Electrosynthesis and characterizations of a multielectrochromic copolymer based on pyrrole and 3,4‐ethylenedioxythiophene

A copolymer based on pyrrole and 3,4‐ethylenedioxythiophene (EDOT) was electrochemically synthesized on an indium tin oxide ITO/glass electrode in acetonitrile containing lithium perchlorate (LiClO₄). The resultant copolymer is characterized via cyclic voltammetry, FTIR, SEM, XPS, and spectroelectrochemical analysis. The spectroelectrochemical analysis revealed the copolymer film has distinct electrochromic properties with respect to the homopolymers, and presented four colors (amaranth, brick red, dark grey, and light blue) under various applied potentials. For the copolymer in the neutral state, the calculated onset energy for the π–π* transition (E_g) is 1.69 eV, and the absorption peak (λ_max) is located at 508 nm. The maximum transmittance contrast (ΔT%) is 39.2% at 946 nm between the fully oxidized and intermediate(?0.4 V) states. Successive cyclic voltammograms and electrochromic switching experiment indicate the good stability of the copolymer because of the incorporation of EDOT units into the polypyrrole. It retains 81% of the original electroactivity and 71.8% of contrast after 2000 cycles. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

环【8】吡咯及其衍生物的一锅法合成、表征及光谱分析

一锅法合成了环【8】吡咯及其衍生物环【6]吡咯和环[7】吡咯,用正交实验获得了合成的最佳条件,使产率分别达到32％,20％,9％,对三个化合物进行了核磁共振氢谱、核磁共振碳谱、元素分析表征,研究了环[n】吡咯（n=6,7,8）的紫外可见吸收光谱和荧光发射光谱。     

橡胶混炼过程功率曲线新的物理意义

根据密炼机流变理论和橡胶混炼流变理论,赋予混炼过程功率曲线新的物理意义。指出从密炼机混炼过程功率曲线的变化可判断混炼过程是否最佳,打滑是否严重,胶料粘度是偏大还是偏小,加入油料时间是否适时等     

Sorption and diffusion of water,salt water,and concrete pore solution in composite matrices

In recent years, the use of fiber‐reinforced polymer composites in civil infrastructure has been promoted as a solution to the deterioration of bridges, buildings, and other structures composed of traditional materials, such as steel, concrete, and wood. Any application of a polymer composite in an outdoor environment invariably involves exposure to moisture. There is also potential for exposure to saline conditions in waterfront or offshore structures, and alkaline environments, as would be encountered by a reinforcing bar in a cementitious material. This study characterizes the sorption and transport of distilled water, salt solution, and a simulated concrete pore solution in free films of vinyl ester, isophthalic polyester (isopolyester) and epoxy resins, all commercially important materials for use in structural composites. Diffusion of all three liquids in each of the three materials was observed to follow a Fickian process. Mass loss was observed for the isopolyester in salt water and concrete pore solution at 60°C, suggesting hydrolysis that was accelerated by the high temperature exposure. Both the rate of uptake, as well as the equilibrium uptake, were greater at 60°C, compared with ambient conditions. Diffusion coefficients calculated from the mass uptake data revealed that, although the epoxy resin had the highest equilibrium uptake, it had the lowest diffusion coefficient. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 483–492, 1999     

橡胶轮胎胎坯硫化前微波预热的研究

传统的轮胎硫化工艺一直沿用着外加热及热传导方式进行,这种加热方式存在着温度梯度大、加热速率慢等问题,致使轮胎质量受到一定影响.为解决这一问题,国内外的一些研究者及研究机构,寻找更加合理的硫化工艺方法,以实现轮胎胎坯内外温度的一致,提高轮胎质量.采用微波加热新技术,研究和试验了在橡胶轮胎硫化前进行预热的技术.研究表明,用微波预热轮胎胎坯,可使其内外温度达到均匀,克服硫化过程中外部温度很快达到硫化介质温度,而内部温度经过很长时间才有所上升的不足,以期实现轮胎硫化质量和硫化效率的提高.     

尿素生产中缩二脲的形成及降低其含量的措施

研究了缩二脲在尿素生产过程中各工序的形成原理,通过适当的生产控制措施,降低了生产过程中缩二脲的生成量,提高了尿素的品质。     

凹凸棒复合滤料生物过滤去除苯酚性能研究

利用凹凸棒复合滤料良好的吸附性和生物挂膜性能对普通滤池进行生物强化,研究生物过滤对原水中苯酚的去除效果及影响因素。实验结果表明,原水浓度在0.25mg/L时,苯酚的去除率达到93.75%;温度在23℃时,苯酚的去除率达到95.97%;原水溶解氧浓度在7.4mg/L时,苯酚的去除率达到96.46%;反冲洗对生物过滤去除苯酚的影响较小,去除率在冲洗2h后能够恢复到冲洗前的水平。     

Tm3+和Ho3+共掺KYb(WO4)2晶体生长与光谱特性

以K2W2O7作为助熔剂,Yb3+为敏化剂,采用泡生法生长掺8%(摩尔分数,下同)Tm3+和1%Ho3+的Tm,Ho∶KYb(WO4)2(Tm,Ho∶KYbW)晶体.采用X射线衍射(X-ray diffraction,XRD)分析了晶体的结构;测试了晶体的红外光谱和Raman光谱,并对出现的峰值进行了振动归属;测量了晶...     

离子色谱法测定水的硬度

EDTA法测定硬度时,某些水样干扰严重,硬度不易测准。采用离子色谱法来测定硬度,可避免此类干扰。将水样经0.45μm微孔膜过滤后一次进样,同时测出水样中的钙、镁离子含量,然后换算成以碳酸钙表示的硬度,该方法的回收率在98.2%～102.0%之间,相对标准偏差为0.94%～1.21%。     

新型桥式固态故障电流限制器

文中提出了一种新型桥式固态故障电流限制器,该装置由二极管、晶闸管和限流电抗等组成。在系统正常运行时,新型故障电流限制器运行于整流桥模式,对系统影响很小;在故障发生时,限流电抗能自动无延迟地限制短路电流第1个峰值,且通过对晶闸管的控制,实现装置由整流桥模式进入限流模式,限制短路电流稳态值。该方案无需另设旁路限流电抗,也无需全控型器件,结构简单,可靠性高。文中提出了该方案的控制策略,并通过实际系统仿真分析及与现有桥式故障电流限制器对比,证明了该方案的可行性和技术优势。