基于最小曲率半径的软波导安全裕度校核方法

针对传统软波导安全裕度校核方法存在不够准确和/或计算量难以承受的缺陷,文章提出一种基于最小曲率半径的软波导安全裕度校核方法,分析其可行性、便利性及准确性,并给出具体的计算步骤.对同一个算例的分析结果表明,与传统方法相比,此方法可以更加准确地反映软波导的安全裕度.     

Analysis of crack opening stresses for center- and edge-crack tension specimens

Accurate determination of crack opening stress is of central importance to fatigue crack growth analysis and life prediction based on the crack-closure model. This paper studies the crack opening behavior for center- and edge-crack tension specimens. It is found that the crack opening stress is affected by the crack tip element. By taking the crack tip element into account, a modified crack opening stress equation is given for the center-crack tension specimen. Crack surface displace- ment equations for an edge crack in a semi-infinite plate under remote uniform tension and partially distributed pressure are derived by using the weight function method. Based on these displacements, a crack opening stress equation for an edge crack in a semi-infinite plate under uniform tension has been developed. The study shows that the crack opening stress is geometry-dependent, and the weight function method provides an effective and reliable tool to deal with such geometry depen- dence.     

Investigations into sensing characteristics of circular thin-plate electrostatic sensors for gas path monitoring

Circular thin-plate electrostatic sensors are promising in gas path monitoring due to their advantages of non-intrusiveness and easy installation. The spatial sensitivity and filtering effect are two important performance parameters. In this paper, an analytically mathematical model of induced charge on a circular thin-plate electrode is first derived. Then the spatial sensitivity and filtering effect of the circular electrostatic sensor are investigated by numerical calculations. Finally,experimental studies are performed to testify the theoretical results. Both theoretical and experimental results demonstrate that circular thin-plate electrostatic sensors act as a low-pass filter in the spatial frequency domain, and both the spatial filtering effect and the temporal frequency response characteristics depend strongly on the spatial position and velocity of the charged particle. These conclusions can provide guidelines for the optimal design of circular thin-plate electrostatic sensors.     

一航计测研制的“1-20kHz水声声功率标准装置位移系统”通过现场验收

本刊讯2008年12月9日，一航计测（国防科技工业第一计量测试研究中心）电测室为中国船舶重工集团公司第七一五研究所水声一级计量站研制的“1～20kHz水声声功率标准装置位移系统”通过现场验收，双方代表在验收报告上签字后，系统正式交付使用。     

接触式干涉仪技术改造

介绍了一种接触式干涉仪数字化改造的方法。改造后的接触式干涉仪采用高精度电感式位移传感器采集数据，由计算机直接输出测量报告；减少了人为的读数误差和对线误差，具有测量精度高、测量速度快、操作简单易掌握等优点。     

基于电容充放电的湿度测量仪

目前 ,用于湿度测量的仪表、变送模块 ,一般存在着线性不好、互换性较差、缺乏调校手段、价格较高等问题。针对这些问题 ,笔者以法国 Humirel公司的HS110 0湿敏电容和美国 ATMEL公司的 AT89C2 0 5 1单片机为核心设计了一种结构简单、成本低廉、标定方便的空气相对湿度测量仪。1     

一种新型恒温—温补晶体振荡器

提出了一种ＯＣＸＯ的恒温控制方法。该方法是利用乙醇的沸点制成换态式恒温箱。这种温度控制方法既可以用作中准确度的ＯＣＸＯ，又可以作为精密双层控温ＯＣＸＯ的外层恒温装置，还可以与简单的温补线路结合，构成高准确度的ＯＴＣＸＯ。     

产品动态

传感膜由传感器专家(Sensor Expert)公司生产的传感膜可即时记录精确的压力分布和压力量级。该膜看起来就像塑料膜,很薄。它是通过膜上色彩的变化来反应压     

刚性环加强的圆柱壳体的强度分析

给出一端固定,一端自由,自由端有刚性环加强的圆柱壳体的内力和位移的计算公式,以及最大应力的计算公式.对所得公式简化处理,用简单的无矩理论的解来表示复杂的有矩理论的解,使之便于工程计算.本文采用工程壳体理论,对于薄壳,文中给出的解具有足够的精确度.     

国内要闻（2004年12月1日-31日）

12月1日．重庆江北国际机场新候机楼开始由建设单位移交给机场相关使用单位管理。