The Densification of Cu／Ti System by Spark Plasma Sintering

In order to unclose the dynamics of SPS densification, a special sintering sample (Cul Ti wires compact) was designed. Characters of the shrinkage rates during sintering process and mierostructures of products fabrieated by the spark plasma sintering( SPS ) and hot-press .sintering were investigated. The experimental results reveal that a higher temperature field is formed at the connected area and conductive net of the compact. These high-temperature parts deformed more easily than other parts, which is believed to be the main cause of SPS fast densification, according to a hard-core and soft-hell material model.     

Research on Poly （Styrene-Crylicacid）-Suported Neodymium Complex Catalytic Copolymerization of Styrene and 4-Vinylpyridine

Research on Poly(Styrene-Crylicacid)-Suported Neodymium Complex Catalytic Copolymerization of Styrene and 4-Vinylpyridine     

一种耦合表面络合吸附作用的地下水溶质迁移模型初探

地下水中溶液化学作用对溶质迁移的影响日渐引起人们的关注，特别是发生于固-液表面的吸附作用，对溶质迁移的影响具有非常重要的作用。关于吸附机理的解释很多，其中表面络合吸附是近年来解释吸附作用比较成功的假说之一。本文建立了一个基于表面络合吸附作用的地球化学模式，并将其与传统的对流-弥散模型相耦合，建立了一个能够考虑表面络合吸附影响的溶质迁移模型。通过与已发表的某著名算例的结果进行的对比分析，与前人结果吻合较好，表明本文所建立的模型获得了初步成功。     

图像编码中的容错方法分析

随着信息社会的到来,互联网以及正在迅速发展的移动通信技术,逐渐成为人们获取信息的中心。而这些信息的传输都必须由具有较强鲁棒性的压缩数据来保证。所以,在有干扰的信道中如何保护传输的压缩数据不受干扰成为人们关注的问题。针对现代信息中的最主要的图像数据的传输问题,对一些差错控制方法,特别是在JPEG2000及MPEG-4标准中所采用的新的容错工具和方法进行了较详细地分析。     

电力电容器的相控技术

讨论分析了电力电容器连续相控（ＴｈｙｒｉｓｔｏｒＣｏｎｔｒｏｌｌｅｄＣａｐａｃｉｔｏｒ）ＴＣＣ新技术。其中主要阐崐述了ＴＣＣ技术的工作原理、波形分析结果和谐波抑制方法。     

高精度七米激光测长机的误差补偿技术

简要介绍一笔者研制的大型计量测试仪器－“高精度七米激光测长机及其计量管理系统”的工作原理，详细地介绍了其测量过程中采用的误差补偿技术并进行实验验证。     

基于边界表示的曲面实体造型系统的数据结构

实体造型是ＣＡＤ系统的核心模块，而二次曲面在工程中常用来描述轴，孔及圆角等形状特征。讨论了在微机上实现的一个基于边界表示的实体模型的数据结构，并针对二次曲面的特点，实现了对自封闭曲面的无二义性拓扩定义，为顺利进行曲面的拼合运算打下了基础。     

A flexible and recoverable client/server database event notification system

A software architecture is presented that allows client application programs to interact with a DBMS server in a flexible and powerful way, using either direct, volatile messages, or messages sent via recoverable queues. Normal requests from clients to the server and replies from the server to clients can be transmitted using direct or recoverable messages. In addition, an application event notification mechanism is provided, whereby client applications running anywhere on the network can register for events, and when those events are raised, the clients are notified. A novel parameter passing mechanism allows a set of tuples to be included in an event notification. The event mechanism is particularly useful in an active DBMS, where events can be raised by triggers to signal running application programs. Received July 21, 1995 / Accepted May 30, 1996     

A novel integrated silicon capacitive microphone-floating electrode“electret” microphone (FEEM)

A novel principle “electret” microphone, i.e., floating electrode electret microphone, is proposed and implemented in this study. Single-chip fabrication and corrugation technique are used in the design and fabrication of the microphone. The floating electrode is encapsulated by highly insulated materials to ensure that there is no electric-leakage passage between the floating electrode and the electrodes of the microphone. Net-free electronic charges (not “bonded” charges as in traditional electret) in the floating electrode can excite the electric field, which is similar to that of the traditional electret. The floating electrode can be easily charged by use of the “hot” electron technique, available using the avalanche breakdown of the p⁺-n junction. Therefore, the electret microphone is rechargeable, which can greatly increase the lifetime of the device. The preamplifier has been on-chip integrated in a junction-field-effect transistor (JFET) source-follower type with resistors by use of ion implantation. Electret charges are banded in a deep potential trap, thus, this microphone can operate at a high temperature (as high as 300°C) and has high stability and reliability. Experiments show that the prototype has a 3-mV/Pa sensitivity and a larger than 21-kHz frequency bandwidth in a 1 mm ×1-mm diaphragm area. Microphone performance can be further improved by optimized process and design. The fabrication is completely integrated-circuit (IC) compatible, hence, the microphone shows promise in integrated acoustic systems