流动注射在线液-液萃取FAAS法测定地表水中痕量铜

研讨了流动注射在线液－液萃取火焰原子吸收光谱法测定地表水中痕量铜的分析方法。采用ＡＰＤＣ为螯合剂,ＭＩＢＫ在线萃取后注入原子吸收光谱仪测定,其相对标准偏差（ＲＳＤ）为３．５％;检出限（３σ）为９．１１＊１０＾－２μｇ．Ｌ＾－１,加标回收率为９５％－１０３％。     

流动注射—溶剂萃取—原子吸收光谱法测定微量锰（Ⅱ）

本文研究了一种新的在线流动注射－溶剂萃取预富集－原子吸收光谱分析方法。它具有原理简单，萃取装置，萃取效率高，易操作等特点，经对地表水，人发和中草药中Ｍｎ（Ⅱ）进行在线ＦＩＡ－ＥＸＴ－ＡＡＳ分析得到比较好的结果。方法检出限为０．０７６μｇ．ｍｌ＾－１，ＲＳＤ１．０２％线性范围０．５－５．０μｇｍ．ｍｌ＾－１回收率９４－１０２％。     

流动注射（FI）－在线柱预富集ICP－AES体系中的去溶效应研究

本文设计了一种简易的加热／冷凝去溶装置，并使之与流动注射（ＦＩ）－柱预富集－ＩＣＰ－ＡＥＳ体系联接。研究了在不同情况下进样体积、去溶温度、载液流速等对分析信号强度、检出限和精密度的影响，并与非去溶体系相比较。结果指出，去溶温度为１２０℃时，体系的去溶效率为３４．２％，进样效率为７２．５％；方法的检测限比非去溶体系改善近７倍。实验结果还表明，ＦＩ－柱预富集－去溶ＩＣＰ－ＡＥＳ体系获得了ｎｇ／ｍｌ～亚ｎｇ／ｍｌ级的检出限，可望用于超痕量组分的测定。     

流动注射在线萃取石墨炉原子吸收光谱法测定地质样品中痕量金

采用流动注射在线萃取石墨炉原子吸收光谱法测定了地质样品中痕量金,研究了二苯硫脲-甲基异丁酮在线萃取金的实验条件和流路参数。试验表明,该法有效地消除了基体干扰。测定含金量为0.051μg／g标准物质相对标准偏差(n=8)为4．2％,检出限为0．6ng／g,采样速率为20样／h。     

在线螯合树脂柱预富集分离ICP－AES测定生物试样中镉

本文报道了采用国产Ｄ４１２螯合树脂的在线微型螫合树脂柱预富集分离ＩＣＰ－ＡＥＳ法测定痕量镉的技术，选择了最佳的在线预富集条件，对生物标准参考物质中的痕量镉进行了测定，结果与标准值吻合。     

多道ICP-AES多元素瞬时信号检测、处理集成软件的开发

介绍了多道ＩＣＰ－ＡＥＳ多元素瞬时信号检测处理集成软件的研制过程,应用该软件实现了多道ＩＣＰ－ＡＥＳ和多种瞬时进样技术在线联用的信号采集、处理。     

在线螯合树脂柱预富集分离ICP—AES测定生物试样中镉

本文报道了采用国产Ｄ４１２螯合树脂的大线性微型螯合树脂柱预富集分离ＩＣＰ－ＡＥＳ法测定痕量镉的技术，选择了最佳的在线预富集条件，对生物标准参考物质中的痕量镉进行了测定，结果与标准值吻合。     

流动注射－溶剂萃取－原子吸收光谱法测定微量锰（Ⅱ）

本文研究了一种新的在线流动注射－溶剂萃取预富集－原子吸收光谱分析方法。它具有原理简单，萃取装置方便，萃取效率高，易操作等特点。经对地表水、人发和中草药中Ｍｎ（Ⅱ）进行在线ＦＩＡ－ＥＸＴ－ＡＡＳ分析得到比较好的结果。方法检出限为０．０７６μｇ·ｍｌ－１，ＲＳＤ１．０２％，线性范围０．５～５．０μｇ·ｍｌ－１，回收率９４～１０２％     

ICP—AES法测定高纯二氧化锆中痕量杂质

介绍了高纯二氧化锆中痕量杂质元素Ｆｅ，Ｎａ，Ｓｉ，Ｔｉ的ＩＣＰ－ＡＥＳ测定方法。样品以浓Ｈ２ＳＯ４及（ＮＨ４）２ＳＯ４溶解，采用空白背景校正法消除基体Ｚｒ的光谱干扰，以基体匹配法补偿基体效应。各元素平均回收率为９５％－１０６％，相对标准偏差为１．３％－３．０％。     

辐照三烷基氧化膦萃取锶和铯的研究

研究了γ辐照后的３０％％ＲＰＯ－煤油－ＨＮＯ３体系萃取Ｓr和Ｃs的性能。利用ＩＣＰ－ＡＥＳ及ＡＡＳ分别测定两相中Ｓr和Ｃs浓度，分配比。试验了辐照剂量对分配比的影响。结果表明，γ射线辐照对ＴＲＰＯ的萃取笥能无显著影响。     

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.