钐的时间分辨激光荧光光谱分析方法研究

本文利用Ｓｍ－ＴＴＡ－ＥｔＯＨ液体荧光体系，采用时间分辨激光荧光检测手段，建立了散的时间分辨光荧光分析法，该法的线性范围为０．０１～１０μｇ／ｍｌ，检出限为３．３ｎｇ／ｍｌ，０．５μｇ／ｍｌ钐标样测定的相对标准差为３．７％（ｎ＝１２），结合混合稀土中多种元素共存的特点，实验确定了装置的有关参数，用标准加入方法对实际样品进行了测定，并与其他方法测定结果进行了比较，结果满意，本法测定实际样品中钐的相对     

稀土元素荧光增强效应的研究─RE对Eu－苯甲酰三氟丙酮－溴化十六烷基三甲基铵体系的荧光增强

本文详细研究了稀土元素Ｌａ３＋、Ｇｄ３＋、Ｔｂ３＋、Ｌｕ３＋、Ｙ３＋及Ｓｃ３＋对铕苯甲酰二氟丙酮（ＢＴＡ）－阳离子表面活性剂体系的荧光增强效应。结果表明，在上述增强离子的分别存在下，体系的荧光强度分别增加１７、７５、６５、５、５５和１８倍，铕浓度在１．０×１０－１０－８．０×１０－７ｍｏｌ／Ｌ范围内与荧光强度成线性关系，最低检出限为１．０×１０－１１ｍｏｌ／Ｌ利用标准加入法测定了混合稀土氧化物中的铕，结果满意。     

铕（Ⅱ）—噻吩甲酰三氟丙酮—丙烯酸三元配合物及其聚合物发光性质研究

研究了铕（Ⅲ）与噻吩甲酰三氟丙酮（ＨＴＴＡ）、丙烯酸（ＨＡＡ）的三元配合物及与甲基丙烯酸甲酯（ＭＭＡ）成键聚合物（ＣＰＥｕ（ＴＴＡ）２ＡＡ）和掺杂聚合物（Ｅｕ（ＴＴＡ）２ＡＡ／ＰＭＭＡ）发光性质，测量了配合物中Ｅｕ＾３＋的＾５Ｄ０和＾５Ｄ１能级的荧光衰减，对其传能过程和荧光寿命进行了讨论，测量了配合物及聚合物ＴＨＦ溶液的荧光光谱，配合物的聚合有收交配体发生明显红移，且存在配体到中心离子的传能，指出     

Eu（Sm）—DBM—CPB体系的激光感生时间分辨荧光光谱的研究

用自装的激光感生时间分辨荧光光谱装置，研究了Ｅｕ，Ｓｍ－二苯甲酰甲烷（ＤＢＭ）体系在阳离子表面活性剂溴代十六烷基吡啶（ＣＰＢ）存在下的光谱特性和荧光衰减动力学特性。给出同时测定Ｅｕ和Ｓｍ的激光感生时间分辨荧光光谱分析方法，用于高纯氧化物中痕量Ｅｕ和Ｓｍ的测定，获得了满意的结果。     

Eu（Sm）－DBM－CPB体系的激光感生时间分辨荧光光谱的研究

用自装的激光感生时间分辨荧光光谱装置，研究了Ｅｕ、Ｓｉｎ－二苯甲酰甲烷（ＤＢＭ）体系在阳离子表面活性剂溴代十六烷基吡啶（ＣＰＢ）存在下的光谱特性和荧光衰减动力学特性。给出同时测定Ｅｕ和Ｓｉｎ的激光感生时间分辨荧光光谱分析方法，用于高纯氧化物中痕量Ｅｕ和Ｓｉｎ的测定，获得了满意的结果。     

二安替比林—（邻—乙氧基）苯基甲烷褪色光度法测定微量铜的研究

合成了新试剂二安替比林－（邻－乙氧基）苯基甲烷（ＤＡｏＥＭ），根据Ｃｕ＾２＋对Ｈ３ＰＯ４－Ｍｎ（Ⅱ）－Ｃｒ（Ⅵ）－ＤＡｏＥＭ显色体系的干扰褪色作用，建立了一个测定微量铜的新方法，其检出限为４×１０＾－６ｇ／Ｌ，铜离子含量在２０－１６０μｇ／Ｌ范围内与１ｇ（Ａ０／Ａ）成良好线性关系，体系稳定性和选择性良好，用于铅样中痕量铜的测定，结果满意。     

析相光度法测定铜（Ⅱ）的研究

本文研究了Ｃｕ－ＰＥＧ－ＤＤＴＣ（铜试剂）（ＮＨ４）２ＳＯ４体系的析相光度法并应用于测定Ｃｕ。最宜酸度为３．６－９．０（ＮａＡｃ－ＨＡｃ，ＮＨ４Ｃｌ－ＮＨ３．Ｈ２Ｏ）缓冲溶液，其络合物的最大吸收位于４５０ｎｍ，表观摩尔吸光系数为９．０５×１０＾３Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，Ｃｕ浓度在０－３０μｇ／Ｌ范围内服从比耳定律，铜与ＤＤＴＣ形成组成为１：２的稳定络合物。该方法用于铝合金中铜的测定，获得了满     

DCP—直读光谱法测高纯氧化镧中的Ce,Pr,Nd和Sm

本文提出用ＤＣＰ－ＡＥＳ方法直接测定高纯Ｌａ２Ｏ３中的Ｃｅ，Ｐｒ，Ｎｄ和Ｓｍ。方法简单、快速。检出限分别为Ｃｅ，０．０１２μｇ／ｍｌ；Ｐｒ，０．０２１μｇ／ｍｌ；Ｎｄ，０．０２１μｇ／ｍｌ以及Ｓｍ，０．００９μｇ／ｍｌ。     

ICP—AES法直接测定高纯Eu2O3中14种稀土元素

建立了ＩＰＣ－ＡＥＳ测定高纯Ｅｕ２Ｏ３中１４种稀土元素的方法，用正交设计法优化仪器测量条件，实验了基体Ｅｕ２Ｏ３对被测元素的干扰和对方法测定下限的影响。１４个稀土元素的测定下限为：Ｙｂ２Ｏ３０．５μｇ．ｇ＾－１，Ｙ２Ｏ３１μｇ．ｇ＾－１，Ｄｙ２Ｏ３，Ｈｏ２Ｏ３，Ｔｍ２Ｏ３和Ｎｄ２Ｏ３５μｇ．ｇ＾－１、Ｇｄ２Ｏ３、Ｓｍ２Ｏ３、Ｅｒ２Ｏ３、Ｃｅ２Ｏ３、Ｐｒ６Ｏ１１和Ｌａ２Ｏ３１０μｇ．ｇ＾－１，Ｌｕ２     

流动注射氢化物发生原子吸收法测定血液中硒

采用流动注射分析与氢化物发生原子吸收相结合的方法测定了血液中痕量硒。采用ＨＮＯ３－ＨＣｌＯ４体系溶解样品，取样量少，样品处理简单，快速。本法检出限为０．０６μｇ／Ｌ＾－１（３σ），进样频率为１２０－１５０样次／小时。讨论了砷对硒测定时的干扰及其排除方法，用该法测定了３００个正常人全血和７５个血清样品，其硒含量范围分别为０．０５６－０．１１８μｇｍ１＾－１和０．０４０－０．０７６μｇｍ１＾－１，回收     

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.