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。     

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。     

原子吸收分光光度法测定焊尘中铁,镍,锰

建立了一个焊尘中铁，镍，锰的测定方法，优化了仪器工作参数，在优化后的条件下，铁，镍，锰三个元素的灵敏度分别为０．０４μｇ／ｍＬ／１％，０．０４μｇ／ｍＬ／１％，０．０２μｇ／ｍＬ／１％。线性范围分别为铁０．１－１０μｇ／ｍＬ，镍０．０１－２μｇ／ｍＬ，锰０．０５－５μｇ／ｍＬ。该方法回收率大于９２％，用此方法成功地测定了焊尘中三元素的含量。     

原子吸收光度法测定钢铁及合金中的铌量

本法叙述了一氧化二氮－乙炔火焰原子吸收光度法测定铌量，用鞣酸沉淀分离和在盐酸－氢氟酸介质中加入增感剂三氯化铝，灵敏度１２μｇ／ｍＬ／１％吸收，检出限６．１μｇ／ｍＬ。     

导数光谱法同时测定甲硝唑和维生素B6的研究

本建立了以０．１ｍｏｌ／ＬＨＣｌ为介质，采用三阶导数光谱法，同时测定甲硝唑和维生素Ｂ６的新方法，方法检测限为０．８１μｇ／ｍＬ甲硝唑和０．１６μｇ／ｍＬ维生素Ｂ６，二测定的线性范围均为１．６－２２．４μｇ／ｍＬ，直接用于复方甲硝唑片剂中甲硝唑和维生素Ｂ６的测定，两种生物的测定变异系数分别小于２．２６和２．６０％，回收率分别为９３－１０２％和９９－１０１％．     

荧光法直接测定环境中邻羟基苯甲酸和苯酚混合物的含量

本文研究了用荧光分光度法测定环境水中苯酚和邻羟基苯甲酸的含量碘在ＰＨ〉１１时直接测定邻羟基苯甲酸的含量,波长为λｅｘ／λｅｍ＝２８９／３３８ｎｍ,检出 为３．４ｎｇ／ｍＬ,线性范围０－６．０μｇ／ｍＬ。在ＰＨ＝６,波长为λｅｘ／λｅｍ＝２７０／２９７ｎｍ测得苯酚含量,检出限为４．０ｎｇ／ｍＬ,线性范围在０－０．８５μｇ／ｍＬ,回收率为９８－１０１％,,结果满意。     

溴乙锭的化学发光性质研究

首次研究了溴乙锭的化学发光性质,发现在强配性介质中,ＲＮＡ能增强溴乙锭与高锰酸钾反应的化学反光强度,在ＥＣ－ＫＭｎＯ４－ＲＮＡ体系中获得的化学发光强度与ＲＮＡ浓度在一定范围内成线性关系,因此,建立一种测定ＲＮＡ的化学发光分析新方法,并用于合成样品中的ＲＮＡ含量的测定。方法的线性范围为０．１０～１０．０μｍ／ｍＬ,检测限为０．０６０μｇ／ｍＬ,测定浓度为３．５μｇ／ｍＬ的ＲＮＡ溶液１２次,求得相对标     

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。     

动力学荧光法测定溴离子的研究

利用溴离子对溴酸钾氧化荧光素的催化作用，建立了动力学荧光法测定微量Ｂｒ＾－的新方法，方法的检出限为１．９４×１０＾－２μｇ／ｍＬ，线性范围为６．０～１２．０μｇ／２５ｍＬ，将方法用于溴吡斯的明药片中Ｂｒ＾－含量的测定，结果满意。     

火争原子吸收法测定钢铁中铅时阴离子表面活性剂的增感效应及其机…

火焰原子吸收法测定钢铁中铅，采用０．２％十二烷基硫酸钠和０．００１ｍｏｌ／Ｌ硝酸介质，加入硫脲消除共存元铋的干扰，铅的浓度在０－２０μｇ／ｍＬ范围内服从比耳定律。方法检出限为０．１０μｇ／ｍＬ，相对标准偏差为２．３０％，回收率９７％－９９％，样品测定结果令人满意。并对阴离子表面活性剂增感机理进行了探讨。     

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.     

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.     

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.