火焰原子吸收光谱法测定阳春砂仁中铜、锌、锰和铁

样品经灰化处理后,用火焰原子吸收光谱法测定样品中铜、锌、锰和铁的含量,平均加标回收率为85.5%-99.4%,相对标准偏差(RSD)为1.70%-2.70%.在给定范围内呈现良好的线性关系,相关系数大于0.998,方法简便,快速,结果可靠.     

火焰原子吸收光谱法测定龙眼肉中微量元素

用微波消解龙眼肉样品,火焰原子吸收光谱法测定样品中钙、镁、铁、铜、锌、锰微量元素的含量,该方法的加标回收率在98.40%-100.59%范围,相对标准偏差(RSD)≤1.68%,测定结果准确.为研究龙眼肉的药理、药效提供了有用的数据.     

火焰原子吸收光谱测定花椒及椒皮、椒籽中钢、锌、铁、锰含量

用硝酸、高氯酸混合酸消解样品,原子吸收光谱法测定河南太行山区的花椒及椒皮、椒籽中铜、锌、铁、锰的含量,并对其结果进行了分析.结果显示:各元素在实验范围内,线性关系良好,回收率在92%-103%之间.花椒及椒皮、椒籽中均含有微量元素,花椒中铜、锌、铁、锰的含量分别为11.571、90.868、18.818、78.851μg·g-1,其中铁、锰含量丰富.铜、锌、铁的分布量为椒籽＞椒皮;锰的分布量为椒皮＞椒籽.测定结果为探讨花椒的高药用价值提供了有力的证据,椒籽中铜、锌、铁含量高于椒皮,应该大力开发利用.     

微波消解原子吸收光谱法测定八角茴香中金属元素

采用微波辅助消解八角茴香样品,用火焰原子吸收光谱法测定八角茴香的钙、镁、铁、铜、锰和锌含量,回收率在96.68%-101.75%之间,相对标准偏差(RSD)≤1.32%.该法准确,快速,简便,结果令人满意.     

ICP-AES同时测定南极石中的22种元素

电感耦合等离子体原子发射光谱法(ICP-AES)同时测定南极石中的铜、铁、锌、钙、镁、锰、钴等22种元素的含量.优化了消解样品用酸,选择了适合的元素分析线.各元素测定的相对标准偏差为0.13%-5.14%,加标回收率为95.43%-108.68%,方法简单、可靠,具有良好的准确度和精密度.     

FAAS测定电解镉中的Zn、Cu和Fe

采用火焰原子吸收光谱法测定电解镉中铜、铁和锌的方法,确定了最佳仪器工作条件和样品处理方法.在选择好的实验条件下.测定铜的特征浓度为0.006#g/mL/1%吸收;铁的特征浓度为0.015μg/mL/1%吸收;锌的特征浓度为0.0031μg/mL/1%吸收.回收率分别为铜97.5%-98.0%,铁99.1%-100.2%,锌97.4%-99.1%.     

FAAS法测定硫酸中的铜、铁和锌

采用火焰原子吸收光谱法测定硫酸中铜、铁和锌,确定了最佳仪器工作条件和样品处理方法.在选择好的实验条件下,测定铜的特征浓度为0.005μg/mL/1%;铁的特征浓度为0.014μg/mL/1%吸收;锌的特征浓度为0.002μg/mL/1%吸收.回收率分别为铜97.7%-98.2%,铁98.2%-99.4%,锌96.8%-98.7%.     

ICP-AES测定铜-锌合金中锌及杂质元素砷、铅、锑和铋

采用ICP-AES同时测定铜-锌合金中锌、砷、铅、锑和铋含量,优化了样品溶样条件.方法检出限为0.0003%-0.0012%,回收率为86%-112%,RSD为0.30%-5.17%,测试结果表明,该方法是测定铜锌合金的简单准确快速的方法.     

ICP-MS测定土壤样品中的有效锰、铜和锌

以DTPA提取土壤中的有效锰、铜、锌,不经分离富集,电感耦合等离子体质谱直接测定土壤样品中的有效锰、铜和锌,方法检出限分别可达0.042μg/L、0.039μg/L、0.028μg/L.通过对国家土壤有效态一级标准物质测试,测定结果基本一致;GBW 07412标准物质11次测定锰、铜和锌的相对标准偏差(RSD)分别为3.49%、3.72%、5.65%.     

ICP-AES测定铝-钛-硼合金中的16种元素

电感耦合等离子体-原子发射光谱法(ICP-AES)测定铝-钛-硼合金中钛、硼、铁、硅、镓、铜、锶、锆、锌、镁、锰、镍、铅、钒、镉和铬等16种元素含量.对分析线的选择、铝基体的干扰,样品的预处理过程进行了探讨.经实验,方法的回收率在95%-110%之间,测定结果的相对标准偏差(n=6)在0.4%-3.0%之间.该方法准确...     

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.     

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.     

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.     

Improvement of four-wave mixing-based wavelength conversion efficiency in dispersion shifted fiber by 40-GHz clock pumping

40-GHz clock modulated signal as a pump to improve the efficiency of four-wave mixing (FWM)-based wavelength conversion in a 26.5-km dispersion shifted fiber (DSF) is investigated. The experimental results demonstrate that the conjugated FWM component has higher intensity with the clock pumping than that with the continuous-wave (CW) light pumping. The improvement of FWM-based wavelength conversion efficiency is negligible when the pump power is less than Brillouin threshold. But when the pump power is greater than Brillouin threshold, the improvement becomes significant and increases with the increment of pump power. The improvement can increase up to 9 dB if pump power reaches 17 dBm.     

Characterization of PolyA and PolyC mismatches by Raman spectroscopy

A.C mismatches are studied by Raman spectral characterization of PolyA, PolyC, and their equimolar complex in solution of 0.14 mol/L Na ,pH7.0.Experimental results show that A·C mismatches occur to be A/B (mainly A) conformers, and unlike Watson-Crick base pairing, this kind of mismatches is stabilized by only one hydrogen bond involving cytosine N4H2 and adenine N7.The formation of A·C complex makes the base stacking interactions much stronger, and conformation of the backbone more ordered, which leads to obvious Raman hypochromic effect with some shifts in corresponding bands.