GaAs MESFET欧姆接触可靠性研究进展

报道了ｎ型ＧａＡｓ上欧姆接触的制备及其可靠性，以及基于欧姆接触退经的ＧａＡｓＭＥＳＰＥＴ的失效分析，结果表明，ｎ型ＧａＡｓ上欧姆接触的制备已日趋成熟，接触电阻有所减小，表面形貌及热稳定性方面都得到了很大程度的提高，接触材料也日趋丰富ＧａＡｓＭＥＳＦＥＴ的失效分析方法也有明显改进。     

测量聚合物薄膜厚度的一种简便方法

本文介绍了用准波导耦合ｍ线技术测量聚合物薄膜厚度的方法。测量结果表明，薄膜样品厚度的误差为３．６２×１０＾－２μｍ。并对测量精度作了分析和讨论。     

应用傅里叶全息滤波器的光电图像形态学处理系统

介绍一种使用傅里叶全息滤波器的光电图像形态学处理系统，其中关于图像结构元的扩张，侵蚀及开和闭等基本运算于傅里叶全息光学方法产生的图像与结构元的卷积结果，其迭代过程使用了计算机控制的电寻址空间光调制器，该系统具有结构简单、能反复迭代、易于根据图像设计、更换及使用计算机制全息图产生结构元等优点。     

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.     

Forward-bias impedance of GaAs1-xPx LED's

The forward bias impedance characteristics of GaAs_1-xP_x LED's have been determined. In all cases, the equivalent parallel capacitance reaches a maximum and then either saturates (x = 0.4) or becomes negative at certain frequencies (x = 0.85 and x = 1). The current densities at which C_p maxima are reached are below typical values for display, multiplexing or optical emitters applications (i.e. J_F = 1 A/cm² for x = 0.85). It is suggested large series resistances for x = 0.4, and conductivity modulation effects for x > 0.4 are responsible for the above impedance behavior.     

TiO2 catalysed reduction of Cr(VI) in aqueous solutions under ultraviolet illumination

The photoassisted reduction of Cr(VI) to Cr(III) in aqueous suspensions of TiO₂ under ultraviolet (UV) illumination has been studied by determining the amount of Cr(VI) photoreduced at different irradiation times, the mass of catalyst in suspension, the Cr(VI) initial concentration and the pH. Samples of wastes from metal-surface treatment industries have been used to test this photocatalytic procedure for Cr(VI) elimination in a real ease. It has been observed that the presence in these samples of certain species such as Fe(III) and Cr(III) at low concentrations can increase significantly the yield of Cr(VI) photoreduction. It is assumed that these cations act by maintaining the pH during the photoreduction process, preventing the alkalization by hydrolysis of the solution.     

田菁冻胶在毛细管及多孔介质中滑移效应研究

本文用实验方法研究了田菁冻胶压裂液在毛细管和多孔介质中的流动特性,求得相应的滑移效应,提出本构方程及C·H.B.模型,并得以验证.     

Hybrid Turbo FEC/ARQ Systems and Distributed Space-Time Coding for Cooperative Transmission

Cooperative transmission can be seen as a “virtual” MIMO system, where the multiple transmit antennas are in fact implemented distributed by the antennas both at the source and the relay terminal. Depending on the system design, diversity/multiplexing gains are achievable. This design involves the definition of the type of retransmission (incremental redundancy, repetition coding), the design of the distributed space-time codes, the error correcting scheme, the operation of the relay (decode & forward or amplify & forward) and the number of antennas at each terminal. Proposed schemes are evaluated in different conditions in combination with forward error correcting codes (FEC), both for linear and near-optimum (sphere decoder) receivers, for its possible implementation in downlink high speed packet services of cellular networks. Results show the benefits of coded cooperation over direct transmission in terms of increased throughput. It is shown that multiplexing gains are observed even if the mobile station features a single antenna, provided that cell wide reuse of the relay radio resource is possible.