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％。     

甘薯中微量铝的分光光度法测定

采用分光光度法与Al-CAS-CTMAB-OP四元络合物显色相结合，对甘薯中的铝含量进行了测定。A1^3 浓度在0-0．24μg／mL范围内遵守朗伯-比耳定律，相关系数r＝0．9996。回收率为91．4％-102．6％，对甘薯样品测定的结果为190．8μg／g，δ＝1．59，RSD＝0．83％(n＝5)。因甘薯中铝含量相对较高，建议在开发健康食品时应作特殊的前处理或进一步改良品种。     

火焰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理探讨

火焰原子吸收法测定钢铁中铅，采用0．2％十二烷基硫酸钠（SDS）和0．001mol／L硝酸介质，加入硫脲消除共存元素铋的干扰，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％，回收率为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。     

催化动力学光度法测定芦丁

在盐酸介质中，微量芦丁对重铬酸钾氧化靛红的反应有明显的催化作用，据此建立了测定芦丁的催化动力学光度法。优化了动力学反应的条件，测定了反应级数。方法的线性范围是0.003-0.09μg／mL和0．10—1．00μg／mL，检出限为0.003μg／mL。方法简便、快速、灵敏度高，用于芦丁片剂和槐米中芦丁含量的测定，结果令人满意。     

荧光法直接测定环境水中痕量苯酚

研究了荧光分光光度通过控制酸度直接测定环境水中苯酚的新方法。在pH＝1时，直接测定苯酚的含量，波长为λex／λem＝270／297nm，检出限为4．0g/mL，线性范围为0－3．2μg/mL。回收率为99％－101％。     

富氧空气-乙炔火焰原子吸收光谱法测定锶

于试样溶液中加入含有0．5％镧的溶液，在富氧空气－乙炔的条件下，可有效地降低溶质干扰及电离效应，具有较高的原子化效率，可直接用于饮用水与矿泉水中锶的测定。方法的检出限为0．006μg/mL；灵敏度为0．02μg/mL。     

富氧空气-乙炔火焰原子吸收光谱法测定钡

于试样溶液中加入0．25％镧和0．5％氯化钾，在富氧空气－乙炔火焰的条件下，可有效地降低干扰及电离效应，具有较高的原子化效率，方法的检出限为0．001μg/mL，灵敏度为0．12μg/mL，可用于矿泉水中钡的测定。     

原子荧光光谱法测定中药中的汞

采用原子荧光光谱法测定了中药中汞，考察并优化了影响汞原子荧光强度的实验条件；提出硫脲-柠檬酸-Fe^3 作为增感剂以增强汞的荧光信号；探讨了共存离子对汞测定的干扰及其消除方法。在最佳工作条件下，方法的检出限为5．748μg／L；相对标准偏差为1．56％；线性范围为0—1000μg／L。用于6种中药样品中汞的测定，回收率为90．4％-109．6％。     

微量悬浮液进样-火焰原子吸收光谱法测定霜类化妆品中的铅

基于悬浮液技术处理霜类化妆品样品,将样品悬浮在1.00g/L琼脂溶液中制成均匀的悬浮液,采用微量进样技术建立了火焰原子吸收光谱法快速测定霜类化妆品中的铅。方法的检出限为0.030μg/mL,回收率为98.8%—101.5%。方法应用于实际样品的测定,结果满意。     

原子吸收光谱法分析铝土矿中氧化镁

本文提出了将试样用氢氧化钠熔融后，转换为酸性溶液，在盐酸介质中直接引入原子吸收测定。主体元素铝、钛，硅对测定有干扰，用氯化锶消除。本方法操作简便、更现性好、灵敏度高，MgO 0-40μg/50mL呈良好线性关系，测量下限可达0.03％，适用于铝土矿中氧化镁的测定。     

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.