叶酸修饰的凹凸棒土对Pb(Ⅱ)的吸附

用叶酸化学修饰凹凸棒土得到的新型固相萃取剂(ATP-FA)对样品溶液中的铅离子定量吸附并用电感耦合等离子体-原子发射光谱法(ICP-AES)进行测定.研究了pH值、吸附剂用量、样品溶液流速、洗脱剂体积与浓度、共存离子干扰等条件对Pb(Ⅰ)分离富集和测定的影响.方法对铅离子的饱和吸附容量为23.59μmol/g,测定Pb(Ⅱ)的检出限为0.37μg/L.用本法测定国家标准试样的结果与标准物参考值一致,对实际样品中铅离子的加标回收测定结果令人满意.     

铜钴铈复合体系对甲醇脱水催化性能的研究

以铜钴铈的氧化物为活性组分,对ZSM-5分子筛进行改性,用微反-色谱装置在线对甲醇脱水制二甲醚催化性能评价。从实验中可以发现：铜钴氧化物的摩尔分数之比为5：5,铈的摩尔百分含量为20%,450℃煅烧的催化剂的活性最高。     

铝-邻苯二酚紫-四元鎓盐离子对在胶束体系中的分配平衡的研究——分光光度法测定铝

以分光光度法研究了在表面活性剂胶束溶液中铝-邻苯二酚紫络合物与氯化十四烷基二甲基苄基铵(zeph),溴化十六烷基三甲铵(溴化HTA)或氯化四苯基磷(氯化TPP)所形成的离子对的分配平衡。在胶束中离子对的溶解引起光谱的紫移。测定铝选择了TPP体系,因为TPP离子对在水和曲拉通X-100之间的分配,比HTA或zeph离子对的少。在0.1%曲拉通X-100溶液中,波长为710纳米处,摩尔吸收系数为64000升/摩尔·厘米。本方法曾用于测定海藻中的铝。     

高纯金属钕中镧、铈、镨、钐和钇的ICP光谱测定

本文提出了用ICP－AES直接同时测定高纯金属钕中镧、铈、镨、钐和钇的新方法。描述了在钕样品溶液中加入乙醇后对测定灵敏度的影响，乙醇量的影响以及ICP的几个主要工作参数的选择等。当样品溶液中衡土元素的总浓度为5毫克／毫升，乙醇浓度为70％（V／V）时，测定下限分别为镧0.0020%，铈0.0030%，镨0.010%，钐0.0050%和钇0.0010%其相对标准偏差为2.9-5.7%。     

高纯金属铈的ICP—AES分析和稀土元素间的光谱干扰及其校正

本文采用乙醇预去溶方式进样,ICP-AES直接同时测定了>99.99%的高纯金属铈中5个痕量稀土杂质元素,并讨论了基体量对检测限的影响,稀土元素间的光谱干扰及其校正方法等。当样品溶液中铈的浓度为5mg/ml时,铈中稀土杂质元素的测定下限为:镧、钕和钇0.001%,镨和钐0.003%。其相对标准偏差为1.9～6.4%。     

高能离子在稠密等离子体中的传输和能量沉积

用相对论福克-普朗克方程对高能离子在稠密氘氚等离子体中的碰撞动力学进行了研究，用球谐函数来展开方程的解：格林函数，然后简明地求出了不同能量质子和α粒子在等离子体中的停止时间、减速距离、纵向弥散距离和横向偏转距离.与以前研究离子在等离子体中运动的方法相比，没有假设高能离子在等离子体中损失能量远远小于入射离子能量，求解了纵向弥散距离；并且可以求解横向偏转距离.这些计算对实验上用高能离子加热冷的稠密等离子体，然后进行科学研究具有指导作用，并且可以用来研究快点火的可能性. 关键词： 高能离子 福克-普朗克方程     

溶剂萃取—ICP—AES同时测定化探样品中痕量钨和钼

本文提出了一种适用于测定化探样品中痕量钨和钼的分析方法。在硫氰酸盐的存在下,用甲基异丁酮(MIBK)萃取钨和钼的硫氰酸络合物,然后直接将有机相导入ICP进行测定。方法的实际测定下限为W.0.01μg/ml,Mo.0.005μg/ml。     

电热石墨炉原子吸收法测定贵金属——(三)岩石矿物中超痕量金的测定

本文提出了用0.5ml N-正辛基苯胺-间二甲苯萃取测定岩石矿物中超痕量金的电热石墨炉原子吸收分析方法。对萃取剂的性能、萃取金的条件、其它离子的干扰情况以及在HGA-500型石墨炉中测定金的最佳条件进行了研究。样品用盐酸过氧化氢分解后,溶液进行萃取,有机相直接测定,大量的其它离子不干扰测定,为超痕量金的定量测试提供了简便、高灵敏的方法。本法绝对灵敏度为2.0pg/1%吸收,可检测0.00005g/T金。对含金量为0.0006g/T的矿样重复溶样测定11次,其相对标准偏差为4.4%。     

电感耦合等离子体-原子发射光谱法测定石墨中的钙

用电感耦合等离子体-原子发射光谱法测定了石墨中的微量钙,并对测试条件等进行了考察,结果表明,在所选择的最佳仪器条件下,方法的检出限(LD)为0.3866μg/g,测定下限(LOD)为1.93μg/g,精密度(RSD,n=10)为0.347％-3.913％.经美国国家标准方法(ASTMC 560-2005)分析验证,电感...     

浊点萃取-火焰原子吸收光谱法测定微量锌

研究了浊点萃取-火焰原子吸收光谱法测定微量锌的新方法.实际样品采用微波消解,利用非离子表面活性剂TritionX-100、络合剂5-Br-PADAP浊点萃取试样中微量锌(Ⅱ).探讨了溶液pH、试剂浓度等实验条件对浊点萃取及测定灵敏度的影响.在最佳条件下,富集10.0mL的Zn2 溶液,用火焰原子吸收光谱法测定,锌的检出限为4.4ng/mL(3o),富集倍数为10倍,RSD为1.21[C=0.20(μg/mL,n=5)],线性范围为0.15-1.00μg/mL.该方法用于中药及黄豆试样中锌含量的测定,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.     

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.