An attenuated total reflectance far-UV spectrometer

An ultraviolet spectrometer based on attenuated total reflection (ATR) has been developed and tested for liquid water (light and heavy water) in the wavelength range from 140 to 300 nm, which includes the far ultraviolet (FUV) region. One of the principal limitations of FUV transmission spectra is the strong absorption of the solvent itself. High absorptivity of the n --> sigma(*) transition in water molecule has thus far prevented meaningful spectral measurements of aqueous solutions in the wavelength region under 170 nm. Our technique uses the evanescent wave created through total reflection when light is passed through an internal reflection element (IRE) in contact with the sample. Since the evanescent field is used as an optical path length, the method allows spectral measurements favorably comparable with that of transmittance method with a shorter path length than the wavelength of FUV light. In this study, we have designed an original miniature IRE probe made of sapphire that allows detection of the whole n --> sigma(*) transition absorption band of water down to 140 nm. The obtained ATR-FUV spectra closely match calculations based on the Fresnel formula. It is also confirmed that this spectrometer is equally effective for spectral measurements of nonaqueous solvents with significant absorptivities in the FUV region.     

Thermostatting of condensed samples in the spectrometer when using the attenuated total reflectance method

The created external thermostatting system of condensed samples in the cell of a MIDAC M4000 infrared Fourier spectrometer is described. A thermostabilized metal bar that was worked out by the authors is the basic element of the system. The system is intended for investigating the IR spectra of samples using the attenuated total reflectance method (ATR spectroscopy method). When the ATR method is used, the standard range of thermostatting of samples in this spectrometer model is from room temperature to 100°C with an accuracy of ±1°C. The desired temperature of the bar is set by the flow of a cooling fluid, which is supplied from an external thermostat, and it is registered with two thermometers (contact for the cell and infrared for a sample). The proposed approach allows samples to be thermostatted in the temperature range from ?12 to 80°C with an accuracy of ±0.5°C.     

Development of a time-resolved soft x-ray spectrometer for laser produced plasma experiments

A 2400 lines/mm variable-spaced grating spectrometer has been used to measure soft x-ray emission (8-22 A?) from laser-produced plasma experiments at Lawrence Livermore National Laboratory's Compact Multipulse Terrawatt (COMET) Laser Facility. The spectrometer was coupled to a Kentech x-ray streak camera to study the temporal evolution of soft x rays emitted from the back of the Mylar and the copper foils irradiated at 10(15)?W/cm(2). The instrument demonstrated a resolving power of ～120 at 19 A? with a time resolution of 31 ps. The time-resolved copper emission spectrum was consistent with a photodiode monitoring the laser temporal pulse shape and indicated that the soft x-ray emission follows the laser heating of the target. The time and spectral resolutions of this diagnostic make it useful for studies of high temperature plasmas.     

多重衰减全反射红外光谱测定加氢渣油四组分方法的建立

采用多重衰减全反射附件测定加氢渣油的红外光谱 ,讨论渣油组成的红外光谱信息 ,用偏最小二乘法 (PLS)建立红外光谱测定渣油四组分的 4个校正模型 ,该方法的测定结果与经典洗脱色谱法 (EC)的结果吻合。与EC法相比 ,该方法具有快速、操作简单、不需分离、重复性好等优点     

In situ multipurpose time-resolved spectrometer for monitoring nanoparticle generation in a high-pressure fluid

We developed a multipurpose time-resolved spectrometer for studying the dynamics of nanoparticles generated by pulsed-laser ablation (PLA) in a high-pressure fluid. The apparatus consists of a high-pressure optical cell and three spectrometers for in situ measurements. The optical cell was designed for experiments at temperatures up to 400 K and pressures up to 30 MPa with fluctuations within ±0.1% h(-1). The three spectrometers were used for the following in situ measurements at high pressures: (i) transient absorption spectrum measurements from 350 to 850 nm to investigate the dynamics of nanoparticle generation from nanoseconds to milliseconds after laser irradiation, (ii) absorption spectrum measurements from 220 to 900 nm to observe the time evolution of nanoparticles from seconds to hours after laser ablation, and (iii) dynamic light scattering measurements to track nanoparticles with sizes from 10 nm to 10 μm in the time range from seconds to hours after laser ablation. By combining these three spectrometers, we demonstrate in situ measurements of gold nanoparticles generated by PLA in supercritical fluids. This is the first report of in situ time-resolved measurements of the dynamics of nanoparticles generated in a supercritical fluid.     

低成本光谱仪的研制

为了满足高校教学和人才培养的需求,便于系统的小型化、低成本,设计了低成本光谱仪的光学系统和机械结构,制作了低成本的光谱仪实物并完成了对仪器的性能测试。该光谱仪的工作波长为400~800nm,分辨率为20nm,仪器尺寸为200mm×120mm×80mm,成本控制在2 000元以内。通过对仪器的测试,获得了六个光谱特征峰,验证了低成本光谱仪系统光学设计的可行性和合理性。     

微处理器控制的离子迁移计样机的研制

介绍了离子迁移计的基本原理;概述了一种微处理器控制的离子迁移计样机的设计,包括总体结构、信号采集方法和主程序流程;给出了用本仪器测得的二氯二乙硫醚的负离子信号谱图.离子迁移计的灵敏度很高,可以应用于环境监测和化学侦察.     

国内辉光放电光谱仪的研制

本文介绍了辉光放电光谱仪（GD—OES）的结构与基本原理。分别对仪器各部件（如辉光放电光源、直流恒流供能源、光学系统、自动控制系统、数据采集处理系统）的研制进行了详细地阐述。采用研制的辉光放电光谱仪分别对样品进行了成分分析和深度分析,取得了很好的分析结果。所研制的辉光放电光谱仪在光学系统的PMT负高压、直流恒流供能源、光源不同部位的不同抽速等多方面都有相应的技术创新。     

荧光光谱仪红外波段荧光强度的校正

一般荧光光谱仪由于光栅闪耀效果和OCD响应下降，导致1μm波长附近接收到的荧光发射信号减弱。本文介绍一种通过数学处理和基线调整校整荧光光谱仪红外波段荧光强度的方法，从而可以在一般荧光光谱仪上获得与高档荧光光谱仪接近的荧光光谱图。     

基于AD8302的生物阻抗频谱测量仪的研制

对正弦信号幅值和相位的准确检测是生物阻抗频谱测量中的关键和难点.AD8302是AD公司首款可同时测量两输入信号之间幅度比和相位差的单片集成芯片.本文针对目前生物阻抗频谱测量中的难点,设计了一种基于AD8302的便携式生物阻抗频谱测量仪.文中详细介绍了AD8302的特点和具体的电路设计方法.实测结果表明在20kHz～1MHz的频率范围内,阻抗幅值的相对误差小于0.36%,相位的绝对误差小于0.26°,实现了生物阻抗频谱的准确测量.     

Development of multi-channel electron spectrometer

In order to obtain the angular dependent electron energy distributions, we developed a multichannel electron spectrometer (MCESM) with high energy and angular resolutions. The MCESM consists of seven small electron spectrometers set in every 5° on the basement, each of which detection range is up to 25 MeV. In the experiment, we successfully obtained electron spectra from imploded cone-shell target as well as gold plane target irradiated by ultraintense (300 J/5 ps) laser beam.     

原子荧光光度计测定水中总汞的不确定度的评定

本文依照标准文件的原则对原子荧光光度计测定水中总汞的不确定度进行评定。笔者提出利用校准曲线的残差来量化曲线拟合带入的不确定度分量。这不仅减少工作量而且更符合监测工作实际,使评定程序更具可操作性。经评定,原子荧光法测定总汞水样(1.00μg/L)的扩展不确定度为3.0%。     

Fully automated spatially resolved reflectance spectrometer for the determination of the absorption and scattering in turbid media

We describe a fully automated setup which is based on measurements of the spatially resolved reflectance for the determination of the reduced scattering and absorption coefficients in semi-infinite turbid media. The sample is illuminated with a xenon light source in combination with a monochromator enabling the scan of the wavelength from 450 nm to 950 nm. Reflected light from the sample is detected with a CCD camera providing a high spatial resolution. The essential steps for signal processing including, e.g., the consideration of the optical transfer function and the correct treatment of the background subtraction, are presented. The solutions of the diffusion theory and of the radiative transfer theory are investigated regarding the exact detection and illumination geometry. Systematic errors caused by using the different theories for fitting the optical parameters are characterized. The system was validated using liquid phantoms which contain Intralipid 20% and ink, and the measurement range of the system is specified. Further, we carefully characterized the optical properties of Intralipid 20% in the wavelength range between 450 nm and 950 nm.     

二维多光栅折叠光谱分析仪的研制

宽光谱、高分辨、高速光谱获取和分析技术在光电子材料、太阳能、化学、生物医学、环境、国防等领域具有重要的研究意义和应用价值,是现代光谱分析仪器的核心。为了实现宽光谱、高分辨率和快速的光谱测量和分析,在本研究中,突破传统单光栅和棱镜等色散元件有限色散角和光谱效率的限制,采用二维CCD面阵光电探测技术,将具有不同闪耀角和色散特性的10光栅进行集成组合,在200～1000nm光谱区,获得10重折叠光谱,成像在CCD面阵探测器的焦平面上,从而将光谱的有效探测区长度扩展了10倍,达到268mm。经系统定标后,测量结果显示,无需任何机械位移部件,新的光谱分析系统可达到优于0.1nm的分辨率,能够在0.1s时间内完成200～1000nm全光谱数据的快速获取和分析,将能够在科学研究和高科技领域获得重要应用,体现了高性能光谱分析技术研究和发展的趋势。     

时间分辨荧光光纤生物传感器的研制及应用

首次研制了一种完全利用光纤实现光耦合及传输的时间分辨荧光光纤生物传感器.该传感器以镧系离子(铕离子)作为被检测物质的荧光标记物,根据铕离子的荧光特性,利用时间分辨检测技术进行生物医学检测.光学部分采用光纤耦合器和石英光纤作生物样品激发光的传导光学元件,生物样品受激发产生的荧光也同样由光纤耦合器及光纤收集和传导,实现了该传感器的紧凑性和小型化,提高了检测灵敏度.经性能测试,该仪器不稳定性小于2.3%,重复测量的互相关高达99.9%.测铕离子标准液的检测限为7.3×10^-10g/L,达到国外有关文献报道的水平.     

金标免疫试纸条反射式光度计的研制

为使金标免疫分析术能对目标被检物进行高灵敏度快速定量检测,成功研制一种金标免疫试纸条反射式光度计.根据纳米金颗粒对绿光的强烈吸收特性,以绿光激光器为照明光源,以扫描方式测量金标免疫试纸条上经生物反应而结合上去的纳米金颗粒的分布,通过特定算法计算出样品中目标被检物的浓度.该光度计对人绒毛膜促性腺激素标准样品的检测灵敏度达到5 mIU/ml,在5～500 mIU/ml浓度范围内具有良好的线性响应特性,相关系数R2～0.99,使用研制的光度计对同一生物反应稳定的金标试纸条进行20次重复测量,测量结果的变异系数(CV)小于2%.该光度计具有快速、稳定、灵敏的工作性能.     

Development of neutron spectrometer toward deuterium plasma diagnostics in LHD

Neutron spectrometer based on coincident counting of associated particles has been developed for deuterium plasma diagnostics on Large Helical Device (LHD) at the National Institute for Fusion Science. Efficient detection of 2.5 MeV neutron with high energy resolution would be achievable by coincident detection of a scattered neutron and a recoiled proton associated with an elastic scattering of incident neutron in a plastic scintillator as a radiator. The calculated neutron spectra from deuterium plasma heated by neutral beam injection indicate that the energy resolution of better than 7% is required for the spectrometer to evaluate energetic deuterium confinement. By using a prototype of the proposed spectrometer, the energy resolution of 6.3% and the detection efficiency of 3.3×10(-7)?count/neutron were experimentally demonstrated for 2.5 MeV monoenergetic neutron, respectively.     

宽波段近红外多通道光谱仪器的研制

多通道近红外光谱技术用以对近红外光谱进行快速测试,但探测器的性能限制了测试的光谱范围.本篇论述了采用两波段双光谱仪器技术,即将700～1700nm波段分为700～1100nm与1050～1700nm两个波段的方法,实现宽波段的近红外多通道光谱测试的仪器设计.同时也对食醋、酱油、牛奶等进行了吸收光谱测试.     

用于生物量浓度在线检测的光纤衰减全反射传感器

为了在生物膜滴滤塔降解有机废气过程中实现生物量浓度的测量,设计了光纤衰减全反射(ATR)生物量浓度传感器,给出了传感器组成原理、结构参数、光路分析及其理论解释。根据光波进入光密介质(Si晶体)与光疏介质(生物菌液)的分界面时所产生的隐失波现象,以及生物菌液对隐失波的散射和吸收引起接收光能量变化的物理机理,建立了一种新的生物量浓度测量方法。实验选用可见光源,在25℃恒温情况下对生物量浓度测量进行了实验研究。实验结果表明:测量结果的相对误差均值为2.217%,基本上满足生物量浓度在线测量要求。该传感器的设计原理和方法具有一定的普遍意义,可应用于制剂、制酒、生化等行业。     

成像光谱仪运动补偿扫描镜的研制

基于光、机、电一体化的设计思想,研制了一套高精度扫描镜机构,用于提高空间相机对某些特定暗目标的观测能力.首先,根据相机总体下达的性能指标,讨论了可行的驱动方案,确定了以步进电机为核心的系统控制方法.然后,介绍了驱动单元、精密轴系和扫描镜支撑结构3项关键技术.最后,给出了扫描镜机构的工程分析结果并进行了相关例行试验.试验...