Use of rheology, dielectric analysis and differential scanning calorimetry for gel time determination of a thermoset

Measurements of gel time of the epoxy system DGEBA(n=0)/m-XDA were carried out using rheometry and dielectric analysis with the objective of checking the validity of Mangion-Johari equation (DEA) and Harran-Laudouard criterium (rheometry) for gel time determination. In this work, gel times obtained by rheometry and dielectric analysis are compared and conversions at gel time calculated. From the experimental results obtained for gel times it was found a reasonable agreement between the two techniques that lead to gel conversion values very close to those obtained using Flory equation.     

连轧机用人字轮齿轴断裂失效分析

用宏观断口分析、化学检验、力学性能测定、低倍检查、金相组织及夹杂物评定鉴别、受力分析及强度寿命定量估算的方法，对人字轮被动齿轴端断裂失效原因进行分析，并提出改进措施。     

舰载火箭武器系统随机响应分析

利用随机振动复模态分析，提出了一种求解时变线性系统，在确定性激励与随机激励共同作用下非平稳随机响应的计算方法，并以舰载火箭武器系统为研究对象，用该法探讨了海浪对舰面火箭发射初始扰动和系统振动特性的影响。     

本钢炼焦煤最佳配比分析

结合本钢的生产实际，对炼焦煤的最佳配比作了比较具体的分析，同时对资源，质量、成本也作了比较详细的调查，并提出了本钢焦化厂最佳配煤比方案，由此可看出，最大限度地降低采购成本，继续开发合理的配煤比例，具有广阔的前景。     

小型水电站联网改造应注意的几个问题

针对铜鼓县小水电站联网时存在的问题及其不利影响进行了分析，井提出了改进途径，指出小水电站的联网改造应立足安全，争取效益。     

实验应变／应力模态分析若干问题的进展评述

本文评述了实验应变／应力模态分析进展的若干基本问题。主要是：应变响应与位移响应的关系；应变频响函数矩阵的特点及其测量方法；应变模态的加权正交性及其识别方法；以及其他问题。     

Analysis of brushless three-phase synchronous generator without exciter

Recently, a demand for small-capacity generators has been increasing as electric sources in small ships and automobiles or as portable electric sources driven by engines. It is desired that the structure of small-capacity generators be simple and robust, and that the generators be highly reliable, easily maintained and controlled. This paper describes an analysis of the original brushless synchronous generator without exciter. The output voltage can be adjusted in the wide range by controlling the stator dc current. To analyze the characteristics of this generator, the finite element method is applied. It is found that the results of theoretical analysis agree well with the experimental results.     

铸铁热分析用试样新型激冷剂的实验研究

从冷却曲线上相变段倾角最小原则出发，研究了新型激冷剂的配比与热分析法检测铸铁成分精度的关系，实验结果表明，能使相变段倾角最小的成分配比，也能提高对铸铁成分的热分析和检测精度。     

胜利油区放射性同位素测井的粒径选择

根据胜利油区的地层渗透率、孔隙度，在２７个低渗透油田和４６个中、高渗透油田的放射性同位素测井中进行了粒径为１００～３００μｍ、３００～６００μｍ、６００～９００μｍ放射性同位素１３１Ｂａ微球粒径选择实验，确定了放射性同位素１３１Ｂａ微球的选择原则。当油藏渗透率Ｋ＜１００×１０－３μｍ２、孔隙度＜２０％时，放射性同位素粒径为１００～３００μｍ；当油藏渗透率Ｋ＞１００×１０－３μｍ２、孔隙度＞２０％时，放射性同位素粒径为３００～６００μｍ或６００～９００μｍ。在此基础上得到胜利油区选用同位素粒径明细表，对于指导施工，提高放射性测井资料的可靠性具有重要意义。