中压变频器在宣钢炼钢厂除尘风机中的应用

本文介绍了SIMOVERT MV中压变频器在宣钢炼钢厂一次除尘风机中的应用情况。变频器现场运行表明，采用中压变频器对转炉除尘风机进行调速节能获得了成功，节能效果明显。     

Impact of temperature cycle profile on fatigue life of solder joints

In this paper the influence of the temperature cycle time history profile on the fatigue life of ball grid array (BGA) solder joints is studied. Temperature time history in a Pentium processor laptop computer was measured for a three-month period by means of thermocouples placed inside the computer. In addition, Pentium BGA packages were subjected to industry standard temperature cycles and also to in-situ measured temperature cycle profiles. Inelastic strain accumulation in each solder joint during thermal cycling was measured by high sensitivity Moire interferometry technique. Results indicate that fatigue life of the solder joint is not independent of the temperature cycle profile used. Industry standard temperature cycle profile leads to conservative fatigue life observations by underestimating the actual number of cycles to failure.     

热重分析对高分子材料中碳酸钙的定量研究

碳酸钙是高分子材料中常用的无机填料，在高温时会同二氧化碳而失重。利用热重分析可准确定出高分子材料中碳酸钙的含量，同时还可测出聚合物，挥发物的含量，热重分析法样品用量小，灵敏度高，所需时间短。     

玻璃两面重叠手印拍摄机理

根据斯涅尔定律和菲涅尔公式阐述清水衬底法消除玻璃下界面手印或玻纹的影像，以及用偏振光，紫外线拍摄玻面痕迹的方法和机理。     

基于遗传算法的水轮机最优工况参数计算

利用遗传算法计算水轮机的最优工况参数，给出遗传算法的具体实现步骤，并结合某电站的实际运行参数进行计算，结果表明，利用遗传算法计算水轮机的最优工况是可行的，而且寻优效率高，结果可靠。表2个。     

川中丘陵区一种新型小流域径流输沙模型的建立与应用

径流输沙模型对定量评价水沙的输出响应具有重要的意义。本研究在已有研究成果的基础上，通过对四川盐亭县林山西沟小流域的径流、泥沙进行现场观测与分析，提出含沙量单位线的定义及其确定方法，建立了适应该小流域的径流输沙模型。并应用实测资料进行比较，表明模型的模拟结果可靠，模拟过程确定性系数达0．8以上，为川中丘陵区小流域径流输沙过程的预测预报提供了一个新方法。     

新型涂料增稠剂的化学成分鉴定

本文用红外光谱法对一种新型涂料增稠剂进行了化学成分鉴定,其主要成分为羟丙基甲基纤维素与蒙脱土。     

Tunable circular patch antennas

A method to control the resonant or operating frequencies of circular patch antennas has been investigated experimentally and theoretically. It consists of the placement of passive metallic or tuning posts at approximate locations within the input region of the antenna. Comparison of measured and analytical results seems to establish the validity of a theoretical model proposed to determine the input performance of such circular patch antennas.     

对构建高校后勤危机管理体系的思考

本文根据高校后勤服务的特点，引出高校后勤危机和高校后勤危机管理的概念，并在进一步分析了高校后勤危机的诱因、主要特点、特殊性和构建高校后勤危机管理体系的必要性等基础上，提出了构建高校后勤危机管理体系所依据的理念、原则和三个阶段。