电解液对有机绝缘材料泄痕击穿的影响

前言目前,在电缆、电机、开关板和引出线中,采用大量的有机材料作为电气绝缘材料。由于这些装置常用于严酷的环境中,有机绝缘材料表面的泄痕击穿已成为一个严重问题。有机绝缘材料的这种泄痕击穿现象对电气装置的安全性和可靠性有着重大的影响。在局部放电时绝缘材料表面会形成局部高温,致使有机绝缘材料碳化和击穿。对湿态条件下泄痕击穿的许多研究已经报导。在湿润条件下泄痕击穿的可能过程通常可描述如下: (1)材料表面润湿和污染。 (2)由“焦耳热”形成干带。 (3)沿干带出现紫色电晕放电。 (4)开始形成碳。 (5)红色或桔红色闪烁放电(瞬间电弧),使碳迹通道扩展。     

256×128线ZnS:Mn ACTFEL矩阵显示

本文介绍了一种我们研制的256×128线交流薄膜电致发光显示器件的工作原理,结构形式,基本工艺,性能参数及整机驱动技术。     

形成SIMOX结构的PIII新技术的研究

本文报道了一种形成ＳＩＭＯＸ结构的等离子体浸没离子注入（ＰＩＩＩ）的新技术．与传统的离子注入相比，这种新技术具有高离子束流，大面积离子注入，极短的注入时间和低成本等优点．实验中，衬底硅片浸没在高离子密度的氧的等离子体中．在衬底所加的负高压的作用下，氧离子直接注入硅片之中．我们研究了ＰＩＩＩ的工艺条件，用ＰＩＩＩ制得了具有２０到５０ｎｍ厚的顶层硅层和２０到５０ｎｍ厚的氧化硅埋层的超薄ＳＩＭＯＸ硅片，并用ＲＢＳ、ＸＴＥＭ等技术对样品进行了测试．     

电磁波局域化和电子学

在非吸收介质中局域化波的某些特性，如窄共振、大传输起伏、强空间相关和对介质介电函数变化的高敏感性等，有可能产生新的一类小型滤波器、传感器和开关。在微波通过金属和介电球的随机混合体传播时，已观察到这些效应的前兆。     

Estimation of wave fields of incident beams in a transmission electron microscope by using a small selected-area aperture

The direction of an electron beam in a nanometer-sized area is measured directly by utilizing a selected-area aperture. By the measurements at several areas in a beam, the wavefront curvature and thus the defocus value of the beam are detected. From the defocus value, the wave field at the specimen plane is also reproduced in consideration of the influences of the condenser aperture and spherical aberration of the illumination lens. The result shows that phase deviation of 2π is caused only at about 10?nm apart from the beam center in a beam with a typical diameter for high-resolution transmission electron microscopy. Based on the defocus value, the convergence angle of the beam is also estimated to be about 6?mrad without being influenced by the partial coherence, that is, independently of the type of the electron gun. Measuring the defocus values for only two beam diameters enables us to determine geometrical parameters peculiar to the illumination system, based on which wave fields of any beam diameters by any condenser aperture sizes can be estimated. The technique proposed in this paper is effective in evaluating the influence of wavefront curvature of incident beams on various kinds of precise measurements conducted in transmission electron microscopes.     

用电选法对分散矿粒的精密分级

本文介绍了用摩擦吸附和流态化床层静电分选机分选微细分散物料的基本理论和试验结果。研究工作是利用固体粉末间作用的力、微细粉末的流态化和带电,最后在聚集电场中进行分级。     

A novel speech-processing strategy incorporating tonal information for cochlear implants

Good performance in cochlear implant users depends in large part on the ability of a speech processor to effectively decompose speech signals into multiple channels of narrow-band electrical pulses for stimulation of the auditory nerve. Speech processors that extract only envelopes of the narrow-band signals (e.g., the continuous interleaved sampling (CIS) processor) may not provide sufficient information to encode the tonal cues in languages such as Chinese. To improve the performance in cochlear implant users who speak tonal language, we proposed and developed a novel speech-processing strategy, which extracted both the envelopes of the narrow-band signals and the fundamental frequency (F0) of the speech signal, and used them to modulate both the amplitude and the frequency of the electrical pulses delivered to stimulation electrodes. We developed an algorithm to extract the fundatmental frequency and identified the general patterns of pitch variations of four typical tones in Chinese speech. The effectiveness of the extraction algorithm was verified with an artificial neural network that recognized the tonal patterns from the extracted F0 information. We then compared the novel strategy with the envelope-extraction CIS strategy in human subjects with normal hearing. The novel strategy produced significant improvement in perception of Chinese tones, phrases, and sentences. This novel processor with dynamic modulation of both frequency and amplitude is encouraging for the design of a cochlear implant device for sensorineurally deaf patients who speak tonal languages.     

露天坑内可移式粗破碎机

在北美的大型露天矿采矿中存在着一个极为重要的物料运输问题。通常,这些矿山每天都要输送十万吨以上的矿石和废石,水平搬运的路程达数千英尺,垂直搬运的距离有几百英尺。在总的采矿费用中,运输费用所占     

有希望用于非线性光学元件的聚合物材料

聚合物材料容易生产,成本低,也许能改变全息摄影术、无损测试及安全应用。