关于单位工程施工进度计划两种表示方式的研究

通过实例指出单位工程施工进度计划的两种表示形式在应用中出现的不同结果,并分析了其中的原因。     

电流模式n阶传输函数的OA-OTA实现

提出了一种新的实现任意 n阶电流模式传输函数的网络结构。该电路仅含运算放大器 (OA)和运算跨导放大器 (OTA)有源器件 ,因而适于全集成。适当设置 OTA的跨导值能实现任意高阶传输函数 ,且传输函数的系数可独立调整。文中推导了滤波器的设计公式 ,并给出了截止频率为 1 0 0 k Hz的三阶巴特沃斯低通滤波器实例 ,PSPICE仿真结果表明所提电路及设计公式是正确的     

Development of ultra light magnesium-lithium alloys

Magnesium-lithium alloys are among the lowest density metallic materials. Addition of lithium, with a relative density of 0·53, in magnesium reduces the density of the alloy significantly. Furthermore, addition of nearly 11 wt.% lithium converts hexagonal close packed structure of pure magnesium to a body centered cubic lattice, markedly improving formability of the alloy. The development of these alloys, however, had been hampered due to the high reactivity of lithium and magnesium in the molten state and also, due to poor creep resistance and instability of mechanical properties at room temperature. In an attempt to indigenize these ultra light alloys for possible applications in Indian satellite programme, detailed research work was initiated in DMRL. The difficulties associated with producing sound cast ingots have been overcome by controlling melting and casting parameters of these alloys. Extensive work has been done on structure-property correlation of alloys with varying lithium content and minor alloying additions. Based on these work, advanced magnesium-lithium alloys have been developed with improved tensile properties, room temperature stability and creep resistance. Wrought products (plates/sheets) of magnesium-lithium alloy have been supplied to ISAC, Bangalore and are being used in their INSAT-2 programme. This paper describes the systematic studies carried out in the laboratory to indigenize these ultra light alloys.     

Effects of shear flow on long-ranged correlations,spinodal demixing kinetics,and the location of the critical point and cloud point

A derivation of an expression for the shear rate-dependent Ornstein Zernike structure factor is discussed, together with the resulting anomalous behavior of the turbidity. The predicted scaling behavior of the turbidity, comprising the effect of both temperature and shear rate, is in good agreement with experiments on binary fluids. Then initial spinodal decomposition is discussed, and an explicit expression for the time- and shear rate-dependent effective diffusion coefficient is derived, which shows all the typical characteristics of anisotropic light scattering patterns that are observed experimentally for binary fluids. Next it is shown that the spinodal is shifted linearly with the (bare) Peclet number for not too large Peclet numbers, whereas the cloud point is singularly displaced into the unstable region due to a shear now. This is in agreement with an experiment on a two-polymer/solvent mixture and binary fluid mixtures. It is argued that light scattering is useless to determine the location of the spinodal of a sheared system.Paper presented at the Twelfth Symposium on Thermophysical Properties, June 19–24, 1994, Boulder, Colorado, U.S.A.     

单站被动定位及光电实现

目的　光电技术实现的单站被动定位具有重要的军事价值 ,本文介绍了其原理、方法和发展 .方法　本文中 ,单站被动定位分为激光和红外两部分内容讨论 .结果　明确了采用激光和红外技术的单站被动定位工作原理和存在的技术难点 ,同时 ,指出了被动定位的研究动向 .结论　文章表明单站被动定位及光电实现值得进一步研究 .     

甲醇蒸汽转化炉炉管损伤分析及修复

通过对乙烯厂甲醇车间蒸汽转化炉炉管的材料成分、力学性能、金相组织等的分析，确定定其失效模式为高温蠕变损伤，找到造成及影响炉管失效的主要因素。并对炉管的修复以及预防提出了有效的方法及建议。     

钇铝榴石晶体的超高温强度和流变性

在温度高达２０２３Ｋ，可控氧分和不同应变速率条件下，对钇铝榴石晶体进行了蠕变实验，研究表明，钇铝榴石晶体的脆－延性转变温度高达１８３３Ｋ，在温度低于２０２３Ｋ和应变速率大于１０＾－５．ｓ＾－１的条件下，其蠕变流动强度高于３０００ＭＰｑ对钇铝榴石晶体蠕变机制的研究表明，其高温塑性变形起因于晶体的位错滑移，晶体在高温下的高强度与其很高的Ｐｅｉｅｒｉｓ力相关，钇铝榴石晶体在高温晶体稳定性和超高强度使其菜     

微控制器与嵌入式RISC处理器的发展现状

综述了新一代微控制器与嵌入式RISC处理器的主要特点和发展方向；详细介绍了目前国内外最流行的不同字长的系列机种、结构特点、专有特性及系统应用等；最后预测了它们的世界销售市场与国内发展前景。     

也谈轻型钢结构房屋柱基设计

对柱脚抗剪键的设置和计算中所取用的荷载组合提出个人观点,同时对轻钢结构柱脚螺栓受拉计算提出注意事项.     

PIC单片机在激光电源中的应用研究

论述了单片机控制激光电源的原理，提出了产生PWM控制的基本思想及整个控制系统的硬件组成和软件设计方法。