Vertical spinal electronic device with large room temperature magnetoresistance

We report experimental transport measurements of a vertical hybrid ferromagnetic (FM)/III-V semiconductor (SC)/ferromagnetic(FM) type structure, i.e., Cr(20ML)/Co(15ML)/GaAs(50 nm, n-type)/Al/sub 0.3/Ga/sub 0.7/As(200 nm, n-type)/FeNi(30 nm). The current-voltage (I-V) characteristics reveal Schottky/tunneling type behavior in the direction of FeNi/Semiconductor/Co and observed to be dependent on external magnetic field. The magnetoresistance (MR) behavior shows a strong dependence on the measured current and field. At low fields no significant change in MR has been observed with increasing current. However, at high fields the MR initially increases with increasing current and becomes stable beyond a critical current of 10 /spl mu/A. A maximum of 12% change in the MR has been observed at room temperature, which is far larger than that of the conventional AMR effect. This property of the device could be utilized as field sensors or magnetic logic devices.     

基于JCZ型传感器的扭矩和转速测量方法

讨论了基于JCZ型扭矩转速传感器的扭矩和转速测量方法;介绍了相位差检测电路,对相位差检测电路中各结点的信号波形和检测电路输出波形进行了分析;提出了基于P89LPC932单片机的等精度测量的信号处理方法,该方法有效地消除转速对扭矩检测的影响,提高了测量精度。     

国产32位S698处理器的嵌入式教学平台

介绍一种基于S698处理器的嵌入式系统教学平台,平台针对嵌入式系统开放式、设计型教学的特点进行设计;详细描述教学平台的硬件系统设计和软件实现。该教学平台具有易学习,简洁美观,方便实用等特点。     

快速浮点加法器的FPGA实现

讨论了3种常用的浮点加法算法，并在VirtexⅡ系列FPGA上实现了LOP算法。实验结果表明在FPGA上可以实现快速浮点加法器，最高速度可达152MHz，资源占用也在合理的范围内。     

基于RSView的电泳柔性自动生产线实时监控系统

根据铝型材氧化着色电泳自动生产线的布局结构及其PLC控制网络系统的特点，应用组态软件RSView32及嵌入式VBA开发该生产线的自动监控系统。介绍了监控工作站与PLC站点的数据通信接口及实现方法。应用基于事件驱动的动态调度方法实现行车的动态调度与决策，并给出了主要程序模块的工作流程图。     

Applications of optimal mathematic-physical models in metallurgical manufacture scheduling system at Baosteel

The transfer of mass flow between ironmaking and steelmaking process at Baoshan Iron and Steel Co. Ltd. has been analyzed. The mathematic-physical models of transport scheduling for hot metal manufacturing have been researched combined with the practical problem in the metallurgical manufacture procedure. Taking into account these models, the scheduling software has been designed, programmed and tested on-line. The new automation system of production scheduling has been implemented successfully at Baosteel, which produces a great economic benefit.     

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)     

基于Director8<自动控制原理>多媒体实验教学课件的制作

本文全面地介绍了基于Director8开发的《自动控制原理》多媒体实验教学课件，详细地阐述了该课件的设计目标、实现过程及其关键技术。     

用VB实现通用电力分析仪(PM3300)测量数据的通信

本文介绍了在电机智能化测试系统中，利用VB实现通用电力分析仪(Universal Power Analyzer)PM3300与计算机之间的数据通信方法。详述了其硬件连接及软件设计，并给出了系统中测量数据的通信实例。     

基于CB的端口读写方法应用

本文全面介绍了CB(C Builder)编程语言和接口插板端口通信的编程及应用方法。