Schnell-Methode zur Umsetzung von Kohlenwasserstoffen zu Wasserstoff für die Isotopenanalyse

Es wird eine weiterentwickeltes, isotopenanalytisches Verfahren zur probenchemischen Umsetzung von Kohlenwasserstoffen mit Chromium zu Wasserstoff bei 1300 K vorgestellt. Die erzielten Testergebnisse zeigen anhand der gemessenen δD-Werte, daβ Quarzöfen bei diesen Temperaturen noch keine die Isotopenmeβwerte beeinflussende Diffusion von Wasserstoff durch die Wandung zulassen. Auβerdem erfolgte die Reaktion nahezu spontan und vollständig, was die Methode zeitlich sehr effektiv macht.

A modified isotope analytical method is presented for the chemical reaction of hydrocarbons with chromium at 1300 K to form hydrogen. The test results obtained (i.e. the measured δD-values) show that at this temperature quartz heating tubes do not allow hydrogen to diffuse through the wail, which fact would influence the isotopic composition. Furthermore the reaction proceeds nearly spontaneously and quantitatively, which yields an effective method, especially with respect to time.     

G伺服在光纤筛选设备中的应用

文章探讨了新型G系列伺服系统的特点,其在光纤筛选设备上的应用;光纤筛选设备的控制原理,在光纤生产环节中的作用,发挥G系列伺服优异性能,提升筛选速度提高设备的利用效率.     

Electronic Structure and Thermoelectric Properties of Si-Based Clathrate Compounds

Thermoelectric properties of Au-substituted Si-based clathrates, Ba₈AuGa₁₃Si₃₂ and Ba₆A₂AuGa _x Si_45−x (A = Sr, Eu, x = 13, 14), were experimentally and theoretically investigated. The polycrystalline samples of the Au-substituted Si-based clathrates were prepared by using the spark plasma sintering technique. The electronic structure of Ba₆A₂AuGa₁₃Si₃₂ was theoretically calculated by ab initio calculations, and the thermoelectric properties of Ba₆A₂AuGa _x Si_45−x were estimated through the calculated electronic structure. The effective mass of Ba₆A₂AuGa _x Si_45−x was experimentally estimated to be greater than that of Ba₈AuGa₁₃Si₃₂. Experimentally observed electronic properties agree with the calculations for Ba₆A₂AuGa _x Si_45−x . The maximum ZT value of Ba₆Sr₂AuGa₁₄Ge₃₁ is about 0.5 at 850 K. The calculated thermoelectric properties agree very well with the experimental results in the range from room temperature to 900 K.     

Size Effect on Properties of Varistors Made From Zinc Oxide Nanoparticles Through Low Temperature Spark Plasma Sintering

Conditions for the elaboration of nanostructured varistors by spark plasma sintering (SPS) are investigated, using 8‐nm zinc oxide nanoparticles synthesized following an organometallic approach. A binary system constituted of zinc oxide and bismuth oxide nanoparticles is used for this purpose. It is synthesized at room temperature in an organic solution through the hydrolysis of dicyclohexylzinc and bismuth acetate precursors. Sintering of this material is performed by SPS at various temperatures and dwell times. The determination of the microstructure and the chemical composition of the as‐prepared ceramics are based on scanning electron microscopy and X‐ray diffraction analysis. The nonlinear electrical characteristics are evidenced by current–voltage measurements. The breakdown voltage of these nanostructured varistors strongly depends on grain sizes. The results show that nanostructured varistors are obtained by SPS at sintering temperatures ranging from 550 to 600 °C.     

基于模糊神经网络的雷达对抗效能评估

雷达对抗装备作战效能评估是一个复杂问题,涉及因素多,而且部分因素存在信息不完全和不确定的问题,而模糊系统理论是处理这类问题的有力工具。提出利用模糊系统理论来评估雷达对抗装备的作战效能,建立了作战效能评估的指标体系,结合神经网络的自适应功能,提出了基于模糊神经网络的作战效能评估模型。仿真结果表明该方法简单有效而且可行。     

论现场总线系统及其应用技术

介绍FCS的结构、特点，及其与DCS系统的对照与集成并用。最后简述了以FCS为基础的控制系统与网络系统的构建、形成与开发，并结合我国目前的实际情况提出FCS在应用中要考虑的一些实际问题，及选择FCS的一些建议。     

GIS在网络设备管理中的应用

众多设备制造商的不同类型的通信设备服务于通信网，由于每个设备没有位置信息，因而无法知道相应设备的位置和覆盖范围，势必带来设备管理的困难。解决方法是将地理信息系统（GIS）应用于网络设备管理系统中。GIS支持地理空间数据的采集、存储和显示，并能将地理空间数据与相关参考数据关联以提供信息壹询与分析。文章提出了一种结合了GIS技术的网络设备管理系统，并给出了相应的系统框架、系统模块、系统管理流程，认为该方案能更有效地管理和维护网络设备。     

广电宽带设备集中供电初探

结合有线电视集中供电特点，提出了一种解决广电宽带系统设备供电的新途径。     

支持和保护国内通信设备制造业

加入ＷＴＯ后,直面国外同行的强大实力,国内电信设备制造商将遇到空前挑战。我们要利用ＷＴＯ的各项保护条款对国内通信企业实行合法合理的支持和保护。同时,还要发挥政府作用,将电信设备制造业纳入“特定工业”,通过财政拨款、银行贷款、减免税和出口鼓励等政策实行行业扶持,借助宏观政策、关税结构调节、打击走私等手段进行适度和合理的市场保护．     

激光合成新型线性NTC热敏电阻材料

本文采用CO2激光器作热源合成了Al2O3-WO3系热敏电阻材料,该材料具有负的温度系数,在一定温区内阻温特性呈线性变化。并对材料的导电机理进行了初步探讨。