聚偏氟乙烯及其共聚物的分子链旋转势能计算

文章计算了聚偏氟乙烯和三氟乙烯共聚物分子链旋转时势能曲线。结果表明势能曲线不存在“六阱势”理论所预防假设的准六度对称性。由此推论“六阱势”理论不是描述这种有机铁电共聚物极化反转的适合的理论模型。     

丙烯酸氟烷基酯乳液聚合的研究

以甲基丙烯酸氟烷基酯(Zonyl TM)、甲基丙烯酸甲酯、丙烯酸正丁酯为原料,采用氧化-还原引发体系,以十二烷基硫酸钠和全氟辛酸铵(1∶1)为乳化剂,经超声波预乳化后进行聚合,制备了一系列高氟单体含量的三元共聚物乳液,系统研究了聚合条件对乳液稳定性等影响.考察了氟元素含量对共聚物表面性能的影响,含氟共聚物对水和对油的接触角最高可分别为116°和77.5°.     

环氧改性氟树脂涂料研究

用环氧树脂改性偏二氟乙烯－四氟乙烯－六氟丙烯共聚物（氟树脂２４６）,可以大大提高氟树脂在底材表面的附着力。实验结果表明,改性氟树脂涂料有良好的机械性能和耐有机溶剂性能,具有广泛的应用前景。以大     

聚偏氟乙烯均聚物和共聚物的结晶行为研究

通过研究PVDF均聚物和PVDF与六氟丙烯的共聚物的结晶行为,来掌握与六氟丙烯共聚后,PVDF结晶行为的变化.研究结果表明,在结晶过程中,均聚物和共聚物都形成具有球晶结构的α晶型.相比于均聚物,共聚物的结晶(熔融)温度、平衡熔点和结晶度均下降.两种聚合物在等温结晶时,随着结晶温度提高,结晶速率下降.在相同的过冷度下,共聚物的结晶速率低于均聚物.     

耐低温氟弹性体的研究进展

本文介绍了耐低温氟弹性体的性能特点、国内外生产厂商和应用领域,总结了制备耐低温氟弹性体的所需单体、聚合助剂、聚合方法和聚合工艺,综述了降低耐低温氟弹性体玻璃化温度的三种方法,即改变共聚物组成、引入低温改性共聚单体、加入低温改性助剂,并介绍了耐低温氟弹性体的混炼胶配方和双酚AF硫化的耐低温氟弹性体.     

聚合物光纤用氟树脂材料性能特征

聚合物光纤POF用氟树脂材料首要的性能特征是具有低折射率、无定形、高透明特征,透光率以大于90%为佳,当氟树脂在POF中应用时要求同另一材料有匹配性要求:两者折射率相差0.03以上、膨胀系数及玻璃化温度相近;这种氟树脂不仅是优异的光纤皮材,而且是优异的光纤芯材.氟树脂用作POF芯材时,可降低POF的传输损耗,提高POF的耐温性、POF的传输带宽和POF的耐老化性能等,透明氟树脂是优异的POF芯皮材.     

聚偏氟乙烯共聚物薄膜铁电性能和电容特性研究

制备了以聚苯乙烯磺酸(PSSH)为上下界面层的聚(偏氟乙烯)(PVDF)二元共聚物聚(偏氟乙烯-三氟乙烯)[P(VDF-TrFE)]及聚(偏氟乙烯-氯氟乙烯)[P(VDF-CTFE)]的三明治结构电容器,研究了P(VDF-TrFE)和P(VDF-CTFE)2两种共聚物薄膜的铁电性能和电容特性。结果表明,厚度为60nm的Ti/PSSH/P(VDF-TrFE)/PSSH/Ti超薄薄膜表现出优异的铁电性能;而厚度为100nm的Ti/PSSH/P(VDF-CTFE)/PSSH/Ti薄膜表现出较好的电容特性,存储能量密度高达60J/cm3。研究结果为其在电子器件上的应用提供理论指导。     

锂离子电池用固态偏氟乙烯-六氟丙烯共聚物电解质的研究进展

固体聚合物电解质具有质轻、安全、易加工等优点,在锂离子电池中具有极大的应用价值.综述了以偏氟乙烯-六氟丙烯(PVDF-HFP)共聚物为基的聚合物电解质的研究工作,介绍了PVDF-HFP固体电解质的制备方法,分析了影响此聚合物电解质性能的因素,并讨论了PVDF-HFP电解质的改性措施,对今后的发展方向作了简要展望.     

P(VDF/CTFE)共聚物薄膜的驻极体行为

通过不同条件下的正负电晕充电,等温表面电位衰减测量,热刺激放电（TSD）电流谱分析和热脉冲技术,首次研究了偏氟乙烯（VDF）和三氟氯乙烯（CTFE）共聚物P（VDF／CTFE）的驻极体性质,结果指出：共聚物驻极体的空间电荷热稳定性明显优于PVDF;TSD谱分析说明这种材料驻极体也是极性驻极体,即体内同时包含有偶极和空间电荷。本文还对样品的正负电晕充电后的电荷储存稳定性做了对比;研究了材料的能阱分布,确定了样品在不同温度电晕充电时平均电荷重迁移规律。     

氟代丙烯酸酯/MMA共聚物合成工艺研究

通过溶液聚合合成了氟代丙烯酸酯与甲基丙烯酸甲酯(MMA)的共聚物,并初步表征了产物结构。最佳反应温度80℃,单体浓度50%,引发剂用量1.5%,氟单体与MMA的比例为1∶3,此时转化率最好。     

Thin‐Film Transistors

Thin‐film transistors (TFTs) matured later than silicon integrated circuits, but in the past 15 years the technology has grown into a huge industry based on display applications, with amorphous and polycrystalline silicon as the incumbent technology. Recently, an intense search has developed for new materials and new fabrication techniques that can improve the performance, lower manufacturing cost, and enable new functionality. There are now many new options – organic semiconductor (OSCs), metal oxides, nanowires, printing technology as well as thin‐film silicon materials with new properties. All of the new materials have something to offer but none is entirely without technical problems.     

Possibility of the application of the computational intelligence in the production of superhard materials. Report 2

A new system to control a 630-ton and a 2500-ton presses has been developed. By using this system it has been made possible to define new parameters related to pressure and temperature and the influence of certain factors on them. Furthermore, the new system has been shown to indicate that other parameters, such as height of the gasket formed (h _c ), electrical resistance of the reaction cell, and the frequency of activation of the pump or multiplier, can serve as important indicators of the improvement of superhard material production technologies, implementing the Computational Intelligence (CI).     

A new three-parameter cubic equation of state for refrigeration engineering calculations

A new three-parameter cubic equation of state is proposed in which the repulsion pressure term of the semiempirical van der Waals equation has been modified based on the hard-sphere potential and a functional form similar to Redlich-Kwong attraction term is adopted for the attraction term. All three parameters are treated as functions of temperature. For the purpose of examining the applicability of the new equation, it was applied to describe the thermodynamic properties of difluoromethane (R-32) and pentafluoroethane (R-125). It has been found that the essential thermodynamic properties are represented by the new equation as accurately as a conventional far-complicated modified Benedict-Webb-Rubin equation in the working range of refrigeration equipment. The new cubic equation was also compared with the Peng-Robinson equation and the Carnahan-Starling-De Santis equation.     

Simple method for prediction of activation energies of the thermal decomposition of nitramines

A novel general method has been introduced to predict activation energies of thermal decomposition of nitramines as an important class of energetic compounds. It is shown that the activation energies of acyclic nitramines can be expressed as a function of optimized elemental composition. The resultant relationship as a core correlation can be corrected for cyclic nitramines that contain more than five member ring. R(2) value or the coefficient of determination of the new correlation is 0.94. The new correlation has the root mean square (rms) and the average deviations of 5.67 and 3.98 kJ/mol, respectively, for 14 nitramines with different molecular structures. The new method is also tested for some cyclic and acyclic nitramines with complex molecular structures, e.g. two new nitramines 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (HNIW) and 4,10-dinitro-2,4,6-tetroxa-4,10-diaazaisowurtzitane (TEX), so that it can predict relatively good results as compared to the experimental values.     

硫化矿炸药自爆新判据和治理措施研究

在现场试验研究的基础上,分析了硫化矿山炸药自爆机理,以Fe2+为指标代替了以往的炸药自爆判据,建立了矿样水溶液中Fe2+与其pH值关系的回归经验公式,提出了以pH值为指标的炸药自爆新判据和简便实用准确的检测方法以及按炸药自爆危险程度对采区进行有效分区的治理措施,较好地防止了矿山炸药自爆且节约了爆破成本。实践证明,本研究成果是实用和安全的,具有明显的经济效益和社会效益,为进一步深入研究炸药自爆理论与预防措施提供借鉴。     

Implementation of a new type of time-of-flight laser anemometer

A new time-of-flight (TOF) laser anemometer system utilizing a spatial lead-lag filter for bipolar pulse generation has been constructed and tested. This new TOF has been modified to enable measurements in turbulent flows near walls. Good results have been obtained as close as 100 microm from a surface, with a 140-mm focal length final lens. Lading's theory for the behavior of the measurement variance has been confirmed for this configuration.     

New-generation DuPont Dow fluoroelastomers: Viton fluoroelastomer made with Advanced Polymer Architecture

Viton made with the Advanced Polymer Architecture (APA) has been described as the beginning of a new era in specialty fluoroelastomers, providing faster curing, shorter cycle times and significantly enhanced demolding and end-use performance. Now that DuPont Dow Elastomers has been delivering the new products to compounders and seal and hose manufacturers for more than two years, is the breakthrough technology living up to that bold claim? This article reviews the new APA polymer types, looks at industry applications, and reports on customer experiences.     

周期性复合材料等效传热系数预测的渐进均匀化新算法及其实现

渐进均匀化方法具有严格的数学基础,预测周期性复合材料的等效热传导系数具有较高的计算精度。本文提出了基于渐进均匀化方法预测周期性复合材料等效热传导系数的新算法。相比原有的算法具有两个优点：它的实现与代表体元方法一样简单,新的算法以现有的有限元商业软件为黑箱,通过简单的几个分析步骤,即可以获得复合材料的等效热传导系数;可以利用商业软件提供的多种单元类型去离散同一个单胞,在处理复杂几何单胞结构时,可以节约大量的计算费用。通过几个典型的算例,验证了方法的有效性。该工作对于推广渐进均匀化方法在预测复合材料等效热传导系数的广泛应用具有积极作用。     

Optical properties of a new two-photon absorbing chromophore

A new dye, trans-4-[p-(pyrrolidinyl)styryl]-N-methylpyridinium iodide, has been synthesized, and the two-photon-absorption (TPA), TPA-induced frequency upconversion emission, and two-photon-pumped (TPP) frequency upconverted lasing properties of this new dye were experimentally studied. This new dye has a moderate TPA cross section of varsigma(2) = 5.7 x 10(-48) (cm(4) s(-1))/photon at 1064 nm but exhibits high lasing efficiency. The slope efficiency of the TPP cavity laser with this new dye as the laser medium is 1.6%.     

新气源气相起爆系统起爆网络实验研究

作者选择液化石油气加氧气为气相起爆系统新型气源,经原理探索后研制成第一轮相起爆器。在对新型混合气源在长管道中的传爆性能研究基础上,对气相起爆网络作了系统实验研究。