棉红-Ru(Ⅲ)-KBrO3催化体系动力学及痕量钌的测定

在磷酸介质和热水浴中,Ru(Ⅲ)催化溴酸钾氧化棉红褪色,由此建立了动力学光度法测定痕量钌的新方法.钌的质量浓度在0.00-0.10μg/mL范围内与lgA0/A呈良好的线性关系,其线性回归方程为:lgA0/A=0.2926CRu-0.003,相关系数r=0.9997,检测限为4.06×10-8g/mL.实验考察了影响催化反应的因素,确定了反应的最佳条件,测定了催化动力学参数,反应的表观活化能Ea'=53.02kJ/moL,表观速率常数k'=1.75×10-4s-1,确立了反应速率方程,探讨了反应机理,试验了20多种共存离子的影响,方法用于合成水样和矿样中钌的测定,回收率94.8％-104.0％,相对标准偏差0.6％-2.4％.     

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。     

催化动力学光度法测定痕量甲醛

在稀盐酸介质中,痕量甲醛对溴酸钾氧化甲基橙褪色反应具有显著的促进作用,研究了动力学条件,建立了测定痕量甲醛的催化光度分析方法,线性范围为0.4—60μg/25mL,检出限为2.32×10-8g/mL,灵敏度高,选择性较好。该方法可用于水质及空气中甲醛的测定。     

催化动力学光度法测定水中痕量铁

本文研究了ｐｈ５．０的ＨＡｃ－ＮａＡｃ介质中，痕量铁催化过氧化氢氧化紫脲酸的褪色反应，建立了催化动力学光度法测定痕量铁的新方法，方法的线性范围０－０．４０，０．４０－２．０μｇ／２５ｍＬ，检出限为８×１０＾－１１ｇ／ｍＬ，用于水样中痕量铁的测定，结果满意。     

铟(Ⅲ)-8-羟基喹啉-核酸三元荧光体系的研究与应用

基于核酸对铟(Ⅲ）-8-羟基喹啉配合物的荧光增强作用，应用铟(Ⅲ)-8-羟基喹啉为荧光探针，研究了铟(Ⅲ)-8-羟基喹啉与核酸的作用，建立了新的核酸测定方法。在最佳条件下，ctDNA、hsDNA、smDNA和yRNA的线性范围分别为0．20-1．40μg／mL、0．20-1．60μg／mL、0．10—1．40μg／mL、0．20—1．20μg／mL。检出限(3o／K)分别为0．004μg／mL，0．002μg／mL，0．002μg／mL，0．002μg／mL；测定实际样品，回收率为90．9％-103．5％。     

辣根过氧化物酶催化动力学光度法测定汞

基于辣根过氧化物酶催化H2O2-4-氨基安替比林-2,4-二氯苯酚的反应中,汞离子对于酶催化的抑制作用,建立了用动力学分光光度法测定Hg2 新方法.测定范围为1.0-5.0μg/mL,检出限为5.78×10-7g/mL,优化了测定Hg2 的实验条件并讨论了共存离子对测定的影响.本法简单、快速.     

考马斯亮蓝催化分光光度法测定微量甲醛

在H3PO4溶液中,甲醛强烈催化KB rO3氧化考马斯亮蓝褪色,确定了反应最佳条件,测定了反应级数、表观速率常数和表观活化能,确立了反应速率方程,探讨了反应机理,建立了一种测定甲醛的新方法。该方法的检出限为0.091μg/mL,线性范围为0—2.1μg/mL。方法选择性好,直接用于废水中甲醛的测定,结果满意。     

阻抑动力学光度法测定痕量砷(Ⅲ)的研究

研究了在硫酸介质中砷(Ⅲ)对碘化钾催化碘酸钾氧化甲酚红褪色的阻抑反应,建立了阻抑动力学光度法测定痕量砷(Ⅲ)的方法.方法的检出限为1.08×10-9g/mL,线性范围为0-2.0μg/25mL.RSD<4%,平均回收率为98.8%.方法应用于环境水样中痕量砷的测定,结果满意.     

甲基橙褪色分光光度法测定亚硝酸根

基于硫酸介质中亚硝酸根催化溴酸钾氧化甲基橙的褪色反应建立了测定痕量亚硝酸根的新方法,方法检出限为8.1×10-2μg/mL,线性范围0.1—0.4μg/mL,本方法可用于水及蔬菜中痕量亚硝酸根的测定。     

催化动力学光度法测定痕量铁

论文研究和建立了催化动力学褪色光度法测定痕量Fe(Ⅲ)的新体系,反应介质为盐酸-邻苯二甲酸氢钾(pH2.2)缓冲溶液,催化体系为痕量Fe(Ⅲ)催化过硫酸铵氧化邻甲氧基酚的自聚反应。研究了此反应体系的最佳条件、动力学参数及反应机理,考察了21种干扰离子的影响,建立了一种新型催化动力学光度法测定痕量Fe(Ⅲ)的方法。本法的线性范围0.07～1.1μg·(25mL)~(-1)。方法灵敏度远远高于普通光度法,检出限为5.4×10~(-8)g·L~(-1)。方法应用于自来水、河水、城市污水、豆奶粉和茶叶中痕量Fe(Ⅲ)的测定,相对标准偏差为0.36％～3.4％,标准加入回收率为97.3％～102.7％,结果满意。     

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.     

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.     

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.     

Multi-pulse operation of a Kerr-lens mode-locked femtosecond laser

Our experimental results show that the presence of a proper amount of negative group velocity dispersion is essential to multi-pulse operation of a Kerr-lens mode-locked femtosecond laser. We demonstrate that the pulse separations and the number of pulses contained within a cavity round trip are strongly dependent on the initial perturbations. The results allow us to get a better understanding on the influences of the convoluted self-phase modulation and intra-cavity dispersions on the stable multi-pulse oscillation in a Kerr-lens mode-locked femtosecond laser.     

Propagation of Helmholtz-Gauss beams in weak turbulent atmosphere

Based on the Rytov approximation of light propagation in weak turbulent atmosphere,the closed-form expressions of field and average irradiance of each one of the four fundamental families of Helmholtz-Gauss (HzG)beams:cosine-Gauss beams,stationary Mathieu-Gauss beams,stationary parabolic-Gauss beams,and Bessel-Gauss beams,which are propagating in weak turbulent atmosphere,are obtained.The results show that the field and average irradiance can be written as the product of four factors:complex amplitude depending on the z-coordinate only,a Ganssian beam.a factor of complex phase perturbation induced by atmospheric turbulence,and a complex scaled version of the transverse shape of the non-diffracting beam.The effect of weak atmospheric turbulence on irradiance distribution of the HzG beam can be ignored.     

An effective method for reducing speckle noise in digital holography

An effective method for reducing the speckle noise in digital holography is proposed in this paper.Different from the methods based on classical filtering technique,it utilizes the multiple holograms which are generated by rotating the illuminating light continuously.The intensity images reconstructed by a series of holograms generated by rotating the illuminating light possess different speckle patterns.Hence by properly averaging the reconstructed intensity fields,the speckle noises can be reduced greatly.Experimental results show that the proposed method is simple and effective to reduce speckle noise in digital holography.     

Influence of purity of HfO2 on reflectance of ultraviolet multilayer

The impurities in two kinds of HfO2 materials and in their corresponding single layer thin films were determined through glow discharge mass spectrum technology and secondary ion mass spectrometry(SIMS) equipment respectively.It was found that ZrO2 was the main impurity in the two kinds of HfO2 either in the original HfO2 materials or in the electron beam deposited films.In addition,the difference of Zr content in the two kinds of HfO2 single laver films was much laxger than that of the other impurities such as Ti and Fe.which showed that it was just ZrO2 that made the difference between the optical performance of the film products including the two kinds of HfO2.With these two kinds of HfO2 and the same kind of SiO2.we deposited HfO2/SiO2 multilayer reflective coatings at the wavelength of 266 nm.Experimental results showed that the reflectances of these two mirrors were about 99.85% and 99.15% respectively,which agreed well with the designed results what were based on the optical constants obtained from the corresponding single layer thin films.     

Speech enhancement by array crosstalk resistant ANC and spectrum subtraction

Microphone array-based speech enhancement has great importance for speech communications and speech recognition. To reduce the aperture of the microphone array and to increase the effect of the speech enhancement will greatly broaden the application areas of the microphone array. An array crosstalk resistant adaptive noise cancellation method is therefore presented. And then an improved spectral subtraction algorithm is further cascaded to obtain better enhancement results. Theoretic analysis and experiments indicate that the proposed scheme needs only a very small microphone array while it simultaneously achieves a higher SNR improvement. Besides, the proposed scheme can be used in many noisy environments and is easy for real-time implementation.