Pulsed and cw operation of helium-water vapor laser at 28 microm

The operating characteristics of a water vapor-helium laser working at 28 microm are presented. Comparison is made of power output in continuous and pulsed operation for various gas mixtures and discharge currents for the same laser cavity.     

Feature-based registration of retinal images

Registration of retinal images taken at different times frequently is required to measure changes caused by disease or to document retinal location of visual stimuli. Cross-correlation has been used previously for such registration, but it is computationally intensive. We have modified a faster algorithm, sequential similarity detection (SSD), to use only the portion of the template that contains retinal vessels. When compared to standard SSD and cross-correlation, this modification improves the reliability of detection for a variety of retinal imaging modalities. The improved reliability enables implementation of a two-stage registration strategy that further decreases the amount of computation and increases the speed of registration.     

激光相变硬化的温度控制

稳定吸收的功率密度是获得沿着扫描轨迹的均匀硬化层深及适当的硬度分布的先决条件。然而,激光输出功率及专门的或涂覆的表面的吸收实际上是波动的,从而导致沿着扫描轨迹的吸收功率通量的变化,甚至在准稳定处理条件下也是如此。可以通过适当的包括一台快速高温计及一台比例积分微分控制器(PID)的控制系统来克服这个困难。通过监视最大温度点上的表面温度场及激光输出功率的控制来保持恒定的吸收。     

FORMATION OF MANGANESE SILICIDE THIN FILMS BY SOLID PHASE REACTION

1. IntroductionThe transition metal silicides have attraeted much attention because of their potentialapplicatiOIl in very large scale integration (VLSI) de.ice[1]. Near-noble metal silicides canbe used as Schottky al1d ohn1ic col1tacts in silicon-based d…     

反向洗涤装置的计算

文中公式与图表有助于溶质回收率、洗液速率和洗涤段数的计算,从而使反向洗涤装置的设计最为经济合理。用适宜的溶剂以洗     

六六六生产中异构体分配的控制

六六六生产中异构体分配的控制采用下法实验: 实验方法实验使用两种仪器装置:用过量的苯作溶剂时,采用500毫升三口烧瓶,装有搅拌器、温度计、气体进口及取试料口。一或二个100瓦Mazda灯,125瓦Hanovia灯,或400瓦AH-1灯作光源。改变灯与反应器的距离,或在固定的距离下改变电压,以加强或减弱光的照度,进行试验。不含硫茂的苯(熔点5.5℃)200克放入烧瓶中,反应系统用氮充分洗涤。开灯,用水浴调节温度,由少量氮(0.05克分子/小时)稀释的氯通过流量计(0.2～0.4克/分     

卤代烷灭火剂的替代物研究

本文对1970～2000年世界卤代烷灭火剂 Halon1211、1301的生产、消费进行了统计和预测,介绍了卤代烷对环境影响的研究结果,筛选替代物的方法和部分有前途的替代物。     

制备奥托金的几种可供选择的方法

本文叙述三种由乌洛托品制备奥托金(HMX)的新方法,每种方法都是先进行乙酰化然后再硝化,其中以DADN为中间产物的方法的HMX得率,比目前以乌洛托品和醋酐为基础的Bachmann法要高,但要采用后者不必采用的硫酸和聚磷酸。已经表明,DADN可在中间规模以良好的得率快速连续地生产,废酸回收也没有什么问题。