Analysis of influence of atmosphere extinction to Raman lidar monitoring CO2 concentration profile

Lidar （Light detection and ranging） system monitoring of the atmosphere is a novel and powerful technique tool. The Raman lidar is well established today as a leading research tool in the study of numerous important areas in the atmospheric sciences. In this paper, the principle of Raman lidar technique measurement CO2 concentration profile is presented and the errors caused by molecular and aerosol extinction for CO2 concentration profile measurement with Raman lidar are also presented. The standard atmosphere extinction profile and ＇real-time＇ Hefei area extinction profile are used to conduct correction and the corresponding results are yielded. Simulation results with standard atmosphere mode correction indicate that the errors caused by molecule and aerosol extinction should be counted for the reason that they could reach about 8 ppm and 5 ppm respectively. The relative error caused by Hefei area extinction correction could reach about 6%. The errors caused by the two components extinction influence could produce significant changes for CO2 concentration profile and need to be counted in data processing which could improve the measurement accuracies.     

Capability of Raman lidar for monitoring the variation of atmospheric CO2 profile

Lidar （Light detection and ranging） has special capabilities for remote sensing of many different behaviours of the atmosphere. One of the techniques which show a great deal of promise for several applications is Raman scattering. The detecting capability, including maximum operation range and minimum detectable gas concentration is one of the most significant parameters for lidar remote sensing of pollutants. In this paper, based on the new method for evaluating the capabilities of a Raman lidar system, we present an evaluation of detecting capability of Raman lidar for monitoring atmospheric CO2 in Hefei. Numerical simulations about the influence of atmospheric conditions on lidar detecting capability were carried out, and a conclusion can be drawn that the maximum difference of the operation ranges caused by the weather conditions alone can reach about 0.4 to 0.5km with a measuring precision within 30ppmv. The range of minimum detectable concentration caused by the weather conditions alone can reach about 20 to 35 ppmv in vertical direction for 20000 shots at a distance of 1 km on the assumption that other parameters are kept constant. The other corresponding parameters under different conditions are also given. The capability of Raman lidar operated in vertical direction was found to be superior to that operated in horizontal direction. During practical measurement with the Raman lidar whose hardware components were fixed, aerosol scattering extinction effect would be a significant factor that influenced the capability of Raman lidar. This work may be a valuable reference for lidar system designing, measurement accuracy improving and data processing.     

返魂草的高效液相色谱法指纹图谱研究及成分分析

采用高效液相色谱法,建立了返魂草的指纹图谱,并与相同条件下获得的同属植物千里光图谱进行了比较;通过液相色谱-质谱联用法及与对照品比照研究,对其5种共有成分进行了鉴定;并对以上成分的含量进行同步测定。结果表明,此指纹图谱能够用于区分返魂草及其混淆品千里光;5种成分在各自的浓度范围内线性关系良好(r=0.9995～0.9998),10批样品中原儿茶酸、绿原酸、咖啡酸、金丝桃苷、异槲皮苷含量分别为0.03～0.07 mg/g,0.10～1.04 mg/g,0.01～0.05 mg/g,0.07～0.35 mg/g和0.02～0.74 mg/g。本方法可用于返魂草的鉴别及药材的质量评价。     

气溶胶激光散射信号的特征分析

本文应用Mie散射理论对微球体粒子光散射的性质进行了理论分析与数值计算,得出了散射光分布与微球体尺度参数、复折射率之间的关系。结果表明:不同尺度参数的粒子的散射光强的分布相差极大,随着尺度参数的增加散射光强越来越集中于前向;复折射率的变化对散射光强影响不大。并且在边界层大陆乡村型霾的气溶胶模型下对大气气溶胶的体角散射系数进行了分析与数值计算,得出:气溶胶粒子的散射光强主要分布在前向,并且随着散射角的增加有规律的减小。由此提出了利用气溶胶粒子体散射系数的性质,通过测量散射点前向散射光强和延迟时间来实现激光束的近轴定位的方法。     

国外大学生数学竟赛试题与解答

国外大学生数学竟赛试题与解答王莲芬（中国人民大学１００８７２）问题问题Ａ—且将一个顶点为（，０），（，０），（；３）和（２，３）边长为２Ｘ３的矩形，绕点（２，０》ｌ匝时针旋转９０”，再绕点（５，０）顺时针旋转９０”，然后再绕点（７，０）顺时针旋转９０...     

简易Mie散射数值计算方法的研究

在回顾光散射理论发展史的基础上,分析了常规Mie散射计算实现过程中的问题,并论述一种改进的简易Mie散射数值计算方法。参照科学记数法定义了一种“EDecimal”类型的数据结构及其基本数学运算和三角函数运算。采用动态链表技术实现了高效的C++ Mie散射计算程序。该程序不仅可以用来处理极端条件下的Mie散射计算,而且显著降低了算法的时间复杂度,提高了执行效率。与相同精度要求下采用Wiscombe编写的MIEV0程序的计算结果进行了比较,并指出此程序精确可靠。     

次声波及次声武器

在分析了次声波的产生、特点和对人体危害的基础上,介绍了次声武器的杀伤机理、特点、发展概况及应用前景,并指出了次声武器实用化所必须克服的两大技术难题．     

高精度消色差相位延迟器性能测试研究

基于偏振调制原理，搭建了一套测量菱体型消色差相位延迟器延迟量的实验系统.利用本系统对高精度消色差相位延迟器进行了性能测试，实验结果表明特殊角入射的高精度消色差相位延迟器的设计原理正确，具有良好的消色差性能.对该系统进行误差分析表明系统测量误差小于1%，具有较高的精度，能够满足菱体型相位延迟器性能测试的使用要求，具有实际使用价值. 关键词： 偏振 消色差 延迟器 高精度     

基于光纤光栅的应变与温度分离技术的研究

理论分析了光纤光栅交叉敏感的物理机制,重点研究了基于双波长矩阵法和双参量矩阵法的应变与温度分离技术。提出了一种基于双参量矩阵法的应变与温度测量系统,该系统传感头由FBG和非本征型F-P干涉腔(EF-PI)构成,其中FBG对应变敏感,EFPI测温精度高。