火焰原子吸收光谱法连续测定饲料中的铅和镉

火焰原子吸收法连续测定饲料中的铅和镉 ,方法灵敏、准确。无须富集、萃取 ,操作简便 ,铅和镉的回收率分别在 95 .0 %— 1 0 5 .0 %和 94 .0 %— 98.0 %之间 ,相对标准偏差分别在 0 .4 8%— 1 .4 0 %和 2 .5 6 %—3.5 0 %之间     

鸡精和味精中铅、镉含量的测定

采用原子吸收法测定了鸡精和味精中污染元素铅、镉的含量。结果表明,不同品牌的鸡精和味精所含铅、镉的量不同。该方法简便、快速、准确、实用。测定的线性范围为铅0.00～10.00 μg·mL-1,镉0.00～4.00 μg·mL-1。铅和镉的精密度试验的相对标准偏差分别为3.15%和4.26%,并进行了回收实验,回收率铅在96.7%～102.1%,镉在91.9%～107.6%之间。     

化妆品中铅、镉含量的测定

原子吸收光谱法测定了化妆品中的铅和镉 ,铅和镉分别在 0 .5 0— 10 .0 0 μg·m L-1和 0 .2 0— 8.0 0 μg·m L-1范围内有良好的线性关系 ,相关系数分别为 r=0 .9989和 r=0 .9997;标准偏差分别为 RSD≤1.6 7%和 RSD≤ 4 .71% ;标准加入法测定铅和镉的回收率分别为 93.5 %— 10 6 .0 %和 94 .0 %— 10 5 .5 %。方法简单 ,结果准确。     

微波消解-石墨炉原子吸收光谱法测定蔬菜中铅和镉

铅、镉是自然界分布很广的两种有害元素。本文利用微波消解-石墨炉原子吸收光谱法测定蔬菜中的铅、镉。方法简便、快捷,铅的回收率在94.5%—101.5%之间,镉的回收率在92.0%—97.5%之间。     

卫生纸中铅、镉含量的测定

用原子吸收光谱法对卫生纸中污染元素铅、镉进行了测定。铅在 0 0 0～ 10 0 0 μg·mL- 1 (r =0 9989) ;镉在 0 0 0～ 4 0 0 μg·mL- 1 (r=0 9997)范围内均具有良好的线性关系。本文法的RSD≤ 3 0 8% ,回收率在 94 8%～ 10 4 5 %。方法快速简便 ,结果准确。可用于卫生纸中铅、镉含量的监测     

新疆孕马结合雌激素原料药中铅、镉、砷、汞、铜含量测定

建立了测定孕马结合雌激素（CE）原料药中铅、镉、砷、汞、铜残留量的方法。采用石墨炉原子吸收光谱法（AAS）测定铅、镉、铜含量;原子荧光光谱法（AFS）测定砷、汞含量。铅、镉、砷、汞、铜的回收率（n=6）分别为93.4%,98.2%,102.8%,95.0%,96.4%。该方法操作简便,快速,可用于原料药中铅、镉、砷、汞、铜重金属残留量的测定。     

进口复合肥中重金属铅、镉、铬的测定

本文报道了复合肥中铅、镉、铬的检测方法。采用微波消解为前处理手段 ,石墨炉原子吸收法测定铅、镉、铬 ,并对基体改进剂及用量等一些条件进行了优化选择。复合肥中铅、镉、铬的检出限分别为 6 .9×10 - 1 1 g、4 .5× 10 - 1 2 g、4 .6× 10 - 1 1 g;回收率为 94 %— 10 8%。     

水性涂料中可溶性铅、镉、铬和汞的测定

本文研究了测定水性涂料中可溶性铅、镉、铅和汞的影响因素。结果表明，铅、镉、铬和汞的影响因素。结果表明，铅、镉、铬和汞的溶出量主要取决于酸度、时间、温度、搅拌速度以及膜干燥方式和干燥程度等因素。本法6次测量的相对标准偏差均小于5．5％。     

原子吸收光谱法测定粉葛中铜、铅和镉

用火焰原子吸收光谱法测定粉葛中铜的含量,石墨炉原子吸收光谱法测定粉葛中铅、镉的含量。在实验条件优化情况下,测定方法铜、铅、镉的检出限分别为:0.03mg·L^-1、0.243μg·L^-1和0.012μg·L^-1,回收率在97.26%—105.60%之间,相对标准偏差均小于5%。实验结果表明,该方法简便、快速、灵敏。所测不同产地粉葛样品中铜、铅和镉3种重金属元素含量均在《药用植物及制剂进出口绿色行业标准》的限量指标内。     

微波消解-石墨炉原子吸收光谱法测定蜂花粉中铅、镉和铜

建立蜂花粉中铅、镉和铜3种重金属含量的测定方法。采用浓硝酸和过氧化氢(体积比4:1)混合液对样品进行微波消解,石墨炉原子吸收光谱法测定铅、镉和铜的含量。该方法对花粉样品中铅、镉和铜测定的加标回收率分别为93.3%、101.0%和99.4%,相对标准偏差(RSD)分别为1.1%、6.0%和3.0%,准确度和精密度良好。本法用微波溶样,石墨炉原子光谱法测定铅、镉和铜,具有简便快速、灵敏准确,重复性好的特点,并且节省试剂、污染少。该法可为蜂花粉质量控制提供方法参考。     

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.     

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.     

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.     

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.