催化光度法测定痕量铁的研究

本文研究了在ｐＨ４．５的ＨＡｃ－ＮａＡｃ介质中，有非离子表面活性剂ＴｒｉｔｏｎＸ－１００存在下，痕量铁催化水中溶解氧氧化双硫腙褪色的指示反应，建立了胶束增溶催化动力学光度法测定痕量铁的新方法。方法的线性范围为０－１．５μｇ／２５ｍＬ，检出限为１．６×１０￣（－１０）ｇ／ｍＬ。用于人发中痕量铁的测定，结果满意。     

Fe(Ⅲ)-灿烂绿-过氧化氢测定痕量铁

本文研究了在ＰＨ＝３．０的酸性条件下,利用铁催化过氧化氢氧化灿烂绿的反应,建立了催化动力学光度法测定痕量铁的新方法。方法检出限为４＊１０＾－９ｇ／ｍＬ,线性范围内０．１－１．０μｇ／２５ｍＬ,ε＝２．５０＊１０＾４ｃｍ＾－１,Ｌ．ｍｏｌ＾－１,用于水样中痕量铁的测定,结果满意。     

Fe(Ⅲ)-H_2O_2-固绿FCF-1,10-菲啉体系催化褪色光度法测定痕量铁

基于ｐＨ４．０的弱酸性介质中铁离子对过氧化氢氧化固绿ＦＣＦ褪色反应的催化作用，提出了催化褪色光度法测定痕量铁的新方法。研究了该方法的适宜反应条件，方法的检出限为９．７×１０－７ｇＦｅ（Ⅲ）／Ｌ，线性范围为０－１．５μｇＦｅ（Ⅲ）／２５ｍＬ，方法用于水中痕量铁的测定，结果满意。     

三氟乙酰丙酮—Gd（Ⅲ）—CTMAB配合物体系荧光法研究及应用

本文研究了Ｇｄ－三氟乙酰丙酮－ＣＴＭＡＢ的三元配合物荧光体系，并用钇的测定，最低检测限为：０．００３μｇ／ｍＬ，Ｇｄ在０．００５－０．４μｇ／ｍＬ范围内呈线性关系，回归方程Ｆ＝３１．６５ｃ＋０．２１，相关系数为ｒ＝０．９９９６，将此法用于稀土矿的痕量Ｇｄ的测定，与ＩＣＰ－ＡＥＳ法相比，结果令人满意。     

次甲基绿—溴酸钾体系催化光度法测痕量钒（V）的研究

本文基于在抗坏血酸存在下，痕量钒（Ｖ）对溴酸钾氧化次甲基绿褪色的新指示反应，建立了一个催化动力学光度法测痕量钒（Ｖ）的新方法。线性范围为０－０．１２μｇ／２５ｍＬ和０．１２－０．２０μｇ／２５ｍＬ，方法检出限为３．４×１０＾－１０ｇ／ｍＬ。用于人发、水样中痕量钒（Ｖ）的测定，结果满意。     

催化动力学光度法测定痕量铂的研究

利用痕量铂在稀硫酸介质中对溴酸钾氧化酸性铬蓝Ｋ的催化作用，建立了催化动力学光度法测定痕量铂的新方法。方法的线性范围为０－０．８μｇ／２５ｍＬ，检出限为７．９３×１０＾－１１ｇ／ｍＬ。用于合成样品及含铂催化剂中铂的测定，结果满意。     

催化动力学光度法测定痕量铁(Ⅲ)的研究

在弱酸性介质中,利用铁（Ⅲ）对高磺酸钾氧化溴酚蓝的催化作用,建立了催化光度测定痕量铁（Ⅲ）的新方法。该方法线性范围在０－１．２μｇ／２５ｍＬ之间,检出限为３．１＊１０＾－１０ｇ．ｍＬ＾－１。测定出反应表观活化能为Ｅａ＝９８．６６ｋＪ／ｍｏｌ。此法用于水样中微量铁的测定,结果令人满意。     

次甲基绿－溴酸钾体系催化光度法测痕量钒（Ⅴ）的研究

本文基于在抗坏血酸存在下，痕量钒（Ⅴ）对溴酸钾氧化次甲基绿褪色的新指示反应，建立了一个催化动力学光度法测痕量钒（Ⅴ）的新方法。线性范围为０—０．１２μｇ／２５ｍＬ和０．１２—０．２０μｇ／２５ｍＬ，方法检出限为３．４×１０~（－１０）ｇ／ｍＬ。用于人发、水样中痕量钒（Ⅴ）的测定，结果满意。     

催化动力学光度法测定亚硝酸根－NO_2~－－KBrO_3－酸性铬蓝K体系中痕量亚硝酸根

本文研究，在稀磷酸介质中，亚硝酸根催化溴酸钾氧化酸性铬蓝Ｋ的退色反应，建立了催化动力学光度法测定痕量亚硝酸根的新方法。方法的线性范围为０－１０μｇ／２５ｍＬ，检出限为１．８×１０－９ｇ／ｍＬ，用于水样中痕量亚硝酸根的测定，结果满意。     

Fe（Ⅲ）—H2O2—固绿FCF—1,10—菲罗啉体系催化褪色光度法测定痕量铁

基于ＰＨ４．０的弱酸性介质 离子对过氧化氢氧化固绿ＦＣＦ褪色反应的催化作用,提出了催化褪色光度法测定痕量铁的新方法。研究了该方法的适宜反应条件,方法的检出限为９．７×１０＾－７ｇＦｅ（Ⅲ）／Ｌ,线性范围为０－１．５μｇＦｅ（Ⅲ）／２５ｍＬ方法用于水中痕量铁的测定,结果满意。     

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.     

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.