氢化物发生-原子荧光法测定中药中痕量汞

应用AFS-2202a型双道原子荧光分光光度计和断续流动的氢化物发生技术,采用HNO₃-H₂O₂体系和聚四氟乙烯高压釜消解中药样品,并优化了实验条件,建立了氢化物发生-原子荧光法测定中药中痕量汞。同时,研究了硼氢化钾浓度,光电管负高压,灯电流,原子化器高度,屏蔽气和载气流量等因素对测定结果的影响。在选定实验条件下,汞的检出限为0.021 μg·L-1, 桃叶(GBW08501)验证结果与推荐值一致,6次测定结果相对标准偏差为0.34%。此方法简便、快速、灵敏、准确,以工作曲线法和加入作图法对照,对于实际中药样品的测定得到了满意的结果。     

氢化物发生-原子荧光光谱法测定中药中的痕量砷

建立了氢化物发生-原子荧光光谱法测定中药中痕量砷的测定方法。应用AFS-2202a型双道原子荧光分光光度计和断续流动的氢化物发生技术,研究了不同湿法消解体系对测定结果的影响,选用HNO3-H2O2体系消解中药样品。同时,研究了硼氢化钾浓度、屏蔽气和载气流量、灯电流、原子化器高度等因素对测定结果的影响。在选定实验条件下,砷的检出限为0.069μg/L,桃叶(GBW08501)验证结果与推荐值一致,6次测定结果相对标准偏差为2.46%。该方法简便、快速、灵敏、准确,对实际中药样品进行测定得到了满意的结果。     

微波消解-氢化物发生-原子荧光光谱法测定大米中痕量汞

采用微波消解 氢化物发生 原子荧光光谱法对大米中痕量汞进行了消解、测定。以微波消解为样品前处理方法 ,建立了大米微波消解的最佳分析条件。确定了原子荧光光谱仪的参数设置 ,最佳氢化反应条件以及影响汞测定的相关环境参数。检测限 0 0 0 5ng·mL-1 ,测定大米中汞成分分析标准物质 (GBW 0 85 0 8)中汞的含量 ,其结果与证书值相吻合 ,精密度 2 1 % ,回收率 95 2 %～ 1 0 6 4 %。     

微波消解-原子荧光法测定不同种类中药中的痕量汞

针对不同种类的中药样品,采取不同的微波消解程序,建立了氢化物发生-原子荧光法测定中药中痕量汞的分析方法.在最佳工作条件下,线性方程为IF=809.1X-3.327 5,相关系数r=0.999 998,线性范围为0～80 ng·mL-1,仪器检出限为0.014 ng·mL-1(n=11),RSD为2.03%.样品回收率为96.8%～102.80%(n=6),方法检出限为1.17 ng·g-1.对于不同种类的中药样品,分别选择大米(GBW08508)、杨树叶(GBW07604)、贻贝(GBW08571)国家标准物质,对方法的准确度进行了验证.实验结果表明,该方法简便灵敏、快速准确,应用于29种不同种类的中药中汞的测定,结果令人满意.     

氢化物原子荧光光谱法测定涂料中可溶性汞

用酸泡法(GB18582-2001)处理粉碎的涂料干膜样品,氢化物原子荧光光谱法测定样品中可溶性汞含量,选择最佳实验条件,荧光强度与汞浓度在0—10ng·mL-1范围内呈线性关系,检出限为0.0015ng·mL-1,加标回收率为90.0%—103.3%,进行了大量样品测定,结果满意。     

水浴浸提-氢化物发生-原子荧光光谱法检测土壤中痕量砷和汞

采用盐酸-硝酸混合酸水浴浸提土壤样品,以氢化物发生-原子荧光光谱法(HG-AFS)测定土壤中砷和汞,同时对前处理酸的用量和样品介质(盐酸)进行了试验,筛选出检测土壤中砷和汞的浸提最佳实验条件为6mL HCI、0.5mL HNO3、样品介质(盐酸)3mL HCl,并对国家级土壤标准物质GBW07402、GBW07404和土壤样品进行验证,测定结果与标准值相吻合.方法的检出限为As:0.096 μg·L-1,Hg:0.031 μg·L-1;加标回收率为As:90.41%,Hg:82.22%.相对标准偏差As:3.3%,Hg:5.19%.     

微波消解-氢化物发生-原子荧光光谱法测定羊栖菜中汞

建立了微波消解-氢化物发生-原子荧光光谱法测定羊栖菜中汞的方法,系统地研究了微波消解、氢化物发生的最佳条件,利用加标回收试验,对分析方法进行了验证.本方法具有简便、快速、灵敏度高等优点,检出限为0.05μg/L,RSD为1.5%,样品加标回收率为93.8%-105.3%.     

微波消解氢化物发生原子荧光光谱法测定鱼中痕量硒

微波消解氢化物发生原子荧光光谱法 (HG- AFS)测定了鱼中痕量硒。硝酸 -过氧化氢消解样品 ,在3mol· L-1盐酸介质中产生氢化物 ,2 % (W/V) KBH4为还原剂 ,研究了微波消解条件、预还原条件。方法准确快速。用本法测定国家标准物质的结果与推荐值及国标法测定结果相一致     

氢化物发生-原子荧光光谱法测定化探样品中砷、锑、铋和汞的注意事项

针对氢化物发生-原子荧光光谱法测定化探样品中砷、锑、铋和汞的空白、试样制备和分离、干扰、污染、设备和配件故障等同题,分析并总结出应注意的事项和解决方法.     

氢化物发生-原子荧光法测定中药葶苈子和黄连中的铅

采用HNO2-H2O2体系和高压釜消解中药样品，以AFS-2202a型双道原子荧光分光光度计和断续流动的氢化物发生法，测定了中药葶苈子和黄连中的铅。优化了光电管负高压，灯电流，屏蔽气和载气流量等实验条件。铅的检出限为0．08μg／L，相对标准偏差为0．34％。对实际样品的测定，结果令人满意。     

Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide

Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·10⁴ Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.     

Femtosecond Transform-Limited Pulse Generation by Compensating for the Linear Chirp of SPM Spectra in Dispersion Shifted Fibers

A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.     

Theoretical analysis and simulation of conjugate heights for dual-conjugate AO system in lidar

A multi-conjugate adaptive optics （MCAO） can offer a possibility of widening field of view （FOV） characterized by the isoplanatic angle, and the choose of conjugate height becomes a basic problem for MCAO, which influences the size of iosplanatic angle. Considering the application of lidar, the isoplanatic angle＇s expressions of two deformable mirrors （DMs） MCAO for uplink and downlink are deduced. The effects of conjugate heights for dual-conjugate AO are thoughtfully discussed, and the isoplanatic angles are further analyzed. The results show that the isopanatic angle varies with the conjugate height and reaches the maximum as the conjugate height is at the optimal altitude. Moreover, the optimal conjugate height changes with the propagation distance.     

Quick single-photon detector with many avalanche photo diodes working on the time division

Due to the limit of response speed of the present single-photon detector, the code rate is still too low to come into practical use for the present quantum key distribution (QKD) system.A new idea is put up to design a quick single-photon detector.This quick single-photon detector is composed of a multi-port optic-fiber splitter and many avalanche photo diodes (APDs).Au of the ports with APDs work on the time division and cooperate with a logic discriminating and deciding unit driven by the clock signal.The operation frequency lies on the number N of ports, and can reach N times of the conventional single-photon detector.The single-photon prompt detection can come true for high repetition-rate pulses.The applying of this detector will largely raise the code rate of the QKD, and boost the commercial use.     

Measurement of nonlinear coefficient of optical fiber based on small chirped soliton transmission

We measure the waveform and phase curves of short optical pulses before and after transmission over different lengths of fibers by use of the pulse analyzer with the frequency-resolved optical gating (FROG),and numerically simulate pulse evolution under the experimental conditions.The nonlinear coefficient of the fiber is given by comparing the experimental results with the numerical ones.Difference between the experiment and numerical simulation is analyzed.     

Resonance scattering of canonical elastic shells in absorbing fluid medium

Resonance scattering of elastic spherical shell and cylindrical shell while the surrounding fluid medium has absorption is studied. The normal mode solution derived using exact elastic theory and the separation of variables is still applicable. However, the scattering form function has to be modified for the absorbing medium, otherwise the unreasonable result would be obtained. The backscattering form function in the absorbing medium is redefined, and the form function of elastic spherical and cylindrical shell with vacuum or solid matter filled is calculated in various absorption conditions. The results show that the absorption of surrounding fluid leads to notable attenuation of the coincidence resonances in the mid-frequency, but it has a little influence on the low-frequency resonance scattering induced by the filler inside the shell.     

Single-beam self-referenced phase-sensitive surface plasmon resonance sensor with high detection resolution

A versatile and low-cost single-beam self-referenced phase-sensitive surface plasmon resonance(SPR)sensing system with ultra-high resolution performance is presented.The system exhibits a root-mean-square phase fluctuation of ±0.0028.over a period of 45 min.i.e.a resolution of±5.2×10-9 refractive index units.The enhanced performance has been achieved through the incorporation of three design elements:a true single-beam configuration enabling complete self-referencing so that only the phase change associated with SPR gets detected,a differential measurement scheme to eliminate spurious signals not related to the sensor response,and the elimination of retardation drifts by incorporating temperature stabilization in the liquid crystal phase modulato .Our design should bring the detection sensitivity of non-labeling SPR biosensing closer to that achievable by conventional fluorescence-based techniques.