缩短电视扫描电路机辅瞬态分析机时的途径

本文以工业电视扫描电路为例,提出对电路进行适当的分割、设定合理的初始值和采用合适的步长来缩短机辅瞬态分析机时的几个途径。     

层析成像技术在过程检测中的应用──电容式两相流层析成像系统

介绍一种采用电容式传感器的两相流层析成像新方法。该法利用安装在两相流管道 周围的多个电容极板对流体扫描测量，并将所测得的数据输入计算机进行成像，得到 管道某截面上的两相分布图像。一台采用８个电极的系统模型已在最近组装完毕，并进 行了对静态分布模型的成像实验。对实验结果进行了分析并讨论了上述系统改进的可能 性。     

地震波跨孔旅行时层析成象分辨率的估计

依据费马原理分析了地震波跨孔旅行时层析成象技术对几种简单速度异常体的分辨率，给出了分辨率估算式与数值算例和射线追踪模拟算例。数值算例表明地震波跨孔旅行时层析成象技术的分辨率相当高，特别是对高速异常体和与观测井垂直或斜交的二度异常体的分辨率是如此。对低速异常体而言，存在一个由多种因素决定的临界速度值，当异常体的速度低于此值且走时扰动量不小于走时判读精度时能分辨其轮廓，但不能重建其实际速度场。临界速度值可用以检验射线追踪算法与反演算法的精度。     

蝗虫三种触角扫描电镜研究

采用扫描电镜的方法对白膝网翅蝗Ａｒｃｙｐｔｅｒａ ｆｕｓｃａ ａｌｂｏｇｅｎｉｃｕｌａｔａ ｌｋｏｎｎ的丝状触角、条纹鸣蝗Ｍｏｎｇｏｌｏｔｅｔｔｉｘ ｊａｐｏｎｉｃｕｓ ｖｉｔｔａｔｕｓ（Ｕｖ．）的剑状触角及西伯利亚蝗Ｇｏｍｐｈｏｃｅｒｕｓ ｓｉｂｉｒｉｃｕｓ（Ｌ．）的棒状触角表面进行了扫描电镜观察，结果表明三种蝗虫触角不仅在形态上差异显著，而且在感觉器种类组成、分布及化学感觉能力上有明显不同，主     

鼻咽癌放疗后鼻咽局部复发的早期CT诊断

追踪观察了鼻咽癌放疗后的患者４３例，其中证实复发者１１例，鼻咽显示异常，但经追踪观察而否定复发者３２例，将复发与未复发病例的各种ＣＴ征象进行比较分析，提示在鼻咽癌放疗后局部复发的早期诊断中，“茎突内侧软组织增厚致密”为一重要征象，而“顶后壁增厚、侧壁增厚和咽隐窝变浅或消失”信     

扫描电镜低电压操作技术

本文叙述了低电压扫描电子显微术的优点和限制，介绍了低电压实际操作的要领。     

用于舞台布景的微机激光图形扫描系统

本文描述了一个为舞台布景而设计的微机激光图形扫描系统。该系统由后援微机、RS—232异步通信接口、单板微机控制器、激光源及其反射偏转执行装置等组成。在系统软件支持下,能用光笔进行图形设计与编辑。在激光源及其编转振镜的支持下,可对少于四路的各种类型的激光束进行控制,以显示二维图形。其偏转角度为士7~0、定位精度为0.5％,还可用于广告宣传及工艺雕刻等方面。     

基于三维人体测量的参数化人台的研究

为了提高服装的合体性，在对三维人体测量结果统计分析的基础上，提出了参数化人台设计技术路线．在VC＋＋．net单文档视图模式下调用OpenGL，通过多边形曲面造型方法实现了可用按钮和键盘来控制的参数化人台设计．结果生成了反映人体特征的标准系列人台和个性化人台，用于三维服装CAD和服装人台的制作。     

Image Retrieval Based on Objects’ Spatial Orientation Relationships

0Introduction Inmanyapplicationsoftheimagedatabase,imagesgeneral lycompriseavastmajorityofacquiredandprocessedda ta[1,2].Theimageofapictureisoftenstoredandrepresentedintwoforms,theoriginalfull sizedanditssymbolicform[3].Thesymbolicversionisanobject basedi…     

Fine three-dimensional P-wave velocity structure beneath the capital region and deep environment for the nucleation of strong earthquakes

A detailed 3-D P-wave velocity model of the crust and uppermost mantle under the capitol region is determined with a spatial resolution of 25 km in the horizontal direction and 4-17 km in depth. We used 48750 precise P-wave arrival time data from 2973 events of local crustal earthquakes, controlled seismic explosions and quarry blasts. These events were recorded by 123 seismic stations. The data are analyzed by using a 3-D seismic tomography method. Our tomographic model provides new information on the geological structure and complex seismotectonics of this region. Different patterns of velocity structures show up in the North China Basin, the Taihangshan and the Yanshan Mountainous areas. The velocity images of the upper crust reflect well the surface geological, topographic and lithological features. In the North China Basin, the depression and uplift areas are imaged as slow and fast velocity belts, respectively, which are oriented in NE-SW direction. The trend of velocity anomalies is the same as that of major structure and tectonics. Paleozoic strata and Pre-Cambrian basement rocks outcrop widely in the Taihangshan and Yanshan uplift areas, which exhibit strong and broad high-velocity anomalies in our tomographic images, while the Quaternary intermountain basins show up as small low-velocity anomalies. Most of large earthquakes, such as the 1976 Tangshan earthquake (M 7.8) and the 1679 Sanhe earthquake (M 8.0), generally occurred in high-velocity areas in the upper to middle crust. However, in the lower crust to the uppermost mantle under the source zones of the large earthquakes, low-velocity and high-conductivity anomalies exist, which are considered to be associated with fluids, just like the 1995 Kobe earthquake (M 7.2) and the 2001 Indian Bhuj earthquake (M 7.8). The fluids in the lower crust may cause the weakening of the seismogenic layer in the upper and middle crust and thus contribute to the initiation of the large crustal earthquakes.