Some effects of an electric field on the plastic deformation of metals and ceramics

 The external parameters generally considered in the plastic deformation of metals and ceramics are the temperature, pressure or stress and time. Usually neglected are the effects of electric and magnetic fields. However, such fields can often have a significant influence, especially when applied concurrently with the more common parameters. Some examples of the effects of an electric field on the plastic deformation of metals and ceramics found by the author and his coworkers are presented. Included are the following: (a) the influence of electropulsing on the flow stress of metals at 78–300 K, (b) the effect of an external electric field (surface charge) on the superplastic deformation of the 74754 Al alloy, (c) the influence of an electric field on the flow stress and ductility of polycrystalline NaCl at 0.28–0.75 T_M and (d) the effect of an electric field on the superplastic deformation of 3Y-TZP. Mechanisms responsible for the observed effects are considered. Received: 1 January 1998 / Accepted: 1 March 1998     

一种雷达目标航迹仿真器

叙述了雷达仿真器的设计方案及其主要软硬件。本仿真器模拟各种海空航迹并据此产生雷达视频回波串,调制产生雷达中频或射频信号,经过雷达接收和信号处理,点迹录取,最后对目标进行自动跟踪,形成航迹信号输出。产生的航迹包括海空目标。这样,本仿真器既可以检验雷达性能指标,又可以提供部队进行雷达捕获目标的训练。     

介绍一种地下洞穴断面测量方法

地下洞穴断面测量，采用全站仪、半站仪加国产ZZ1500掌上电脑，进行半自动、自动化测量垂直于洞穴轴线的断面或垂直于洞穴任意轴线的断面。测量断面上各点的水平角和垂直角，将其输入到掌上电脑，用编制的断面测量软件计算，自动获得断面尺寸和断面图，并计算断面的面积和洞穴的容量。     

DR582CW多普勒测速雷达系统误差分析

本文对丹麦托马(TERMA)公司研制的DR582测速雷达作了系统精度分析.不仅弄清了该系统的特色,而且还为设计同类型雷达指出了一些应予重视的关键问题.     

常规飞航导弹低RCS外形方案设计方法研究

以导弹基本气动特性要求为判据来实现常规飞航导弹的外形优化。阐述了以面元法为基础的设计原理、公用几何模块设计和 RCS 优化设计方法,并介绍了相关的绘图及图形显示软件。     

Design of Laser Radar Fiber Optic Liquid Level Sensor System

A novel fiber optic liquid level sensor based on laser radar(ladar)is reported here.Using the perfect technique of ladar in which the phase of amplitude modulated light wave reflected from the liquid suface is compared with that of original modulation signal,the disance can be measured precisely.A special symmetric compensating coaxial optical system is proposed to eliminate many adverse effects.It realized the one-time electronic-free optical measurement on a simulated oil tank and achieves an accuracy of 0.3%.,within a temperature range of -10℃- 40℃ over a measuring of 0-10m。     

雷达与光学景像共性特征提取与匹配算法研究

雷达与光学景像匹配本质是一个低信噪比的图像匹配问题。为了提高匹配性能，必须设法提高信噪比。     

多功能HF雷达海洋回波谱模拟软件

介绍了一种多功能的ＨＦ雷达海洋回波谱模拟软件，该软件是基于Ｂａｒｒｉｃｋ一阶，二阶ＨＦ雷达海洋散射截面方程并考虑了影响海洋因波Ｄｏｐｐｌｅｒ谱的多个因素编制而成的。     

Saw minimum peak sidelobe filter for 15-bitM-sequence phase code signals

This paper presents computation results of the minimum peak sidelobe filter (LP filter) for the 15-bitM-sequence phase coded signal with feedback connection [4,3,0] and initial condition 1001. The design of the filter resorts to the linear programming method. The peak sidelobe level is reduced to −21.47 dB by the LP filter of length 15, and is 7.49 dB lower than that by the matched filter. The LP filter can suppress the peak sidelobe even more by increasing its length. The minimum peak sidelobe filter for the 15-bitM-sequence phase coded signal (initial condition 1001) has been implemented with a surface acoustic wave (SAW) device. Experiments show that the peak sidelobe level of the manufactured filter is −19 dB and, thus, only differs from the theoretical value of −21.47 dB by 2.47 dB.