Sensitizing Mechanism and Adsorption Properties of Dye—Sensitized TiO2 Thin Films

The dye-sensitized TiO2 complex films were prepared by the dye coat onto TiO2 surfaces,and the sensitizing mechanism and adsorption properties of the dye-sensitized TiO2 complex films were inverstigated.The influence of the application conditions of dye adsorbed on TiO2 films on the amount of dye adsorption was discussed.Experimental results show that the concentration,the temperature of dye solutions and the dipping time of TiO2 films in the dye solutions have a significant influence on the amount of dye adsorption.Cell test indicates that the conversion efficiency of light to electricity increases with the amount of dye adsorption.     

单模光纤最小群速度色散波长附近的调制不稳定性

利用修正的非线性Ｓｃｈｒｏｄｉｎｇｅｒ方程研究了单模光纤最小群速度色散波长附近的调制不稳定性，发现了一个新的由光纤四色散导致的调制不稳定性区域，该区域的调制范围与初始入射脉冲的功率和四阶色散有关。     

液相添加剂对PTCR陶瓷电性能的影响

液相添加剂ＡＳＴ（Ａｌ２Ｏ３＋ＳｉＯ２＋ＴｉＯ２）对ＢａＴｉＯ３陶瓷材料电性能的影响很大，随着Ａｌ２Ｏ３含量的增加，材料的电性能降低；ＳｉＯ２、ＴｉＯ２的物理特性对材料电性能影响较大；过量ＴｉＯ２对材料ＰＴＣ效应有重要影响，适当过量ＴｉＯ２含量，可得到性能优良的ＰＴＣＲ陶瓷。     

含羧基的聚乙烯醇胺肟螯合纤维吸附钯的研究

研究了含羧基的聚乙烯醇胺肟（ＰＶＡＡＯ－ＡＡｃ）螯合纤维对钯的吸附，讨论了ｐＨ、温度、浓度、吸附时间对吸附率及回收率的影响。确定了最佳吸附条件，吸附钯的纤维用５％硫脲＋０．１０ｍｏｌ／Ｌ硝酸溶液可以解吸。     

氮化硅的性能及其聚合物材料

叙述了氮化硅（Ｓｉ３Ｎ４）的性能并制备了含Ｓｉ３Ｎ４的聚合物材料，这种材料在医学上具有重要价值，对改变医学方面的概念、和对促进人类健康长寿具有重要意义。     

美籍华裔专家讲通信工程技术新动态

本文扼要介绍１９９５年北京中美工程技术研讨会通信组五位美籍华裔专家关于通信技术新动态的专题报告。一是宽带综合业务数字网的同步数字系列（ＳＤＨ）和异步转移模式（ＡＴＭ）；二是光纤通信系统的光放大器（ＯＦＡ）、波分多路（ＷＤＭ）、光电子集成（ＯＥＩＣ）、色散补偿和新型光纤；三是蜂窝网车载移动通信和全国性个人通信业务（ＰＣＳ）、时分多址（ＴＤＭＡ）和码分多址（ＣＤＭＡ），四是智能网（ＩＮ）体系结构、概念模型和业务管理系统（ＳＭＳ）；五是数字传输网的恢复（ＦＡＳＴＡＲ）、维护（ＴＭＰ）和供应（ＴＳＮＯＷ）三种管理平台，及综合网络管理系统（ＩＮＭＳ）。     

Kinetic model for water/oil absorption of mesquite gum (Prosopis juliflora) and gum arabic (Acacia senegal)

The water and oil uptake of mesquite and arabic gums in powdered form was studied at temperatures of 23, 35 and 45°C. A previously proposed equation to predict osmotic equilibrium was tested using the experimental data with both gums and a good statistical fit was obtained. Mesquite gum showed the highest water and oil absorption at all temperatures studied. Temperature dependence of the reciprocal of the S₁ and WL_∞ were determined using an Arrhenius equation. The activation energy for water and oil absorption for gum arabic was 21.98 and 39.57 kJ mol⁻¹, compared to that of mesquite gum having values of 15.79 and 46.16 kJ mol⁻¹, respectively. A second order kinetic model was obtained for water and oil absorption for both gums.     

强度调制／直接检测（IM／DD）光纤通信系统色散限制的研究

通过引入归一化脉宽Ｐ和相对脉冲展宽因子ｑ，提出了一个适用于ＩＭ／ＤＤ系统中各种眼图恶化量ｘ和归一化脉宽Ｐ的色散限制改进公式。通过与其它理论的比较、计算机仿真和对实验数据的分析，验证了该公式的正确性，并给出了其它结果的限制条件。研究表明：当眼图恶化量ｘ为１ｄＢ左右时，对２．５Ｇｂ／；外调制信号（α＝０）而言，非色散位移光纤ＩＭ／ＤＤ系统的色散因子γ约等于０．７９，所对应的系统再生中继距离约为９００余公里。     

The mechanics of compressive kinking in unidirectional fiber reinforced ductile matrix composites

Three distinct stages of kink band formation and propagation exist in ductile matrix composites subjected to compressive loading. These stages are called incipient kinking, transient kinking and kink band broadening. Each stage involves a different deformation mode. The mechanics governing each stage are discussed. Incipient kinking, where the peak load is attained, and kink band broadening, where the load attains a steady-state, are important in structural design. Two design philosophies are presented. References to pertinent literature are made throughout.