be used for first-line protection of medical staff during the anti-epidemic period masks without "medical" logo are not recommended for medical staff ordinary people can use them Masks conforming to GB19083 above Grade 1 can not only achieve 95% filtration but also prevent liquid penetration and can be used for various operations in medical institutions 3 Why is KN95/N95 mask anti-virus Viruses usually do not exist in the air alone but are attached to particles such as Full Body Disposable Coverall droplets dust and dander The filtering mechanism of KN95 and N95 mask is to block these fine particles through the high-performance filter layer in the mask to build a protective barrier Therefore when wearing KN95/N95 respirators namely self-priming filter particulate respirator masks attention should be paid to the tightness KN95 Face Mask with Five Layers which should be close to the face and never leave a "convenient door" for viruses and bacteria It is recommended to use masks with "exhalation valves" with caution 4 What is the difference between medical and non-medical masks in KN95/N95 mask The main difference is that the outer surface of the medical mask is hydrophobic while the surgical mask of GB19083-2010 and YY0469-2011 clearly put forward the requirement of "synthetic blood penetration" and the parameter index of "surface moisture resistance" which clearly define the protective effect of medical protective masks on blood body fluids and other liquids Generally speaking just like a drop of water falling on a lotus leaf the liquid cannot be soaked on the surface of the mask which can block alcohol blood and the like frequently touched by medical staff and prevent the rapid penetration of the alcohol and the blood; and a non-medical type KN95/N95 mask is not subjected to the special treatment The filter layer of KN95 and N95 protective masks has the most protective function The filter layer is made of polypropylene melt-blown superfine fiber electret material The outer surface of the mask has not been hydrophobic treated When it comes into contact with water and alcohol the structure of the material will be destroyed and the filtering effect will be greatly reduced Moreover blood often contains bacteria viruses and so on and the application scenarios of hospitals determine that medical staff are likely to be exposed to the blood environment of patients Therefore hydrophobic treatment on the surface of medical masks is indispensable Ordinary people are not likely to encounter alcohol and blood as long as they change their masks regularly it is not harmful to their outside without this treatment 5 What is the protective effect of KN95/N95 mask with breather valve KN95/N95 mask is also divided into breather valve and non-breather valve For masks permeability and filtering efficiency are always a pair of contradictions if the filtering effect is good they often feel more suffocating Breathing valves are designed to relieve breath-holding The exhalation valve and the inhalation valve are a mechanical switch the valve is closed when inhaling and opened when exhaling the air is "screened" by the filter layer and the valve is opened when exhaling to reduce the sense of resistance The problem is that it is not clear whether the mechanical switch will suddenly break down when worn or whether it will be stuck by fine particles allowing harmful particles carried by air that have not passed through the filter layer to enter Therefore medical masks do not have breathing valves Return to Sohu to see more Responsible Editor zjyuan-group.com |
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| New rules for wearing medical masks! The third edition of "Guidelines for the Prevention and Control of Novel Coronavirus" is coming _ Protection | Jobs - Employee | 2022-08-16 | No Picture |
| New rules for wearing medical masks! The third edition of "Guidelines for the Prevention and Control of Novel Coronavirus" is coming _ Protection
Original Title New Rules for Wearing Medical Masks! bra tape measure The third edition of "Guidelines for the Prevention and Control of Novel Coronavirus" is coming Compared with the previous edition of the guide what are the differences in the third edition and what are the main adjustments On September 13 2021 the National Health Commission issued the Technical Guidelines for the Prevention and Control of New coronavirus Infection in Medical Institutions (the third edition) (hereinafter referred to as the "Guidelines") only five months after the publication of the second edition The first edition of the guide was released on January 23 2020 Compared with the previous edition the new edition of the guidelines mainly increased the contents of "medical staff protection" and "closed-loop management of fever clinics and designated hospitals" The content structure has not been greatly adjusted which is divided into four chapters "overall requirements" "prevention and control strategies" "basic requirements" and "technical requirements of key departments and departments" Since this year there have been many hospital infection incidents requiring hospitals to refine the sensory control program Since this year hospital infection incidents have occurred in many places which has sounded the alarm bell for hospital infection control On January 19 the official website of the National Health Commission issued a circular on the inadequate prevention and control of COVID-19 in Gaocheng People's Hospital of Shijiazhuang City and Xinle Hospital of Traditional Chinese Medicine in Hebei Province which included 14 positive cases including a 70-year-old hospital nurse who was diagnosed Problems such as confusion in hospital management failure of health departments and local prevention and control command departments to perform their duties have been exposed and Hebei Province and Shijiazhuang City have held relevant personnel accountable At the end of July a large-scale hospital infection broke out in the Sixth People's Hospital of Zhengzhou and nearly 150 hospital staff and patients were infected As a former "anti-epidemic star" of KN95 Mask with Fast Shipping Henan Infectious Disease Hospital Ma Shuhuan Secretary of the Party Committee of the hospital was dismissed after the hospital infection occurred The Sixth Hospital of Zhengzhou is still in the period of recovery and reconstruction and has not yet been opened Expand the full text In September the epidemic broke out again in Yangzhou Jiangsu Then came the epidemic centered on Putian City and Xiamen City in Fujian Province Yesterday the First Affiliated Hospital of Xiamen University announced that the nucleic acid test results of a logistics service staff of a third-party company in the hospital were positive These incidents are reminding medical institutions to guard against weak links in the work of sensory control Especially after the occurrence of large-scale nosocomial infection in Zhengzhou Sixth Hospital the Joint Prevention and Control Group of the State Council issued three documents on strengthening the sensory control of designated hospitals improving the sensory control mechanism of medical institutions and strengthening the management of sensory control personnel in medical institutions within a month which provided more norms for hospital sensory control work The contents of these documents are also reflected in the guidelines released this time The guidelines require strict implementation of the requirements of the above documents including equipping a team of highly professional infection control personnel according to the requirements; medical institutions should formulate detailed training programs for all staff of infection prevention and control in their institutions and further strengthen the awareness that "everyone is a practitioner of infection control" To strengthen protection some medical staff masks should be tested for tightness "Proper Use of Personal Protective Equipment" is part of the "Essential Requirements" section of the guide The content of the old guide is Medical institutions should strengthen the management of personnel protection and reserve protective materials of good quality and sufficient quantity Medical staff should correctly and rationally use medical surgical or medical protective masks goggles or protective screens gloves isolation clothes or protective suit according to exposure risks and diagnostic and therapeutic operations so as to ensure that personal protection of medical staff is in place At the same time they should guide and supervise patients and their accompanying personnel as well as other personnel entering medical institutions to do a good job of personal protection The latest edition of the guidelines adds a paragraph to the above content requiring some medical staff masks to be tested for tightness In isolation wards fever clinics nucleic acid sampling points nucleic acid testing laboratories and other key places medical staff who are more likely to come into contact with the novel coronavirus should strengthen protection and strictly implement the requirements of wearing medical protective masks The personnel working in the fever clinic and the isolation ward of the designated hospital shall be tested for the suitability and tightness of the medical protective mask and only those who are qualified shall be allowed to work; before entering the fever clinic and the isolation ward of the designated hospital the tightness of the medical protective mask shall be tested What should I do if the mask falls off carelessly in the polluted area CE Certificate KN95 Mask Guidelines require posting of disposal procedures For the contaminated areas of designated hospitals and wards for COVID-19 treatment the old version of the guidelines requires that "the contaminated areas should be equipped with individually packaged personal protective equipment and occupational exposure emergency disposal boxes for emergency use" while the new version of the guidelines also requires that "the disposal procedures after respiratory occupational exposure (see Annex 4) should be posted in obvious places" Annex 4 reads as follows Disposal process after respiratory tract occupational exposure 1 Virus Prevention Mask 3 Ply with Earloop Respiratory exposure Close contact with patients diagnosed with COVID-19 due to lack of respiratory protective measures damage to respiratory protective measures (such as loose masks falling off etc) use of ineffective respiratory protective measures (such as use of masks that do not meet the requirements of the specification); contact with mouth and nose by hands contaminated by COVID-19 etc II Disposal Process (1) When occupational exposure to respiratory tract occurs in a medical staff measures shall be taken immediately to protect the respiratory tract (covering the mask with the hand after the implementation of standardized hand hygiene or adding a layer of mask urgently etc) and the contaminated area shall be evacuated according to the prescribed procedures (II) Pass through the unloading area in an emergency and unload the protective equipment according to the requirements of the specifications (3) Clean and disinfect the oral cavity or/and nasal cavity with clean water 01% hydrogen peroxide solution and iodophor according to the situation and leave after wearing a medical surgical mask (4) Timely report to the director of the department concerned the head nurse and the competent department of the medical institution (5) Medical institutions shall organize experts to conduct risk assessment as soon as possible including confirming whether isolation medical observation preventive medication and psychological counseling are needed (VI) Persons with high risk exposure shall be managed as close contact persons and shall be isolated for medical observation for 14 days (7) Fill in the occupational exposure record form of COVID-19 medical staff in time especially the causes of exposure and carefully summarize and analyze them to prevent similar incidents Some fever clinics also need closed-loop management The technical requirements for key departments and departments in the guidelines are independent These key departments and departments are fever clinics emergency departments departments/departments where patients need to remove masks when receiving diagnosis and treatment measures hemodialysis centers (rooms) general wards (rooms) designated hospitals and wards for the treatment of COVID-19 infected persons and COVID-19 nucleic acid testing laboratories Among them the new guidelines have greatly increased the contents of the two sections of "fever clinics" and "designated hospitals and wards for the treatment of novel coronavirus infected persons" For fever clinics the new guidelines put forward more specific requirements for protection medical staff entering and leaving fever clinics and observation wards should wear medical protective masks work caps gloves boots or shoe covers (protective suit do not need to wear boots if they already have boots) wear isolation gowns or protective suit (observation wards should wear protective suit) and wear goggles or protective screens according to the operation of diagnosis and treatment And part of the fever clinic staff to strict closed-loop management this part is reception entry domestic high risk areas and focus on the isolation point of fever patients and other high-risk groups of fever clinics All personnel in the isolation ward travel at two points and one line In the old version of the guidelines the isolation wards of designated hospitals were required to carry out closed-loop management while the new version of the guidelines put forward one more point "strict implementation" Specifically during the working period a single person will be arranged to live in a single room and all personnel will travel between the station and the designated hospital at two points and one line with fixed commuting vehicles and no station will be arranged in the designated hospital The new guidelines also specify the scope of "all staff" in the isolation wards of designated hospitals Including medical management security cleaning catering medical waste collection and transportation personnel and other staff who directly or indirectly contact with COVID-19 infected persons (including medical staff such as imaging examination and closed-loop management personnel who provide services for COVID-19 infected persons) In addition for designated hospitals the new guidelines also have several provisions that the old version did not have in principle the reserve should meet the needs of designated hospitals to operate at full capacity for 30 days; fever clinics should immediately transfer new coronavirus infected persons to designated hospitals; For the management of accompanying and visiting the expression of "in principle" has been deleted from the old version of "no arrangement for visiting and accompanying in principle" that is "no arrangement for visiting and accompanying" Source Medical think tank Author Wei Xiaoning Proofread by Zang Hengjia Editor Zheng Huaju The medical profession strives for the accuracy and reliability of its published contents at the time of approval but does not make any commitment and guarantee to the timeliness of the published contents and the accuracy and completeness of the cited information (if any) nor does it assume any responsibility arising from the fact that such contents are outdated or that the cited information may be inaccurate or incomplete Relevant parties are requested to check separately when they adopt or use it as a basis for decision-making Click "Read the original article" to see more information and return to Sohu to see more Responsible Editor zjyuan-group.com |
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| Medical disposable protective suit waterproof adhesive tape brief introduction _ production | Jobs - Employee | 2022-08-16 | No Picture |
| Medical disposable protective suit waterproof adhesive tape brief introduction _ production
Original title Brief Introduction of Medical bra tape measure Disposable protective suit Waterproof Adhesive Strip (Die-cutting House April 8) medical protective suit as a kind of anti-chemical clothing is mainly used for medical staff to wear The ideal medical protective suit should be multifunctional not only able to protect medical staff from toxic and harmful liquids gases or infectious viruses and microorganisms but also comfortable to wear with barrier properties but also breathable antibacterial and anti-allergenic not harmful to human health In addition the choice of protective suit fabrics should also consider the cost and environmental protection after waste Requirements to achieve "three refusals and one resistance" that is water-repellent blood-repellent alcohol-repellent and antistatic medical protective suit are different from general woven materials using special composite materials which can be compounded with different materials such as polyethylene/polypropylene spunbonded non-woven fabrics with breathable microporous films or other non-woven fabrics or with spunlaced non-woven Or the wood pulp is used for compounding the spunlaced nonwoven fabric At present the nonwovens used in several medical protective suit being sold and developed in the domestic market are mainly as follows Polypropylene spunbonded fabric Spunlaced fabric composed of polyester fiber and wood pulp Polypropylene spunbond-meltblown-spunbond composite nonwoven fabric ie SMS or SMMS Polymer-coated fabric Polyethylene breathable film/nonwoven composite cloth TPU moisture permeable film/nonwoven composite fabric Common medical protective suit usually consist of hats jackets and trousers which have strict standards in production including protection (sealing) clothing safety and hygiene Through the cutting sewing on the elastic adhesive tape to produce medical protective suit involving the process can not be separated from these three flat seam overlock pressure glue The reason why protective suit can achieve such a high sealing is that it can not be separated from the most important step of pressing glue Aft that protective suit is sewn by a lathe work all stitches and pinholes in the protective suit need to be sealed by pressing glue through a heat seal machine so as to prevent dust or liquid from entering from the sewn pinholes and enhance the isolation performance and use safety of the protective suit As shown in the figure below the adhesive pressing is to press the heat-sealing adhesive tape at the pinhole position of the protective suit through the heat-sealing machine to ensure the sealing of the pinhole position The outbreak of the COVID-19 epidemic with the spread of the epidemic the demand for medical supplies around the surge the most scarce is medical protective suit During the Spring Festival the import protective suit and inventory protective suit played an Medical Quickly Delivery Antivirus Coverall important role and the follow-up protective suit supply was mainly domestic The Ministry of Industry and Information Technology takes the following measures Expand the full text 1 Make greater efforts to increase production and expand capacity; 2 Do a good job of docking supply and demand and fully guarantee the needs of epidemic prevention and control; 3 Strengthen the control of the whole process of allocation to ensure that key medical supplies are controllable and arrive on time In view of the shortage of medical protective suit many garment enterprises have responded to the call of the state to start production of "protective suit" while working overtime to improve production capacity The official website of the Ministry of Industry and Information Technology also released a proposal for collecting information on layering machines for medical protective suit production on February 9 saying that the output of medical protective suit has increased but it is still difficult to meet the current demand for epidemic prevention and treatment Among them the lack of layering machines (also known as hot air seam sealing machines stickers heat sealing machines) and matching heat sealing tapes are the bottlenecks restricting the increase of production and capacity The popular disposable medical protective suit materials on the market are mainly as follows The corresponding sealing processes of these materials are also different Polypropylene non-woven fabrics and SMS non-woven fabrics can be sealed by hot pressing that is two layers of fabrics are heated by a hot press and directly bonded together The hot pressing part will cause the fluctuation of hydrostatic pressure due to the insufficient uniformity of hot pressing Polyethylene microporous membrane/non-woven fabric shall be sealed by means of heat sealing The special polyethylene heat-sealing adhesive tape (hereinafter referred to as PE heat-sealing adhesive tape) for polyethylene microporous membrane shall be pressed at the suture position by using a heat-sealing machine to ensure airtightness The sealing method of TPU film/non-woven fabric is the same as that of polyethylene microporous film/non-woven fabric Use a heat sealer to press the TPU heat-sealing adhesive tape at the suture position to ensure the airtightness PE heat sealing rubber strip PE heat sealing adhesive tape shall be used together with polyethylene microporous film/non-woven fabric The production method of the PE heat sealing adhesive tape is to coat the hot melt adhesive on a special base material which is mainly divided into polyester + hot melt adhesive EVA + hot melt adhesive and PE/EVA + heat melt adhesive The base material is produced first and then the hot melt adhesive is compounded on the surface of the base material The polyolefin hot melt adhesive used is also called TPR in the industry Protective suit sealing strip structure (Source Quickly Delivery Disposable Protective Clothing Jiangmen Yingtong Company) First of all we need to make fabrics dyeing and finishing which belongs to the textile industry and the production speed is greatly limited At the same time the melting point of the coated hot melt adhesive is very low at 50-70 deg C and most of the hot melt adhesive is produced in a scrape coating mode namely a base material is produced first then the hot melt adhesive material is scraped on the surface of the base material after being melted by a solvent and then is coiled into a coil after being dried; or the hot melt glue material can be cast on the surface of the base material in a casting extrusion mode and then is coiled into a large coil Finally cut the large roll of adhesive tape into small rolls of adhesive tape Because the production process starts from fiber manufacturing textile dyeing and finishing as well as resin synthesis processing and coating the industrial chain is relatively long and the process is complex Because of the low strength of TPR resin the basic strength must be provided by the fabric layer so the fabric and resin are indispensable There are Medical Disposable Coverall several drawbacks in the production process of PE heat-sealing adhesive tape The production process contains solvents which will pollute the environment If the solvents are not completely volatilized there may be residues The production efficiency of the scraping process is low about 5m/min which seriously affects the efficiency The hot melt adhesive material extruded by casting flows on the base material and the melting point of the hot melt adhesive material is too low by 50-70 deg C so that the processing is difficult and the production speed is slow Because the melting point of the polyethylene material is relatively low (100-120 ℃) the temperature setting of the heat sealing machine is also relatively low the speed of pressing the adhesive tape will be 5-8 m/min too fast may scald the polyethylene microporous film resulting in water leakage and the processing requires workers with high proficiency and technical requirements TPU heat sealing adhesive tape TPU heat sealing adhesive tape shall be used together with TPU film/non-woven fabric because TPU adhesive tape is incompatible with PE film and cannot be bonded The production of TPU heat-sealing adhesive tape is relatively simple and convenient It can be completed by using TPU blown film or TPU casting production equipment to produce films and then cutting them into small rolls The production speed of one set of TPU film making equipment is about 15m/min (equivalent to 100-120m/min when converted into the width of adhesive tape) which is much faster than that of PE heat-sealing adhesive tape Moreover the TPU film production equipment has strong versatility and the production capacity is not a problem at all The TPU heat-sealing adhesive strip can be of a two-layer structure wherein one layer is a high-temperature TPU which provides excellent barrier property and strength and the other layer is a low-temperature hot-melt adhesive TPU which provides excellent welding fastness and bonding speed Because the tensile strength of TPU is very high usually up to 30 ~ 50 MPa which is 5 ~ 6 times higher than that of TPR so the TPU waterproof strip does not need a plant layer at all and its strength is enough to meet the requirements of waterproof infiltration and bacteria resistance (the casual clothes and mountaineering clothes on the market at present are all of this structure) Moreover the TPU industry has been greatly developed in China from raw material synthesis to various production equipment the technical level of membrane enterprises is very high the products have a high cost performance and also have a very strong competitiveness in the international arena TPU sealant strip The melting point of the high-temperature TPU film is 150-170 deg C which is much higher than that of the polyethylene film and the melting point of the low-temperature hot melt adhesive TPU can be 70-120 deg C so that the speed of pressing the adhesive tape can reach about 15m/min the efficiency is greatly improved and the processing difficulty is relatively low The national standard "Technical Requirements for Medical Disposable protective suit" GB 19082 2009 stipulates that the hydrostatic pressure at the key parts of the protective suit should not be less than 1 67 kPa (17 cm H2O) The standard of hydrostatic pressure is actually very low Many garment customers of our company require that the hydrostatic pressure at the position of the adhesive tape should be more than 30 kPa (300 cm H2O) after the finished clothes are made; The hydrostatic pressure at the slightly higher adhesive tape pressing position is required to be more than 50 kPa (500 cm H2O) which is dozens of times of the hydrostatic pressure requirement specified by the protective suit and the TPU adhesive tape can easily meet the requirement As a high-tech enterprise in China Zhongshan Boruisi New Material Co Ltd is the pioneer of TPU film products in China's national industry It has rich experience in designing and producing all kinds of original films for sealant strips including single-layer and multi-layer structures with different temperature ranges and different pressing speeds The company's medical protective clothing bacteria-resistant and moisture-permeable film is used for medical protective suit fabrics with the highest protection level Can be matched with pure TPU adhesive tape for rapid production With the deepening of anti-epidemic work we are pleased to see that more and more protective suit manufacturers begin to use composite TPU film fabrics The production of corresponding TPU sealing strips is also gradually keeping up For more industry information go to the application market to download the die-cutting home APP return to Sohu to see more Responsible Editor zjyuan-group.com |
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| Detailed explanation of the production and disinfection process of medical masks with pictures and texts, with guidelines for the selection of masks _ production | Jobs - Employee | 2022-08-16 | No Picture |
| Detailed explanation of the production and disinfection process of medical masks with pictures and texts, with guidelines for the selection of masks _ production
Original title Detailed explanation of the 3 Ply Disposable Protective Face Mask production and disinfection process of medical masks with pictures and texts with guidelines for mask selection According to the statistics of the Development and Reform Commission on February 5 as of February 3 the output of masks in 22 key provinces in China had reached 148 million an increase of 31% over the previous day of which N95 mask had reached 116000 an increase of 48% other medical masks had reached 998 million an incr ease of 36% and ordinary masks had reached 471 million The production of masks showed a continuous upward trend While sharing the good news with you Mr Process also brings you a detailed explanation of the production of medical masks The article is accompanied by a guide to the selection of masks as well as the resumption of work of domestic PP enterprises and the scheduling of medical and health materials It is full of dry goods! The article is longer it is recommended to read after collection In addition on February 2 Huang Libin a spokesman for the Ministry of Industry and Information Technology also said At present the main shortage of materials in Wuhan is medical protective supplies such as medical protective suit and medical N95 mask China has made every effort to promote the resumption of production in key enterprises By February 1 the daily output of medical protective suit had reached 20000 pieces a significant increase compared with 8700 pieces on January 28 and the production was basically used in Hubei At present China implements unified management and allocation of medical protective suit and the Ministry of Industry and Information bra tape measure Technology is doing everything possible to implement the supply of goods step up the organization of production and transportation increase the conversion of international standards expand international procurement for domestic use and strive to ensure demand In the face of the epidemic in addition to medical and health enterprises such as masks and protective suit PP enterprises in the plastic industry also resumed production during the holidays Up to now the number of PP enterprises in China has reached 14 and the number of medical and health materials scheduling enterprises has reached 31 (See the annex at the end of the article for the specific list and the data is still being updated in real time) What material is the N95 mask of an article published by Mr Process last week Which domestic chemical enterprises produce related raw materials There is also a detailed explanation of the mask materials Welcome to read Expand the full text So how are medical masks made How to disinfect the factory Let's take a look at a set of detailed graphic introductions The following content comes from MadeWithFun (ID MadeWithFun) thanks to the original author's hard work Let's take a look! At least three floors If you cut out the mask you can see that there are at least three layers of non-woven fabrics which are required by the production regulations at least three layers When we look at the inferior masks that have been exposed on the market only one layer of non-woven fabric is used which is the serious jerry-building of unscrupulous manufacturers What do you mean by "non-woven fabric" "Non-woven fabrics" (also called "non-woven fabrics") are named for the process by which they are made They are not woven All kinds of clothes we often wear such as cotton linen and silk are always woven into shape little by little on the machine And the "non-woven fabric" is similar to the needling method we use to make felt There is no knitting It uses N needles to keep poking and poking so that the cotton structure is tangled and solidified together and then processed into such a flat layer of cloth This is not a precious material either Grandpa and grandma went to participate in a health activity for the elderly and most of the "environmentally friendly bags" they got were made of "non-woven fabrics" The middle filter layer of medical masks is made of melt-blown cloth that is KN95 Face Mask PP (polypropylene) and other chip particles are heated and melted pressurized and sprayed from small holes into very fine silk sprayed onto the net curtain and transported to the heated roller for hot pressing and shaping into cloth The inner and outer layers are generally made of spunbonded cloth which has similar cloth forming process and different functions of hydrophilicity and hydrophobicity The inner and outer layers can also be changed The outer layer is lined with needled cloth to improve the thickness and hardness but it can only block droplets not viruses The inner layer is changed to a softer ES hot-rolled cloth to improve comfort Then why is there a shortage of masks after so many days Because the market is in short supply As a disposable consumable More than one billion people across the country want to have a few people every day All of a sudden there is an explosive demand In addition the supply of raw materials is tight The big manufacturing countries urgently resume work and rush to work day and night but they can't supply for a while Merge three layers Such three layers of non-woven raw materials are stacked together through the production machine as shown in the figure below Have you noticed the small horn in the upper left corner of this machine There is a string of wire through the bell mouth and keeps sending it in Sew into the nose clip This depends on the second structure of the mask the bendable metal wire on the upper part of the mask When wearing the nose clip should be pinched and fixed to the bridge of the nose so that the mask can be worn tightly Otherwise without this structure the air leakage of my flat nose is more serious and the sealing is not tight which affects the protective effect Let's take a look at a close-up which is to match and convey the metal wire along one side of the non-woven fabric and then roll the edge of the structure in the following picture and then sew it up and it's done Stacked portion The main part of the mask is the layered structure shown in the picture below 3 Ply Disposable Protective Face Mask which can be pulled open to completely cover the mouth and nose and the big face is not afraid The cross section of this laminated structure is so long that it needs a machine folding link This is the mechanical design as shown in the figure below There are three adjustable inclined planes and a small bevel angle is set so that a large piece of non-woven fabric gradually narrows from left to right along these inclined planes to form a "folding structure" Then there is a tabletting link to flatten the surface of the mask Cutting link Most of the individual cutting and hemming of masks are fully automatic without manual processing And different masks have slight manufacturing differences some are sewn edges some are directly hot-pressed and glued small details What comes out is a separate main body of the mask It's not over yet There are still several steps ahead Complement edge pressing The picture below is the mask I bought Pay attention to the edge of the mask There is a non-woven fabric to reinforce and press the ear rope so as not to tear it off There are two large rolls of non-woven fabrics on the left and right waiting to reinforce the edge of the mask After one side is wrapped it is immediately pressed flat and glued At this time the masks that had been cut out were linked together again This is really the endless hatred since ancient times So we still need a link to cut and reinforce the edge and make a clean break Hot-press and fix the ear rope Adhesive is also needed on the edge of the mask As shown in the picture below the mechanical claw on this side sends the ear rope and the adhesive on the other side fixes the ear rope on the mask In this way a flat mask is finished After that of course we have to bring out our "manual quality inspection" In the recent news of mask factories we often see employees pulling ear ropes to test or tidy up masks Some little cuties are worried about sterility Don't worry they have to be sent to disinfect and sterilize again Open type mask Before disinfection let's look at the production of an open mask which is common in anti-smog mask or with higher protective specifications such as the kind with a breathing valve The feeding in the picture below is very clear There are five rolls of non-woven fabric on the right which shows that there are five layers of structure The orange turntable is the metal wire at the nose clip The most important structure of the open-type mask is shown in the picture below A whole piece of flat fabric is folded together through this V-shaped structure and then cut into a single one Then the production of edge cutting sewing reinforcing and ear sealing lines are almost the same so I won't repeat them Disinfection and sterilization Speaking of non-woven fabrics have you heard the old people complain that this kind of environmental protection bag is not strong and it is easy to break if you use it several times Fragile non-woven fabrics are generally not sterilized by high temperature but by using ethylene oxide a colorless gas to kill bacteria mold and fungi After finding an animated demonstration batches of masks were sent to the disinfection room and then ethylene oxide gas was introduced (the yellow color in the picture below is for highlighting in fact it is colorless) After reaching a certain concentration the disinfection process was completed After that air and nitrogen should be introduced into the disinfection room to dilute and remove ethylene oxide and so on until the residual amount of ethylene oxide on the surface of the mask reaches the standard There are also medical bandages sutures surgical instruments and some items that are not resistant to high temperature disinfection which can be disinfected with ethylene oxide In addition radiation disinfection is widely used in the disinfection of high-grade medical protective masks which mainly uses the ability of ionizing radiation to kill pathogenic microorganisms to disinfect disposable medical supplies It is superior to heating method and ethylene oxide chemical disinfection method and is a very mature sterilization method in radiation processing The internationally accepted disinfectant dose is 25 kGy and some countries tend to prescribe higher doses (eg 30 to 50 kGy) At present in addition to the military industry there are about thirty or forty such subsidiaries of China Nuclear Power Group and China Guangzhou Nuclear Power Group providing irradiation disinfection technology services and all of them have been invested in this epidemic Sanitary products such as masks after radiation sterilization are safer and the radiation penetration is strong the disinfection is uniform and thorough and there is no harmful residue (Thank you for your supplement If you have any professional opinions please tell me in the comment area) During the epidemic period we will teach you how to choose the right mask not to over-protect so that emergency supplies can play the greatest role (Source Chinese Center for Disease Control and Prevention) Appendix 1 Production and Work Resumption of PP Enterprises Pictures from Jin Lianchuang Appendix 2 Investigation on Production Scheduling of PP Fiber/Medical Materials Pictures from Jin Lianchuang On January 31 Sinopec announced that during the anti-epidemic period the prices of medical and health materials and related raw materials produced by Sinopec will not rise Meanwhile Sinopec expects to continue to put 95000 tons of various medical and health raw materials into the market in February an increase of 30000 tons over January Subsequently PetroChina made a statement masks and other medical and health materials to produce more fast production to ensure first-line supply! In view of the shortage of medical materials such as medical masks PetroChina's refining and chemical enterprises have increased the load of equipment and produced at full capacity to ensure the supply of raw materials for the production of medical materials Other responsible enterprises have also tried their best to help fight against the "epidemic" In order to alleviate the shortage of raw materials in the market they have made every effort to produce and guarantee supply If downstream enterprises encounter difficulties in resuming work they will actively cooperate coordinate and make due contributions to the country and society Disclaimer This article only represents the author's personal views and has nothing to do with the petrochemical industry going out alliance The authenticity completeness and timeliness of this article and all or part of its contents are not guaranteed or promised by the petrochemical industry going out alliance Readers are only for reference and please verify the relevant contents by themselves Source Process Industries _ _ _ _ Return to Sohu to see more Responsible Editor zjyuan-group.com |
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| Shanghai College Entrance Examination Is Coming, Shanghai Education Examination Authority Issued an Important Reminder _ Candidates _ Test Points _ Nucleic Acid | Jobs - Employee | 2022-08-16 | No Picture |
| Shanghai College Entrance Examination Is Coming, Shanghai Education Examination Authority Issued an Important Reminder _ Candidates _ Test Points _ Nucleic Acid
Original Title Shanghai College Entrance Examination Is Full Body Disposable Coverall Coming Soon Shanghai Education Examination Authority Issued an Important Reminder Original Title The 2022 Shanghai College Entrance Examination Is Coming Soon Shanghai Education Examination Authority Issued an Important Reminder Before the Examination On July 1 the reporter learned from the Shanghai Education Examination Institute that the 2022 Unified Cultural Examination for Enrollment of Shanghai General Colleges and Universities (hereinafter referred to as the "College Entrance Examination") will be held from July 7 to 9 The specific time and subject arrangement are as follows In order to ensure that candidates can take the exam smoothly the Shanghai Education Examination Institute reminds candidates to pay attention to the following matters First do a good job in epidemic prevention and control 1 Please be sure to do a good job of personal protection Continue to maintain two points and one line at home or school as required Parents or co-residents of candidates should also try to achieve two points and one line do not participate in gathering activities do not have dinner do not enter crowded public places and avoid contact with people and articles at risk of epidemic Candidates are requested to download and truthfully fill in the "2022 Shanghai General College Enrollment Unified Culture Examination Candidates Examination Safety Commitment" and continue to do a good job in health monitoring 2 Before the exam Three days later all candidates are requested to complete two nucleic acid tests according to the regulations (one on July 6) In order to ensure the efficient sampling and centralized delivery of nucleic acid testing for examinees and to achieve quick delivery and quick results each district has a special designated nucleic acid sampling point for Medical Disposable Coverall examinees From 800 am to 1100 am every day from July 4 to 6 single-person and single-tube sampling service is provided for examinee Candidates must go to the nearest special nucleic acid sampling point to complete the sampling Each district has special samples for examinees and the district recruitment agencies will also publish them on the website From July 7 to 8 candidates will be tested for nucleic acid at the test site Please print the paper nucleic acid code in advance After the foreign language listening and speaking test on July 9 candidates are requested to return to the community to complete the nucleic acid test on that day 3 If the examinee has a fever before the exam (Body temperature ≥ 373 ℃) dry cough sore throat decreased sense of smell (taste) diarrhea and other symptoms should immediately go to the hospital for treatment the city's fresh graduates at the same time inform the school social candidates to register in the district recruitment agencies report each district recruitment agencies emergency contact 4 The day of the exam Candidates are required to complete an antigen test before leaving for the test site If there is any abnormality report it to the school or district recruitment agency at the first time Candidates should wear N95/KN95 masks on their way to and from the test site When entering the examination site they should line up in an orderly manner according to the requirements of epidemic prevention under the guidance of the staff of the examination site In addition to checking certificates candidates must wear masks throughout the process Candidates in the general examination room of the regular examination center are recommended to wear disposable general medical masks throughout the examination after entering the examination room Candidates in other examination rooms must wear at least surgical masks throughout the examination Expand the full text Candidates with fever and other symptoms before the examination candidates with abnormal body temperature when entering the examination site and candidates who fail to meet the requirements of nucleic acid screening will be arranged to take the examination in the spare isolation examination room of the written examination site (the listening and speaking test will be arranged in the designated examination site) Please take full account of traffic weather and other factors go out as early as possible reserve sufficient time for security check temperature measurement and other links before entering the test site and arrive at the test site address on the admission ticket at least 45 minutes in advance (unless otherwise notified) 5 Before the exam Candidates should report in time if they are (1) Confirmed or asymptomatic infection or positive after going out of the cabin; (2) leaving the cabin on or after June 16; (3) It is clearly close or sub-close; (4) Those who are located in the medium and high-risk areas of the city (including returning to Shanghai from the medium and high-risk areas in China within 14 days before the examination); (5) Those who return to Shanghai from low-risk areas in China within 7 days before the examination; (6) Those who are closed due to sudden epidemic situation; (7) Other abnormal conditions Graduates in this city must report to their schools at the first time (social candidates report to the recruitment agencies in the districts where they register) and at the same time candidates and parents (legal guardians) are requested to maintain smooth communication before the exam and prepare for the exam in strict accordance with the requirements of the schools or district recruitment agencies If the closed-loop transfer is involved the examination certificates KN95 Face Mask protective articles and other personal related articles shall be prepared in advance as required Second prepare for the exam 6 Candidates must take the examination in strict accordance with the time and place of the written examination admission certificate and the listening and speaking test admission certificate 。 On the morning of the 7th candidates are prohibited from entering the examination site 15 minutes after the start of the Chinese subject examination (915 am); on the afternoon of the 7th candidates are prohibited from entering the examination site 15 minutes after the start of the math subject examination (315 pm); on the afternoon of the 8th candidates are not allowed to enter the examination center 15 minutes before the start (245 pm) of the foreign language written examination (including listening); On the 9th the foreign language listening and speaking test must report to the examination site 45 bra tape measure minutes in advance according to the examination session on the admission ticket and enter the preparation room 35 minutes in advance 7 Candidates must carefully read the rules and precautions of the examination room Take the exam in strict accordance with the requirements In order to familiarize candidates with the process of foreign language listening and speaking test the Municipal Education Examination Institute has produced a video on the operation of foreign language listening and speaking test candidates in the National Unified Examination for Enrollment of Shanghai General Colleges and Universities Please watch it carefully 8 Close contact Candidates with closed-loop transshipment such as sub-close contact or medium and high-risk areas must complete all their subjects on the same day before leaving the test site Relevant candidates should bring their own lunch 3 Comply with the examination rules 9 Candidates must consciously abide by the rules of the examination room 5integrity test Beware of false information on the Internet protect their own interests and do not take chances Any violation or illegal act will be dealt with seriously in accordance with the Education Law of the People's Republic of China the Measures for Handling Violations of the National Education Examination and the Amendment (9) to the Criminal Law of the People's Republic of China 10 Candidates are not allowed to use mobile phones Smart bracelets (watches) and other mobile communication devices are brought into the test site It is suggested that candidates put their mobile phones at home or send them to their parents and teachers for safekeeping Once the examinee is found carrying a mobile phone in the examination room after the opening of the examination whether it is opened or not it will be treated as cheating Fourth relax and take the exam 11 Please adjust your attitude Relax Before and during the examination candidates should maintain normal eating habits and pay attention to dietary hygiene and nutrition Because of different personal feelings about room temperature candidates are advised to bring a coat to take the exam 12 The exam is over Candidates must obey the command of the examination center wear masks as required take their belongings leave in an orderly manner and do not stay 13 Parents should avoid crowds gathering around the test site Keep communication open during the examination (Reporter Wang Dianjia) Source CCTV News Client Return to Sohu to see more Responsible Editor (function() { function getBrandHtml() { var brands = [] html = ''; for(var i = 0; i < brandslength; i++) { var brand = brands[i]; if(brandslength i+1) { html+= ''+brandname+''; } else { html+= ''+brandname+'、'; } } return html; }; if(documentgetElementById('linkBtn')){ documentgetElementById('linkBtn') = function() { $('#brands')removeClass('brand');$ ( '# tipInfo')text ( 'Real name responded'); $ ('#linkBtn')remove();$ ('real-response content')css('line-height' '20px');$ ('real-response time')css('line-height' '20px'); }; documentgetElementById('brands')innerHTML = getBrandHtml(); }; })();。 zjyuan-group.com |
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| Summary of knowledge on dental bur needle _ taper | Jobs - Employee | 2022-08-16 | No Picture |
| Summary of knowledge on dental bur needle _ taper
Original Title Summary of Oral Needle Knowledge bra tape measure Pay attention to receiving this every day Summary of the most complete knowledge about dental needle 1 Classification of needles Classification by function high speed low speed (163045 jrpm) Classification by length standard short stem super short stem (17-26 mm) Classified by thickness coarse standard fine and ultrafine Classification by use restoration preparation of abutment preparation of cavity etc Classification by form various forms Classified by the type of corundum natural artificial Classification by service life Disposable Repeatable 2 Model explanation T (Tapper) tapered series (full crown preparation) TF (Tapper Flat) Flat conical head right-angled top used to prepare the shoulder of metal porcelain teeth TC (Tapper Cone) pointed cone with sharp tip used for axial plane preparation TR (Tapper Round) round conical head with rounded top corner which can be used for the preparation of all-ceramic crown shoulder F-Series FO Flame-like cusp used on the occlusal surface and lingual surface of anterior teeth Expand the full text S (Straight) straight/parallel series no polymerization angle except SI used for cavity preparation SF Flat head straight line no polymerization degree top right angle SR Round head straight line no polymerization degree top rounded corner SO pointed straight shape no polymerization degree top 45 degrees B (Ball) ball series ball drill BC Ring-shaped ball drill with emery cuff BR Spherical ball drill without emery cuff Other models SI Single inverted taper inverted taper drill DI Double inverted taper drill WR Discoid CR inlay preparation series CD Children's Cavity Preparation Series EX Special Shape Size identification S-Short handle SS-Very Short Shank C-thick F-fine EF-very fine L-elongated type Color marking It is the indication of particle size which is black green blue red yellow and white from coarse to fine Black extra coarse grinding needle particle size is about 150 microns/blade number is not more than 8 and extra coarse is represented by MLX Green Coarse grinding needle particle size is about 125 microns/blade number is not more than 8 and coarse is represented by C Blue Standard grinding needle particle size about 105 microns/blade count not more than 8 no letter/ML indicates standard Red fine grinding needle particle size about 45 microns/blade count 10-14 F means fine Yellow Polished needle particle size about 25 microns/blade count 16-20 extra fine as EF/XF White particle size approx 15 microns/blade count 26-30 fine as UF Generally the blue marking ring or the one without color marking is the commonly used standard grain size needle and the cutting efficiency is higher when the grain size is medium The cutting force of the coarse grain needle is strong but the cutting surface is rough and the texture is obvious The close degree between the crown and the prepared body is poor and the fine grain needle can be used to refine it Adaptive symptom of different forms of bur needle Our commonly used dental preparation needles include carborundum needles tungsten steel needles and so on Tapered Rock Bit Carborundum needle Diamond has high hardness and excellent physical and chemical properties The diamond grains with a certain acute angle are adhered or electroplated according to a certain direction and spacing with the central axis of the stainless steel needle as the center of the circle to make a diamond needle with a certain ability to cut hard tissues There are pure nickel coating nickel-chromium coating and nickel-chromium-manganese coating according to different coatings According to the different density of surface sand-plating it can be divided into two-layer sand-plated needle three-layer sand-plated needle full-sand grinding head etc with the thickness ranging from several microns to tens of microns The increase of the plating thickness can prolong the service life of the needle improve the cutting rate and be more environmentally friendly and cleaner Tungsten steel needle Is formed by welding tungsten carbide powder and cobalt powder which are sintered at high temperature in vacuum or molded at high pressure on a steel rod and is processed and trimmed by a large diamond grinding wheel The tooth prepared in this way has a smooth surface which can make the impression more accurate so as to produce an all-ceramic restoration with more accurate and close-fitting edges Tungsten steel bur meets the requirements of minimally invasive preparation of teeth Tungsten steel lathe needle is flat and has good performance which is suitable for fine preparation of teeth such as preparation of grooves barreled holes dovetails etc Example of ISO code for the needle Every regular needle that conforms to international standards has a set of ISO codes However the ISO code is usually indicated at the same time especially the third and fifth groups of labels indicating the shape and diameter of the burr needle which is convenient for clinicians to choose and use These five sets of numbers represent certain categories and meanings The first group of three digits-806 refers to the carborundum needle and the tungsten steel needle is 500 The second group of three digits indicates the thickness and total length of the drill body of the bur The first digits 1 2 and 3 indicate that they are suitable for constant mining drill bit speed straight machine constant speed bending machine and turbine respectively 4 in the last digit indicates the regular length and less than or greater than indicates extra short or extra long and extra long respectively The third group of numbers is represented by six digits and the first three digits represent the shape of the drill bit such as round conical inverted conical etc 233-inverted cone The last three digits indicate the type of drill bit such as fine edge wide edge etc The last group of numbers indicates the maximum diameter of the working end of the needle and 012 indicates that the maximum diameter of the working end is 12 mm Generally speaking the smaller the diameter of the needle tip the greater the allowable rotation speed and vice versa Problems should be paid attention to when using the needle 1 The selected needle shall be not easy to deform have high stability and fracture resistance have no tip collapse or desanding and have good concentricity in rotation 2 When cutting the tooth tissue should be cut orderly and effectively with appropriate force (30 ~ 60 G) 3 Attention should be paid to the rotating speed of the needle especially when operating large-diameter needles and coarse-grained needles If the rotating speed of the needle is too high it will produce excessive heat causing damage to the pulp and dental tissue 4 Do not force the needle into the turbine If it is difficult to install check the mobile phone and the needle carefully 5 Please pay attention to the FG mark on the package which is the needle used on the high-speed turbine 6 Disinfect and sterilize the needle before each use Needles should be cleaned frequently with a nylon brush or ultrasonic cleaner Autoclave the needle at 135 degrees for at least 10 minutes 7 After disinfection or cleaning dry the needle and store it in a clean and moisture-free environment 8 It is common in clinic that the tip of carborundum bur wears faster than the tail At this time the bur should be replaced in time to avoid low cutting efficiency 9 Turbine cooling water shall be used up to 50ml per minute 10 After the tungsten steel needle is used it should be cleaned and disinfected with high temperature and high pressure Do not use chlorine-containing disinfectant to soak the needle otherwise it will cause the tungsten steel needle to rust and become blunt Return to Sohu to see more Responsible Editor wt-dthtools.com |
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| Running 10: Zhou Shen challenges the Olympic champion, contracts the whole period to watch, and the hot search topic breaks ten million seconds! _ Lv Xiaojun _ Chang Ning _ Guest | Jobs - Employee | 2022-08-16 | No Picture |
Running 10: Zhou Shen challenges the Olympic champion, contracts the whole period to watch, and the hot search topic breaks ten million seconds! _ Lv Xiaojun _ Chang Ning _ Guest Original title Running 10 Zhou Shen challenges the Olympic bra tape measure champion contracts the whole period to watch and the hot search topic breaks tens of millions of seconds! The tenth program of "Running Bar 10" was still filmed in Changji Xinjiang At the beginning of the program the whole staff appeared in Changji Stadium The powerful singers in the music world Zhou Shen and Bai Lu appeared in the same frame wearing a sportswear a white coat with red sports pants showing a special style of painting with a sense of CP They also put out the shape of "white crane shining wings" He looks very handsome in everything All kinds of flying kicks make all the guests laugh which is worthy of being the laughing point of the whole program Where there is Zhou Shen there will be laughter which can bring us unexpected surprises every time This time unlike previous programs the running man family will face the challenge of "kicking the hall" That is to say the flying guests in this program are all here to "smash the field" and fight with the six champions The first flying guest is weightlifter Lv Xiaojun The program also took Zhou Shen white deer baby as an example After watching his personal short film Zhou Shen's face was full of envy When shaking hands with Lv Xiaojun the program also gave Zhou Shen the word "seconds" In fact it's not that Zhou Shen is afraid to meet with athletes but out of respect You know Zhou Shen is the only image spokesman for the Beijing Winter Olympics Expand the full text In front of the sportsmen there was no star shelf at all and his face was full of smiles Comedian Sha Yi deliberately accosted Lv Xiaojun and pretended to be very familiar with him Once again he was a real "iron fool" The second was Xu Mengtao who had just participated in the skiing ceiling of "Riding the Wind and Breaking the Waves 3" not long ago Sigong regretted to withdraw from the competition which became a difficult feeling in the hearts of many audiences Her departure caused Cyndi Wang's team to dance again overnight Unfortunately she sprained her foot For Mango TV without the pistachio Xu Mengtao it was really a big loss I never thought that she would be in the same frame with Zhou Shen in Running Man 10 One is the famous pistachio the other is the little prince They are bound to put dth drill bits on a good show The third is the champion of the women's volleyball team Zhang Changning who is 195 meters tall Zhou Shen is very cute He shakes hands with her while jumping In front of Zhang Changning Zhou Shen is more like a middle school student Zhang Changning also deliberately lets Zhou Shen clap hands with himself but it is not difficult for Zhou Shen to jump and easily touch his opponent's right hand It can be seen that Zhang Changning is also a die-hard fan of Zhou Shen Otherwise he would not only interact with Zhou Shen The fourth one is Gao Tingyu a flying man on ice and the fifth one is Liu Huihong a good friend of Jay Chou He reproduces the famous fitness scene and is known as the Godfather of fitness From a certain point of view this program should be called "Athletes Special Show" As soon as he came out he made a big move The muscles on his body successfully attracted Zhou Shen's attention Finally the finale was the good friend of the champions Xie Na's apprentice and Zhou Shen's good friend Wei Daxun His style was extremely different He looked more like the silly son of the landlord's family Before opening the game Liu Huihong led the whole team to warm up and danced the popular "calisthenics" again The background music is also Jay Chou's masterpiece "Compendium of Materia Medica" Zhou Shen has learned it well and every movement is in place which is in sharp contrast to other guests The plot of Zhou Shen and Liu Huihong dancing "aerobics" is enough to be recorded as a famous scene in the Chinese music world The first game is called'Summit Duel ' The two teams decide their own order of playing The members with the same serial number will have a one-to-one battle They will tear up their nametags and decide the size of their nametags by drawing lots The more they tear up the more chances they have to win After listening to the rules of the game Zhou Shen shouted' Is there only one game recorded today ' No one expected that the program group would play so much at the beginning Sha Yi was the second to appear on the stage His opponent was Zhang Changning He was led by the nose from beginning to end He had no initiative at all He lost without any suspense Invisibly he also created a lot of famous scenes in the circle Zhou Shen played in the third round against weightlifter Lu Xiaojun At this time Zhou Shen's strength was far less than that of the other side but he had a special Olympic spirit If you want to challenge choose the character of the king level Only when the strong fight against the strong can you rub out different chemical reactions After the start Zhou Shen is particularly methodical He used the legendary'Lion Roaring Skill 'to give the other side a blow first He pulled the momentum full and his hands and feet were extremely flexible But Lv Xiaojun did not play cards according to the routine He grabbed Zhou Shen's hand and refused to let go When the other side was not paying attention dth button bits his firepower was all open Netizens also called it "deep stubbornness" In order to help the team win the honor Zhou Shen used all his strength and was thrown one after another which made people feel very distressed Although he lost to the other side it was still glorious to lose As long as he worked hard after all the other side was an athlete In the end the brother team lost to the champion team with a score of one to five The second round of the game is called'Fast Meteor ' The two teams take turns to send people to challenge Members choose the distance to challenge press the button and the ball begins to fall Members need to receive the ball before it falls to the ground The challenge is successful The test is the speed of the guests Each person has two chances to challenge It has to be said that the program group is so good at playing that they try their best to torment the guests Zhou Shen as usual had a special group soul He was the first to represent his brother team He chose to challenge the distance of 8 meters After starting he was as fast as lightning and successfully caught the volleyball Because he was too serious he was also hit in the throat It can be called "one ball seals the throat" But Zhou Shen did not complain at all He always sent out the positive energy of his idol and refreshed the previous cognition of netizens In the second round the difficulty increased and the challenge was 91 meters As expected a kneeling slip like a rocket caught the ball steadily and won the applause of the whole team He proved himself with his strength Interestingly when it was Zhang Changning's turn to challenge Zhou Shen compared her arm length with her leg length showing the most adorable height difference which made many audiences laugh In addition to Sha Yi the brother team played very well and successfully pulled back a game In the third round of the game the members of the two teams were leggings six people and seven groups They needed to complete the forward roll paper cup pass cross the high ground waist pole jump rope a total of five checkpoints Finally the team with the shortest time won testing the tacit understanding of the members After listening to the rules Zhou Shen reappeared the classic expression package In the process Zhou Shen contracted all the jokes I believe that many audiences like me pay attention to Zhou Shen all the way Any link is completed perfectly When the paper cup is passed the singer's strong vital capacity is brought into full play The paper cup is passed without hands The lower waist passes easily Finally under the leadership of Zhou Shen he completed the challenge in 4 minutes and 39 seconds When it was the champion team's turn the brother team kept making trouble and lost successively when they went down to cross the pole In this regard Zhou Shen's online singing of "Lonely Brave Man" "Love You don't Kneel" once again filled the comedy effect of this program All the audience in the bullet screen shouted "I haven't heard enough" The final competition was a comprehensive endurance race of marbles To put it bluntly let the marbles compete The marble Zhou Shen got was'Dalmatian ' and the white deer got'Little Jelly' and Sha Yi got'Desert ' Li Chen was the first in the first round Zhou Shen's'Dalmatian' played in the second round He felt that Zhou Shen was more excited than he was to participate in the competition He shouted'Come on Dalmatians' all the way but unfortunately none of them rushed into the finish line Finally the champion team'Win-win 'won the victory of this issue The audience was very satisfied with the result After all This period want to convey is professional ability and sportsmanship After the broadcast ZhouShen as always was pushed on the micro Bo hot search Hot words'Running man vs world champion'Reading volume until today Reached 3249 million In addition The topic'ZhouShen speed skating catch '' ZhouShen vital capacity is how strong'Hot search seconds break ten million Zhou Shen This shows how strong the influence of idol Zhou Shen is I don't know if everyone has any different views on Zhou Shen's performance Welcome to collect forward leave a message one key three! Return to Sohu to see more Responsible Editor (function() { function getBrandHtml() { var brands = [] html = ''; for(var i = 0; i < brandslength; i++) { var brand = brands[i]; if(brandslength i+1) { html+= ''+brandname+''; } else { html+= ''+brandname+'、'; } } return html; }; if(documentgetElementById('linkBtn')){ documentgetElementById('linkBtn') = function() { $('#brands')removeClass('brand');$ ( '# tipInfo')text ( 'Real name responded'); $ ('#linkBtn')remove();$ ('real-response content')css('line-height' '20px');$ ('real-response time')css('line-height' '20px'); }; documentgetElementById('brands')innerHTML = getBrandHtml(); }; })(); wt-dthtools.com |
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| High risk but high salary! What is unknown behind the mysterious "construction site water ghost"? _ Drill Bit _ Work _ Engineering | Jobs - Employee | 2022-08-16 | No Picture |
| High risk but high salary! What is unknown behind the mysterious "construction site water ghost"? _ Drill Bit _ Work _ Engineering
Originally published as High risk but high salary! bra tape measure What is unknown behind the mysterious "construction site water ghost" "It is said that this is a profession with high salary and high risk If you come up you will get 20000 yuan If you don't come up you will get 1 million yuan" "You have to be a mother pulling a rope on the top before you dare to go down not a daughter-in-law; or a father and son partner husband and wife team is not safe to avoid being framed by the people above" "Sign a statement of life and death beforehand and life and death depend on fate and wealth" "If it really can't come up the construction party will pour concrete directly into it and even some project parties will deliberately bury the water ghost below blood sacrifice to bless their project smoothly" …… The above rumors describe the "water ghost" of the construction site in a mysterious way! The work of "site water ghost" is basically to salvage drill bits underwater because it needs to dive deep in the mud pit so the risk factor is very high so the name "site water ghost" is very famous Water ghosts are not real ghosts They are the name of professional divers on the construction site They refer to people who are engaged in underwater work They specialize in fishing out the head of the drill bit in the construction site doing some underwater cutting or adjusting the drill pipe and other work Note The drill bit of this percussion drill may fall off Water ghost is a high-risk occupation such work has a high pay some people think that as long as the courage is good enough to do in fact this is a wrong perception Their work is so dangerous that if they are not careful they will die This work is much more dangerous than other diving operations It is said that it is difficult to be a "water ghost on the construction site" DHD Drill bit Where is the difficulty The main reasons are as follows 1 The diving space is very narrow The diameter of the drilling hole in the general construction site is between 80 CM and 2200 CM which is the space they can dive into When the water ghost dives under the hole he needs to wear a heavy diving suit and it is very difficult to turn around when working underwater 2 The hole wall can collapse at any time Because of the narrow diameter of the borehole there will be a steel sleeve near the ground to prevent the hole from collapsing but there is no steel sleeve below and the whole hole is protected by mud If you encounter a layer of soil or loose rock the water ghost will rotate its body below and the wall of the hole may collapse Expand the full text 3 The medium that the water ghost enters is mud with zero visibility We know that some mud is drilled out of the engineering borehole The water and mud in the whole borehole are mixed together to become sticky mud There is a lot of resistance to move forward in the mud If you don't pay attention to it the diving suit will be cut 4 The depth of diving will not be too shallow If the drill bit is lost in a shallow drilling hole the construction site can be salvaged by itself Generally water ghosts are invited to salvage because the holes are too deep some of them are more than ten meters or even more than 20 meters In addition the density of mud is high so the pressure of divers can be imagined They have to work in such a dark environment Under the holes they rely on experience and construction records to explore It is precisely because of this the water ghost industry is very dangerous not ordinary people can do it Since it is so dangerous why is there a water ghost industry The original large-scale engineering construction such as bridge construction high-rise building construction is the need for piling piling process is not foolproof when the drill bit encounters complex geology the drill bit of the impact drill may fall or be stuck there is a pile driver drill anchor situation at this time the engineering side will often hire the water ghost to go down to salvage The cost of salvage is not low and it costs tens of thousands of yuan Why do we have to fish the drill out The drill bit of the pile driver is the most important part of the whole process when driving piles on a large construction site The drill bit of the pile driver is divided into many forms such as spiral drill bit and straight spiral drill bit Among them the conical double screw bit is suitable for hard rock while the double screw bit is suitable for all kinds of frozen soil weathered bedrock pebbles and other geology The weight of the pile head of each pile driver is not light Generally it weighs several tons The drill bit of cross and plum blossom generally weighs about three tons The price of the drill bit is expensive According to the size and function the price ranges from 10000 to tens of thousands of yuan The drill bit of the pile driver is made of alloy and a safety rope is tied on the drill bit when the pile is driven It is very rare for a pile driver bit to fall off but there are always accidents If the drill bit of the pile driver falls off the engineering side will try to fish it up because if it is not fished up the hole will be useless To know the design of the project the location of each pile has been repeatedly studied and verified If the hole is abandoned the redesign of another place will have a huge impact on the project For large-scale projects such as road repair and bridge repair changing a pile hole may affect the whole body If the position of a pile foundation is changed dozens of kilometers of boreholes may have to be redesigned and re-constructed This will not only cost a lot of money but also affect the progress of the project the loss is incalculable Besides the price of a drill bit is not cheap If it falls underground if the engineering party does not salvage it it needs to be replaced immediately This is heavy and expensive and it takes time to replace it which also affects the progress of the project Therefore in the process of construction if the drill bit of the pile driver falls the engineering side will try to fish it out In fact every time the pile head falls it is not necessary to ask the water ghost to salvage the construction side can try to salvage by itself The construction party will slowly try to hook up the drill bit with a hook because there is a circle of safety rope on the drill bit if the hook can hook the circle of safety rope it can be fished up But the pile hole is often mud water and mud mixed together completely unable to see the underground situation like a blind man touching the lamp So how do the water ghosts salvage the drill bit It turned out that in the process of salvage two people were needed to cooperate One person wore a protective suit down the hole bit an oxygen mask and a safety rope tied to his body They dived into the sticky mud It was dark in the mud and nothing could be seen They needed to dive tens of meters or even hundreds of meters At this time danger is likely to occur so a surface person is needed to ensure his safety The security personnel standing outside the wellhead need to provide enough oxygen and air supply pressure for the diver Because the more people sink the greater the pressure of the water underwater divers need a certain amount of air supply pressure to offset the impact of the surrounding water pressure to ensure that they can smoothly dive to the downhole drill bit When divers dive to the bottom of the pile hole they will immediately report to the telephone operator or support personnel above through electronic equipment and then ventilate to adapt to the underwater environment immediately In fact in the well what they have to do is very simple that is take the rope and dive to the drill bit to tie the lifting point As long as the steel cable can firmly bind the lifting point of the drill bit and pull it up it is the matter of the machine After finishing this work they will ask to leave the bottom of the water The surface security personnel will help them adjust the air volume buoyancy can not be too large the rising speed can not be too fast otherwise it will cause safety accidents If they complete the task they can get a reward of 120000 yuan If there is any problem in the process of diving into the water the ground security personnel will immediately pull the safety rope and pull the person up Therefore two people need to cooperate with each other and trust each other A netizen asked The salvage price is so expensive the salvage process is so dangerous why not drain the water in the well First of all because the specific gravity of the mud is very large between 13 and 14 if the mud is pumped out the pressure of the hole wall will disappear and the hole wall may collapse so it is very difficult to fish out the drill bit Moreover some boreholes are tens of meters or hundreds of meters deep and have reached the underground water layer where the water may not be pumped out in ten days and a half months For the engineering side time is money but they can not afford it Others say why not use robots instead of human beings In fact as far as the current level of science and technology is concerned there is no machine that can replace manual work to salvage drill bits underground If it is operated by a machine it will be more difficult to fish out the drill bit if it fails to fish out once and destroys the hole Some netizens also suggested that a large magnet could be used to suck up the drill bit It is true that some people have used this method but it must have a strong enough electromagnet and the weight of the drill bit will not be too heavy the key drill bit must also be made of iron if it is made of alloy this method is not feasible Although the work of water ghost is very dangerous there are still people who are willing to work in such a high-risk industry because of its higher remuneration So what kind of conditions do you need to engage in this industry 1 First of all we need to be young Because they are young and strong they can dive underwater for a longer time because young people have better physical strength and can withstand greater external pressure than old water ghosts The resistance of moving forward in the sticky mud is very great and it also consumes a lot of physical strength Only young people with good physical strength can go down and come up Generally the age of water ghost is before 30 years old and after 30 years old the physical strength is poor so few people go down the well After the age of 40 I can't do this job because I can't bear the strong pressure underground 2 A strong water effort is required Although they wear diving suits and masks they also need good water work to work under complex holes My uncle said that with the deepening of the depth underwater the pressure is very high the breathing sound is getting thicker and thicker and there are all kinds of water grunts 3 Professional training is required They have to undergo professional training understand all kinds of possible situations of drill bit falling learn all kinds of coping methods they must hold certificates and hang in qualified companies 4 To have good psychological quality and professional skills every time they receive a task they must make a professional assessment of the underground situation Of course we need a few partners to cooperate with each other If there is any accident in the person who sneaks into the borehole the people on the ground should pull him up immediately Conclusion Some people think that the wages for salvaging drill bits are too expensive If everything goes well it will be 20000 yuan an hour They will think that the water ghost has made a lot of money In fact this profession is very dangerous In addition not every construction site will have the phenomenon of drill bit anchoring Sometimes they only receive a job in ten days and a half months Such dangerous work is not often available and the fees are naturally higher If twenty thousand yuan is salvaged every day it will be six hundred thousand yuan a month I think even if it is a dangerous job there must be a lot of people competing to do it In short every line has its own rules There are many dangerous jobs in today's society such as installing air conditioners at high altitude and being a firefighter Which job is not full of danger No matter how dangerous it is someone will do it because we really need money to live We can't do it without money don't you think Return to Sohu to see more Responsible Editor (function() { function getBrandHtml() { var brands = [] html = ''; for(var i = 0; i < brandslength; i++) { var brand = brands[i]; if(brandslength i+1) { html+= ''+brandname+''; } else { html+= ''+brandname+'、'; } } return html; }; if(documentgetElementById('linkBtn')){ documentgetElementById('linkBtn') = function() { $('#brands')removeClass('brand');$ ( '# tipInfo')text ( 'Real name responded'); $ ('#linkBtn')remove();$ ('real-response content')css('line-height' '20px');$ ('real-response time')css('line-height' '20px'); }; documentgetElementById('brands')innerHTML = getBrandHtml(); }; })();。 wt-dthtools.com |
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| Down-the-hole drill for construction of steel pipe pilot | Jobs - Employee | 2022-08-16 | No Picture |
Down-the-hole drill for construction of steel pipe pilot Original Title Down-the-hole Drill for fastest dth hammer Steel Pipe Pile Construction Summary of steel pipe pile construction of Xiaoxi Bridge in expressway from Dejiang to Wuchuan in Guizhou Province This paper makes a comprehensive evaluation of the technology quality inspection standards and methods in the construction of steel pipe piles so as to determine the best technology and construction method establish a model project for the future guide the large-scale construction of subsequent steel pipe piles and prevent the quality and safety problems that may arise in the subsequent construction and production Construction summary The abutment of Wuchuan bank of Xiaoxi Bridge is provided with a pile foundation to effectively transfer the load to the bra tape measure middle of the slope and reduce the impact on the bank slope; the accumulation body at the lower part of the cliff is supported by an anti-slide pile foundation There are 4 anti-slide piles and 25 steel pipe piles The steel pipe pile is a D245 × 10mm steel pipe with a bundle of steel bars placed in the center Each bundle is composed of three D28 steel bars The pile top is connected by No16 I-steel to form a framework and the pipe is filled with M75 cement mortar In the first project the steel pipe pile A-1 of the left 2 # pier of Xiaoxi Bridge is 20m long the diameter of the steel pipe pile is D245 × 10mm the design concrete strength is M75 and the concrete volume is 94m3 The construction equipment includes 10 sets of Hongwuhuan high wind pressure down-the-hole drills 4 sets of air compressors 2 sets of GY100 engineering drilling rigs 2 sets of cranes 1 set of generators and 3 sets of concrete transport vehicles Construction process flow of steel pipe pile Clear the site around the pile hole position the steel pipe pile put the down-the-hole drill in place form the hole for the steel pipe pile clean the bottom of the hole for the lower steel pipe and grout the steel pipe to clear the site and demobilize 1 Clean the site around the pile hole According to the actual site the site around the pile hole shall be cleared and the construction platform shall be erected The platform shall be firmly erected at the opening of the pile hole and can bear 2 t heavy engineering drilling rig 2 Positioning of steel pipe pile During construction professional surveyors and constructors shall be organized to arrange the positions of steel pipe piles according to the requirements of design drawings and in combination with the actual situation on site and the positions shall be marked with red paint 3 mining dth bit Drilling rig in place Expand the full text After the engineering crane lifts the drilling rig to the working platform the drilling rig shall be adjusted according to the hole position of the steel pipe pile 4 Steel pipe pile pore-forming The construction of steel pipe pile hole formation shall be carried out according to the drawing design and relevant technical specifications A special 100 type drilling machine is used to drill holes according to the requirements of the design drawings The hole diameter is controlled to be 273mm with an allowable error of ± 1 ° In order to ensure the depth of the hole the depth of rock into the dth rock bit bearing stratum is required to be 200mm greater than the design depth 5 Hole cleaning at the bottom of steel pipe pile The diameter of the steel pipe pile this time is 245 mm and it will be difficult to clean the hole by conventional measures Therefore when the drilling is nearly completed the depth of the hole shall be measured with a measuring rope to prevent the drilling depth from failing to meet the design requirements and to avoid errors in the placement of the steel pipe After the completion of the hole the sediment at the bottom of the hole shall be cleaned with a special bottom cleaning drill for engineering geology to avoid sediment at the bottom of the holes 6 Steel pipe pile construction The diameter of the steel pipe pile in this project is D245 × 10mm and the length of the steel pipe pile is designed to be 20m According to the design requirements the pile length shall not be less than 1/2 when passing through the corrosion groove and entering the complete bedrock Before lowering the steel pipe pile the rust oil stain and other dirt at the end of the steel pipe pile shall be carefully checked and must be removed and the pile body shall be checked for cracks or damage If there is any damage the pile shall not be lowered before reasonable treatment Anti-corrosion and anti-rust treatment measures shall be taken for the outside of the pile body (such as brushing two layers of anti-rust paint) After lowering the pipe M75 cement mortar shall be injected into the pipe Quality control during the construction of steel pipe pile the deviation of pile position shall be controlled within ± 50 mm; the flatness of each pipe end shall be ≤ 5 mm; the pile insertion position shall be correct and the verticality shall be less than 05%; 7 Steel pipe pile grouting the pipe is filled with M75 cement mortar 8 Construction of lower steel pipe pile repeat the above steps (3)- (7) 9 After drilling remove the construction platform clean the site and prepare for demobilization After the construction of steel pipe piles is completed the bearing capacity shall be tested by static load test The number of piles to be tested shall not be less than 1% of the total number and shall not be less than 3 Return to Sohu to see more Responsible Editor wt-dthtools.com |
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| Analysis of the Most Complete Stone Mining Technology and Equipment in History _ Mine | Jobs - Employee | 2022-08-16 | No Picture |
| Analysis of the Most Complete Stone Mining Technology and Equipment in History _ Mine
Original Title Analysis of the Most Complete Stone Mining rock drilling tools Technology and Equipment in History The most complete stone mining technology and equipment in history For your reference This article is divided into four sections for you to sort out The article is long so you can collect it first Read patiently welcome to forward and share! [Types and Elements of Stone Mines] [Deposit development and development transportation method] [Mining process of stone deposit] [Classification of Mining Methods for Stone Mines] [Types and Elements of Stone Mines] I Types of Stone Mines The types of stone mines include open-pit mining and underground mining Open-pit mining is divided into hillside open-pit mining sunken open-pit mining and well mining Underground mining is divided into cave mining and shaft mining 1 Open-pit mining A stone mine in which the overburden and weathered layer on the surface of the stone ore body need to be stripped before mining An open trench is dug from the ground and a working face is created to extract the block from the working face According to the topographic conditions of deposit burial the mining above the lowest level of stope surface is called hillside open-pit mining; the mining below the lowest level of stope surface is called depression open-pit mining Open-pit mining on hillside Basically according to the principle of top-down mining sequence Expand the full text Hillside open-pit mine Open pit mining Basically according to the principle of top-down mining sequence Sunken open-pit mine Well-type mining In fact it is a special case of open pit mining With the deepening of stone mining operations many stone mines have gradually mining dth bit evolved from hillside open-pit type to depression open-pit type and eventually to well mining The depth of many well-type mines in foreign countries exceeds 50 meters or even reaches 80 meters or more Portuguese pink marble CARRARA Italy 2 Underground mining Stone mines that need to be excavated from the surface to reach the ore body can be divided into roadway (cave) mining and chamber (roadway) mining Cave type Open-pit mines with steep mountain shape large amount of stripping and extremely dangerous mining operations such as some marble mines in Baoxing County Sichuan Province; sunken open-pit mines with inclined ore bodies with the increase of mining depth need to strip a large thickness of overburden such as white marble mines in Fangshan Beijing; With the increase of mining depth the mining of some well-type marble mines will not be able to continue The cave mining method will make the mining operation more practical The main mining process is similar to that of the sunken open-pit mine but the difference is that a rectangular channel development process is added before the formal mining and a new free surface is developed on the ore body with only one free surface 1997 CARRARA Marble Mine-4 (Tunneling) Shaft type Use the roadways left by other engineering transportation facilities or mining projects to pass through the stone mines excavated inside the roadways II Composition elements of open pit 1-Work platform 2-Safety Platform 3-Cleaning platform 4-Transport channel α β-final slope angle GF-Lower final line of open pit H-Final mining depth of open pit AB-Upper final boundary line of open pit ABGHF-Final state of open pit 1 Bench When stone is mined in the open pit the ore body to be mined is usually divided into horizontal layers with a certain thickness and mined layer by layer from top to bottom When two or more horizontal slices are mined at the same time a certain advance distance shall be kept between the upper and lower slices A step shape is formed in the space during the mining process and at the end of the mining process These step-like working surfaces are called steps The bench is the basic element of the stone open pit and also the unit of the independent quarry operation 2 Working platform horizontal part of each step 3 Safety platform the stope boundary is reserved to ensure the safety of the lower production platform and the stability of the slope 4 Cleaning platform one cleaning platform shall be set every 2-3 safety platforms 5 Transportation channel transportation road between the ground and each horizontal layer [Deposit development and development transportation method] I Deposit development (transportation system) 1 Concept It is a transportation channel connecting each working bench inside the mine to the block yard or the external transportation system and the waste rock yard and plays a role in preparing various tunnel projects of new mining level in time Set up a connection stone quarry Engineering of the transport system of the yard and transport ground 。 2 Tasks (1) The mined blocks are transported outward or sent to the block yard (2) Transport the waste rocks and muck to the waste rock yard (3) Transport tools materials equipment and personnel into or out of the working face Straight Ditch Road Transportation System of Blue Pearl Granite Mine in Norway Larvik Mine Norway II Development of transportation methods 1 bra tape measure Highway development and single automobile transportation Applicable conditions simple terrain (few bends large radius) small stope height difference large range convenient for highway line development large block specifications large transportation volume and small highway capital construction quantities 2 Applicable conditions for transportation and development of slope winch Mines with complex terrain large elevation difference (20o ~ 40o) small mining area hillside or sunken mining area with difficulty in highway development to transport blocks with small size and small amount of waste rock and soil The slope hoist is generally located outside the mining boundary In the stope the blocks need to be loaded on the trolley by other means of transportation 3 Applicable conditions for joint development of fixed mast crane and truck transportation Mines with large stope height difference small range complex terrain difficult road development and less waste rock and dregs The mast crane is usually located at the edge of the stope The blocks outside the hoisting range shall be transported to the hoisting range of the mast crane by the traction winch or loader and then lifted to the truck of the transport platform by the mast crane 4 Development of aerial ropeway transportation The rope crane is used to complete the loading lifting transportation and loading operations at one time Applicable conditions stone mines with complex and steep terrain large elevation difference deep valleys difficult highway development large investment small scale and small block size 5 Applicable conditions for open chute transportation and development The terrain is complex the elevation difference is large the slope is steep (greater than 40o) and there is a shortage of capital construction funds 6 Joint development [Mining process of stone deposit] The mining process is divided into seven processes Stripping — Separation — Top turning — Segmentation — Shaping — Hoisting and transportation — Slag removal and waste discharge 1 Stripping 1 Basic concepts (1) Stripping range all parts within the mining range that do not meet the processing and use requirements; (2) External stripping the stripping of the surface and surrounding parts of the mineable ore body that do not meet the processing and use requirements before the mining of the deposit so as to expose the mineable parts; (3) Internal stripping the stripping of the part inside the ore body that cannot become blocks due to the existence of joints fissures and vein rocks (4) Stripping ratio refers to the ratio of the amount of earth and stone stripped to the volume of block mined (5) Block rate the ratio of the volume of blocks mined within a certain mining range to the volume of raw ore within the range is called the block rate 2 Basic principle simultaneous mining and stripping stripping first 3 Requirements The integrity and block formation of the ore body shall not be affected Butterfly Green (XIII) II Separation-the main process of stone mining 1 Concept separate the strip-shaped block stone with a volume several times that of the block from the ore body 2 Requirements (1) Do not damage the ore body and ore-take protective measures (2) The specification size of the strip block stone shall be equal to the integral multiple of the specification size of the block plus the processing amount required for dividing the block (3) According to the natural conditions of the ore body make full use of natural fissures and bedding (4) According to the technical performance of the mining equipment give full play to the role of the equipment improve efficiency and reduce costs The width of the strip block stone is generally the height of the mining bench and the length is a part of the mining bench Three top turn over-fall stone 1 Purpose It is convenient to divide into blocks according to the required specifications 2 Method traction winch loader top stone machine water pressure package and air pressure package 3 Key points use protective measures to prevent the stone from breaking when it is overturned The kerf width of diamond saw mining is only 12 mm When all the stones are separated from the ore body it is very difficult to move or overturn the stones weighing hundreds of tons from the ore body directly through the 12 mm kerf At present domestic stone mines generally adopt the method of drilling a 25 × 25 × 50cm stone trough on the parent ore body and placing a hydraulic stone jacking machine to separate the stone from the displacement which destroys the integrity of the ore body after the trough is drilled and affects the outturn rate of the ore body behind New technology of air pressure pushing bag The pneumatic pushing bag is inserted into the 12 mm saw kerf formed by the beaded wire sawing and the compressed air is used to inflate the bag so that the bag expands to generate dozens of tons of thrust and the lever principle is used to push the stone to move or turn it over so that the stone can be disintegrated in the subsequent process to produce blocks The bag body is made of high-strength polymer rubber material and can be repeatedly stretched and used Air pressure push bag (I) Air pressure push bag (II) Air pressure push bag (III) 4 Partition Dividing the strip block stones into rough blocks or blocks on the overturned strip block stones according to the specification of the required blocks Quarry stone a cuboid or cube with certain specifications and no cracks which can meet the processing requirements of decorative plates Rough block the shape basically meets the specification requirements of the block but the surface is uneven with a positive error of more than 3 and the block stone needs to be shaped Metering block the actual metered volume of the block after inspection It is the actual effective volume of the block after deducting the excess volume caused by the size deviation Methods Chiseling splitting sawing mechanical drilling and cutting controlled blasting Five plastic surgery 1 Purpose Trim the rough blocks into blocks that meet the requirements of specifications so as to reduce the redundant workload in hoisting transportation and processing and reduce the cost For example if the top surface of granite blocks is shaped and leveled by a fixed bead saw the total error of the flatness is within 2cm and the total error of the flatness only by manual leveling is up to 10 cm and the time required for the saw blade of a sand saw to complete the "cut-in" stage is nearly doubled 2 Method wedging splitting and sawing According to the shaping method the blocks are divided into two categories a Saw face block (SS) All six sides are blocks shaped by the sawing method b Split face block (CS) Block with one or more sides shaped by chiseling 3 Shaping equipment Large diameter circular saw chain arm shaping machine diamond band saw shaping machine bead saw shaping VI Hoisting and transportation 1 Mast crane (mast crane) Large lifting capacity wide service range strong adaptability easy operation high equipment price large installation or displacement workload slow lifting speed The maximum lifting weight of 50 tons means that 18 cubic meters of block can be lifted 2 Truck (wheeled) crane Need to install fixed feet poor road adaptability large tire loss small lifting capacity strong flexibility and versatility 3 Crawler crane Can be directly hoisted does not need to install fixed support legs and has strong adaptability to roads large lifting capacity and strong flexibility Crawler crane 4 Front end loader The multipurpose mining equipment can be used for shoveling stripping hoisting hauling cleaning working steps prying stones and other operations 5 Crawler excavator As above the front end is the loading device and the rear end is the digging device 6 Gantry crane A crane of the bridge type in which a horizontal bridge is set on two legs to form a gantry Gantry crane 7 Cable crane A bridge crane in which the trolley travels on a carrying rope 8 Traction winch (1) Mine multi-purpose equipment can be used for ① Traction power of slope winch ② Pull the blocks to the working range of the lifting equipment ③ Expanding joints and pouring stones ④ Power of lifting equipment (2) Operation mode Various hauling operations can be completed by configuring different pulleys VII Slag removal and waste discharge Before the construction of stone mines it is necessary to consider the construction of a dregs yard with sufficient capacity which is a necessary preparation for continued production and safe production Attention should be paid to the protection of resources the protection of the environment the comprehensive utilization and the improvement of efficiency According to the requirements of the Technical Specification for Decorative Stone Open-pit Mines Mining Drilling Equipment the comprehensive recovery rate of decorative stone mines should not be less than 50% [Classification of Mining Methods for Stone Mines] I Mining method Splitting blasting cutting burning etc II Selection basis of mining method 1 Geological conditions of the deposit joint occurrence development degree orebody shape … The thick orebody is favorable for mechanized mining and the thin orebody is suitable for manual mining Chisel hole splitting method should be used if the fissures and joints are developed and irregular 2 Rock type For example basalt and gabbro without quartz can not be cut by flame and the compressive strength of the rock is about 30 times of the tensile strength and 10 times of the shear strength The splitting wedge is used to produce compressive tension on the rock to break the rock which is especially suitable for deposits with developed horizontal joints and fissures 3 Mine scale 4 Specifications of blocks required 5 Physical and geographical conditions 6 Environmental protection requirements 7 Technical and economic indicators 8 Output efficiency and benefit Chisel split method I Splitting mechanism and applicable conditions Mechanism 1 The tensile strength of rock is relatively small 2 The principle of "splitting" is applied to produce greater tension on the rock and the rock breaks after being stressed 3 When wedging the action time of the force is short the speed is fast and the kinetic energy of the wedge is large Applicable conditions 1 It is applicable to rocks with nearly horizontal cracks 2 The tensile strength of granite is less than that of marble so it is more suitable for granite mining 3 Rock is an anisotropic body with different tensile strengths in different directions so the parameters of wedge holes are also different in different directions 2 Artificial wedging and splitting method 1 Types and structures of tools-wedges A — Flat wedge; B — Pyramid wedge; C — Compound wedge 2 Operation method hand-held rock drill For manual wedging and splitting of shallow holes and deep holes (rows of holes drilled on the splitting surface) the spacing between rows of holes is related to the splitting performance and the minimum spacing is only 10-15 cm 3 Advantages and disadvantages simple tool simple method and low cost The labor intensity is high the efficiency is low the squareness of the block is poor and the shaping workload is large When mining granite it is generally necessary to drill 10 meters of holes for each cubic meter of total ore and rock According to the calculation of 30% of the block rate it is necessary to drill 30-40 meters of holes for each cubic meter of finished block Shallow borehole artificial splitting Disintegrating large granite material by artificial splitting method Shaping granite blocks by artificial splitting method Deep hole manual splitting mining disintegration separation body III Splitting method of hydraulic splitting machine The principle is the same as that of manual splitting which usually refers to the use of hydraulic splitters and deep-hole splitting for mining Compared with the manual wedging method the method ensures the consistency of hole arrangement and splitting reduces the labor intensity and improves the efficiency During operation a drill hole for placing the hydraulic composite splitting wedge is drilled on a rock by a rock drill according to the presplitting direction the hydraulic composite splitting wedge is placed in the hole the splitting wedge and a hydraulic pump station are connected high-pressure oil is transmitted to a hydraulic splitting head through an oil pipe the hydraulic splitting wedge generates extrusion tension to two walls in the hole under the action of the high-pressure oil and the rock is broken after being stressed Borehole blasting method Applicable conditions for all kinds of rocks with few natural fissures separate large stones from rock mass by slight blasting Classification of methods It can be roughly divided into ordinary blasting conventional controlled blasting and grooved controlled blasting Advantages simple operation high efficiency strong applicability and low cost Disadvantages poor squareness low block rate reduced stone strength and many unsafe factors I Ordinary blasting method 1 Agent black powder 2 Blasting parameters Hole diameter 30 ~ 40 mm Hole spacing horizontal hole spacing 1 ~ 15m; Vertical pitch 08 ~ 12m Hole depth horizontal hole depth 45 ~ 60% of separation block width Vertical hole depth 60 ~ 80% of the height of the separation block Charge 20 ~ 25% of hole depth Detonation detonator or electric detonator Note Measures to prevent excessive concentration of blasting force Block charge and gun hole should not be packed too tightly II Controlled blasting 1 Concept Controlled blasting is a kind of precisely designed blasting with different explosives and ignition methods which can not only achieve the desired effect but also control the hazards caused by blasting within the specified allowable range This kind of blasting with dual control of blasting effect and blasting hazards is called controlled blasting 2 Agent Black powder detonating cord No2 rock explosive blasting tube metal incendiary agent static expansion agent (1) Detonating cord It takes the single substance high explosive RDX or TEK as the core and its external image is the fuse slightly thin and the color is mostly red The explosive charge of the detonating cord in China is 12 ~ 14 G/m and the detonation velocity is 6500 ~ 6800 m/s It can be detonated by fire detonator or electric detonator and the hole spacing is 20 ~ 40 The internal drilling medium for placing the detonating cord can be air or water Mining site by detonating cord controlled blasting (2) Metal incendiary agent (high-energy incendiary agent) The metal oxidant reacts with the metal reducing agent to generate high-temperature expansion gas and the rock is cracked under the combined action of the expansion pressure and the thermal effect Such as 2Al + 3MnO2 = Al2O3 + 3Mn + 221 kcal (or + 952 × 105 J) Commonly used oxidants MnO2 CuO Fe3O3 … Commonly used reducing agents Al Mg Fe + Mg … (3) Static expansion agent Calcium oxide inorganic salt and organic additives and the tension generated by the volume expansion of the reaction after adding water Such as CaO + H2O-Ca (OH) 2 + 155 kcal with volume expansion of 3 times the expansion stress is about 30 ~ 50Mpa (the tensile strength of rock is about 5 ~ 12MPa) Mechanical cutting method Concept Separation of rock blocks or blocks directly from the rock mass with the aid of mechanical equipment in accordance with the required block specification The invention has the advantages of no damage to the ore body and the block flat cutting surface no need of shaping high block rate large block size low labor intensity and high production efficiency Advanced technology technology and equipment Common equipment rock drill steel cable stone sawing machine diamond wire saw chain saw disc saw 1 Steel cable stone sawing machine sawing method It appeared at the end of the 19th century and was used for marble mining with quartz sand as raw material It was discontinued at the end of the 20th century II Diamond wire saw cutting method 1 Equipment composition (1) Driving device (2) Diamond rope (3) Working column and guide wheel The steel wire rope is sealed by spring injection molding rubber injection etc Fixed diamond bead 2 Working methods (1) Ring traction cutting method When the ore body has two or more free surfaces a horizontal hole and a vertical hole are drilled along the designed sawing surface so that the two holes are connected and on the same cutting surface (2) Rope pressing and cutting method When the number of the free surfaces of the ore body is less than two a hole is drilled on the working face of the bench a rope pressing wheel is arranged on a multi-purpose drilling machine or a cutting upright post and is placed in the hole and a carborundum rope bypasses the rope pressing wheel and forms a closed loop with a driving wheel of a sawing machine to work Diamond wire saw traction cutting Diamond wire saw traction cutting 3 Applicable conditions of diamond wire saw It can be used for full sawing and mining of marble and granite or combined mining with other equipment; it can also be used for stone processing and block shaping 4 Advantages and disadvantages The mining cost is high but the sawing surface is flat the sawing area is large and the block rate is high 4 Sawing method of arm-type stone sawing machine According to the cutting tool it is divided into 1) fixedly instal a hard alloy or diamond segment cutting edge on a cutting arm transmission chain to form a hard alloy cut chain or a diamond cutting chain; 2) Polyurethane injection molded cutting tape with diamond cutting segments The main body of the diamond cutting belt is a rectangular diamond segment threaded on six side-by-side stainless steel wire ropes for aviation and the segments are all sealed by special polyurethane injection molding BENETTI Italy JB-990 mining band saw vertical cutting operation The vertical and horizontal cutting of the ore body can be carried out and the vertical and horizontal cutting positions can be quickly and flexibly switched at the same installation position It is suitable for the mining of soft stones such as marble limestone and travertine with medium hardness At present the maximum vertical cutting depth of large chain arm saw can reach 8 meters the longest horizontal cutting depth can reach 48 meters and the chain width is generally 335 mm The maximum cutting depth of the mining band saw can reach 48 meters and the width of the saw gap is generally 38 mm At present the maximum vertical cutting depth of the arm saw has reached 8 m and the mining bench with a height of 8 m can be mined 5 Disc stone sawing machine sawing method A saw blade with a diameter of 42 m can be mined to a height of 19 m and the main machine of the circular saw and the saw blade are moved during mining The diameter of the saw blade used for mining circular saw blade is 1600 4200 mm and it is usually used in groups of 2 or 3 pieces If the cutting depth is 125 m the combination of saw blades with diameters of 16m 22m and 28m can be used; if the cutting depth is 19 m the combination of saw blades with diameters of 22m 3m and 42m can be used The final width of the kerf is 15-20 mm Photo of vertical sawing by double-blade mining circular saw with a diameter of 35m Flame rock cutter cutting method I Cutting mechanism Use the flame of the flame thrower to burn the rock to form a cutting surface to divide the rock It can only be cut vertically The loss of the cutting groove is large In the case of three free surfaces two surfaces are generally cut at most It is better to cut only one surface and the other two surfaces are separated by blasting or wedge method Due to the difference of thermal expansion coefficients of different minerals in the rock quartz changes from α-quartz to β-quartz at 573 ℃ and the volume of quartz decreases resulting in disintegration II Applicable conditions Vertical cutting of rocks with high quartz content not horizontal cutting The higher the quartz content is the higher the cutting efficiency is; the lower the quartz content is the lower the cutting efficiency is III Equipment composition Air compressor oil supply system oxygen supply system flame thrower Operation Drawing of Downward Trench Excavation by Flame Cutting Machine IV Advantages and disadvantages High efficiency (15 ~ 25 ㎡/H) flexibility large cutting depth (up to 10 m) large cutting area smooth cutting surface not affected by season and climate High noise (100 ~ 120 db) high dust high fuel consumption high cost (200 ~ 250 yuan/㎡) and high labor intensity so it must be combined with other mining methods Flame cutting machine combined with hand-held rock drill drilling row holes combined with splitting mining method (referred to as burning rock drilling mining method) is the traditional longest and most widely used granite mining method Copyright notice If it involves copyright issues please contact us to delete it! Return to Sohu to see more Responsible Editor wt-dthtools.com |
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| Short-path molecular distillation equipment operation process _ proceed | Jobs - Employee | 2022-08-15 | No Picture |
| Short-path molecular distillation equipment operation process _ proceed
Original title Operation process of short-path thin film distillation molecular distillation equipment During the operation of the short-path molecular distillation equipment it is necessary to pay attention to certain operation procedures to avoid the unavailability of the entire short-path molecular distillation equipment and the unavailability of the supporting Wuxi Shengze refrigeration and heating temperature control system due to improper operation Generally the short-path molecular distillation equipment has passed the hydrostatic test and test run before delivery and the indicators meet the requirements Start the motor and observe whether the running direction of the motor is correct It should rotate clockwise not reversely winterization filtration Measure whether the radial swing and axial displacement of the shaft meet the requirements and check whether the seal is tight Check whether the oil level of the reducer is in a normal state and whether the cooling water of the mechanical seal is kept unblocked Turn on the circulating cooling water pump of the short-path molecular distillation equipment to keep the condenser in operation The concentrate container is then opened and the vacuum valve is drawn Open the feed valve and pump in the feed liquid Turn on the power supply start the motor and observe whether the rotation direction of the motor is correct Slowly open the steam valve and connect the steam trap so that the steam pressure is about 015 MPa Observe the discharging condition of the short-path molecular distillation equipment After the equipment runs stably for 5 minutes molecular distillation systems sample and analyze the concentration of the concentrated solution If the concentration is not up to the standard adjust it When the liquid level of the concentrated solution container is about to be full it shall be switched to another container and the switching shall be carried out according to the steps The shutdown sequence of normal short-range molecular distillation equipment is as follows close the steam valve close the feed valve drain the feed liquid close the discharge valve flush the equipment stop the motor stop the circulating water pump and jet pump and open the vacuum breaking valve When the short-path molecular distillation equipment has no feed liquid or is full of feed liquid the motor cannot be started for stirring It is strictly prohibited to run the motor in the reverse direction When running do not touch the rotating parts with your hands Do not press the button with wet hands to prevent electric shock Short-path molecular distillation equipment should pay attention to some safety knowledge as much as possible during operation to avoid some safety accidents because safety production is very important (This article comes from the network if there is infringement please contact to delete) Return to Sohu to see more Responsible Editor toptiontech.com |
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| Discussion on the Development Prospect of Rotary Evaporator — — Horizon _ Evaporator | Jobs - Employee | 2022-08-15 | No Picture |
| Discussion on the Development Prospect of Rotary Evaporator — — Horizon _ Evaporator
Original Title Discussion on the Development rotovap distillation Prospect of Rotary Evaporator — — Horizon As we all know the rotary evaporator also known as the rotary evaporator is a very widely used evaporation instrument in the market so do you know what its development prospects are Let's get to know it together with Xiaobian today Nowadays the structure of China's rotary evaporator market is still dominated by traditional multi-effect evaporators and supplemented by local MVR evaporators The rotary evaporator is electronically controlled to rotate the flask at a constant speed at a suitable speed to increase the evaporation area The evaporation flask was brought to a negative pressure state by a vacuum pump An evaporation flask is place in a water bath for constant temperature heat while rotating and that solution in the flask is heated diffused and evaporate in the rotating flask under negative pressure The reason for this situation is that the MVR evaporator is a new product and people do not understand its application; secondly the price of imported MVR evaporator is very expensive However the development trend of evaporator market at home and abroad is that MVR evaporator will gradually replace the traditional multi-effect evaporator and MVR evaporator will gradually replace the traditional multi-effect evaporator in time According to expert analysis the MVR evaporator industry is still a hot industry with technical potential (referring to the possibility of personal ability development) in China However as a large number of chemical equipment consumer manufacturers want to get involved in this product it will not take much time It is estimated that in two years most of the chemical equipment manufacturers will come to participate so the improvement of MVR evaporator in the chemical pharmaceutical industry is just around the corner Industry insiders predict that rotary evaporators will undergo major changes in the next five years rotary vacuum evaporator The main changes are not in technology but in the integration of market scope marketing system management system and so on Rotary evaporator is an evaporation instrument widely used in laboratories It is suitable for reflux operation rapid evaporation of a large amount of solvents concentration of trace components and reaction processes requiring stirring The rotary evaporator system can be sealed to reduce the pressure by 400 to 600 mm Hg; the solvent in the distillation flask is heated by a heating bath and the heating temperature can be close to the boiling point of the solvent; at the same time the rotary evaporator system can rotate at a speed of 50 to 160 revolutions per minute so that the solvent forms a film and the evaporation area is increased Rotary evaporators wiped film distillation will continue to grow rapidly in the market and the market scope will be doubled compared with today The promising market prospects will make more companies enter the industry to stop playing games but the market analysis of entrants will become more rational Generally speaking the whole industry of rotary evaporator is facing a new round of golden period of development In the process of rapid development there must be fast fish eating slow fish and big fish eating small fish which is the rule of the market game but also an opportunity for the company to develop Only by adjusting the development strategy in time and innovating the management form can the rotary evaporator enterprises persist in vitality growth and development Special Disclaimer The article is sourced from Vision Network (shijiezx Com/news/show PHP Itemid = 37ee0509061c5d02) For more information please click (shijiezx Com/news/) Return to Sohu to see more Responsible Editor toptiontech.com |
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| Research progress on the separation and extraction of lignin _ cellulose | Jobs - Employee | 2022-08-15 | No Picture |
| Research progress on the separation and extraction of lignin _ cellulose
Original Title Research Progress on Separation and Extraction of bra tape measure Lignin Lignin is a natural macromolecular material with phenolic structure which widely exists in woody plants herbaceous plants and vascular plants It is the second largest natural macromolecular material in nature after cellulose in quantity and the only aromatic compound that can be obtained from renewable resources in industry Lignin is widely used in building materials industry petroleum industry light industry and agriculture Lignin is also an important component of human Dietary fibres (DF) which can change the activity of microorganisms in the intestinal system reduce the content of cholesterol and blood sugar in the blood and prevent cardiovascular diseases [2]; lignin also has antioxidant activity [3] and cancer cell inhibition activity [4] As a natural antioxidant active substance the anti-free radical activity of lignin in wood and crop straw has been extensively studied [5] while the research on lignin in dietary fibers such as vegetables and fruits is rare [6] Lignin was extracted from carrot and its structure and antioxidant activity were studied It is expected to get a natural non-toxic side effects of antioxidant active substances which has a wide range of applications in food industry cosmetics health products and so on The extraction and separation methods of lignin generally include acid alkali supercritical aqueous two-phase ionic liquid organic solvent and other means among which the organic solvent method has become the most popular extraction and separation method in recent years because of its environmental protection economy and easy separation However most of them require high temperature and high pressure conditions and there are still many technical difficulties in its complete industrialization which greatly limits its application Therefore this paper also introduces several improved methods by using organic solvents and focuses on the experimental process of extracting and separating carrot lignin by using high boiling solvent The individual unifies the reading material the elaboration hoped has the help to everybody Method for extracting and separating lignin Expand the full text Acid precipitation method Klason [7] used 64% ~ 72% concentrated sulfuric nutsche filter dryer acid to hydrolyze carbohydrates to separate lignin which was called Klason lignin Due to Klason wood The simplicity of lignin measurement makes it widely used in many measurements but this method is not suitable for the study of lignin structure Willstatter [8] first used 40% ~ 42% fuming concentrated hydrochloric acid to dissolve cellulose at 0 ℃ to separate hydrochloric acid lignin or Willstatter lignin Compared with Klason lignin it can be applied to structural studies Although acid solution can hydrolyze cellulose into aqueous solution and precipitate lignin this separation method itself has great disadvantages Because under the action of temperature rise and protons lignin produces positive carbon ions under acidic conditions Alkali precipitation method Wang Sanfan et al Used alkali precipitation method to treat papermaking black liquor from different cooking processes which proved that it was effective to extract lignin by alkali precipitation method [9] The mechanism of alkali precipitation is that the lignin in the black liquor of papermaking contains phenolic hydroxyl group phenolic alcohol group carboxylic acid group carbonyl group and other easily chelated groups which is a typical multi-group ligand and can form a lignin chelate with "chelation" with the added metal ions The main factors affecting the precipitation rate of lignin were pH value and the dosage of metal ions Lignin chelate could be formed only by adding high valence metal cations under alkaline conditions and the precipitation rate of lignin increased with the increase of pH value; the higher the valence state of metal ions and the smaller the radius the easier the chelation and the greater the dosage the greater the precipitation rate of lignin Ultrafiltration Lignin is a kind of macromolecular compound which can be extracted from black liquor of papermaking by ultrafiltration in principle Li Zhongmin et al discussed the feasibility of recovering lignin by ultrafiltration The experiment proved that the ultrafiltration method could effectively recover lignin from papermaking black liquor and the recovery rate was 955% The permeation flux of high concentration solution was smaller than that of low concentration solution and the time needed to achieve constant permeation flux was shorter; Treatment of ultrafiltration membrane with 5 G/L polyoxyethylene sorbitan monolaurate surfactant can reduce the deposition or adsorption of solute on the membrane surface and improve the anti-fouling performance of ultrafiltration membrane [10] Supercritical extraction of lignin Cellulose and lignin are selectively separated by utilizing the different distribution of cellulose and lignin in the solvent under the supercritical condition With the increase of CO2 pressure the conditions of supercritical extraction become more and more similar to those of organic solvent extraction due to the use of organic solvents as additives However with the continuous optimization of the selection of additives the operating pressure of CO2 will continue 50l rotovap to decrease and supercritical extraction becomes a competitive separation process [11] Separation of Lignin by Aqueous Phase Extraction Two-phase aqueous extraction is widely used in the extraction of bioactive substances because of its mild extraction conditions ABS process can solve the problem of high consumption of chemicals and energy in traditional pulping process and the operation of temperature and pressure is relatively easier than that of organic solvent extraction Lignin and cellulose were separated from each other by adding different concentrations of K2CO3 (NH4) 2SO4 and NaOH into Stock solution PEG-6000 according to the different partition coefficients in the two aqueous phases of lignin and cellulose The use of two aqueous phases for lignin extraction will likely be a powerful adjunct to the delignification process in pulping [12] Organic solvent method At present with the widespread recognition and acceptance of the concept of sustainable development green chemistry process has become a hot research topic This requires the components to be separated The process should not only achieve the multi-level effective utilization of the separation products but also take into account the more effective recycling of the separation reagents In this context organic solvents have attracted much attention Compared with the existing alkaline or acid pulping method the method for separating the cellulose the hemicellulose and the lignin by using the organic solvent has the following advantages (1) vacuum drying is used so that the extract and the solvent can be quickly and effectively separated; (2) the extract can be recycled by condensation so that the emission of pollutants to the environment is reduced; And (3) the organic solvent is used so that the extraction environment is relatively mild the denaturation degree of the lignin is less and the implementation of subsequent chemical modification is facilitated However organic solvent pulping still requires high temperature and high pressure and there are still many technical difficulties in complete industrialization which greatly limits its application Several methods of improvement using organic solvents are described below Inorganic alkaline aqueous solution method and organic solvent-water mixed solvent method The inorganic alkaline aqueous solution method and the organic solvent-water mixed solvent method adopted by Fuzhou University can effectively separate the residue of straw fermentation Xtracting the enzymolysis lignin The separation and extraction process of the lignin does not go through chemical processes such as high temperature high pressure strong acid strong alkali and the like The structure is kept well and the chemical reaction activity is high Inorganic Alkaline Aqueous Solution Method and Organic Solvent-Water Mixed Solvent Method Adopted by Fuzhou University It can effectively separate and extract enzymolysis lignin from the residue of straw fermentation The lignin is separated and extracted without high temperature and high pressure The chemical structure of natural lignin is well maintained and has high chemical reactivity in chemical processes such as strong acid and strong alkali 262 High-boiling solvent method (HBS) with microwave radiation as heating source From the point of view of energy saving and emission reduction energy saving and environmental protection and in line with the current reality and green needs microwave radiation is used as the heating source Lignin was extracted from carrot by using ethylene glycol as extractant and the results were satisfactory The microwave radiation is used as a heating source so that the method has the advantages of rapidness energy conservation high efficiency and cleanness; and the extracting agent namely the aqueous solution of ethylene glycol has the characteristics of low toxicity and difficult volatilization can be recycled through distillation after extraction basically has no pollutant discharge and has the advantages of zero emission and no pollution In this method water-insoluble lignin is dissolved in a high-boiling alcohol solvent under heating conditions to separate from cellulose and then lignin is obtained by water precipitation which can better maintain the original structure and activity of lignin and has broad application prospects [13 14] The following is a specific experiment Extraction and Separation Process of Carrot Lignin by High Boiling Solvent Rinse fresh carrots and dry at room temperature Cut the carrot into 05 mm thick slices with a clean stainless steel blade Stored at room temperature and ventilated for different periods of time The above carrot slices were quickly de-enzymed in a blast drying oven at 120 ℃ then dried to constant weight at 60 ℃ ground into powder sieved with a sieve with an aperture of 0 088 mm to obtain carrot fine powder and placed in a drying vessel for later use Weigh 163 G of carrot powder and place it in an autoclave After being added into the ethylene glycol solution with the mass fraction of 80% according to a certain feed liquid mass ratio the mixture is heated to a certain temperature and is cooled to 60 deg C after reacting for a certain time The reaction mixture was filtered under reduced pressure and the filter cake was washed with warm water at 70 ° C to obtain lignin solution At room temperature 3 volumes of water were added and stirred for 15 min and the lignin was precipitated Filtering under reduced pressure and washing the filter cake with warm water at about 60 deg C to obtain brown powdery coarse lignin Wrap 0 decarboxylation after extraction 5 G of crude lignin with filter paper and put it in a fat extractor and extract it with a mixed solvent of V (benzene) V (ethanol) = 11 for 8 H until the extract from the upper part of the fat extractor to the lower part is colorless The lignin was removed and vacuum dried to give 046 G of purified lignin [15] After a series of experiments the optimum conditions of extracting carrot lignin with HBS were as follows fresh carrot slices as raw material mass ratio of raw material 16 reaction temperature 210 ℃ reaction time 2 H Under these conditions the yield of lignin was the highest Application of lignin Lignin is a renewable natural macromolecular organic compound Its development and comprehensive utilization are of great significance to the rational use of resources economic development and environmental protection In agriculture it is used as a slow-release pesticide Lignin can be used as a carrier to prepare lignin slow-release pesticides by physical adsorption and chemical reaction with pesticides fungicides herbicides and plant growth regulators under specific conditions On the one hand because lignin has a variety of active groups it has a strong combination with pesticide molecules which reduces the release rate of pesticides On the other hand the slow degradation of lignin by microorganisms in nature also slows down the release of pesticides Therefore lignin slow-release pesticides can prolong the efficacy reduce toxicity improve the utilization rate of pesticides reduce environmental pollution and have great application potential in modern agriculture It can also be used to make fertilizer Because of the difficulty of alkali recovery the black liquor of non-wood pulping is often discharged directly into the natural environment resulting in serious pollution of the soil and rivers where the sewage is discharged The main method to solve the problem is the ammoniation reaction of lignin At present the production of "ammonia-nitrogen lignin" by oxidative ammonolysis is mostly studied under oxidative conditions lignin can undergo ammoniation reaction to produce nitrogen-modified lignin which can be used as a potential agricultural nitrogen fertilizer or humus Generally nitrogen fertilizer will be released rapidly after application which will seep into the groundwater system and cause secondary pollution while nitrogen-modified lignin has long-term and slow effects and to a certain extent it can reduce environmental pollution In addition lignin can also be used to produce functional fertilizers such as chelated fertilizer activated phosphate fertilizer soil improvement fertilizer and so on Lignin can be used as a coating material Therefore lignin-coated urea can be prepared which has better slow-release effect and yield-increasing effect than common urea and its slow-release characteristic has stronger after-effect than common urea It can maintain the continuous and balanced supply of nutrients improve the utilization rate of nitrogen fertilizer and reduce the environmental pollution caused by nitrogen fertilizer [16] In addition to agriculture lignin is widely used in industry and construction Conclusion The above materials show that the separation extraction and purification of lignin has been widely concerned and the method has reached the level of a hundred schools of thought contending and a hundred flowers blooming The technology of extracting lignin by organic solvent has obvious advantages Because of the good volatility of organic solvent organic solvent can be recovered and lignin can be purified by distillation The recovered organic solvent can be recycled repeatedly a closed circulation system is formed in the whole process and no waste water or a small amount of waste water is discharged so that the method is an effective technical approach for realizing pollution-free or low-pollution 'green environmental protection' is also an effective way for extracting and purifying the lignin and provides a new approach for large-scale development and utilization of lignin resources in industry The extraction and purification technology of lignin needs to be improved and the lignin with high purity as raw material can be used to produce lignin products with good performance Our country has done some work in the utilization of lignin However it is far from keeping up with the needs of the development of the national economy Organize the research work of lignin in a planned way It will be an urgent task to develop China's lignin industry and catch up with the international advanced level In addition the anti-free radical activity of lignin in wood and crop straw has been extensively studied while the research on lignin in dietary fibers such as vegetables and fruits is rare Lignin in dietary fiber is of great significance in food cosmetics and health care products which is in line with people's urgent need for high-quality life Therefore the study of lignin in dietary fiber will be a very promising work and we should increase this research References [1] Jiang Tingda Lignin Beijing Chemical Industry Press 2001 [2] WiUiarns R L． Elliot M S． Antioxidants in Grapes and Wine：Chemistry and Health Effects． In Natural antioxidants：Chemistry，Health Effects and Aapplications[M]． Shaihidi F，Ed． AOCS Press：Champaign，IL，1997：150 [3] shaIIidi F，Janitha P K，Wanssundara P D． Food sci Nutr[J]，1992，32：67 [4] Wang H B． Nair M G，Strasburg GM，Chang Y C，Booren A M，Gray J I，DeWitt D L． J Nat Prod[J]， 1999，62：294 [5] VinardeU M P，Ugartondo V，Mitjans M． 1nd Crops Prod[J]，2008，27：220 [6] Nawirska A，Kwasniewska M． Food Chem[J]，2005，91：221 [7] ChikakoAsadaYoshitoshi Nakamura Fumihisa KobayashiWastereduction system for production of useful materials from unutilizedbamboousingsteam explosionfollowedbyvarious conversionmethods[J]BiochemicalEngineeringJournal200423131～137 [8] Freudenberg KNeish A CConstitutionandBiosynthesis of Lignin[M]BerlinSpringer-Verlag196851 [9] Wang Sanfan Zhang Guojun Xue Xiangdong et al Treatment Mechanism of Lignin and Papermaking Black Liquor by Alkaline Precipitation China Water Supply and Drainage 2002 18 (6) 51 ~ 53 [10] Li Zhongmin Tong Zhangfa Study on the Recovery of Lignin from Black Liquor by Ultrafiltration Chemical Engineering 2003 (1) 49 ~ 52 [11] Sun Yong Li Zuohu Xiao Wei Chen Hongzhang Research progress of lignin separation methods Environmental Governance 2005 26 (10); 3 [12]HeatherDWillauerJonathanGHuddlestonMianLi etalInvestigationofaqueousbiphasicsystemsfortheseparationoflignins from cellulose in the paper pulping process[J]J Chromatogr B2000，743127～135 [13] Liao Junhe Luo Xuegang Cellulose Science and Technology [J] 200311 (04) 60 [14] Chen Yunping Cheng Xianwa Fang Huashu Chen Yuexian et al Cellulose Science and Technology [J] 200311 (01) 19 [15] Peng yuanhua Zeng Xiangqin Lu Hongmei Guizhou Chemical Industry [J] 200631 (4) 16 [16] Zhang Guimei Liao Shuangquan et al Research progress on extraction methods and comprehensive utilization of lignin Tropical Agricultural Science 2005 25 (1) 66 ~ 70 Return to Sohu to see more Responsible Editor toptiontech.com |
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| Shanghai's seven CBD, you only know Lujiazui, then you are OUT! | Jobs - Employee | 2022-08-15 | No Picture |
| Shanghai's seven CBD, you only know Lujiazui, then you are OUT!
Original title Shanghai's seven CBD do you only know hemp extraction centrifuge Lujiazui then you are OUT! When it comes to Shanghai's Central Business District (CBD) the first impression of all Chinese people is the famous Lujiazui but what you don't know is that there are actually seven CBDs in Shanghai and Lujiazui is just one of them Next I will take you to explore the other six CBDs in Shanghai The picture shows Lujiazui CBD in Shanghai which is the headquarters of many multinational banks in Greater China and East Asia and one of the most influential financial centers in China In the picture is the CBD of Shanghai People's Square which is the geographical center transportation hub and heart of the urban area of Shanghai integrating office tourism commerce exhibition and art There are more than ten large shopping malls dozens of well-known enterprise headquarters and hundreds of logistics trade information industry network and other enterprises settled here known as the "super giant CBD" in the city center Expand the full text The picture shows the CBD of Nanjing Road in Shanghai which is the famous CBD center in Shanghai especially the three commercial buildings of Meilong Town Henglong Square cbd centrifugal extractor CITIC Pacific and the nearby Portman Hotel which activate the fashion of the whole business center The picture shows the CBD of Huaihai Road in Shanghai the high-end commodity consumption area from Huangpi South Road to Shaanxi South Road Jiahua Center and other emerging commercial office buildings as well as the surrounding French buildings full of bra tape measure exotic life style which constitute the prosperous CBD commercial belt of Huaihai Road The picture shows Shanghai Xujiahui CBD one of the four major urban sub-centers in Shanghai The computer market in the region is very dense the commodities are very rich and the consumer groups are extensive so Xujiahui has become one of the areas where Shanghai residents buy computers and digital products At the same time there are also many businesses operating luxury goods high-end clothing various entertainment and catering industries in the region The picture shows Shanghai Hongqiao CBD located in the west of Shanghai Relying on the comprehensive transportation hub of Hongqiao it has been built into a cbd crystallization equipment gathering area of Shanghai's modern service industry a new platform for the construction of Shanghai International Trade Center a gathering place for the headquarters of domestic and foreign enterprises and trade institutions and a high-end business center serving the Yangtze River Delta region the Yangtze River Basin and the whole country The picture shows Shanghai Wujiaochang New Jiangwan City one of the four sub-centers of Shanghai which echoes Xujiahui in the southwest of the central city of Shanghai With the continuous development of modern business facilities transportation and ecology the overall advantages of the region have been fully highlighted and it has developed into one of the most prosperous areas in the North Shanghai Business Circle and even the whole Shanghai Return to Sohu to see more Responsible Editor toptiontech.com |
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| In the plastic restriction order, the emergence of PE recycled material film has made a difference? _ Plastics _ Production _ Pollution | Jobs - Employee | 2022-08-15 | No Picture |
| In the plastic restriction order, the emergence of PE recycled material film has made a difference? _ Plastics _ Production _ Pollution
Original Title In the Plastic Restriction wiped film evaporator Order Does the Emergence of PE Recycled Material Film Make a Difference Over the past few years the development concept of the plastic ban has been widely disseminated As a major producer and consumer of plastics China promulgated the Law of the People's Republic of China on the Prevention and Control of Solid Waste Pollution as early as 1995 Since then from the "plastic ban" and "plastic restriction order" to the promulgation of the "14th Five-Year Plan" action plan for plastic pollution control China has attached great importance wiped film distillation to plastic pollution control What are the benefits of using PE recycled film Compared with the original plastic film recycled plastic film uses less natural resources and energy reduces waste and landfill and is widely used in packaging of various products Therefore the application of recyclable plastics will be more and more extensive and the demand for customers will be more and more Especially for foreign trade enterprises many European and American customers have recently asked for the use of recycled plastic bags certified by GRS PE film that meets the global recycling standard GRS certification is an environmentally friendly product that meets customer requirements and can be recycled In terms of plastic restriction order Hualong film is guaranteed Hualong Film has obtained GRS certification thin film distillation which is equivalent to obtaining a green pass in the field of flexible packaging which can meet the needs of brand owners for PCR (Post-consumer Consumer Recycled material PCR) and achieve the unity of commercial value and social value Hualong Film will operate in strict accordance with the requirements of GRS system documents in the process of procurement production and sales so as to provide strong guarantee for customers Return to Sohu to see more Responsible Editor (function() { function getBrandHtml() { var brands = [] html = ''; for(var i = 0; i bra tape measure < brandslength; i++) { var brand = brands[i]; if(brandslength i+1) { html+= ''+brandname+''; } else { html+= ''+brandname+'、'; } } return html; }; if(documentgetElementById('linkBtn')){ documentgetElementById('linkBtn') = function() { $('#brands')removeClass('brand');$ ( '# tipInfo')text ( 'Real name responded'); $ ('#linkBtn')remove();$ ('real-response content')css('line-height' '20px');$ ('real-response time')css('line-height' '20px'); }; documentgetElementById('brands')innerHTML = getBrandHtml(); }; })();。 toptiontech.com |
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| Do you know the surface treatment of titanium and titanium alloy? Polishing | Jobs - Employee | 2022-08-15 | No Picture |
| Do you know the surface treatment of titanium and titanium alloy? Polishing
Original title Do you know the surface Titanium 6Al4V wire treatment of titanium and titanium alloy Titanium is easy to react with O H N and other elements in the air and Si Al Mg and other elements in the investment at high temperature and a surface contamination layer is formed on the surface of the casting so that the excellent physical and chemical properties of the casting are deteriorated the hardness is increased the plasticity and elasticity are reduced and the brittleness is increased The density of titanium is small so the inertia of titanium liquid flow is small and the titanium filler rod fluidity of molten titanium is poor resulting in low casting flow rate Due to the large temperature difference (300 ℃) between the casting temperature and the mold the cooling is fast and the casting is carried out in a protective atmosphere it is inevitable that there are defects such as pores on the surface and inside of titanium castings which have a great impact on the quality of castings Therefore the surface treatment of titanium casting is more important than other dental alloys Because of the unique physical and chemical properties of titanium such as small thermal conductivity low surface hardness low elastic modulus high viscosity low conductivity and easy oxidation the surface treatment of titanium is very difficult and it is difficult to achieve the desired effect by conventional surface treatment methods Special processing methods and operation methods must be adopted The later surface treatment of the casting is not only to obtain a smooth and bright surface reduce the accumulation and adhesion of food and plaque maintain the normal oral microecological balance of the patient but also to increase the aesthetic feeling of the denture; More importantly through these surface treatment and modification processes the surface properties and suitability of castings are improved and the physical and chemical properties of dentures such as wear resistance corrosion resistance and stress fatigue resistance are improved I Removal of Surface Reaction Layer The surface reaction layer is the main factor affecting the physical and chemical properties of titanium castings Before the titanium bar gr5 grinding and polishing of titanium castings the surface contamination layer must be completely removed to achieve satisfactory polishing effect The surface reaction layer of titanium can be completely removed by the method of acid cleaning after sand blasting 1 Sand blasting For the sandblasting treatment of titanium castings it is generally better to use white corundum coarse blasting and the sandblasting pressure is smaller than that of non-precious metals which is generally controlled below 045Mpa Because when the injection pressure is too high the sand impacts the titanium surface to produce intense sparks and the temperature rise can react with the titanium surface forming secondary pollution and affecting the surface quality The time is 15 to 30 seconds and only the burnt-on sand the surface sintering layer and part of the nickel titanium wire oxidation layer on the surface of the casting are removed The rest of the surface reaction layer structure should be removed quickly by chemical pickling 2 Pickling Pickling can quickly and completely remove the surface reaction layer without contamination of other elements on the surface Both HF-HCl and HF-HNO3 pickling solutions can be used for titanium pickling but HF-HCl pickling solution absorbs more hydrogen while HF-HNO3 pickling solution absorbs less hydrogen so the concentration of HNO3 can be controlled to reduce hydrogen absorption and the surface can be brightened Generally the concentration of HF is about 3% ~ 5% The suitable concentration of HNO3 is about 15% ~ 30% Pickling surface titanium plate TA 1 pure titanium plate Expand the full text Sand-blasted titanium plate pure titanium plate II Treatment of casting defects Internal defects of internal pores and shrinkage cavities They can be removed by iso-hot static pressing technology (hot isostatic pressing) but they will affect the accuracy of the denture It is better to use X-ray flaw detection grind the exposed pores on the surface and use laser repair welding The surface pore defect can be directly repaired by laser local welding III Grinding and polishing 1． Mechanical grinding Titanium has high chemical reactivity low thermal conductivity high viscosity low grinding ratio of mechanical grinding and is easy to react with abrasive tools Ordinary abrasives are not suitable for grinding and polishing of titanium It is better to use superhard abrasives with good thermal conductivity such as diamond cubic boron nitride etc The polishing speed is generally 900 ~ 1800 m/min It is appropriate Otherwise the titanium surface is prone to grinding burns and micro-cracks Titanium plate with grinding surface and polished surface Milling surface Milling surface Titanium plate Titanium alloy plate 2． Ultrasonic grinding through the action of ultrasonic vibration the abrasive particles between the grinding head and the ground surface produce relative motion with the ground surface to achieve the purpose of grinding and polishing The advantage is that it is easy to grind grooves pits and narrow parts which cannot be ground by conventional rotary tools titanium plate gr7 but the grinding effect of larger castings is not satisfactory 3． Electrolytic mechanical compound grinding a conductive grinding tool is used electrolyte and voltage are applied between the grinding tool and the grinding surface and the surface roughness is reduced and the surface gloss is improved under the combined action of mechanical and electrochemical polishing The electrolyte is 09 NaCl the voltage is 5V and the rotation speed is 3000 rpm/min This method can only grind flat surfaces and the grinding of complex denture brackets is still in the research stage 4． Barrel grinding The centrifugal force generated by the revolution and rotation of the grinding barrel is used to make the denture in the barrel move relative to the abrasive to reduce the surface roughness Grinding is automatic and efficient but it can only reduce the surface roughness but not improve the surface gloss and the precision of titanium exhaust tubing grinding is poor so it can be used for deburring and rough grinding before fine polishing of denture 5． Chemical polishing Chemical polishing is to achieve the purpose of leveling and polishing through the oxidation-reduction reaction of metal in chemical medium The method has the advantages that the chemical polishing has nothing to do with the hardness of the metal the polishing area and the structural shape all parts in contact with the polishing solution are polished no special complex equipment is needed the operation is simple and convenient and the method is more suitable for polishing the titanium denture bracket with a complex structure However the process parameters of chemical polishing are difficult to control and it is required to have a good polishing effect on denture without affecting the accuracy of denture A better titanium chemical polishing solution is prepared from HF and HNO3 in a certain proportion wherein HF is a reducing agent and can dissolve titanium metal to play a role in leveling the concentration is less than 10% and HNO3 plays a role in oxidation to prevent excessive dissolution and hydrogen absorption of titanium and can also play a role in brightening Titanium polishing solution requires high concentration low temperature and short polishing time (1 ~ 2 min) 6． Electrolytic polishing It is also called electrochemical polishing or anodic dissolution polishing Due to the low conductivity and strong oxidation performance of titanium it is almost impossible to polish titanium with aqueous acidic electrolytes such as HF-H3PO4 and HF-H2so After external voltage is applied the titanium anode is oxidized immediately so that anodic dissolution cannot be carried out However the use of anhydrous chloride electrolyte at low voltage has a good polishing effect on titanium and small specimens can be mirror-polished but for complex restorations it can not achieve the purpose of complete polishing Perhaps the method of changing the shape of the cathode and adding a cathode can solve this problem which needs bra tape measure further study IV Surface Modification of Titanium 1． Nitriding a golden yellow TiN coating was formed on the surface of titanium denture by chemical heat treatment techniques such as plasma nitriding multi-arc ion plating ion implantation and laser nitriding so as to improve the wear resistance corrosion resistance and fatigue resistance of titanium However the technology is complex and the equipment is expensive so it is difficult to achieve clinical application for surface modification of titanium denture 2． Anodizing The anodizing technology of titanium is relatively easy In some oxidizing media under the action of applied voltage the titanium anode can form a thicker oxide film thereby improving its corrosion resistance wear resistance and weather resistance H2SO4 H3PO4 and organic acid aqueous solution are generally used as the electrolyte for anodizing Titanium anodizing and coloring 3． Atmospheric oxidation Titanium can form a thick and firm water-free oxide film in high temperature atmosphere which is effective for general corrosion and interstitial corrosion of titanium and the method is relatively simple 5 Coloring In order to increase the aesthetic feeling of the titanium denture and prevent the titanium denture from being continuously oxidized and discolored under natural conditions surface nitriding treatment atmospheric oxidation and anodic oxidation surface coloring treatment can be adopted to form light yellow or golden yellow on the surface so as to improve the aesthetic feeling of the titanium prosthesis The anodizing method makes use of the interference effect of the titanium oxide film on the light to naturally generate colors and can form colorful colors on the titanium surface by changing the bath voltage VI Other surface treatments 1 Surface roughening In order to improve the bonding performance between titanium and decorative resin the surface of titanium must be roughened to increase its bonding area The Surface of titanium is usually roughened by sandblasting in clinic but the sandblasting will pollute the aluminum oxide on the surface of titanium We use the oxalic acid etching method to get a good roughening effect the surface roughness (Ra) can reach 150 ± 030 μm after etching for 1 H and the Ra is 299 ± 057 It is more than twice the Ra (142 ± 014 μm) of sand blasting alone and its bond strength is improved by 30% 2 Surface treatment for high temperature oxidation resistance In order to prevent the rapid oxidation of titanium at high temperature titanium silicon compounds and titanium aluminum compounds are formed on the surface of titanium which can prevent the oxidation of titanium at temperatures above 700 ℃ This kind of surface treatment is very effective for the oxidation of titanium at high temperature Perhaps the coating of this kind of compound on the surface of titanium is beneficial to the combination of titanium and porcelain and further research is needed More Titanium and Titanium Alloy Surface Treatment Titanium Plate Titanium Anodizing Please Pay Attention to Ruida Titanium Industry Return to Sohu to See More Responsible Editor yunchtitanium.com |
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| Titanium's first MiniLED high-end monitor tailored for eSports players goes on sale _ Technology _ Support _ Picture | Jobs - Employee | 2022-08-15 | No Picture |
| Titanium's first MiniLED high-end monitor tailored for eSports players goes on sale _ Technology _ Support _ Picture
Original Title Titanium's First MiniLED titanium sheet grade 5 High-end Display Tailored for E-sports Players Is on Sale Titanium core selling point 27-inch 25601440 resolution Miniled screen 165Hz refresh rate 1ms (MPRT) fast response HDR1000 support covering 100% sRGB wide color gamut 95% Adobe 95% DCI-P3 cinematic color gamut 10 bit dazzling color depth 10000000 1 contrast ratio 1000 nits peak brightness Adaptive-Sync synchronization technology T V Rhine Certified Hardware Physical Low Blu-ray 65W high-power Type-C reverse charging interface competitive atmosphere lamp ergonomic lifting bracket supporting 90 ° rotation SKY the founder of "China's first e-sports player" has experienced many years of professional e-sports career He knows that the quality of titanium round bar e-sports equipment will greatly affect the performance of players so he has been hoping to make a set of high-end e-sports equipment that everyone can afford Now he has taken another step towards his dream Under the background that the mainstream MiniLED monitors on the market are often five or six thousand or even tens of thousands on July 15 Titanium and Longli Technology (300752) cooperated to launch the first 1000 yuan MiniLED competitive display which is expected to have a promotional price of only 1999 yuan opening the era of MiniLED display "1" Titanium Miniled competitive display uses 27 inches 25601440 resolution and Miniled competitive screen which brings high-end configuration to players Support HDR1000 quantum dot wide color gamut covering 95% DCI-P3 movie-level color gamut 10 bit dazzling color depth T V Rhine certified hardware low blue light 165Hz rapid refresh 1ms (MPRT) rapid response Adaptive-Sync synchronization technology brings high-end e-sports experience ti6al4v Improve the player's operation space and enjoy every minute of the game The high brush is invincible with zero delay In terms of game experience Titanium MiniLED competitive display is designed based on SKY's long-term professional competitive experience It adopts 165 Hz high refresh rate professional competitive level configuration which supports players to show all kinds of extreme operations and control the situation in a natural and unrestrained way When shooting games and MOBA games need to switch the screen quickly the Adaptive-Sync technology can also synchronize the signal transmission between the graphics card and the display reduce the delay prevent the screen from stuttering and tearing even if the player sparks the keyboard and mouse the screen is still silky and clear Expand the full text High-end screen display technology extraordinary ti6al4v eli visual enjoyment If the game experience is well done the visual performance will naturally be of high quality Titanium MiniLED competitive display adopts the industry-leading MiniLED backlight technology Through micron-level fine light control it ensures that the bright area of the picture is not exposed and the dark area can be darkened bringing more delicate and realistic picture performance For players who pursue a more advanced viewing experience they can also turn on the HDR function in the video settings to further enhance the visual performance so that the bright places are brilliant and the dark places are subtle It is worth mentioning that the titanium MiniLED display also uses T V Rhine certified physical hardware low Blu-ray technology comfortable viewing while ensuring eye health The original color presents all things mottled As a product with a wide range of application scenarios titanium MiniLED competitive display can also be used for image processing or graphic design which uses QD quantum dot film technology to cover 95% DCI-P3 movie-grade color gamut 95% Adobe RGB color gamut and supports HDR1000 It not only brings excellent color space and delicate level 3d titanium wire but also provides visual creators with the ability to use and create high-quality HDR content so that every animation and picture works can be fine thorough and lifelike High-end is also carefully carved in detail Strong performance industrial design can not be left behind Titanium MiniLED competitive display uses ergonomic multi-functional bracket which supports players to adjust the screen at will Whether it is horizontal and vertical screen viewing or split-screen dual-screen multi-screen operation it can be adjusted to the appropriate angle greatly improving the use experience As a slash youth in the new era whether the product has a rich expansion interface is also an important criterion for purchasing Titanium MiniLED competitive display provides HDMI Type-C (65W) USB IN and other interfaces Whether it is desktop/notebook XBOX/PS5/Switch or mobile phone/tablet it can be easily connected to enjoy the large-screen experience Its 65W high-power Type-C interface can also be bra tape measure used as a data transmission/fast charging interface to meet the needs of users and continue the battle Intimate after-sales service accompanies every player Strong products can not be without the support of strong after-sales service All users who buy Titanium MiniLED competitive display can enjoy "worry-free after-sales" service including 7-day no-reason refund 15-day quality problem replacement 3-year free warranty and 2-year free on-site service! So that every user can buy at ease use at ease enjoy the happiness and beauty brought by titanium display Excellent performance and high cost performance At present the basic price of displays with MiniLED technology on the market is about 3000 yuan some even as high as 7000 or 8000 yuan and the high price is prohibitive And either lack of low blue light eye protection or poor resolution frame rate etc The emergence of titanium MiniLED competitive display has changed this situation with the first promotional price of less than 2000 yuan physical low blue light HDR1000 165Hz high brush 65W Type-C reverse charging and other mainstream configurations A great choice for a 2000 price point MiniLED eSports monitor! At present Titanium MiniLED competitive display is being pre-sold in titanium tubing price Jingdong The first promotion price is expected to be 1999 yuan and 50 yuan E card will be sent It's better to take action than to be moved Take it into your pocket immediately! Return to Sohu to see more Responsible Editor (function() { function getBrandHtml() { var brands = [] html = ''; for(var i = 0; i < brandslength; i++) { var brand = brands[i]; if(brandslength i+1) { html+= ''+brandname+''; } else { html+= ''+brandname+'、'; } } return html; }; if(documentgetElementById('linkBtn')){ documentgetElementById('linkBtn') = function() { $('#brands')removeClass('brand');$ ( '# tipInfo')text ( 'Real name responded'); $ ('#linkBtn')remove();$ ('real-response content')css('line-height' '20px');$ ('real-response time')css('line-height' '20px'); }; documentgetElementById('brands')innerHTML = getBrandHtml(); }; })();。 yunchtitanium.com |
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| The Latest Review of Huang Jinsong's Nature Journal: Physical Properties of Hybrid Perovskites Applied in Photovoltaic Devices | Jobs - Employee | 2022-08-15 | No Picture |
The Latest Review of Huang Jinsong's Nature Journal: Physical Properties of Hybrid Perovskites Applied in Photovoltaic Devices Original Title Huang Jinsong Nature Subjournal Latest titanium tubing price Review Physical Properties of Hybrid Perovskites Applied in Photovoltaic Devices [Introduction] Over the past few decades researchers have been working to find new photovoltaic materials that are self-cleaning renewable and low-cost Organic-inorganic hybrid perovskites (OIHPs) have attracted much attention in the field of photovoltaic devices due to their abundant raw materials low cost low-temperature batch synthesis and high conversion efficiency However the disadvantages of OIHPs such as heavy metal Pb and poor hydrothermal stability greatly hinder its commercial application Although scientists have made a lot of efforts on these issues the gains are very small In addition there are titanium round bar still no clear design rules in the design of materials Therefore a deep understanding of hybrid perovskite materials is essential to improve the performance of perovskite solar cells and the development of next-generation photovoltaic materials Recently Professor Huang Jinsong of the University of Nebraska at Lincoln (corresponding author) and others published an article entitled "Understanding the physical properties of hybrid perovskites" in the Nature Reviews Materials For photo voltaicapplications "for your article In this review we summarize the latest research progress on the physical properties of three-dimensional and low-dimensional OIHPs with small open-circuit voltage deficit and high efficiency including physical defects ferroelectricity exciton separation process carrier recombination lifetime and photon cycle In addition the article critically evaluates the impact of ion migration on the efficiency and stability of solar cells and discusses some challenges for the commercial application of OIHPs Overview map 1 Charge recombination in perovskite 11 Optical absorption and charge transfer Photovoltaic materials are required to have a large light absorption coefficient The active layer of the material with large absorption coefficient can absorb almost all photons above the band gap in a very thin case reduce the saturation dark current caused by carrier recombination and thus has higher light harvesting efficiency and larger open circuit voltage (VOC) The relationship between film thickness and VOC can be expressed by the Shockley – Queisser model Expand the full text Where bra tape measure K is the Boltzmann constant T is the temperature Q is the elemental charge JSC is the short-circuit current density J0 is the onset current density ND is the doping density τeff is the carrier recombination lifetime Ni is the intrinsic carrier concentration and d is the thickness of the absorber layer OIHPs are almost the most effective absorber among photovoltaic materials For example the absorption coefficient of MAPbI3 in the visible region is larger than 30 × 104 cm ? 1 which is an order of magnitude larger than that of Si The thickness of the thin film in the high-efficiency OIHPs solar cell reported at the present stage is 03-06 μm while the thickness of the thin film in the silicon solar cell is 300 μm The VOC deficit of the photovoltaic materials synthesized by the solution method mainly comes from the energy separating the photogenerated Frenkel excitons and the exciton binding energy (EB) is 02-10 eV Therefore an acceptor/donor heterojunction interface with a large energy offset (> 03 eV) is required to provide the driving force to separate the excitons For photovoltaic devices the smaller EB can reduce the energy loss For example the excitons of Si (EB ~ 15 meV) and GaAs (EB ~ 4 mV) with small band gaps can be separated at room temperature The EB of the hybrid perovskites is 2-75 meV indicating that OIHPs in photovoltaic applications can be classified as non-excitonic materials The non-excitonic character allows perovskite solar cells to be fabricated as planar homojunction or heterojunction thin film structures Figure 1 VOC deficit of OIHPs solar cells EB is sensitive to microstructure In perovskite films with many small grains disordered and different potentials will reduce EB and inhibit the generation of excitons Therefore the stronger exciton peak of MAPbI3 can only appear in larger single crystals Recent studies have shown that excitons are more likely to be generated at high crystallinity and free charges appear at the center of grains with more small grains Figure 2 Photogenerated excitons or photogenerated free carriers of OIHPs (A) Actual (ε ′) and theoretical (ε ′ ′) dielectric constants of MAPbI3; (B) The proportion of free carriers to total carriers in thermodynamic equilibrium; (C) measured EQE of non-excitonic MAPbBr3 and excitonic organic PCBM in the same device; (D) Transient absorption spectra of small crystals (< 200 nm) and large crystals (~ 1 μm); (E) Normalized EQEs of MAPbBr3 polycrystalline thin film with thickness of 3 mm polycrystalline thin film with thickness of 200 mm and single crystal; (F) Absorption spectrum of MAPbBr3 In addition to the chemical composition and microstructure the dimensionality of the crystal also affects the EB 2D materials have a large EB due to the spatial quantum confinement effect With the increase of the number of layers EB tends to be a 3D material 12 Charge recombination rate A longer carrier recombination lifetime requires a larger VOC to provide a higher carrier concentration The carrier recombination lifetime in a semiconductor material can be expressed by the following formula Where G is the carrier generation rate K1 is the unimolecular carrier recombination constant K2 is the bimolecular carrier recombination constant and K3 is the Auger carrier recombination constant In solar cells the recombination probability of Auger carriers is much smaller than that of the other two carriers A series of K1 and K2 values were obtained nickel titanium wire by time-resolved fluorescence spectroscopy (TRPL) transient spectroscopy and time-resolved microwave conductance (TRMC) (Table 1) It can be seen from the table that the single-molecule carrier recombination dominates the carrier recombination in the perovskite film with lower exciton concentration Table 1 Values of K1 and K2 for different materials 13 Charge screening Almost all high-efficiency solar cells such as GaAs and organic bulk-phase heterojunctions are non-Langevin-type bimolecular complexes The Langevin-type bimolecular recombination coefficient is e (μe + μh)/ (εε0) where e μe μh and εε0 are the electron charge electron mobility hole mobility and dielectric constant respectively The recombination coefficient of Langevin-type bimolecular recombination system is related to the carrier mobility Non-Langevin behavior is important for organic molecules with large carrier mobilities In general the charge screening mechanism needs to reduce secondary charge recombination and OIHPs with large dielectric constants can screen electrons and holes There are some other mechanisms to explain why the photogenerated electron-hole recombination of OIHPs is slow Some researchers have hypothesized that perovskites may be ferroelectric creating a polarizing electric field that separates electrons from holes Domain structures have been observed in perovskite structures by piezoelectric force microscopy (PFM) However after excluding the effect of charge leakage no stable magnetization was detected in MAPbI3 by the classical Sawyer – Tower circuit method (Figure 3A) Ferroelastic properties in MAPbI3 polycrystalline thin films and single crystals were confirmed by micro-nano technology (fig 3B) Obvious domain walls at 70 ° and 109 ° were observed by polarized light microscopy and PFM which may be due to the presence of twinned domains with different orientations in the tetragonal MAPbI3 (Figure 3C) Some studies observed ferroelastic domain motion in single crystal and polycrystalline films by polarized light microscopy and PFM (Figure 3D) Researchers have also studied the role of organic cations in carrier recombination It is shown that although the type of organic cation has no obvious effect on the band edge recombination the organic cation plays a large charge screening role in the thermalization of carriers (Fig 3 e f) Figure 3 Electrochemical performance of OIHPs (A) Polarization properties of single-crystalline MAPbI3 for solar cells tested by the Sawyer – Tower circuit method; (B) inversion of domain group observed by reflection polarize microscopy; (C) Schematic diagram of winding structure with two crystal orientations in MAPbI3 single crystal and twin crystal; (D) AFM and PFM of polycrystalline MAPbI3; (E) PL decay dynamics at 23 eV and 26 eV; (F) Crystal structure of MAPbI3 14 Doping of perovskite semiconductor Doping plays an important role in the electrical properties of semiconductors such as conductivity and carrier mobility In solar cells doping can directly change the carrier recombination rate diffusion length contact resistance and VOC The lower doping concentration reduces the scattering and recombination of carriers so that the material has a longer carrier diffusion length Proper doping concentration can reduce the internal resistivity of the solar cell resulting in a larger VOC However it is difficult to achieve extrinsic doping because the structure of OIHPs has low fault tolerance and low activation energy of ion migration In OIHPs self-doping can be achieved because the formation energies of donors and acceptors are similar The self-doping of OIHPs is affected by the composition and synthesis parameters of the precursor for example in the precursor of MAPbI3 thin film more PbI2 makes the thin film become n-type doped material; with the change of Titanium 6Al4V wire MAI content thermal annealing can convert p-type doped material into n-type doped material 15 Photon Cycle The experiment proves that the photon circulation effect of the GaAs solar cell (the reabsorption and reemission of the photoactive layer itself) makes the carriers of the photoactive layer gather thus enhancing the splitting of the quasi-Fermi level which makes it have a higher VOC and the PCE increases from 25% to 29% However it is not known whether there is a photon cycle effect in OIHPs In fact there are many similarities between perovskite and GaAs for example they are both direct band gap materials and have high band edge absorption coefficient which makes the carriers of the materials have high self-separation rate These properties provide preconditions for photon circulation Recently a study has demonstrated for the first time the photon recycling effect in MAPbI3 polycrystalline films The results show that there are photogenerated charges in the light absorption region of more than 50 μm in the polycrystalline thin film (Fig 4a-c) At the same time the photon recycling efficiency of single crystal OIHPs was determined based on the way their polarization differences distinguish between emitted and reabsorbed photons The results show that the photoluminescence signal of the crystal is dominant and the reabsorption and reemission are weak (Figure 4d-f) In these systems the photon recycling efficiency is less than 05% which is negligible for solar cells The lower photon recycling efficiency may be caused by the lower internal PLQY of the perovskite film Fig 4 Photon circulation effect of OIHPs (A) Schematic of the microscope setup for measuring photon circulation; (B) luminescence plot for different separation distances between excitation and collection; (C) Comparison of the experimentally measured (solid line) and theoretically calculated (dashed line) attenuation of the material at 765 and 800 nm; (D) Schematic diagram of photon circulation in perovskite single crystal; (E) Surface PL (blue line) and filtered recovered PL (PLF + PLR; red line) spectra of MAPbBr3 single crystals of 13 mm thickness; (F) Filtered recovered PL (PLF + PLR; red line) and recovered PL (PLR blue line) spectra 16 High electronic dimension Recently the concept of electronic dimension has been used to explain why MAPbI3 has better photovoltaic performance than other metal halide perovskites Generally speaking the structural dimension is an important index to describe the photovoltaic characteristics and device performance of the absorber Electron dimension refers to the connectivity of electron orbitals which can lower the conduction band and raise the valence band Compared with the structural dimension the electronic dimension can better describe the physical properties of materials such as band gap carrier mobility and defect energy levels Although some perovskite materials have three-dimensional structure and electronic dimensions some perovskites with three-dimensional structure have low electronic dimensions The high electronic dimension provides important guidance for understanding the performance of solar cells titanium filler rod 2 Defects in OIHPs 21 Band tail of perovskite The calculated VOCSQ is calculated assuming a perfect break or step absorption coefficient for the light absorber which results in a calculated VOC maximum that is greater than the actual one In real solar cells the absorption spectrum is not abrupt and there is always an absorption band tail in the absorption spectrum due to defects and other reasons Therefore the definition of the maximum achievable VOC (the radiative recombination limit VOCrad) is the balance of the radiative charge recombination current and the photocurrent For solar cells VOCrad (providing a path for VOC losses due to sub-bandgap reorganization) is much smaller than VOCSQ OIHPs photovoltaic devices have a smaller VOC deficit due to their smaller subband gap absorption The absorption spectra of OIHPs have a steep band edge which is characterized by the Urbach energy (the exponential part of the absorption curve) The Urbach energy of polycrystalline MAPbI3 is ~ 15 meV at room temperature which is close to that of single crystal Si (~ 11 meV) and GaAs (~ 75 meV) indicating that the polycrystalline MAPbI3 thin films synthesized by solution method have orderly microstructure and low deep level defect density The experimental results show that the improved crystallinity and phase purity of Cs + -doped perovskite with a wide band gap reduce the Urbach energy thus improving the VOC and efficiency of the device 22 Point Defect Tolerance of OIHPs It is generally believed that in OIHPs solar cells the lower density of charge traps makes them have a larger VOC However at this stage the understanding of charge traps is still in the preliminary stage Although most of the OIHP devices are synthesized by the low-temperature solution method the defect concentration of the OIHP devices is smaller than that of many polycrystalline inorganic solar cells Figs 5 (B) and (C) show the calculated possible point defects of MAPbI3 All the point defects that can form deep levels have large defect formation energies and will not affect the device performance while most of the point defects that exist in the bulk MAPbI3 will form shallow levels In addition the study shows that the energy level of MAPbI3 does not change even if 20% of the I ions in the film are lost (fig 5d) Fig 5 Defect tolerance of OIHPs (A) Defect state density of MAPbI3 polycrystalline thin film and single crystal; (B) Formation energy of intrinsic point defects in MAPbI3; (C) Energy levels of intrinsic donors (left) and intrinsic acceptors (right) in MAPbI3; (D) Defect tolerance of MAPbI3 Polycrystalline OIHPs have a lower defect density another reason is that perovskite materials are easy to crystallize It is found that the crystallization barrier of perovskite is 566 – 973 kJ/mol while that of polysilicon is ~ 471 kJ/mol 23 Defects on surface and grain boundary In addition to point defects extended defects at grain boundaries and interfaces also increase the defect concentration in OIHPs Atoms at grain boundaries and surfaces are not strictly stoichiometric which results in a higher defect concentration here For example after annealing the volatilization of organic components on the surface of the crystal will result in a larger defect density on the surface Even the surface of OIHPs single crystal has many defects and the recombination of surface photogenerated carriers will terminate the photoresponse of short-wavelength light Photoresponse occurs only when the energy of the photogenerated charge is close to the energy band This surface recombination can also explain the phenomenon that the fluorescence lifetime of perovskite single crystals changes with different penetration depths of light (Figure 6a) The surface charge recombination mechanism of perovskite materials is complex The defect density of each crystal plane of the perovskite surface is different There are two crystal planes (100) and (112) on the surface of MAPbI3 single crystal and there are many orientations (110) (202) (310) and (314) on the surface of MAPbI3 polycrystalline film The results show that only (100) is uncharged and the others are charged so there are other ions to balance the surface charge In addition the binding energy of the organic components of different crystal planes is different so that the surface defect density shows crystal plane dependence Fig 6 B shows that the floating of VOC of different crystal planes on the same crystal grain reaches 06 V In addition the surface recombination rate is sensitive to the composition and the ambient humidity The ozone treated MAPbBr3 single crystals showed significant fluorescence enhancement and growth of radiative recombination lifetime at the crystal surface (Fig 6C) Fig 6 Surface charge recombination of OIHPs (A) Schematic of charge recombination and collection under the influence of surface defects and its effect on fluorescence lifetime (bottom left) and narrow-band light detection (bottom right); (B) AFM of the polycrystalline thin film; (C) PL of MAPbBr3 single crystal after vacuum and UV – O3 treatment (left) fluorescence lifetime of MAPbBr3 single crystal after vacuum and air treatment 24 Characterization of Defect Density Accurate characterization of the charge defect density of OIHPs materials is crucial for understanding the relevant optoelectronic properties There is still a lot of defect data unknown at this stage An early method to measure the defect density is thermal admittance spectroscopy which can give the density of defect States at different depth levels The results show that the physical contact of MAPbI3 polycrystalline film with PCBM and C60 can reduce the shallow and deep energy levels by 1 to 2 orders of magnitude indicating that the defects are mainly on the surface of the film (Fig 7A) In order to understand the internal defect density of the single crystal the defect density was evaluated by the trap filling space charge limited current method (fig 7 B) Understanding the defect density of electrons and holes can provide better conditions for designing new perovskite materials with better performance However the current method of measuring defect density can only get the total defect density To separate electrons from holes fig 7c shows a photoconductive element with a carrier acceptor layer of only one type of carrier Fig 7 Charge defect density and surface passivation of OIHPs (A) reducing the defect density of States of deep and shallow level defects by surface passivation of C60 and PCBM; (B) Current-voltage diagram of MAPbI3 single crystal device; (C) Schematic diagram of the symmetrical lateral contact device; (D) Defect density of States (NT) within the band gap 25 Role of ion migration Ion migration is the unique property that distinguishes OIHPs from other photovoltaic materials In this paper we focus on the effect of ion migration on device efficiency and stability Ion migration and aggregation can form a chemical doping effect which is the result of ohmic contacts of high-efficiency solar cells with p – I – n or n – I – p structures (Figure 8 a) A recent study shows that solar cells with n – I – p structure have abnormal photovoltaic effect (Fig 8B) This effect was observed in solar cells with MAPbI3 MAPbBr3 and CsPbBr3 as active layers Some studies have shown that ion migration can improve the short-term stability of materials but weaken the long-term stability of perovskite solar cells Figure 8C shows that the performance of the device degrades under light and can be partially or fully restored after a period of time in the dark This self-healing effect is most likely related to ion migration (Figure 8 d) Because that time it take for the ions to migrate in the film (a few second or minutes) is much shorter than the aging time of the film (day or months) the crystalline phase transition between MAPbI3 and PbI2 causes reversible ion migration so that ion migration has the effect of "repairing" local lattice distortions Self-healing due to ion migration requires sealing of the sample to prevent volatilization of the substance and chemical reaction of the surface with airborne substances In some studies the grain boundaries of MAPbI3 films were filled with polyvinyl alcohol to prevent the volatilization of MA + cations thus playing a self-healing effect to enhance the stability of the device (Fig 8e) Figure 8 Ion migration in OIHPs (A) Schematic diagram of p-type n-type in-situ doping and ohmic contact interface in MAPbI3 solar cell device; (B) Scattered tunnel junctions due to local ion aggregation in electrically poled polycrystalline perovskite films resulting in band shifts and anomalous photovoltaic effects; (C) Self-healing phenomena of two types of perovskite solar cells; (D) in the MAPbI3 film the defect concentration is reduced due to the redistribution of photogenerated carriers; (E) Illustration of self-healing achieved by filling MAPbI3 grain boundaries with polyvinyl alcohol 3 Conclusion and prospect In the past few years great progress has been made in understanding the unique physical properties of OIHPs In this paper the intrinsic optoelectronic properties of OIHPs are discussed and these properties are combined with the device performance The properties of OIHPs prepared by solution method such as optical absorption carrier defect depth exciton binding and charge diffusion length are much better than those of covalent-bonded photovoltaic materials (such as Si GaAs and CdTe) prepared by high temperature and vacuum method However the influence of intrinsic optical and electrical properties such as intrinsic defect concentration charge screening and ion migration on the performance of materials is still not well understood Although great progress has been made in the study of mechanism there are still many important problems to be further explored The ferroelectric properties of MAPbI3 still need to be further studied and the substitution of FA + Rb + Cs + or Co2 + for MA + cations will provide a way to understand the role of ferroelectric dipoles Recent studies have improved the device efficiency by introducing external ions and adjusting the composition The role of external ions needs to be further understood which is conducive to further understanding the shortcomings of MAPbI3 materials with single component Another direction is to understand the internal correlation between the intrinsic characteristics of materials (electrical mechanical optical and spin properties) and device properties Although the larger lattice constant of OIHPs makes the material have ion migration effect the reason why these properties make the material have larger dielectric constant and better structural stability is still unclear The understanding of the unique optoelectronic properties of OIHPs materials will provide conditions for the discovery of perovskite light absorbers that are non-toxic and stable in air for a long time Literature Link Understanding the physical properties of hybrid perovskites for photovoltaicapplications (Nat Rev Mater 2017 DOI 101038/natrevmats201742） This article is contributed by Zhu Xiaoxiu a material person and edited by Material Niu Material Cattle Network focuses on tracking the progress of science and technology and industry in the field of materials It brings together students from universities first-line researchers and industry practitioners If you are interested in tracking the progress of science and technology in the field of materials interpreting high-level articles or commenting on the industry Contribution and content cooperation can be added to the editor's WeChat xiaofire-18 Wu Mei we will invite teachers to join the expert group Contact information of test valley cooperation Tel 010-5742 9831 QQ 3234370334 E-mail kefu@ceshigucom Material Man Cooperative contact Test Valley Material People's One-stop Material Analysis and Testing Solution Platform Has Been Revised and Launched! （http//wwwceshigucom/） Test Business XRD/TEM/SEM/DSC/AFM/Mechanical Test/Thermal Analysis/PPMS/IR/Particle Size Analysis Technical services Thesis polishing/Thesis drawing/Theoretical calculation/EBSD data analysis/MS use guidance/TEM operation guidance Recruitment services release/push/publicize the recruitment needs of enterprises match/customize/recommend talents according to job requirements please contact QQ 3271467181 Business cooperation 15120014412 Material test kefu@ceshigucom Submission email tougao@cailiaorencom Material people are here waiting for you to return to Sohu to see more Responsible Editor yunchtitanium.com |
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| 1.75mm! RM once again surpasses and proves itself _ movement _ balance _ thickness | Jobs - Employee | 2022-08-15 | No Picture |
| 1.75mm! RM once again surpasses and proves itself _ movement _ balance _ thickness
Originally published as 175mm! RM has titanium bar grade 5 surpassed and proved himself again Depth/degree/minute/analysis/member Whenever you mention RICHARD MILLE what do you think of Is it innovative materials high-tech or avant-garde appearance light weight Now there is another pronoun-the king of ultra-thin Just last week RICHARD MILLE launched the RM UP-01 FERRARI watch with Ferrari As we all know since last year the two have formally established a long-term partnership and it is perfectly normal to launch a cooperative model However the reason why this wristwatch has flooded the whole network is that the whole watch has refreshed the latest world record of 18 mm a few months ago with a thickness of 175 mm RICHARD MILLE has never been disappointing bra tape measure">bra tape measure The thickness of the watch case does not seem to matter but it may become a burden for the wearer both visually and physically and ultra-thin watches emerge as the times require But ultra-thin is not just as simple as watch case lightening it has extremely stringent requirements for the movement after a long period of market choice only a few strong watch brands are still working tirelessly to break through and innovate In fact strictly speaking RICHARD MILLE is not an expert in the field of ultra-thin watches but this brand is born to refuse to lose either do nothing or do the best character so that they often break through the imagination of the limits of watches this RM UP-01 6al4v titanium bar FERRARI wristwatch came out in the air It is the best evidence that RICHRAD MILLE has surpassed itself again Expand the full text Many people will find that its design is different from the previous watches at the first sight of the chart from the original vertical barrel type to the horizontal barrel type and behind this change in appearance there are many RICHARD MILLE "" Niubi "technologies Previously in order to achieve the ultimate ultra-thin other brands adopted the design of "using the case as the bottom plate of the movement" but this RM UP-01 FERRARI watch the case and the movement are completely independent the thickness of the whole watch is 175 mm and the thickness of the movement is only 118 mm Because the challenge of ultra-thin watches requires abandoning the traditional movement design of superimposed gears and pointers RICHARD MILLE chooses to disperse the parts that can not be superimposed to a wider plane creating a perfect symbiosis between the movement and the case while ensuring the necessary rigidity of both Seen from the front the time display area is very small In the upper part of the center the upper part of the titanium exhaust tubing left side is the function selector which can select the winding or time adjustment and the lower part is the specific operating point; the upper half of the right side is the explicit balance wheel and the lower part is Ferrari's classic Prancing Horse logo Titanium alloy is selected as the case material of RM UP-01 Ferrari watch because of its lightweight and laboratory-proven impact resistance and its waterproof depth can reach 10 meters Two sapphire crystal mirrors (02 mm at the thinnest point) one mounted on the time indicator with the hands fixed directly to the gears and the other mounted on the balance and hairspring mechanism show the operation of the movement while the thickness is reduced to two tenths of a millimeter and the diameter is carefully calculated to meet the resistance requirements of the test phase In order to ensure the ideal operation of the transmission mechanism the bottom plate and the bridge plate are also made of five-grade titanium alloy which ensures the perfect thinness without affecting the hardness From a technical point of view titanium sheet grade 5 the RM UP-01 FERRARI watch can be 005 mm thinner than 18 mm because RICHARD MILLE has innovated the escapement part and won a patent Traditional Swiss mechanical watches mostly use lever escapements with fork nails and balance plates inside which can prevent the anchor from slipping during the free movement of the balance wheel but the problem is that the structure of these two parts is vertical that is to say they need longitudinal space and can not reduce the thickness In order to reduce the thickness RICHARD MILLE has eliminated the fork nail and the small plate of the balance wheel and through the patented new escapement structure it has replaced these "anti-rollover" elements with the unprecedented use of a longer escapement fork with a new fork mouth At the same time the movement also cancels the fast and slow needle system uses the variable inertia balance wheel made of titanium alloy and is equipped with six weights that can fine-tune and calibrate the speed control mechanism which solves the biggest problem of ultra-thin watches and reduces 005 mm naturally In addition it can be seen that this watch has no crown because in order to ensure the extreme thinness of the watch RICHARD MILLE has rethought the winding mechanism and eliminated the winding shaft titanium plate gr7 (because its minimum diameter is 15 mm it can not be included in such a thin watch) RICHARD MILLE's solution to this is to use two crowns one for function selection and the other for adjustment of the selected function both of which are integrated into the case as movement gears resulting in the design we have seen above As Salvador Arbona technical director of RICHARD MILLE movement said "Even in the ultra-thin series we have to create a watch that meets the brand's standards" In the pursuit of absolute thinness we are not creating a'concept watch ' but making it meet the wearer's daily needs in any environment Like all previous RICHARD MILLE watches the brand always puts practicality in the first place on top of all innovations first of all the necessary shock resistance and impact resistance of the watch so the RM UP-01 movement inside the watch can withstand acceleration of more than 5000 G Looking back on the connection between RICHARD MILLE and Ferrari from the pursuit of high technology to the use of similar materials as well as the passion for their respective fields all of these are based on the common values of both sides courage to try assiduous study and excellence which also gives a competitive spirit to this cooperation project Is essential in an exciting adventure Wen | Xilin Design | Jili Figure | From the brand partly from the network More exciting content can be found on the official WeChat account of Time Square Time Concept Welcome to pay attention! Return to Sohu to see more Responsible Editor (function() { function getBrandHtml() { var brands = [] html = ''; for(var i = 0; i < brandslength; i++) { var brand = brands[i]; if(brandslength i+1) { html+= ''+brandname+''; } else { html+= ''+brandname+'、'; } } return html; }; if(documentgetElementById('linkBtn')){ documentgetElementById('linkBtn') = function() { $('#brands')removeClass('brand');$ ( '# tipInfo')text ( 'Real name responded'); $ ('#linkBtn')remove();$ ('real-response content')css('line-height' '20px');$ ('real-response time')css('line-height' '20px'); }; documentgetElementById('brands')innerHTML = getBrandHtml(); }; })();。 yunchtitanium.com |
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