Soluble and conductive polypyrrole copolymers containing silicone tegomers

Soluble and processable conductive copolymers of silicone tegomers and pyrrole were developed. This was easily accomplished by the oxidative polymerization of pyrrole monomer by Ce(IV) salt in the presence of silicone tegomers with hydroxyl chain ends. The resulting copolymers were soluble in dimethylformamide. The products were characterized by Fourier transform infrared, ¹H‐NMR, and four‐point probe conductivity, and their surface properties were investigated with contact‐angle measurements. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2896–2901, 2003     

螺纹钢牙筋长度不足的原因及解决办法

分析了影响螺纹钢牙筋长度的原因，根据铣床的工作原理，利用刀头夹持长度与凸轮工作轨面半径的几何关系，推导出计算各种不同规格螺纹钢牙筋的工艺参数，解决了螺纹钢牙筋长度不足之问题。     

聚吡咯导电材料合成方法的进展

本文对聚吡咯及聚吡咯导电复合物的合成方法进行了综述。     

中小型变压器供电电机起动方式的选择

通过分析和计算及实例，从允许电压降范围和电动机母线电压校验两方面叙述了电动机起动时如何合理地选择起动的方式。     

最新水冷式全固态数字调幅600kW中波发射机

数字调幅制式是当前国际上较先进的调制技术，ＤＸ系列全固态数字调幅中波发射机的电声指标和工业效率都是很先进的，过去的ＤＸ大功率机采用风冷方式，本文介绍了最新水冷ＤＸ－６００发射机的设备情况和技术特点。     

关于单位工程施工进度计划两种表示方式的研究

通过实例指出单位工程施工进度计划的两种表示形式在应用中出现的不同结果,并分析了其中的原因。     

Electrochemistry of polyaniline: Study of the pH effect and electrochromism

Polyaniline was electrochemically synthesized from an aqueous medium with various acid electrolytes via potentiodynamic and potentiostatic techniques. The electrochemical synthesis of polyaniline was studied over various substrates, including Pt, Ti, Ni, and SnO₂ coated glass, and in various acid electrolytes. Cyclic voltammograms of electrochemically synthesized polyaniline were studied in HCl in a pH range of 1–4. Probable electrochemistry and chemical changes were deduced that occurred when polyaniline film was electrochemically oxidized and reduced between ?0.2 and 1.0 V versus a Ag/AgCl reference electrode in an acidic electrolyte at pH 1, and three corresponding oxidation and reduction peaks were described instead of two redox peaks (as observed by W. S. Huang, B. D. Humphrey, and A. G. MacDiarmid, J Chem Soc Faraday Trans 1 1986, 82, 2385). The electrochromic property was studied with changes in the chemical states of polyaniline during electrochemical oxidation and reduction. A new viscous electrolyte, aqueous AlCl₃ (pH 2), saturated with AgCl was used for the construction of an electrochromic display device. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 378–385, 2002     

Effect of doping polyacrylic acid with some dopants as studied by different techniques

The molecular weight of polyacrylic acid (PAA) was determined by a viscometric method using NaNO₃ as solvent at 30°C. The specific electric conductivities (σ) of PAA as well as PAA doped with carbon black (CB), chromium oxide (Cr₂O₃), and cupferron with different concentrations (from 0.25 to 1 wt %) were measured at a temperature range 360–400 K. IR spectra of some polymers were determined and it was shown that when PAA was doped with 0.5 wt % CB, a C? O? C band appeared at 775–875 cm^?1. The positron annihilation lifetime (PAL) spectra in PAA doped with the above‐mentioned dopants were measured as a function of their concentrations. It was observed that the short lifetime intensity I₁ decreased, whereas the intermediate lifetime intensity I₂, which is related to the conductivity of the material, increased with increasing the wt % of Cr₂O₃ and cupferron as well as at low concentrations of CB. These results are discussed in terms of the conducting island model. It was found that there were distinct positive relationships between σ and I₂. © 2002 John Wiley & Sons, Inc. J Appl Polym Sci 84: 877–883, 2002; DOI 10.1002/app.10381     

自聚焦棒耦合性能的分析

本文采用光线光学的原理分析了自聚焦棒（ＧＲＩＮ）的光学性能，在折射率分布为抛物线近似的条件下，推导出较为简单的ＧＲＩＮ中的光线轨迹方程，并实验测量了ＧＲＩＮ的耦合效率，从而由理论和实验两方面讨论ＧＲＩＮ的聚焦特性。     

弧形小方坯连铸机的引锭杆和铸坯导向及二冷装置

本文介绍了弧形小方坯连铸机几种类型的引锭杆和与不同引锭杆相适应的铸坯导向及二冷装置，并讨论了有关设备的结构特性及其优缺点。