First Cycle Effect of Polycrystalline CuZnAl Shape Memory Alloy during Thermal-Mechanical Cycling

The thermal-mechanical (T-M) cycles at constant strain of a polycrystalline CuZnAl alloy have beenstudied in the. present work. In-situ optical microscopic observations have been made to reveal thefeatures of the phase transitions during T-M cycling. The variation of stress-temperature (S-T)curves and electrical resistance-temperature (R-T) curves accompanying with T-M cycling havebeen measured by tensile test and electrical resistance measurements. It has been found that thepolycrystalline CuZnAl alloy shows apparent morphology changes and properties variations in thefirst cycle during T-M cycling which is called the first cycle effect in the present work. The stabletransformation procedure in the T-M cycle is: martensiteparent phase +residual acicularmartensite. This residual martensite possesses the character of stress-induced martensite.     

各向异性压电陶瓷研究的新进展

本文叙述了几种新型的机电耦合各向异性的压电陶瓷，对各向异性的机理和应用前景作了简单的分析。     

The netlike inference process and stability analysis

In this article, an inference process is defined as a series of events in which the truth values flow from propositions along certain inference channels. the concepts of netlike inference process and solution searching process are then described. the notion of excitedness is defined as a measure of the activeness of thinking. In the context of an inference process, excitedness describes the truth of the proposition or the belief in the proposition. While in a solution searching process, excitedness describes the ability and/or desire to solve the problem. By introducing simple flows and their network graphs, the process of excitedness flows on the network is described be a set of differential equations with steady state solutions and stability analysis performed by applying Markov process theory. By introducing the concepts of complex flows and multi-branch graphs, the process of excitedness flows on the graph is also described by a set of differential equations with steady state solutions and stability analysis performed similar to Prigogine's theory of dissipative structures.¹ Finally, the idea of using computers in netlike inference is proposed.     

CuZnAl形状记忆合金划痕行为研究

本文系统地研究了铜锌铝形状记忆合金的划痕磨损行为,测定了马氏体相、母相及热轧状态记忆合金的划痕曲线,并对划痕形貌进行了观察和研究。     

工业用多级离心压缩机设计及变工况计算方法

本文提出了一种工程实用的多级离心压缩机设计工况及变工况性能的预估方法，据此法编制的计算程序具有很好的通用性，特别适合整机的初步设计。     

CY7C924在光纤通信中的应用

在当前的许多电子系统中,越来越多的数据传输应用中倾向于使用光纤通信技术。CY7C924作为一款高集成度、强灵活性、高可靠度的物理层通信接口芯片,可以方便的应用于光纤通信系统中。本文介绍了CY7C924的功能特性,描述了利用CY7C924分别结合现场可编程门阵列和单片机作为系统主机的光线通信系统应用,并给出了系统仿真结果。采用CY7C924的光纤通信方案预期可缩短系统开发周期。     

DM642在网络视频传输系统中的应用

数字信号处理器TMS320DM642在多媒体通信领域有着广泛的应用。以利用XDAIS算法在DM642上实现网络视频编码器为例，研究了DM642在网络视频传输系统开发中的一般过程，介绍了系统的硬件和软件模块的功能、工作原理和RP5在程序中的使用方法，并详细分析了使用NDK进行网络功能开发的过程。实践证明，所用方法是正确有效的。该系统模型可作为网络视频监控系统的一个通用平台。     

Reliability Analysis of Phased-Mission System With Independent Component Repairs

This paper proposes a hierarchical modeling approach for the reliability analysis of phased-mission systems with repairable components. The components at the lower level are described by continuous time Markov chains which allow complex component failure/repair behaviors to be modeled. At the upper level, there is a combinatorial model whose structure function is represented by a binary decision diagram (BDD). Two BDD ordering strategies, and consequently two evaluation algorithms, are proposed to compute the phased-mission system (PMS) reliability based on Markov models for components, and a BDD representation of system structure function. The performance of the two evaluation algorithms is compared. One algorithm generates a smaller BDD, while the other has shorter execution time. Several examples, and experiments are presented in the paper to illustrate the application, and the advantages of our approach.     

空间信息技术的应用与矿山测量的现代任务

以遥感，全球定位系统和地理信息系统为主导的空间信息技术正日益广泛和深入地应用到包括地学，矿业在内的几乎所有与地理空间信息有关的领域，中，并且给矿山测量提供了瓣的发展机遇，同时提出了新的任务。     

陶瓷刀具材料的研究现状

文章重点综述了纳米陶瓷、梯度复相陶瓷、氧化锆陶瓷等多相复合陶瓷刀具材料的研究现状,全面分析了陶瓷刀具材料的颗粒弥散增韧补强、纤维(或晶须)增韧、相变增韧及多种机理协同增韧等机制的研究动态.