串行通信服务器中的自适应以太网设计

串行通信服务器中的自适应快速以太网,其硬件包括运行操作系统及应用程序的MPC860T主处理器电路及其外围电路.快速以太网接口电路,负责以太网数据的收发.串行通道电路又分,负责配置监控服务器的SMC接口和负责4个HDLC数据收发功能电路.4个HDLC通道提供符合RS-232C和RS-422标准的接口.     

一种加密算法在信息化弹药引信装定系统中的应用研究

针对信息化弹药引信装定系统中数据的安全性问题，通过对DES加密算法和SDES加密算法的分析，提出了采用SDES加密算法实现引信多数据装定信息加密的方法，并设计出了引信多数据装定芯片解密电路。最后通过仿真，验证该模块可以正确实现引信信息的加密和解密的同时还具有较好雪崩效应。     

Dynamic Study on Rigid and Flexible Coupling System for Terminally Sensitive Submunition

A kinetic model of the rigid and flexible coupling system for terminally sensitive submunition is set up with Kane＇s method. The parachute is considered as a flexible body, the flexible displacement is expressed with modal spread method, the position of the parachute is expressed with a hybrid coordinate method, and the kinematics of the terminally sensitive submunition is analyzed. Ten generalized coordinates relative to the attitude of the terminally sensitive submunition are chosen, and the correlative generalized active forces, the generalized inertial forces, the generalized internal forces are calculated in turn. On the base of the Kane＇s method, the ten degrees of freedom dynamic equations for the coupled terminally sensitive submunition are finally set up. This model can be used to expediently simulate and analyze accurately the exterior ballistic trajectory of terminally sensitive submunition, and provide the overall design of the terminally sensitive submunition with some helpful references.     

基于CVI的测试信号滤波和特征提取组件设计

首先简单介绍了LabWindows/CVI中ActiveX/COM的相关知识,重点分析了测试信号滤波和特征提取组件的设计需求、框架和接口.设计的组件应用于某通用故障诊断软件,方便、可靠,具有很强的实用性.     

CAN总线通讯协议设计

通过对CAN通讯系统需要分析,可确定CAN通讯系统的通讯周期、工作方式、码速率.其约束条件包括系统工作周期、通信协议约束、通信格式约定、多字节数据及位标记.分析各个数据的优先级与传输途径确定编码规则,制定CAN通讯协议,可建立高效可靠的CAN通讯系统.     

Correlation between chemical and electrical profiles in Si+, Se+ and S+ implanted bulk and epitaxial GaAs

We compare the chemical profiles of Cr, Mn, Si and Se with the electron concentration profiles in Si, Se and S implanted semi-insulating Cr-O doped bulk GaAs substrates and undoped VPE buffer layers annealed with and without a SiO₂ encapsulant in a H₂-As₄ atmosphere. A higher activation efficiency in the net electron concentration and the gateless saturated channel current is measured for SiO₂ encapsulated wafers annealed under arsine overpressure than for capless annealed ones using Cr-O doped bulk GaAs substrates. On the other hand, the net donor concentration peak is higher for implanted buffer epi layers capless annealed under arsine overpressure than for SiO₂ encapsulated ones. Secondary ion mass spectrometry (SIMS) studies of the Cr decoration of the implant damage indicate that the damage from the 100 keV Si implant anneals out at 840°C while a temperature of 900°C is required to anneal out the 260 keV Se implant damage. An explanation of these differences is provided using an impurity redistribution model and charge neutrality considerations. Excellent Hall electron mobilities at liquid nitrogen temperature of 5400–9200 cm²/V-sec are measured for Si-implanted buffer epi substrates.     

Copolymerization of tetrahydrofuran and propylene oxide

Summary Copolymerization of tetrahydrofuran and propylene oxide catalyzed by modified H₂SO₄.SO₃ system has been studied. Sodium perchloride was used to replace perchloric acid as co-catalyst. The copolymerization rate was obviously accelerated when using the new H₂SO₄.SO₃–NAClO₄ catalyst system. The reaction became less sensitive to the moisture.     

控制混凝土坍落度损失的载体流化剂

利用对高效减水剂等具有强吸附性能的水泥混凝土无机增强剂天然沸石为载体,制作载体浣化剂,用以控制混凝土的坍落度损失,可使混凝土拌合物的坍落度维持2—2.5h不变,添加载体流化剂的混凝土3d、7d以及28d的强度均比不添加的混凝土的强度分别提高10%左右。本文从理论与实践两方面阐明了载体流化剂的作用机理与效果,充分说明了载体流化剂是泵送混凝土的一种良好的改善流动性的外加剂。     

降膜波动特性的研究

本文提出了一种测定膜厚的新方法－双电导探针法，测定了高湍流降膜的厚度沿降膜管管程的变化情况，探讨了径向平均膜厚及膜厚的概率密度分布沿管程的变化规律，证明降膜的波动特性同时受到液相雷诺数和管程的影响。并对平均膜厚和液相雷诺数作了经验关联，得出NT＝（δ^ )^2/3 [8.92(ReL/4)^5/2 6.0×10^-6(ReL/4)^9/2]^2/15。