Performance of Conducting Pani-DBSA and pani-DBSA Fe3O4 Composites as Electrode Materials for Aqueou

set_operating_conditions -analysis -回复[set_operating_conditions analysis]Introduction:When it comes to running a successful business, setting the right operating conditions is crucial. These conditions define the parameters within which a business operates, ensuring efficiency, productivity, and profitability. In this article, we will explore the process of conducting a set_operating_conditions analysis, step by step.Step 1: Identify the PurposeBefore undertaking any analysis, it is essential to identify the purpose of conducting a set_operating_conditions analysis. This purpose could be to improve efficiency, reduce costs, enhance productivity, meet regulatory requirements, or respond to changing market conditions. Having a clear purpose helps focus the analysis and ensures that it aligns with the overall business strategy.Step 2: Identify Key Operating ConditionsThe next step involves identifying the key operating conditions that significantly impact business operations. These conditions may vary depending on the nature of the business. Examples of key operating conditions include temperature, pressure, humidity, time, resource availability, quality standards, safety regulations, and customer demands. It is important to involve relevant stakeholders throughout this process to ensure all perspectives are considered.Step 3: Gather DataOnce the key operating conditions are identified, it is necessary to gather data to understand the current state of these conditions. This could involve analyzing historical data, conducting surveys, observing work processes, collecting feedback from employees and customers, and studying industry standards and best practices. The data collected should provide a comprehensive understanding of the current operating conditions and any gaps or areas for improvement.Step 4: Analyze DataWith the data gathered, the next step is to analyze it to identify patterns, trends, and potential areas of improvement. This analysis can involve statistical techniques, like regression analysis or correlation analysis, to determine relationships between different variables. It is also crucial to consider the business context and any external factors that may influence the operating conditions.Step 5: Identify Opportunities for ImprovementBased on the data analysis, opportunities for improvement can be identified. These opportunities could range from optimizing processes, adjusting resource allocation, implementing technological solutions, enhancing employee training, or revising policies and procedures. Prioritizing these opportunities is essential to ensure that efforts and resources are allocated effectively.Step 6: Develop Action PlanOnce the opportunities for improvement are identified and prioritized, it is important to develop an action plan. This plan should outline the specific actions required, establish timelines,allocate responsibilities, and define key performance indicators to measure progress. It is crucial to involve relevant stakeholders and ensure their buy-in to maximize the chances of successful implementation.Step 7: Implement and MonitorWith the action plan in place, it is time to implement the necessary changes and monitor their effectiveness. This could involve testing and piloting new processes, training employees, acquiring new equipment or technology, or revising policies and procedures. Regular monitoring and feedback loops are essential to assess the impact of the changes and make any necessary adjustments.Step 8: Continuous ImprovementSetting operating conditions is not a one-time process but an ongoing effort. It is essential to foster a culture of continuous improvement within the organization. This could involve conducting regular reviews and audits, seeking feedback from employees and customers, monitoring industry trends and best practices, and staying updated with regulatory requirements. Thedata gathered during these processes can feed into futureset_operating_conditions analyses, ensuring that the business remains adaptable and responsive to changes.Conclusion:Conducting a set_operating_conditions analysis is a critical aspect of running a successful business. By identifying key operating conditions, gathering and analyzing data, identifying opportunities for improvement, and implementing changes, businesses can ensure efficiency, productivity, and profitability. Embracing a culture of continuous improvement is key to staying competitive in an ever-evolving business landscape.。

第49卷第4期2021年4月聚氯乙烯Polyvinyl ChlorideVol.49 ,No.4Apr. , 2021【助剂】双沉积-沉淀法制备的复合载体催化剂在乙炔氢氯化反应中的应用李霖，曾利辉，苏雅文，魏晓航，曾永康，张之翔，金晓东#(西安凯立新材料股份有限公司，陕西省贵金属催化剂工程研究中心，陕西西安710201 )[关键词]复合载体；乙炔氢氯化；沉积-沉淀法；环保无毒[摘要]采用双沉积-沉淀法制备了一种复合载体催化剂，并对其在乙炔氢氯化反应中的催化性能进行了研究。

催化剂的制备过程包括2个步骤：首先将纳米级二氧化铈沉积在活性炭上得到复合载体，然后将金属活性组分沉积在复合载体上得到催化剂。

重点考察了二氧化铈固载量以及金铜比例对乙炔氢氯化反应催化活性的影响。

试验结果表明：该复合载体催化剂具有成本低、活性高、使用寿命长等特点；在连续运行中能够保持良好的性能，制备工艺简单，易于放大；无毒环保，具有良好的工业化应用前景。

[中图分类号]TQ325.3 [文献标志码]B[文章编号]1009 -7937(2021 )04 -0027 -04Application of composite carrier catalyst preparedby double deposition-precipitation to acetylene hydrochlorination LI Lin, ZENG Lihui, SU Yawen, WEI Xiaohang f ZENG Yongkang, ZHANG Zhixiang y JIN Xiaodong(X i'a n Catalyst N ew Materials Co. , L td.,Shaanxi Engineering Research Center o f Noble Metal Catalyst, X i'an710201 , China)K ey w o rd s：composite carrier；acetylene hydrochlorination；deposition-precipitation；non-poison-ous and environmentalA b stract ：A kind of composite carrier catalyst was prepared by double deposition-precipitation andits catalytic performance in the hydrochlorination o f acetylene was studied. The preparation precess o f the catalyst comprised two steps as follow：firstly, the nano-sized C eO, was deposited on the activated carbon to get the composite carrier；then the metal active component was deposited on the composite carrier to obtain the catalyst. The effect o f the load of C e02and the ratio o f Au and Cu on the catalytic activity in hydrochlorination o f acetylene were investigated. The experimental results show that the composite carrier catalyst has the characteristics o f low cost, high activity and long service life；it can maintain good per­formance in continuous operation, the preparation process is simple and easy to scale up ；it is non-toxic and environmental friendly, and has a good industrial application prospect.聚氯乙烯（PVC)曾是世界上产量最大的通用 塑料，应用非常广泛。

聚苯胺和聚乙炔1.1导电聚苯胺作为一种新型的功能高分子材料，越来越受到科学家们的关注。

因为它具有合成方法简单、掺杂机制独特、环境稳定性良好等优点，而且它还具有广阔的开发与应用前景。

聚苯胺在电池、金属防腐、印刷、军事等领域展示了极广阔的应用前景，成为现在研究进展最快、最有工业化应用前景的功能高分子材料。

但是聚苯胺的难溶解、难熔融、不易加工等特性阻碍了聚苯胺的实用化进程。

聚苯胺的合成方法主要有化学氧化聚合法（乳液聚合法、溶液聚合法等）和电化学合成法（恒电位法、恒电流法、动电位扫描法等），近年来，模板聚合法、微乳液聚合、超声辐照合成、过氧化物酶催化合成、血红蛋白生物催化合成法等以其各自的优点而受到研究者的重视。

1984年,MacDiarmid在文献中提出聚苯胺具有以下可以相互转化的4种理想形式:2.1化学合成（1）化学氧化聚合化学氧化法合成聚苯胺是在适当的条件下，用氧化剂使苯胺(An)发生氧化聚合。

苯胺的化学氧化聚合通常是在苯胺/氧化剂/酸/水体系中进行的。

较常用的氧化剂有过硫酸铵、重铬酸钾（K2Cr2O7）、过氧化氢（H2O2）、碘酸钾（KIO3）和高锰酸钾（KMnO4）等。

（NH4)2S2O8由于不含金属离子、氧化能力强，所以应用较广。

聚苯胺的电导率与掺杂度和氧化程度有关。

氧化程度一定时，电导率随掺杂程度的增加而起初急剧增大，掺杂度超过15％以后，电导率就趋于稳定，一般其掺杂度可达50％。

井新利等通过氧化法合成了导电高分子聚苯胺，研究了氧化剂过硫酸铵（APS）与苯胺单体的物质的量之比对PANI 的结构与性能的影响。

结果表明，合成PANI 时，当n（APS）：n（An）在0.8 ～1.0 之间聚合物的产率和电导率较高。

研究表明，聚苯胺的导电性与H+掺杂程度有很大关系：在酸度低时，掺杂量较少，其导电性能受到影响，因而一般应在pH值小于3的水溶液中聚合。

质子酸通常有HCl、磷酸（H3PO4）等，苦味酸也用来制备高电导率的聚苯胺，而非挥发性的质子酸如H2SO4和HCIO4等不宜用于聚合反应。

Performance Enhancing SubstancesBy Jason Arquilla ATC/L, CSCSJump higher, run faster, get bigger, and look leaner We all would like these things right? But at what cost?Students around the country are taking substances they know little or nothing about. I am not referring to illicit drug use. I am talking about supplements, specifically performance enhancing supplements. You know the ones: Creatine, ephedra, Ma Hung, Ginseng, Andro and many others. Some studies have actually shown that when students take these supplements, they don’t know how much they are taking or how much they should take.Not understanding these products can pose several different problems The product can be dangerous to your health Ephedrine that is now controlled by the FDA, was sold by the millions while athletes were dying from its effects on the heart. Phen-fen was a popular diet supplement that was widely used until it was linked to heart disease There is a fear that the use of creatine in teens may cause problems with normal growth. There can be long term risks that are unknown All of the research done, has been done on adults It could be a waste of your time and money (it doesn’t work) Studies have shown that Andro doesn’t work. So it was Mark McGuire’s skill that hit all of those home runs, not the effectiveness of the supplement.This website will provide information on three ways to help improve this problem 1. Education on the substances teens are tempted to take, on understanding claims, and having trustworthy sites to learn about claims. 2. Refocusing on what is important, that is taking the emphasis off winning and putting it on the individual’s performance. 3. A healthy Body Image: Body dysmorphia disorder, for both men and women.EducationIf a guy in a black trench coat came up to your friend on the street and offered him a pill, that would make him a better basketball player; what would you do? Imagine a super star athlete sent your friend an email about this great product that will make him run fast and jump higher. Would you let him take it? The only difference between these two scenarios is the package in which the product is wrapped. The first one is an unknown person on the street; the other is a famous athlete. Neither one you truly know, or should trust with your health. The scary thing is teens are taking supplements all over the country, without understanding what they do or what is truly safe. One of the reasons why is they see the advertisements and think, Hey its natural it has to be OK right? WRONG You see advertisers can say just about anything they want about their product, because most supplements are not regulated as drugs. This means we have to be smart consumers. We have to know more about the product than the advertisers tell us.EDUCATE YOUR SELF Who do you ask that you can trust? Parents Doctors Licensed/Registered Dietitian Health Teachers Where can you get unbiased information? Library Research articles Encyclopedias Books by INDEPENDENT RESEARCHERS ****This is important to understand. Some people do research with the goal of promoting their product. There is a basic problem in this approach. Those selling the product are biased. Unbiased research answers a question, like “Does ingesting 30 grams of creatine daily improve quadriceps strength?” ****Ideally research on a product should be done separately from the company that produces that product. If it is not, there is the risk of the research being biased. This means the company may not be giving you all of the information. Always look to see who did the research and who funded the research. Good sources of product research include government research agencies, like the CDC, NIH etc… ****Web sites that come from universities and government agencies (/or ) are good sources because the content on those sites have been doubled and triple checked for accuracy.Places and claims to be skeptical about Any outrageous claim Decrease you body fat without exercising Lose weight without changing your diet Add muscle mass with out changing your work-outClaims or advertisements without independent research Our scientist found……. Thousands of bodybuilders agree…… I (insert popular supers star) use it and it works great.Websites Those have no or little research backing the product Make outrageous claims Sound too good to be trueSources of Information on Performance Enhancing SubstancesUntied States Antidoping agency / /superstars/template.pl?opt=news&pubid=3681NCAA /education/ /membership/ed_outreach/nutritionperformance/about/articles/performance_enhancing.htmlHow things work /athletic-drug-test.htm/printableTexas Medical Association /ata/nrm/tme/texmedfeb02_performance_enhancers.aspPenn State University /ur/2002/performancdrug.htmlPhysician and Sports Medicine /issues/2002/11_02/guested.htmNew Brunswick Study on Adolescents http://216.239.37.104/search?q=cache:WL4MTcLOS0J:www.unbf.ca/Kinesiology/pilotreport2001.pdf+performance+enhancing+s ubstances&hl=en&ie=UTF-8National Federation of State High School Associations /press/supplement_concern.htmlOther Sites /health-wellness/sportsdrugs/links.htm/faclink/thatten/PPR237/Class_Notes/Chapter%2011.htmWinning at all costsEven when people are educated about these supplements, some still are willing to take the risk of getting sick from them. WHY? They are motivated to win at all cost. Most coaches and athletes focus on the win, versus the performance during the game. One basic concept in taught in sport psychology is the Achievement vs. Performance orientation. Achievement is winning. Performance is how well you do. Sport Psychologists have learned that the athlete should focus on the actual performance, not the achievement or outcome (winning or losing). There are different techniques to do this, but the basic premise is that you should only worry about what you can control, your own performance, not the outcome. There are too many things that effect who wins. No one can control them all. When athletes are coached this way they are more successful. When athletes are coached to focus on winning, they lose. Some sites to get more information on the Sport Psychology theory of Achievement Orientation/dept/coachsci/csa/vol63/grieve.htm /ess/people/newton/newton.html /2003Journal/Vol6-No3/confidence.htm /Standard Pages/NGSSA_Coaching_Philosophy.htm /education/psychology/index.htmlBody ImageOne other reason people may take these supplements is because of body dysmorphia disorder. A very simple definition of body dysmorphia disorder is an unhealthy and unrealistic self body image. The desire to be physically attractive drives us all to do strange things. It is when these strange things become dangerous things that we have a problem. Everyone’s body is different. This makes us all unique and special. But there are different types of bodies. Each type has its own characteristics that are unique to it. There are 3 common body types. 1 Mesomorph 2 Ectomorph 3 EndomorphMore information can be found on Healthy Body Image Everyone has read, or heard about this with girls and women with anorexia/bulimia. Abuse of supplements can be seen as a sign of an eating disorder. But this is not a gender bias problem. Men and teen boys have this issue as well as women and girls. It may show its ugly head a little differently. Boys are more likely to take supplements than girls. Boys are more likely to exercise at an unhealthy level than girls. The problem here is about expectations. Here are some sites that can explain dymorphia better.Some sites to get more information on body image/Communities/Eating_Disorders/peacelovehope/bdd.html /~shumow/iit/health.html /html/reports/fy2001/nimh.html/cgi/content/abstract/157/8/1291?maxtoshow=&HITS=10 &hits=10&RESULTFORMAT=&fulltext=dysmorphia&searchid=1068329440859_828& stored_search=&FIRSTINDEX=0&resourcetype=1&journalcode=ajp/REFERENCESAmerican Academy of Pediatrics. (2001). Though not recommended, young athletes use creatine to improve performance. Pediatrics, Retrieved September 15, 2003, from /creatine.htmlBuhrke, M.S., & Yesalis, C.E. (2002). Determining the efficacy of performance-enhancing substances. Performance-Enhancing Substances in Sport and Exercise. /details/0736036792/display.php C & R research services inc. (2001).BlueCross/BlueShield association’s healthy competition foundation national survey on performance-enhancing drugs in sports. Retrieved September15, 2003, from /hc/news/survey_key_findings.docEichner, R.E. (2001). Ergogenic aids: what are athletes using and why? Physician and Sports Medicine, 25, 70-6, 79, 83Kersotis, P. (2003). Baseball’s laughable drug testing no longer funny. Florida today, Retrieved September 15, 2003, from /MLBdrugtesting.O’Dea, J., & Rawstone, P. (2001). Male adolescents identify their weight gain practices and reasons for desired weight gain and sources of weight gain information. Journal of American Dietetics Association, 101,105-108.Powers, M.(2001). Ephedra and its application to sport performance; another concern for the athletic trainer. Journal of Athletic Training Association, 36, 420-424.Santrock, J.W. (2003). Moral development, values and religion, The self and identity. Adolescence.Schwenk,T.L., & Costley,C.D. (2002). When food becomes a drug: nonanabolic nutritional supplement use in athletes. American Journal of Sports Medicine, 30, 907-917.Smith, J., & Dahn, D.C. (2000). Creatine use among a select population of high school athletes. Mayo Clinical Proceedings, 75, 1257-1274.Winterstein, A.P., & Storrs, C.M. (2001). Herbal supplements: considerations for the athletic trainer. Journal of Athletic Training Association, 36, 435-432.。

Low Temperature Viscosity Measurements -Lovis for Battery ElectrolytesRelevant for: battery industry, electrochemical research, automotive industryPerform viscosity measurements down to -20 °C with Lovis 2000 M/ME with cooling option. Test even highly corrosive solvents for ion salts by using unbreakable PCTFE capillaries with small filling volumes (110 µL or 450 µL). Handling of the sample inside a glove box filled with inert gas and a hermetically closed system prevent contamination or evaporation of the sample.1 IntroductionSince the introduction of the lithium-ion batteries in 1990, the interest in this technology has emerged steadily, not only for portable devices but also for the automotive industry. Their high energy density as well as outstanding cycle stability are the main reasons for commercial success, but several problems arise with the usage of the most common non-aqueous electrolytes, which contain lithiumhexafluoro-phosphate (LiPF6) as conductive salt and a mixture of cyclic and non-cyclic organic carbonates.In addition to the high purity required of all used solvents (e.g. traces of protic impurities such as water can cause severe deterioration of the cell performance after a short life / cycle time) the cell performance has to be stable over a broad temperature range from arctic to tropical conditions without any significant degradation. Therefore, an exact characterization of newly developed electrolytes at different temperatures is an essential part in the lithium-ion cell research today. These challenges have to be considered for every other upcoming battery systems like magnesium ion cells or sulfur cells, too.Therefore, research companies use different standard electrochemical measurements for monitoring batteries. In this connection viscosity, conductivity and – if required – density measurements of the electrolytes support those investigations.The performance of the charge and discharge rate of a rechargeable battery, that is the ion transport, is characterized by the ion conductivity, which depends on the viscosity and the dielectric constant.The viscosity of the solvent, in which the ion salt is solved, affects the mobility of ions, as shown in the Stokes-Einstein equation; mobility is inversely proportional to the viscosity:r ... radius of the solvated ionBased on those viscosity measurements important conclusions on the wettability of the electrode /electro-lyte interface can be drawn, too. Fast, accurate and reproducible viscosity measurement over a wide temperature range is highly desirable for successful development of new electrolyte systems.This application report shows how the Lovis can be used for electrolyte measurements even at tempera-tures below zero. The Lovis, equipped with coolingoption and in combination with the capillary made of PCTFE, enables measurement of highly corrosive substances over a wide temperature range.2 Instrumentation2.1Lovis 2000 M/ME Microviscometer with Cooling OptionFigure 1: Lovis 2000 M with cooling optionThe Lovis 2000 M/ME Microviscometer measures the rolling time of a ball inside an inclined capillary.Variable inclination angles allow for measurements at different shear rates. Temperature control via Peltier elements is extremely fast and provides utmost accuracy.For measuring at temperatures below zero, the Lovis ME Module can be equipped with a lowtemperature option. In combination with a recirculating cooler, it is possible to measure at temperatures as low as -20 °C (lower temperatures down to -30 °C on request, depending on the cooling liquid of the recirculating cooling, ambient temperature and ambient air humidity).The integrated software calculates the kinematic or dynamic viscosity, provided the sample's density value is known.Figure 2: Lovis PCTFE capillariesWith the PCTFE capillaries it is possible to measure nearly every liquid, also corrosive, aggressive or hazardous solvents and electrolytes.The measuring viscosity of a PCTFE capillary ranges from 0.8 mPa.s to 160 mPa.s.Used material:▪ Capillary: PCTFE short (110 µL) ▪ Capillary diameter: 1.62mm ▪ Ball material: Steel ▪ Ball diameter: 1.5 mm2.3 Additional Equipment▪ Glove box filled with argon.▪Circulation cooler plus insulated hoses. How to set up the cooling is precisely described in the documentation of Lovis 2000 M/ME.3MeasurementAll determinations were performed manually without autosampler. The viscosity measurements were performed in a temperature range from -20 °C to +60 °C with steps of 5 °C or 10 °. For temperature table scans (TTS) two density values at two different reference temperatures were typed in manually in the "Quick Settings" ("Lovis Density TS/TTS") for every sample. The instrument automatically extrapolated the missing temperature / density values by linearextrapolation. The density values for the manual input were determined with the SVM™.Every scan was performed twice in order to obtain a repeat determination. To check the reproducibility, all measurements were performed with Lovis and SVM™ in parallel.3.1 Samples▪Different mixtures of organic carbonates, which contain lithiumhexafluorophosphate as conductive salt – for lithium ion batteries (LIB), either commercial available standardelectrolytes or newly developed electrolyte solutions.▪Solvents containing a polar organic solvent and dioxolane added with Li-sulfur-compounds as conductive salts – for future Li-S-cell systems (LiS).▪Solvents containing a polar organic solvent plus Mg-compounds as conductive salts – for prospective Mg-ion batteries.3.2 Instrument Settings Measuring Method: Temperature Table Scan (TTS) Measuring Settings:▪ Temperature: scan between -20 °C to +60 °C ▪ Equilibration Time: no ▪ Measurement Cycles: 3▪ Measuring Angle: Auto Angle * ▪ Variation Coefficient:0.4 % for standard electrolytes ▪ Measuring Distance: Short* Adjustment was performed over an angle range from of 20° to 70° in 10° steps3.3 Filling of the CapillaryAll samples were manually filled in an argon glove box under inert conditions. For each measurement a new steel ball was used to avoid any cross contamination from one measurement to the other. After closing the capillary with the appropriate plug, the hermetically sealed capillary was removed from the glove box.3.4 CleaningThe capillary was cleaned thoroughly with smallbrushes after every test sequence. Ethanol, deionized water and other appropriate solvents were used as cleaning liquids. If necessary, the capillary was placed into an ultrasonic bath (approximately 10 to 20 min, 30 °C, water plus standard detergent). Afterwards the capillary was dried under a pressure-less nitrogen stream.4 ResultsFigure 3: Reproducibility check; standard Li-ion electrolyte V24 measured with Lovis and SVM ™ from +20 °C to -20 °C4.4Temperature Profile of Li-polysulfide4.5Checking the Influence of Conducting Salt5ConclusionBy using the Lovis 2000 M/ME equipped with cooling option, it is possible to perform measurements from -20 °C up to +100 °C. In combination with the capillary made of PCTFE even extremely corrosive substances can be measured under hermetically sealed atmosphere. This allows users to measure theviscosity of electrolytes, which might be destroyed or changed in structure by air and/or air humidity.▪ The small capillary sizes require only littlesample volume (starting from 110 µL). ▪ The small diameter of the PCTFE capillary(1.62 mm) enables also the measurement of very low-viscosity samples (viscosity range from 0.8 mPa.s to 160 mPa.s).▪ The cooling option allows for viscositymeasurements down to -20 °C (lowertemperatures down to -30 °C are possible on request and depending on ambient conditions).▪ The closed system avoids any contaminationand evaporation.▪ The variable inclination angle of themeasurement allows for the variation of the shear rate.▪ Lovis 2000 M/ME is highly modular; it can becombined with DMA™ M Density Meters for automated calculation of dynamic andkinematic viscosity. It can also be combined with an Xsample™ sample changer (see Figure 8) for automatic filling and cleaning of the capillary and measurements with high sample throughput.6ReferencesSpecial thanks to DI Gisela Fauler and Ms. Katja Kapper from VARTA Micro Innovation GmbH who tested the Lovis with cooling option and the PCTFE capillaries and supported Anton Paar with their measurement data.Contact Anton Paar GmbH Tel: +43 316 257-0****************************|。

performance validation 半导体-回复Performance Validation in Semiconductor IndustryIntroduction:The semiconductor industry plays a crucial role in advancing technologies and powering various electronic devices. With the rapid pace of development in this sector, validating the performance of semiconductor devices has become increasingly important. Performance validation ensures that a semiconductor device operates reliably within specified parameters, meeting the demands of modern applications. This article provides astep-by-step explanation of the process involved in performance validation in the semiconductor industry.Step 1: Understanding Performance ValidationPerformance validation involves the assessment of various aspects of a semiconductor device's functionality, efficiency, and reliability. It aims to verify that the device performs optimally and consistently under different operating conditions. The validation process encompasses both physical and electrical tests, analyzingparameters such as power consumption, temperature variation, signal integrity, and overall device performance.Step 2: Test Plan DevelopmentThe first step in performance validation is the development of a comprehensive test plan. This plan defines the objectives, methodologies, and tools to be used during the validation process. It outlines the parameters to be tested, the test environment, and the expected outcomes. Test plans are often tailored to specific semiconductor devices, ensuring that the complete range of functionalities and performance requirements are adequately assessed.Step 3: Test Setup and ExecutionOnce the test plan is established, the next step involves setting up the necessary equipment and executing the tests. This requires specialized test benches, test fixtures, and automated test equipment (ATE). The test setup should replicate the real-world conditions under which the semiconductor device will be used, including factors such as temperature, voltage, and load. Duringexecution, the device is subjected to a series of tests, and data is collected for analysis.Step 4: Data Analysis and ComparisonThe collected data is then analyzed to evaluate the device's performance. Various statistical and analytical techniques are employed to interpret the data and draw meaningful conclusions. The performance metrics obtained through the analysis are compared against predetermined specifications and industry standards. Deviations from the expected performance are identified, and potential issues are investigated for further improvement.Step 5: Performance OptimizationIf any performance issues are detected during the analysis, optimization strategies are implemented in this step. This may involve tweaking the design, adjusting manufacturing processes, or enhancing firmware/software algorithms. The aim is to rectify any performance gaps and improve the overall reliability and efficiency of the semiconductor device. Iterative testing and analysis may berequired until the desired performance levels are achieved.Step 6: Documentation and ReportingOnce performance validation is complete and satisfactory results are obtained, it is crucial to document the entire process for future reference and compliance purposes. This includes recording the test procedures, collected data, analysis reports, and any optimization strategies implemented. A comprehensive final report is generated, summarizing the validation process, the device's performance, and any relevant findings or recommendations.Conclusion:Performance validation plays a critical role in ensuring the reliability and functionality of semiconductor devices. The step-by-step process outlined in this article allows semiconductor companies to thoroughly test and validate their products, which ultimately benefits end users. By proactively identifying and addressing performance issues, the semiconductor industry can continue to provide high-quality devices that meet the demands of evolving technologies.。

ASSESSING THE PERFORMANCE OF A COMPUTERIZED ACCOUNTING SYSTEM作者: Danciu, RaduAbstract: The study aims to present the criteria for assessing the performance of a computerized accounting system starting with completeness, ergonomics, information integration, flexibility, adaptability, accessibility, adaptability, accessibility, adaptability, safety and security in the operations. The study's conclusions formulate a set of minimum requirements for the creation, implementation and use of a computerized accounting system. Key words: computerized accounting system, ergonomics, information integration, flexibility, adaptability, accessibility, operational safety1. IntroductionThe deliverance of an independent opinion, by a group of specialists, referring to the informational system used for organizing and conducting the accounting is one of the modern business management goals. Among the objectives that must be considered in the process of assessing the financial and accounting system we can mention:* checking the operating system's correctness, completeness, flexibility, adaptability, cost of maintenance, ergonomics and operational safety* expressing an opinion on the computerized accounting system's usage facilities and efficiency (computing and software), as well as on the business's place in the informational economic environments, before and after its purchase/creation.* formulating some proposals regarding the achievement of the objectives, the informatics system's development and the elimination of the deficiencies consigned in the assessment reports.In order to be able to quantitatively and qualitatively asses the computerized accounting system one must answer at least the following questions:What is the system's degree of flexibility?Is the system ergonomic and accessible?Is the system adaptable?Is the system complete? Does it cover the information management needs of the enterprise?What kind of operational safety does the system offer?Do the programming language and the databases satisfy the requirements of an enterprise's dynamic modelling system?What are the mutations produced by such a system in the financial and accounting management?After the acquisition or creation of a computerized accounting system and its implementation, the system must undergo an audit to determine the weaknesses in the system's usage.The auditing of the information systems is a very complex operation and it involves the auditor expressing his opinion on real time data processing, database management, system integration, the work with computer networks, etc. The claims for an audit of the computerized accounting system are very high, which involves the implication of some specialists in accounting and in the field of applications design and implementation. Computerized systems audit should include the general examination of the computerized accounting systemand the analytical examination of each application individually.Among the objectives of the computerized accounting system's general examination we may include :* assessing the completeness of the information system, therefore the coverage degree of the accounting needs for organization and management* assessing the integration degree of the system's applications, of the way they communicate* assessing the flexibility and adaptability* assessing the accessibility, reliability and security* assessing the way the minimum conditions to be met by the computerized systems are being respected* assessing the delimitation procedure for the attributions and responsibilities of the people involved in the computerized systems management* assessing the way the computerized system complies with the accounting principles and methods* assessing the system's ergonomics.Among the objectives of the computerized accounting system's analytical examination we may include :* assessing each application's architecture* assessing the integrity and the integrality of the system's main functions and of their usage possibility* assessing the effects of using the application functions and of every function's usage degree* detecting function overlaps in the accounting's implementation* establishing and evaluating the application's additional functions* assessing the automation degree of accounting projects* assessing the degree of detail in the information description, namely the adequacy or inadequacy of the informational attributes necessary to identify the transactions, events and objects* assessing the menus of data collection and validation* assessing the fairness of the data processing and systematization procedures* assessing the manner of creating, consulting and printing the accounting reports as well as their informational content* assessing the manner of database presentation and consultation* assessing the level of maintenance and system administration functions accomplishmentTo facilitate the discovery of an answer for the questions formulated above and to detail the objectives of the computerized accounting system's general and analytical examination, the system's main characteristics will be described: flexibility, adaptability, ergonomics, accessibility, reliability, integration and operational safety.2. Qualitative characteristics of the computerized accounting system2.1. Flexibility and adaptabilityThe flexibility of the computerized applications refers both to the multitude of options available to create a function, as well as to the possibility of going behind some commands or application functions without altering the collected, processed and archived databases. All the application's functions must be characterized byflexibility, namely:User-defined sort keys should provide the opportunity to choose attributes ordering information by seeking data from a database or a table.* The data collecting function should provide at least the following facilities:* accessing auxiliary databases in order to choose data when collecting it through a control key / a command button. For example, when collecting an account, the user, by pressing a key / button control should be able to access the chart of accounts in order to select the desired account* allowing the user, when using the key / command button, to add new items to auxiliary databases or modify existing ones when the data he is searching for is not there* displaying the processed and stored data, useful in the collection process, such as: displaying the quantity available on stock and the stock's output unit price or showing the invoices to be paid to suppliers at the moment when the payment data is being collected, etc.* the data collection function should allow deletion or modification of not validated data* ensure the possibility of operating or de-operating data at a document's level* multi-criteria search and selection of data in order to choose the data by multiple informational attributes combined with mathematical operators: equal "=" lower "<", higher ">", lower and equal "<=", higher and equal ">=", including "$" different "#".* the multiple classification of data by one or more informational attributes, for example: in the case of stock entries sorting can be done by input document type, document number and date, etc. There are two types of ordering keys for flexible applications:- ordering keys defined by software- user defined ordering keys.The user defined ordering keys must provide him with the opportunity to choose the informational attributes based on which he wants the ordering of data from a database or a table to be made.* the generating, consulting and listing function for the financial and accounting statements must offer at least the following facilities:* obtaining accounting reports for any period of time by indicating the starting and closing dates for information to be included in the report* obtaining accounting reports both in foreign currencies and in lei when indicating a different currency than the domestic one* getting full reports or only for a list of indicated entities / objects , such as: accounts, distributors, partners, stock items, etc.* displaying in screen mode all the financial and accounting statements made before listing* listing of the reports with the following options type of printer (local or În network/printer name)- type of printing ( normal or reversed )- first page- final page- document's margins, etc.* the processing or auxiliary database consultation function must at least provide the following facilities:* prohibiting additions, changes and deletion from processed and archived* multi-criteria search and selection of data* enabling the listing of selected data* the application's parameterization and management function should provide at least the following facilities:* saving / restoring data and software from multiple drives. Thus, before performing these operations, the choice of the magnetic disk drive to / from which the backup / restore of data or software will be performed must be leftup to the user* facilitating the access to data belonging to any processing period by simply pointing it out* the possibility to update the readymade applications without intervention from the producer, based on the new software package provided, by using the software update option.The lack of options listed above leads to the creation of a system which is rigid and cumbersome in use. The existence of functions / options is not the only one important, but also the programmer's and analyst's tenacity in putting them into the right place , the control keys / control buttons having to be easy to remember, and to be the same for the same function / option in all applications.In fact, achieving a high flexibility of an integrated computerized system is the result of combining the accounting science with the computer science, which is easier to accomplish when the analyst and the programmer is the same person.The adaptability of the computerized accounting system to the specific conditions of accounting organization and management within an enterprise has two aspects, namely:a. adaptation and integration in the enterprise's computerized economic systemb. adjusting to the accounting's organization and management requirements.In order to express an opinion regarding the adaptation degree of a computerized system to the company's concrete conditions, we must analyze the types of computerized systems, namely:* the self created computerized system which has the following characteristics:* the enterprise's integration in the computerized system is easy to achieve as the computerized accounting system is compatible with other specific applications* the system's design will be made to match the information management requirements and the enterprise's management strategy* system implementation and user education is easier* the system creation in an economists-comp team leads to attachment and loyalty towards the created system, any improvement of the system being easily achievable* the system's production time is long, the system's analysis must be very careful, the making process involving high costs and a higher skilled workforce* the readymade computerized system with the following features:* the user can choose the applications package that meets the utmost of his requirements* the system's architecture and documentation is more comprehensive and complete, because it answers the requirements of many users, many times being updated according to their requirements* regular updating and software maintenance is done at much lower cost than independent upgrading and maintenance* the purchase price of the readymade software is smaller than that of the software developed by themselves, because of the competition on the accounting computerized applications market, and the fact that the development cost is distributed to more buyers* these computerized systems are usually closed systems in terms of analyst and programmer, being directly addressed to the accounting user* this type of software, frequently do not integrate in an enterprise's activity, so, very often the acquiring company's needs do not find themselves in the purchased applications, requiring a working style review, which may or may not have beneficial effect on the economic activity* the applications packages having a high degree of generalization do not have the same efficiency as their own software packages* the company providing readymade software can interrupt it's activity or stop doing business, which is a major impediment for updating and maintaining computer applications while the sources for software and system analysis are not owned by user* the pre-ordered computerized system which has the following characteristics:* the user, according to the delivered command can work under their individual data processing and information systematization requirements* costs may be lower than those for software developed with own forces* it integrates easily into the enterprise's computerized system* the user can take possession of sources and system analysis which helps making it easy to do future changes and updates, even if we are facing an interruption / termination of relationships with companies and program analysis that was used originally.To ensure continuity of he management and information integration principles of the financial and accounting computerized system, the best readymade computer system, completed and adapted where the enterprise information management require it.2.2. Ergonomics, accessibility and reliabilityFor the computerized accounting system to be ergonomic and accessible its component application must stand in line with the following requests:* using the same principles in developing and using the data collection models in all computer applications* using the same combinations of keys / command buttons to collect and access the data* using some information functions on the status and the content of the data in the system, namely:- showing the record statistics which displays the number of basic documents, the number of secondary documents and number of records for each database separately- displaying the selected records number that shows the number of basic documents, the number of secondary documents and the number of records for the database selection- displaying the document type and accounts names, allocators and other elements encoded in the recording where the cursor is positioned- generating at the user's request the list / report with full data / seected from the database- enabling access to explanations on the role and functioning of the application's functions /options. All the explanations given for each feature / option are enrolled in the system's user manual- the existence of a function to perform simple calculations on data, such as adding values in column / selected area- the option of displaying and distributing an account balance with the structure: Account, distribution, money. This function will provide data on:- Opening balance debtor / creditor- Aggregate debit and credit turnover- Monthly debit and credit turnover- Total debit and credit amounts- Final balance debtor / creditor- the option of calculating an expression for the user's need, in order to do some calculations outside offered the information management system- the option of duplicating the content of some information attributes previously collected designed to pick up data from the user common data for two consecutive records in a table.The system's availability refers to setting access levels for each worker individually, ensuring a certain degree of data confidentiality and to limit the rights of changing data collected by other operators or data from auxiliary databases.An accessible computerized system must provide the highlighting of the information by various technical means like:* colour differentiation* differentiation by font size* flashy markings* sound markings* grouping data in boxes* highlighting important data* displaying messages during work time* displaying short explanations for each system function / option.Moreover, a complex computerized system must alert the operator or the user of its abnormal operation, indicating where necessary the system's errors and defects.Particularly important in assessing ergonomics, accessibility and reliability of a computerized system is the tracking of its behaviour in use, at least in terms of the following aspects:* in terms of the system's operational tenacity which also considers the cases and reasons for computerized applications failure* in terms of user requirements, which means assessing the degree of weariness caused to the user after a longer work period and its causes* in terms of work speed, that is the extent to which the system responds to user commands and the reaction times* in terms of accuracy, that is the manner of fulfilling the system's displayed and executed functionsIn the making of an ergonomic and accessible computerized system there are also other important factors:* the creation of some menus with high intelligibility by using short names with intelligibility, logical grouping of data, etc* facilitate the consultation of multiple databases* achieving at least the following reporting features, data collection models, consulting data bases and their associate functions / options:- the high level of information synthesis- information's timeliness- information's completeness- data correctness- data accessibility.The computerized accounting system's reliability refers to the probability that this system will continue to function for a certain amount of time according to the designed and implemented standards. Regarding the reliability assessment of a computer programme, E. Yourdon in the paper "Decline &Fall of the American Programmer" (Oprea, 1999), addresses a number of indicators like:* average time between two failures* average time to remediate troubles* the area affected by failures* the error rate per hour, day, week or month* the error rate on the basic software components* the opportunity of the answer to the errors or the time granted to their remedy* the beneficiary's satisfaction about the quality of the intervention to remedy softdefectsThe system's reliability analysis by using these indicators leads the user to establishing of the software's place, both in the enterprise and comparatively with other software.2.3 Operational safetyThe system's safety includes its security and its capacity to function continuously with no malfunctions, and if malfunctions come up it need to have its own models of remediating them.The system's security is a complex problem, especially when using computer networks for data processing. The main objective of a computerized system's security is represented by insuring the data's confidentiality and integrity. The data confidentiality must be done by:* precisely determining the people who have access to the computer applications* precisely determining the applications and databases the operators and users have access to* precisely determining the access passwords for each person* regularly changing the access passwords and communicating them in maximum confidentialityTo achieve data confidentiality one must establish a Register regarding the use of computer applications inside the computerized accounting system. The structure of this register could present itself as follows:* Ist option considering the person as a benchmark, comprises:- the person - name and position- the computer application or parts of application he has access to- access password- the date of granting / modifying access- acknowledgement signature- observations* IInd option considering the computer application as a benchmark comprises:- the computer application- the people - name and position - having access to the application- access passwords- the date of granting / modifying access- acknowledgement signature- observationsThe data integrity aims to maintain and preserve the collected data, without altering them by data processing and the safe preservation of the processed data, any subsequent intervention being forbidden (change, deletion, mergers, etc.).The system's functioning security must also take into consideration the failure possibility, for them to be able to repair themselves. Some examples of interventions for the maintenance and repairing of the computerized system could be:*for the system's maintenance* database reorganization related to re-indexing them by the index keys defined when the application was created* setting the printing systems used for listing the accounting statements on paper* checking the integrity of the databases that ensure control over the existence of all databases and of their associated indexes* checking the databases structure which ensures the control over the database's structural updates occurring when new versions of the computer applications are created* the database and software saving / restoring, option which provides the saving/restoring of databases on/from floppy disks, local or central hard disks, CD-s, DVD-s, etc.*for the repairing of damaged data* recovery of destroyed database structures* recovery of the system's menus and functions* recovery of archived/saved data, previous to the incidentThe technical methods for carrying out the computerized system's security are:* the physical security which is designed to limit the physical access to the computer system by:- introduction of access codes and installation of alarm systems where the technical items are located- enclosing the microcomputers in protection cabinets or in a protective wrapper- installing a secured mechanism for connecting to the electrical network- storing the data saved on external magnetic devices in maximum security places: safes, safe deposit boxes, etc.* the softsecurity by password access to computers and computer applications, using encryption software for long distance transmitted data, by password access to created data archives, in order for them to only be accessible through the same applications that generated them, by using hidden files and secret file names, etc. If in the case of compute application functions, their completeness must be ensured as well as a wide variety of working options, in the case of features an optimum balance must be achieved, for the computerized system to be able to reach its objectives in the best conditions reported to the highest standards.3. ConclusionsThe introduction and use of a computerized financial and accounting system must ensure reconciliation between the individual vision and the collective network organization, along with the collection, processing, administration and delivery of information in terms of maximum speed and security conditions. For the creation of a computerized information system we may propose the compliance with the following requirements:* the computerized applications must be consistent with any type of computer and created in a performing operating system and programming language with perfecting perspectives* it should have the highest possible accessibility level, so that the level of computer knowledge the user needs to hold to be minimized* it should have a high flexibility degree, therefore to allow changes, deletions, searches, returning to current data, creation of extra reports defined by the user, returning to previous data collections, saving and restoring data collections, etc.* it should be ergonomic, therefore the organizing of the working menus should follow the same principles for all the applications and to be based on simplicity and intuition* to offer operational safety* to ensure data security and privacy by restricting the access to information* the user-computer relationship related to data collection should be as easy as possible and it should comprise explanations regarding every element of information* the mathematical and accounting relations used for validating and calculating the data collected in the system should comply with rules, regulations and laws* it should have a high working speed and data storage capacity* it should protect itself in case of major incidents ( fault of electric current, application failure, etc.) ensuring data preservation.Adapting the experience's effect theory (it comprises: learning effect, innovation effect and the mechanization, automation and robotization effects) to the computerized systems, theory which was elaborated by Boston Consulting Group (B.C.G.), one can say that as the number of financial and accounting computerized products has increased, the tendency of using them has become predominant, using them leads to the discovery of deficiencies and their removal generates the product improvement by eliminating redundant functions, cumbersome models, unnecessary work modules, etc. Perfecting the computer products is not sufficient, the consequences of their use must be insisted on and some accounting areas need to be improved, such as:* developing the accounting standards in line with information's processing and administration in the computerized environments; the financial and accounting computerizes systems must not be treated only as data processing systems, because they are financial and accounting data management systems as well* adapting the common and the special forms regarding the financial and accounting activity to the processing and administration need of the information in the computerized environment* completing the rules on creating and using financial and accounting software with a set of minimum informational attributes required in managing financial and accounting objects, transactions and events* developing a national standard on financial and accounting information processing and management in the computerized environment including:* architectural elements of the computerized system* main functions and characteristics of the computer applications* aspects related to the management of financial and accounting objects, transactions and events* The start of some national research programmes on the changes produced by the use of computerized informational systems and their effects on the accounting science.References1. Danciu, R.;(1994); Computerized accounting systems, Dacia, Cluj-Napoca2. Oprea, D.; (1999); Analysis and design of economic information, Polirom, Iasi3. Tugui, Al.;(2003); Products generalized accounting information, CECCAR, Bucharest4. ***, Manual of Use Systems ERP SAP FICO, MicrosoftDynamics Navision, Clarvision, WinMentor, Siveco Applications 2020, BAAN ERP。

Reflection and absorption contributions to the electromagneticinterference shielding of single-walled carbonnanotube/polyurethane compositesZunfeng Liu,Gang Bai,Yi Huang,Yanfeng Ma,Feng Du,Feifei Li,Tianying Guo,Yongsheng Chen *Key Laboratory for Functional Polymer Materials &Center for Nanoscale Science and Technology,Institute of Polymer Chemistry,Nankai University,Tianjin 300071,ChinaReceived 1August 2006;accepted 17November 2006Available online 19January 2007AbstractThe electromagnetic interference (EMI)shielding of well dispersed single-walled carbon nanotube (SWCNT)/polyurethane compos-ites was studied and the results show that they can be used as effective and lightweight shielding materials.The EMI shielding of the composite shows a reflection-dominant mechanism,while a shift from reflection to absorption was observed with increased SWCNT loading and frequency.This is explained using EMI shielding theory and the intrinsic properties of the components.Ó2006Elsevier Ltd.All rights reserved.1.IntroductionAs commercial,military,and scientific electronic devices and communication instruments are used more and more widely,electromagnetic interference (EMI)shielding of radio frequency radiation continues to be a more serious concern in this modern society.Light weight EMI shielding is needed to protect the workspace and environment from radiation coming from computers and telecommunication equipment as well as for protection for sensitive circuits [1].Compared to conventional metal-based EMI shielding materials,electrically conducting polymer composites have gained popularity recently because of their light weight,resistance to corrosion,flexibility and processing advanta-ges [2–9].The EMI shielding efficiency (SE)of a composite material depends on many factors,including the filler’s intrinsic conductivity,dielectric constant,and aspect ratio [7,9].The high conductivity,small diameter,high aspect ratio,and super mechanical strength and so on of carbon nanotubes (CNTs)make them an excellent option to createconductive composites for high-performance EMI shield-ing materials at low filling concentration.Recently,multi-walled carbon nanotubes (MWCNTs)have been studied with various polymer matrix,including polystyrene (PS)[1],epoxy [10],poly(methyl methacrylate)(PMMA)[11],polyaniline (PANI)[1],polypyrrole (PPY)[1],PU [10,12,13],etc.,for the possible applications as effective and light weight EMI shielding materials and the EMI shielding has been attributed mainly due to the reflection contribution [10,14,15].When Fe is hybridized with CNT/polymer composites,it is observed that the main con-tribution to total EMI SE is absorption rather than reflec-tion [16,17].Also the influences of wall defects [10],aspect ratio [10],and alignment [18]of CNTs on the EMI shield-ing have been investigated.But the composite materials with single-walled carbon nanotubes (SWCNTs)have been largely unexplored for this area so far [10,12].Very recently we reported the first EMI shielding study of the composite materials of SWCNTs with epoxy as matrix in the fre-quency range of 10MHz–1.5GHz [10].But owing to many different,and in many cases superior,properties compared with MWCNTs,SWCNTs warrant more studies for light and effective EMI shielding materials.0008-6223/$-see front matter Ó2006Elsevier Ltd.All rights reserved.doi:10.1016/j.carbon.2006.11.020*Corresponding author.Tel.:+862223500693;fax:+862223499992.E-mail address:yschen99@ (Y.Chen)./locate/carbonCarbon 45(2007)821–827Polyurethane(PU)elastomers are widely used high-per-formance materials with many unique properties,including good elasticity,high impact strength and elongation,resis-tance to low temperature,and excellent bio-compatibility [19,20].And these properties have made them widely used in many civil and military industries[21].In this paper we prepared well dispersed PU/SWCNT composites using a simple physical blending method.An EMI SE up to17dB at the band range of8.2–12.4GHz(so called X band)was obtained for PU/SWCNT composites with20wt%SWCNT loading.The composites show a percolation threshold as low as$0.2wt%.The investigation in the shielding mecha-nism shows a reflecting-dominant mechanism,whereas a contribution shift behavior toward to absorption was observed with increased SWCNT loading and frequency. Using EMI shielding theory,this trend is explained with the intrinsic properties of the components.At high SWCNT loadings and we found the intrinsic properties favored the absorbing ability rather than the reflecting one.2.Experimental2.1.Materials and measurementsSWCNTs were prepared in our laboratory using a mod-ified arcing method[22].Using AFM[23],we found the bundles for the raw SWCNTs(AP SWCNTs)had an aver-age diameter=5.95nm,average length=1430nm.The AP SWCNTs have specific surface area of1500m2/g and contain about50wt%SWCNTs.N,N-dimethyl formamide (DMF,AR)was used as purchased.Polyurethanes were supplied by Tianjin Polyurethane Co.(Mn=20,000,hard-ness=85,density=1.34,synthesized from Diphenyl methane4,4-diisocyanate(MDI),1,4-butadiol,and poly-ethylene glycol adipate(Mn=1000)).The dc electrical conductivity of the SWCNT-epoxy composites was determined using the standard four-point contact method on rectangular sample slabs in order to eliminate contact-resistance effects at room temperature. Data were collected with a Keithley SCS4200.The EMI shielding effectiveness and complex(relative)permittivity data of SWCNT/PU composites were measured with the slabs of dimension of22.86mm·10.16mm·2mm tofit waveguide sample holder using a HP vector network ana-lyzer(HP E8363B)in8.2-12.4GHz(X band).And total 201data points were taken within this frequency range for each sample.The PU/SWCNT samples were freeze-frac-tured in liquid nitrogen and gold coated for imaging on a Hitachi S-3500N scanning electron microscope(SEM). 2.2.Preparation of the PU/SWCNT composites and their filmsWe used the conventional solution process to prepare the composites and theirfilms.As an example,the follow-ing describes the process to prepare the composite with 5wt%SWCNT loading.SWCNTs(2.15g)were added into DMF(1500mL),stirred for2h,and then the mixture was sonicated for2h using a high power sonic bath(300W, modeled KQ-300DB)to disperse SWCNTs in DMF.Then PU(43g)dissolved in300mL of DMF was added to above SWCNT suspension and the formed mixture was then stir-red mechanically for2h.The mixture was further soni-cated for2h using the above sonic bath.Note that more DMF(to keep SWCNT concentration to be$1.5mg/ mL)was used for higher SWCNT loading composites. After the mixture was again stirred mechanically for2h, it was then cast in a large mold to let solvent to evaporate at$140°C.Then the PU/SWCNTfilms were pealed offfrom the mold and vacuum dried at80°C for48h.After a hot pressure process at150°C and15MPa,aflatfilm of PU/SWCNT composite with5wt%SWCNT loading was obtained.The sample was then cut to slabs with desired sizes and then the surfaces of the slabs were pol-ished if necessary.Other composites with different loadings were prepared similarly.As a control,pure PUfilms and slabs were prepared using the same process.3.Results and discussion3.1.Theoretical backgroundFor a transverse electromagnetic wave propagating into a sample with negligible magnetic interaction,the total shielding efficiency(SE T)of the sample is expressed as Eq.(1)[7,24,25]:SE T¼10logðP in=P outÞ¼SE AþSE RþSE Ið1Þwhere P in and P out are the power incident on and transmit-ted through a shielding material.The SE T is expressed in decibels(dB).The SE A and SE R are the absorption and reflection shielding efficiencies,respectively.The third term (SE I)is a positive or negative correction term induced by the reflecting waves inside the shielding barrier(multi-reflections),which is negligible when SE A P15dB [24,25].The terms in Eq.(1)can be described asSE A¼8:68a lð2ÞSE R¼20logj1þn j24j n jð3ÞSE I¼20log1À1Àn21þn2expðÀ2c lÞð4Þwhere the parameters a,n,and c are defined as following equations,l is the thickness of the shielding barrier.a¼ð2p=k0Þffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffie rðffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi1þtan2dpÇ1Þ2sð5Þn¼ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffie rðffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi1þtan2dpÆ1Þsþiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffie rðffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi1þtan2dpÇ1Þsð6Þc¼ð2p=k0Þffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffie rðffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi1þtan2dpÇ1Þ2sþið2p=k0Þffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffie rðffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi1þtan2dpÆ1Þ2sð7Þ822Z.Liu et al./Carbon45(2007)821–827where k0is the wave length,e r the real part of complex rel-ative permittivity,the±andÇsigns are applied for posi-tive and negative e r,respectively.[25]The loss tangent tan d=e i/e r=re0e r,where e i is the imaginary part of the rela-tive permittivity;x=2p F,where F is the frequency;e0is the dielectric constant in free space and r the conductivity. Here we use the alternative conductivity(r ac)to express the conducting ability of the alternative electromagnetic wave in the composites:r ac=xe0e r.The estimation of the SE in this study is in the far-field limit[25],which assumes that the distance from the source to the shielding barrier is long enough and not to apply near-shielding effects.From Eqs.(1)–(7),SE T is tuned by a,n,and l.The intrinsic parameters for the SE T are a and n,which are determined by e r and r ac. From these equations,one can expect high shielding effi-ciency for materials with higher e r and r ac.The thickness of the material l is an extrinsic parameter which can be used to control SE A and SE I.The imaginary part of the complex permittivity e i,also called loss factor,indicates the ability of the materials to absorb radio wave.The term tan d,also called loss tangent,indicates the ability of a material toconvert stored energy to heat.Thus,large values of loss factor and loss tangent would indicate a better radio absorbing material[26].The material with tan d)1exhibits as a good conduc-tor and the material with tan d(1exhibits as a weak con-ductor[27].In case of tan d)1,a can be approximated as a%(xlr/2)1/2and n%(1+i)(r/2xe)1/2,where l is the per-meability.This indicates that for the highly conducting materials,the EMI shielding(including absorption and reflection)shall be decided mainly by r,not e r.In the case of tan d(1,a%(r/2)(l/e0e r)1/2,indicating that the elec-tromagnetic energy dissipation can also occurred in the weak conductors where permeability plays a more impor-tant role.In the present study however,tan d%1(see below),so the above approximated formulas can not be used,and both r ac and e r must be considered when estimat-ing the EMI shielding efficiency.3.2.DC conductivity of the PU/SWCNT compositesAs seen from the EMI theory above,the EMI perfor-mance of composites is highly coupled with thefiller’s intrinsic conductivity,dielectric constant,and aspect ratio[7,9].Fig.1shows the dc conductivity(r DC)of PU/ SWCNT composites as a function of SWCNT mass fraction (p).As can be seen,the conductivity of the PU/SWCNT composites exhibits a dramatic increase at low loadings, indicating the formation of percolating network.For exam-ple,below0.25wt%,the conductivity of SWCNT compos-ites displays a dramatic increase of6orders of magnitude and the conductivity reaches2.2·10À4S/cm at20wt% SWCNT loading.This value is10orders of magnitude higher than that of the pure PU matrix(i.e.,1.2·10À14 S/cm).Thus far,studies on the conductivity of SWCNT–poly-mer composites have been reported low thresholds at various volume fractions with different fabrication methods and different SWCNT aspect ratio[8,28].For real applica-tions,it is critical to have lowfilling threshold,since lower filling fractions imply smaller perturbations of bulk physi-cal properties as well as lower cost.It is well known that the conductivity of a conductor–insulator composite follows the critical phenomena around the percolation threshold (Eq.(8))[29]:r DC/ðmÀm cÞbð8Þwhere r DC is the composite conductivity,m is the SWCNT volume fraction,m c is the percolation threshold and b is the critical exponent.Because the densities of the polymer and SWCNTs are similar,we assume that the mass fraction,p, and the volume faction,m,of the SWCNTs in the polymer are almost the same.As shown in the inset to Fig.1for the log(r DC)vs log(pÀp c)plot,a least-squares analysis of the fits using Eq.(1),shows that the threshold volume p c for the composites was strongly bounded by the regions be-tween the highest insulating and lowest conducting points and the PU/SWCNT composite conductivity agrees very well with the percolation behavior predicted by Eq.(8).The bestfit of the conductivity data to the log-log plot of the power laws gave p c%0.2%,and b=3.74,according to Eq.(8),as shown in the inset in Fig.1.While computer models of conductivity percolation give a critical exponent value of2for a3-d rigid rod network,various values from 1.3to5.3have been reported for different CNT-polymer composites.These included SWCNT composites with crit-ical exponent values of1.5for polyimide[30],1.3and2.68 for epoxy[10,28],and2–3for different SWCNT materials with epoxy[8].Similarly,various values from2.15to5.31 for MWCNT composites have been reported[17].A perco-lation threshold of$16%has been predicted in two-phase random composites when the conducting micro scaledfill-ers with sphere shape are used.However,the percolation threshold p c %0.2wt%in this work is $2orders smaller than the theoretical result and also comparable to other SWCNT composite materials [8,28,31].This low threshold value can be attributed to the large one dimensional aspect ratio and well dispersion of SWCNTs in the composites.The well dispersion was also confirmed with the SEM image in Fig.2for the 20wt%loading of SWCNTs.The SEM image clearly shows that the SWCNTs were distrib-uted rather homogeneously.Note electrostatic dissipation applications typically require a conductivity of 10À5S/cm and thus with only addition of 5wt%SWCNTs,these PU/SWCNT composites should be able to be used for many electrostatic dissipation applications too.plex relative permittivity vs SWCNT loadings and frequenciesRecent studies have shown that SWCNT/polymer com-posites posses high real permittivity (polarization,e r )as well as imaginary permittivity (adsorption or electric loss factor,e i )in the 0.5–2GHz [10]and 500MHz–5.5GHz ranges [32],indicating that SWCNT/polymer composites could be used as light weight and effective electromagnetic shielding mate-rials.We thus measured the complex permittivity of SWCNT/PU composites in the frequency range of 8.2–12.4GHz (X band).Fig.3shows the complex relative per-mittivity spectra of the composites containing 0%–20wt%SWCNTs.As can be seen,the real (e r )and imaginary (e i )permittivity increase dramatically as the concentration of SWCNTs increases from 5to 20wt%.The highest values of the real and imaginary permittivity parts for the compos-ite with 20wt%SWCNT loading reach 38and 26,respec-tively.Overall the real and imaginary parts of permittivity for this PU/SWCNT composites with 20wt%SWCNTs range from 32to 38and 24to 26in the frequency of 8.2–12.4GHz.Furthermore,at low loadings,both the real and imaginary parts of permittivity are almost independent to the frequencies in the range we measured with the same loading.But at higher (e.g.20wt%)loading,the values of the real part of the permittivity intend to decrease with increasing of frequency,while the imaginary values still keep little change.The absolute values of the measured per-mittivity are of the same order of magnitude as those reported by Grimes et al.for SWCNT/polymer composites in the 0.5–5.5GHz range [32].These trends are important to understand the EMI mechanism discussed below.A peak between 8.5and 9.5GHz was found for the composites (10,15,and 20wt%)and it becomes stronger with higher SWCNT loadings.This result implies the existence of a res-onance behavior,which is expected when the composite is highly conductive and skin effect becomes significant [16].Che et al.[16]reported that the frequency at which the peak occurs is determined by the aspect ratio of thenano-scaledFig. 2.A typical SEM image of PU/SWCNT composite containing 20wt%SWCNTs after freeze-fractured in liquid nitrogen and goldcoated.Fig.3.Real (e r )and imaginary (e i )parts of the relative permittivity in the frequency range of 8.2–12.4GHz.824Z.Liu et al./Carbon 45(2007)821–827fillers and they found that the Fe-encapsulated carbon nano-cages have a peak at about 5GHz and the Fe-encap-sulated MWCNTs have a peak at about 7GHz.In this paper,the composites have a resonance peak at about 9GHz.This is probably because a high aspect ratio of SWCNTs compared to that of MWCNTs.3.4.EMI shielding effectiveness of the PU/SWCNT compositesFig.4shows the EMI shielding effectiveness over the fre-quency range of 8.2–12.4GHz for PU/SWCNT composites with various SWCNT loadings.As expected from the above data about conductivity and permittivity,the EMI shielding effectiveness increases with increasing content of SWCNTs in the composite and the contribution to the EMI shielding should come from the addition of SWCNTs.It is also observed that the shielding effectiveness of the composites almost keeps unchanged except for a slight decrease with increasing the frequency for the same load-ing.The shielding effectiveness of the composites contain-ing 20wt%SWCNTs is measured to be 16–17dB over the frequency range of 8.2–12.4GHz.Fig.5shows the tan d values of the composites,from which it can be seen that the tan d values of the composites are in the range of 0.25–0.8,very close to 1,indicating that the composites in this work do not act as good nor weak conductors [27].Therefore the intrinsic parameters e r and r ac must be considered to evaluate the EMI SE.The EMI SE was thus plotted versus e r and r ac ,respectively at 8.2GHz as an example in Fig.6.The data in Fig.6fall on smooth curves,and similar dependence of EMI SE on r ac and e r was obtained.From the fitted curve in Fig.6a,we can see a dramatic increase in shielding effectiveness with the initial variation of r ac ,and then EMI SE increases slowly with the continuous increase in r ac .A similar trendwas observed for the plotting of EMI versus e r .Recall that both r ac and e r increase with SWCNT loadings in Figs.1and 3.The above results indicate that EMI shielding effec-tiveness increases much faster at low SWCNT loadings,which becomes slower with higher SWCNT loadings.3.5.Contribution shift from reflection to absorption at higher SWCNT loading and frequencyAs discussed in Section 3.1,the EMI SE has three con-tributions:reflectivity (R ),Absorptivity (A )and the multi-reflecting correction of waves inside the shielding barrier.For a very approximate analysis,the multi-reflecting part could be neglected,particularly for the cases when total SE A >15dB.Thus we could use the equation of 100%=A +T +R to get all the values of A from the experimental results of T and R to evaluate each contribution for the total shielding.The results are summarized in Fig.7.From Fig.7,it can be seen that the major contribution for EMI SE still comes from the reflection;which is consis-tent with the literatures [14,15]for CNT composites.At low loadings,both A and R increases with increasing load-ing.More interestingly,we can see a general trend at high loadings (e.g.>10wt%loadings)that the absorption con-tribution for EMI shielding increases while the reflection contribution decreases with the increase in the SWCNT loading at the same frequency.For example,in the case of the results at 12.4GHz,the reflectivity of the composite with a p =5wt%is as high as 46.4%,and the absorptivity 18.3%.As the p increases to 10wt%,the reflectivity increases to 69.8%and the absorptivity increases slightly to 21.7%.As the p continues to increase to 15wt%,a con-tribution shift behavior is observed:the reflectivity decreases from 69.8%to 52.8%and the absorptivity increases to 42.7%,almost doubles the one at 10wt%SWCNTs’loading (21.7%).As the p continues toincreasesFig.4.EMI shielding effectiveness for PU/SWCNT composites in the frequency range of 8.2–12.4GHz.Fig.5.The tan d values of PU/SWCNT composites in the frequency range from 8.2to 12.4GHz.Z.Liu et al./Carbon 45(2007)821–827825to 20wt%,the reflectivity continues to decreases to 51.4%and the absorptivity increases to 45.9%.Furthermore,the higher the frequency,the more evident the trend is.Such a contribution shift behavior relates closely to the inner properties of the composite.As we know that the loss tangent tan d indicates the ability of a material to convert stored energy into heat,i.e.,tan d provides an indication for how well the material can be penetrated by an electrical field and how well it dissipates electromagnetic energy as heat.It can be seen from Fig.5that tan d increases with the increase in SWCNT loadings.Tan d is almost zero for the sample without SWCNTs,indicating pure PU can hardly attenuate/absorb the radio wave.As SWCNT load-ing increases to 5wt%and 10wt%,tan d increases to $0.25and 0.55,respectively.Thus A values increase as observed in Fig.7.This is also evident from Eqs.(2)–(6).From Eqs.(2)–(6),we can see at higher frequency,with increasing tan d ,SE A shall increase faster than SE T .A similar trend was found as the increase of frequency with the same SWCNT loading from Fig.7,i.e.,the reflec-tivity decreases and absorptivity increases for the same loading of SWCNTs .For example,for the case of p =20wt%,the reflectivity decreases from 76.0%to 61.5%and then to 51.4%as the frequency increases from 8.2to 10.3and then to 12.4GHz.Such a contribution shift behavior is more evident for the samples with a higher loading.Again this trend could be understood from Figs.3and 5and Eq.(2)–(6).At the same loading,we can see the values of tan d increases as frequency increases but the e r keeps almost unchanged at lower loading and slightly decreases with higher loadings (see Fig.3).Recall the tan d indicates the material capability to absorb radio wave energy;the above trend thus would become expected.This can also be evident from Eq.(2)–(6),as SE A would increase rela-tively faster than SE R when e r keeps almost unchanged with increasing tan d for the same loading of SWCNTs.From Fig.6it can be seen that at the initial stage,EMI SE increases much faster with increase of r ac and e r and from Fig.7we can see a greater increase in R and a smaller increase in A at the same stage.This indicates that at low SWCNT loadings,r ac and e r affect more R than A with the increasing SWCNT loading.Also from Fig.6in the region with high values of r ac and e r ,EMI SE increases slower and from Fig.7we can see a decrease in R and an increase in A .These results thus indicates that at high SWCNT loading,r ac and e r contributes more to A than to R with increasing SWCNT loading.4.ConclusionIn this paper,PU/SWCNT composites with well-dis-persed SWCNTs were prepared using a simple physical mixing method and an EMI shielding effectiveness of $17dB was achieved at the SWCNT loading of 20wt%.Together with PU excellent properties and wide applica-tions,the EMI shielding properties endowed bySWCNTFig.7.Reflectivity (R )and absorptivity (A )vs SWCNT loadings at different frequencies.826Z.Liu et al./Carbon 45(2007)821–827as afiller shall make these composites one of the ideal can-didates for EMI application.The EMI shielding of the composites show a reflecting-dominated mechanism, whereas with the increase in SWCNT loading and the fre-quency,a contribution shift from reflection to absorption was observed at higher loadings.By analyzing the trans-mission behavior of the electromagnetic wave and the intrinsic properties of the composites,we attribute this phe-nomenon to the increase of the tan d due to the increase of the imaginary part of the dielectric constant of the compos-ite materials.Our observations call for a better understand-ing for the EMI shielding mechanism to optimize the design of EMI shielding materials using SWCNTs.Future work will concentrate on studies for this energy transition behavior and the application of this property in electro-magnetic wave absorption.AcknowledgementsWe gratefully acknowledge thefinancial support from MOST(#2003AA302640and2006CB0N0700),MOE (#20040055020)and the NSF Tianjin(#043803711)of China.References[1]Wang Y,Jing X.Intrinsically conducting polymers for electromag-netic interference sheilding.Polym.Adv.Technol.2005;16(4):344–51.[2]Yang YL,Gupta MC,Dudley KL,Lawrence RW.Conductivecarbon nanofiber-polymer foam structures.Adv.Mater.2005;17(16): 1999–2003.[3]Xiang CS,Pan YB,Liu XJ,Sun XW,Shi XM,Guo JK.Microwaveattenuation of multiwalled carbon nanotube-fused silica composites.Appl.Phys.Lett.2005;87(12):1231031–3.[4]Joo J,Epstein AJ.Electromagnetic-radiation shielding by intrinsicallyconducting polymers.Appl.Phys.Lett.1994;65(18):2278–80.[5]Luo X,Chung DDL.Electromagnetic interference shielding reaching130dB usingflexible graphite.Carbon1996;34(10):1293–4.[6]Luo XC,Chung DDL.Electromagnetic interference shielding usingcontinuous carbon-fiber carbon-matrix and polymer-matrix posites Part B1999;30(3):227–31.[7]Joo J,Lee CY.High frequency electromagnetic interference shieldingresponse of mixtures and multilayerfilms based on conducting polymers.J.Appl.Phys.2000;88(1):513–8.[8]Bryning MB,Islam MF,Kikkawa JM,Yodh AG.Very lowconductivity threshold in bulk isotropic single-walled carbon nano-tube-epoxy composites.Adv.Mater.2005;17(9):1186–91.[9]Chung DDL.Electromagnetic interference shielding effectiveness ofcarbon materials.Carbon2001;39(2):279–85.[10]Li N,Huang Y,Du F,He X,Lin X,Gao H,et al.Electromagneticinterference(EMI)shielding of single-walled carbon nanotube epoxy composites.Nano Lett.2006;6(6):1141–5.[11]Kim HM,Kim K,Lee SJ,Joo J,Yoon HS,Cho SJ,et al.Chargetransport properties of composites of multiwalled carbon nanotube with metal catalyst and polymer:application to electromagnetic interference shielding.Curr.Appl.Phys.2004;4(6):577–80.[12]Ma CCM,Huang YL,Kuan HC,Chiu YS.Preparation andelectromagnetic interference shielding characteristics of novel car-bon-nanotube/siloxane/poly-(urea urethane)nanocomposites.J.Polym.Sci.,Part B:Polym.Phys.2005;43(4):345–58.[13]Wu HL,Ma CCM,Yang YT,Kuan HC,Yang CC,Chiang CL.Morphology,electrical resistance,electromagnetic interference shield-ing and mechanical properties of functionalized MWNT and poly(urea urethane)nanocomposites.J.Polym.Sci.,Part B:Polym.Phys.2006;44(7):1096–105.[14]Yang YL,Gupta MC.Novel carbon nanotube-polystyrene foamcomposites for electromagnetic interference shielding.Nano Lett.2005;5(11):2131–4.[15]Yang YL,Gupta MC,Dudley KL,Lawrence RW.A comparativestudy of EMI shielding properties of carbon nanofiber and multi-walled carbon nanotubefilled polymer composites.J.Nanosci.Nanotechnol.2005;5(6):927–31.[16]Che RC,Peng LM,Duan XF,Chen Q,Liang XL.MicrowaveAbsorption Enhancement and Complex Permittivity and Permeabil-ity of Fe Encapsulated within Carbon Nanotubes.Adv.Mater.2004;15(5):401–5.[17]Kim HM,Kim K,Lee CY,Joo J,Cho SJ,Yoon HS,et al.Electricalconductivity and electromagnetic interference shielding of multi-walled carbon nanotube composites containing Fe catalyst.Appl.Phys.Lett.2004;84(4):589–91.[18]Cheng HZ,Jou WS,Lin PT,Huang CC,Chen EC.A novel CNTS/polymer/PE composite with high electromagnetic shielding.Annu.Tech.Conf.Antec.Conf.Proc.2004;2:1662–7.[19]Li YJ,Hanada T,Nakaya T.Surface modification of segmentedpolyurethanes by grafting methacrylates and phosphatidylcholine polar headgroups to improve hemocompatibility.Chem.Mater.2006;11(3):763–70.[20]Shirasaka H,Inoue S,Asai K,Okamoto H.Polyurethane ureaelastomer having monodisperse poly(oxytetramethylene)as a soft segment with a uniform hard segment.Macromolecules2000;33(7):2776–8.[21]Randall D,Lee S.The Polyurethanes Book.New York:John Wiley&Sons;2002.5-30.[22]Lv X,Du F,Ma Y,Wu Q,Chen Y.Synthesis of high quality single-walled carbon nanotubes at large scale by electric arc using metal compounds.Carbon2005;43(9):2020–2.[23]Du F,Ma Y,Lv X,Huang Y,Li F,Chen Y.The synthesis of single-walled carbon nanotubes with controlled length and bundle size using the electric arc method.Carbon2006;44(7):1327–30.[24]Schulz RB,Plantz VC,Brush DR.Shielding theory and practice.Electromagnetic Compatibility,IEEE Trans.1988;30(3):187–201. [25]Joo J,Epstein AJ.Electromagnetic radiation shielding by intrinsicallyconducting polymers.Appl.Phys.Lett.1994;65(18):2278–80. [26]Yussuf AA,Sbarski I,Hayes JP,Solomon M,Tran N.Microwavewelding of polymeric-microfluidic devices.J.Micromech.Microeng.2005;15(9):1692–9.[27]Holzheimer T.A broadband materials measurements technique usingthe full frequency extent of the network analyzer.2002Anten.appl.symp.2002.[28]Kim B,Lee J,Yu I.Electrical properties of single-wall carbonnanotube and epoxy composites.J.Appl.Phys.2003;94(10): 6724–8.[29]Stauffer D,Aharony A.Introduction to Percolation Theory.Seconded.London:Taylor&Francis;1992.17-30.[30]Park C,Ounaies Z,Watson KA,Crooks RE,Smith Jr J,et al.Dispersion of single wall carbon nanotubes by in situ polymerization under sonication.Chem.Phys.Lett.2002;364(3):303–8.[31]Grunlan JC,Mehrabi AR,Bannon MV,Bahr JL.Water-BasedSingle-Walled-Nanotube-Filled Polymer Composite with an Exceptionally Low Percolation Threshold.Adv.Mater.2006;16(2): 150–153.[32]Grimes CA,Mungle C,Kouzoudis D,Fang S,Eklund PC.The500MHz to5.50GHz complex permittivity spectra of single-wall carbon nanotube-loaded polymer composites.Chem.Phys.Lett.2000;319(5-6):460–4.Z.Liu et al./Carbon45(2007)821–827827。

银-DBSA掺杂聚苯胺的制备及应用研究洪敦华;周国云;何为;王守绪【摘要】采用苯胺，过（二）硫酸铵(NH4)2S2O8、硝酸银AgNO3、甲醛、十二烷基苯磺酸钠等为原料，合成了银-DBSA掺杂的聚苯胺。

最佳合成的具体条件：反应温度在0～5℃下，苯胺、(NH4)2S2O8和十二烷基本磺酸钠摩尔比为4：4：1,加入的AgNO3的物质的量为苯胺的10%，反应4.5小时后，再加适量的甲醛还原得到银-DBSA掺杂聚苯胺。

样品的IR光谱表明，通过还原后峰型和峰位都发生了明显的变化。

样品的XRD分析知,银-DBSA掺杂聚苯胺有很强的金属元素银的峰,样品的SEM表明,还原得到的银-DBSA掺杂聚苯胺的颗粒度更小，且有许多银白色的银粒分散在高聚物大分子中。

样品的TG热分析表明，银-DBSA掺杂聚苯胺在420℃以下是很稳定的，说明掺入银后的聚苯胺的热稳定性得到了显著的增强。

用四探针电阻仪测试样品的电导率约为14S/cm，因此它是很有希望用于全印制电路技术的新材料。

%This paper introduces polyaniline, (NH4)2S2O8, AgNO3, formaldehyde, sodium and other raw materials, as well as synthesis of silver-DBSA doped polyaniline. Best synthesis of the specific conditions is:reaction temperature at room temperature. The molar ratio of aniline, (NH4)2S2O8 and sodium dodecyl is 4:4:1, The mole rate of doping AgNO3 is 10%compared with aniline. After agitating 4.5 hours, doping an appropriate amount of formaldehyde into the solution, we have silver-DBSA doped polyaniline. IR spectra of samples showed that signiifcant changes have taken place that appearance and position of peak of samples. The XRD analysis of samples showed that silver-DBSA doped polyaniline has a strong peak of silver metal elements. SEM samples showed thatparticle size of silver-DBSA doped polyaniline smaller than AgNO3-DBSA doped polyaniline, and there are many silver-white silver particles dispersed in polymer macromolecules. TG thermal analysis of samples show that the silver-DBSA doped polyaniline is stable under 420℃, it indicated good thermal stability of synthetic products. The conductivity of samples that tested by four-probes conducting instrument is about 14s/cm. So the silver-DBSA doped polyaniline is a promising new material. It was uesed in all printed cicurit and other aspects.【期刊名称】《印制电路信息》【年(卷),期】2014(000)006【总页数】5页(P45-49)【关键词】导电聚苯胺;导电率;全印制电路;银掺杂聚苯胺【作者】洪敦华;周国云;何为;王守绪【作者单位】电子科技大学微电子与固体电子学院，四川成都 610054;电子科技大学微电子与固体电子学院，四川成都 610054;电子科技大学微电子与固体电子学院，四川成都 610054;电子科技大学微电子与固体电子学院，四川成都610054【正文语种】中文【中图分类】TN411977年白川英树（H.Shirakawa）和MacDiamid等人首次用AsF5或I2对聚乙炔薄膜掺杂后，其电导率达到103 s/cm[1][2]，这是此类导电高分子材料至关重要的突破。