微振动对空间实验室微重力环境的影响研究

针对大型刚柔组合体空间结构(空间实验室)的特点,建立系统的动力学方程,并对机柜内设备、太阳阵的转动、宇航员活动产生的激扰力进行了简化。利用计算机建立组合体的简化模型,对空间组合体在各种微振动激扰下的加速度响应进行了仿真研究,并将这些仿真结果用于空间实验室微重力环境的预测。     

利用AutoCAD绘制机械图

以AutoCAD2004为例,介绍绘制一幅机械图的基本步骤和一些个人经验.     

The hydration characteristics and expansion machanism of expansive cement at low<Emphasis Type="Italic">W/B</Emphasis> ratio

The hydration characteristics and expansion impetus of three kinds of cement paste under free-and confined-curing conditions were investigated, which were respectively mixed with three different kinds of expansive agent at low W/B ratio. The results show that the hydration products of pure cement paste and paste mixed with expansive agent are same, but the amount of hydration products, un-hydrated C₃S and C₂S are obviously different at the same hydration age. At 3 d age, the amount of CH in pure cement paste is less than that of paste mixed with expansive agent, but it is reverse when at 28 d age. The amount of AFt at 3d and 28d age in pure cement paste is less than those of paste mixed with expansive agent. Regardless of under free- or confined-curing condition, the amount of ettringite produced varies little since 3d age. The joint effect of the tumefaction of gel-ettringite due to water absorption and the expansive pressure on the pore caused by the crystalloid ettringite is the cause of the volume expansion of cement paste, and the former effect is much greater than the latter. LU Lin-nu : Born in 1972 Funded by 973 High-tech Project of China (No. 2001CB610704-2) and the Natural Science Foundation of Hubei Province(No. 2002AB075)     

万家寨水电站经济运行的措施

针对黄河近几年来水量逐年减少和电力市场的变化 ,对提高万家寨电站的经济运行效益问题 ,进行了分析     

Fe_2O_3基陶瓷的气湿敏特性

论述了由不同制备工艺获得的Ｆｅ２Ｏ３陶瓷及各种添加剂下表面羟基和吸附氧的形成和性质，分析了表面羟基和吸附氧的酸碱性对气湿特性的影响。     

能量方向保护的实现和试验

本文介绍了数字式能量方向保护装置及其动模试验结果，并论述了能量方向元件的递归算法和用以快速切除线路中近端严重故障的距离保护原理，快速选相方法。     

高纯金属与聚合物膜pH电极的研制

介绍以纯金属为基体,PVC为载体,α-萘胺为活性物质,三氯甲烷为溶剂研制成的聚合物膜电极,将它用于测定溶液的pH,取得了一些成效。     

可持续发展与环境保护对策

可持续发展战略已被纳入我国“九五”计划和２０１０年的中长期国民经济和社会发展计划，而保护环境是可持续发展战略最主要的前提和保障。本文介绍了世界环境问题出现的历史、可持续发展的提出及内涵，概述了发展与环境的辩证关系，结合我国可持续发展面临的严峻环境保护形势，提出环境保护的对策。