Head space gas chromatography with glass capillaries using an automatic electropneumatic dosing system

Head space GC using a special electropneumatic sampling system works well in combination with glass capillaries. Because a homogenous gas mixture is already present most problems inherent with inlet splitters are thus avoided. In cases where the high vapor pressure of the sample can cause problems with the pressure controlled sampling system, the use of narrow bore glass capillaries provides the necessary inlet pressure. The use of this powerful and convenient analytical tool for water pollution analysis, flavour analysis and the analysis of volatiles in crude oil samples is shown by examples.     

Fifty years of light scattering: A perspective

It is 50 years since Debye first described the use of light scattering for the characterization of polymer solution. Ben Chu has been a leader in its subsequent development. Significant advances in theory, experimental techniques, their interpretation, and application during this period are described. © 1993 John Wiley & Sons, Inc.     

Heavy and light traffic in fluid models with burst arrivals

We consider the problem of finding a heavy and light traffic limits for the steady-state workload in a fluid model having a continuous burst arrival process. Such a model is useful for describing (among other things) the packetwise transmission of data in telecommunications, where each packet is approximated to be a continuous flow. Whereas in a queueing model, each arrival epoch,t _n , corresponds to a customer with a service timeS _n , the burst model is different: each arrival epoch,t _n , corresponds to a burst of work, that is, a continuous flow of work (fluid, information) to the system at rate 1 during the time interval [t _n ,t _n +S _n ]. In the present paper we show that the burst and queueing models share the same heavy-traffic limit for work, but that their behavior in light traffic is quite different.Research supported by the Japan Society for the Promotion of Science, during the author's fellowship in Tokyo.Research funded by C & C Information Technology Research Laboratories, NEC, and the International Science Foundation.     

电子闪光灯光路变换的研究

本文主要论述了直接利用电子闪光灯为光源，产生垂直反射偏振光的原理、方法及在刑事摄影中的应用。通过理论研究和试验，设计出了电子闪光灯光路变换系统，解决了直接利用电子闪光灯为光源的拍摄案件现场某些光滑非金属物体时，物体表面产生强烈反射光线或反射光带和对人犯摄影、物证摄影时的强烈阴影干扰，以及无法直接用以电子闪光灯为光源，对遗留在案件现场上的痕迹进行垂直反射摄影的困难。     

Optical Measuring Method for Quality Monitoring Purpose in Laser Welding of Tin－plates

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非傍轴光束的光束质量因子．I特性分析

使用傅里叶变换和施瓦兹不等式证明：非傍轴标量光束的Ｍ２因子存在有一个只能无限趋近、却永远都不可能达到的下限１；并对一些与此相关的问题进行了讨论     

利用三平面腔镜共焦腔产生多模压缩光束

设计了一种阈值下的简并光学参量振荡腔用于产生多模压缩光束,并且利用"薄晶体近似"的方法分析了这个光学参量振荡腔,得到了输出多模压缩光束的噪声谱.数值模拟了多模压缩光束的压缩度和抽运光场或者振荡腔的失谐量之间的关系,得出只有适当选择本底光的相位,抽运光的幅度以及共焦腔的失谐量时,才可以探测到好的信号场噪声谱压缩度.     

光泵铯蒸气激光的动力学模型

建立了一个物理模型描述了光泵铯蒸气激光的动力学过程和激光机理.结合实验参量,经数值求解该模型,定量分析了抽运光参量、缓冲气压和输出镜反射率等对激光输出功率和光光效率产生的影响,得到了与实验基本一致的模拟结果.表明该模型较好地反映了光泵銫蒸气激光的动力学机理和发射过程,为该类激光的优化设计提供了借鉴和参考.     

静态偏振风成像干涉仪中光在四面角锥棱镜中的传播规律研究

简述了自行设计的新型静态偏振风成像干涉仪的原理和四面角锥棱镜的分光机理;应用光线追迹法,推导出了主截面内任意光线在棱镜中的传播方向及出射点坐标,建立了平行光束经角锥棱镜后的偏向角和透过率的理论表达式;采用计算机模拟给出了偏向角和透过率随入射角的变化关系曲线;根据静态偏振风成像干涉仪的具体参数确定了四面角锥棱镜的侧面和底面夹角以及底边长度.该研究为静态偏振风成像干涉仪的研制提供了理论依据.     

应用于白光显示的Tm3+/Ho3+/Yb3+共掺碲酸盐玻璃上转换发光特性研究

用高温熔融法制备了Tm³⁺/Ho³⁺/Yb³⁺共掺碲酸盐玻璃(TeO₂-ZnO-La₂O₃)样品,测试了玻璃样品的吸收光谱和上转换发光光谱,分析了上转换发光机理.结果发现:在975 nm波长激光二极管(LD)激励下,制备的碲酸盐玻璃样品可以观察到强烈的红光(662 nm)、绿光(546 nm)和蓝光(480 nm)三基色上转换发光,红光对应于Tm³⁺离子 关键词： 碲酸盐玻璃 上转换发光 白光 3+/Ho³⁺/Yb³⁺共掺')" href="#">Tm³⁺/Ho³⁺/Yb³⁺共掺