光电经纬仪姿态测量精度分析及室内评价方法

为了实现光电经纬仪姿态测量精度的室内测试和评价,介绍了光电经纬仪姿态测量方法,依据蒙特卡罗方法对测量站的姿态测量误差源进行了分析,得出姿态测量精度的主要影响因素,进而提出了一种室内姿态测量精度检测方法。基于外场理论弹道、目标姿态以及测量站站址,通过逆姿态测量理论计算得到姿态测量原始数据,再将姿态测量原始数据输入姿态测量设备,通过比较理论目标姿态和姿态测量设备给出的目标姿态,得到姿态测量设备的姿态测量精度。依据该方法,对某型号姿态测量设备进行了姿态测量精度检测。通过实验可得到该姿态测量设备的姿态测量精度,即航向角测量误差不大于1.9°,俯仰角测量误差不大于0.4°。     

Surface Tension and Electrostriction in a Suspended Bridge of Dielectric Liquid

The mechanism of the formation of a surprisingly long suspended liquid bridge subjected to a dc electric field has been intensively studied in the past few decades. However, the role of electrostriction and quantitative evaluation of surface tension in the bridge have not been evaluated. We present combined theoretical and experimental studies on this issue. Electrostriction is pointed out to be the driving force that pushes liquid upward against gravity and into the gap between two containers and forms the suspended bridge, which is within the framework of the Maxwell pressure tensor. Through a comparison between experiment and theory, the surface tension is found to play an important role in holding the long suspended bridge. Ignorance of the surface tension leads to much smaller bridge length than the experimental values. The dynamic stability of the bridge with respect to its diameter, length and conductance is also discussed.     

两腔级联纠缠增强的理论分析

高纠缠度的纠缠源是实现高保真度量子信息传输与处理的保障,因为受到光学元器件自身性能不完美的限制,通过有效的操控手段来提高光场的纠缠度是十分必要的.连续变量Einstein-Podolsky-Rosen纠缠态光场可以利用工作在阈值以下的非简并光学参量放大器来获得.将两个非简并光学参量放大器级联,可以利用第二个光学腔来操控第一个光学腔输出的纠缠态光场,在一定条件下实现光场的纠缠增强.本文通过理论分析设计出两种光学腔级联的实验系统,其中,纠缠产生装置采用具有三共振结构的半整块驻波腔,输出到目前为止世界上单腔获得两组份纠缠态光场纠缠度的最高值,操控光学腔采用驻波腔或四镜环形腔的结构.详细对比分析了不同结构的操控腔对纠缠增强效果的影响,得出利用不同腔形作为操控腔的最佳实验方案.同时分析了级联腔输出光场的纠缠度随不同物理参量的变化关系,得出进一步优化的最佳实验系统参量,为实验获得更高纠缠度的纠缠态光场提供了依据.     

Numerical Analysis of Nano-Aperture Light Source for High-Density Optical Data Storage

Two unconventional nano-aperture light sources, an L-shaped nano-aperture source and a 3D nano-aperture source for high-density optical data storage, are numerically investigated. With incidence of a Gaussian beam, the spot size of the Poynting vector coupled into the recording medium is 130 × 175 nm^2 for the L-aperture and 120 × 135 nm^2 for the 3D nano-aperture. The quantitative analyses indicate that the unconventional nanoaperture sources can provide enough power density to record marks in the commercial recording medium. It is feasible to use a laser diode with a nano-aperture as an active nanometer light source for high-density optical data storage.     

A Novel Method to Calculate the Initial Phase Difference between the Two Fibre Arms of Laser Homodyne Iuterferometer

We suggest a novel method to calculate the initial phase difference between two fibre arms of a laser homodyne interferometer. Put the two fibre arms in a temperature controller, whose short term stability is 0.02° C （measured in an hour）, then measure the interference photocurrent and the photocurrents from the two fibre arms at a fixed temperature. With these three photocurrents we can calculate the value of the initial phase difference. We set up a simple laser homodyne interferometer to test the theory. The experimental results are repeatable and the measurement precision is about 0.04°. It is theoretically and experimentally proven that this method is potentially easy and practical.     

国际离子交换会议(ICIE’91)在日本举行

1991年10月2-4日在日本东京工业大学(TIT)国际会议厅举行了国际离子交换学术会议ICIE′91。会议由日本离子交换协会(JAIE)发起,由13个学会支持,并得到日本30多家公司的资助。日本TIT理学部化学系阿部光雄教授为会议主席。出席会议人数为213人,来自世界24个国家和地区。我国学者天津大学姜志新、兰州大学陶祖贻、国家局第二海洋研究所莫     

4,4‘—二苯醚二甲酸的新合成路线

4,4′-二苯醚二甲酸(以下简称醚酸)是一种重要的高聚物单体,用于制备合成树脂、绝缘材料和液晶纤维等,在国防工业和民用工业上有着宽广的前途。但国内至今尚无醚酸产品。醚酸的合成路线归纳起来有两大类:一类是以4,4′-二甲基二苯醚为原料,将甲基氧化成羧基。另一类是以二苯醚为原料,接上相应的基团,再转化成羧基。二苯醚类则由酚和卤苯经 Ullmann 缩合反应制得。由于反应需要200℃以上的高温,长时间加热,因而产品质量     

食品中多元素的ICP发射光谱分析

测定食品中常量和微量元素,是目前人们较关心的问题,因为它关系到人体所必需的有益元素的提供,以及对有害元素的污染控制。以前这种分析大多采用原子吸收光谱、原子发射光谱以及化学分析方法。近几年来,电感耦合高频等离子体发射光谱(ICPES)成功地应用到许多方面,证明它是一种较满意的分析方法,在食品分析方面也是如此。本文报告了ICPES分析饼干、乳制品、糖果等儿童食品中的Ca、Mg、Fe、Al、P、Sr、Zn、Cu、Mn、Cd、Mo、Pb、As、Se等元素,并对分析过程中出现的几个问题进行了讨论。