ICP-AES法测定水中微量磷

用ICP－AES法测定水中磷，并确定了最佳测定条件，检出限为0．02μg.mL^-1，回收率为96．5％－102．1％，RSD为1．65％－2．83％。该法准确、快速、简便，应用于水中磷的测定，结果令人满意。     

流动注射—可见光与原子吸收联机测定血清中磷及钙

采用流动注射一次进样串联测定血清中磷，钙，即以串联的可见分光光度计与原子吸收分光光度计先后连续测定磷和钙，试验了流动注射系统的实验条件。结果磷，钙回收率分别为９９．７％，１０２．０％，变异系数各为２．７％，２．５％，即与手动法结果相同或更优。     

流动注射－可见光与原子吸收联机测定血清中磷及钙

采用流动注射一次进样串联测定血清中磷、钙，即以串联的可见分光光度计与原子吸收分光光度计先后连续测定磷和钙。试验了流动注射系统的实验条件。结果磷、钙回收率分别为９９．７％、１０２．０％，变异系数各为２．７％、２．５％，即与手动法结果相同或更优     

萃取-磷钼蓝比色法测定镍铬丝中磷

在0．7—1．0mol/L的硝酸介质中^[3]，采用萃取-磷钼蓝比色法测定镍铬丝中的磷，络合物的最大吸收峰位于680nm，测定范围为0．001％-0．05％，相对标准偏差为＜3．8％。     

火焰原子吸收光谱法测定固体废弃物磷石膏中微量铜和铅

利用浓硝酸和浓盐酸消解磷石膏固体样品，选择了这两种酸的最佳用最，建立一种磷石膏样品处理方法。研究了应用火焰原子吸收光谱法直接吸取含盐量高的样品溶液，测定其中CU和pb的可行性。一份样品进行7次测定，结果表明，CU和Pb的RSD分别为2．6％和2．0％，加标回收率分别为92.88％一105．04％和91．20％－103．60％。     

铋磷钼蓝分光光度法测定金属硅中磷

本文建立了测定金属硅中磷的方法，检出限为0．0020％，回收率为92％－104％。     

ICP-AES测定电镀高纯铜中微量磷

用浓HNO3溶解高纯铜试样，电感耦合等离子体发射光谱(ICP-AES)测定其中微量磷，并对试样处理、测试方法、提高灵敏度等条件进行了优化实验。结果表明，方法回收率为99．07％-102．0％，RSD(n＝6)为0．22％-0．25％。     

ICP—AES法测定复合肥中磷,钾,锌,锰和硼

用ＩＣＰ－ＡＥＳ法同时测定了复合肥中磷，钾锌锰和硼，确定了仪器的工作参数，对分析线的选择，背景扣除。酸度影响和共存元素间的干扰等进行了研究。方法的回收率为９５％－１０４％，相对标准偏差为２．６６％－５．５４％。     

分光光度法测定纯稀土金属中微量硅

本文研究了纯稀土金属中微量硅的钼蓝测定方法,在ｐＨ＝１．２时,加入酒石酸破坏磷钼酸以消除磷的干扰,以抗坏血酸为还原剂,在λ＝８１０ｎｍ处,测定吸光度,测定浓度范围为０．０００５％￣０．０１５％。     

ICP-AES法测定耐磨合金钢中Ni、Cr、Mo、V和W等十二种元素

本文采用王水、硫磷混酸溶解试样，研究了应用ＩＣＰ－ＡＥＳ技术测定耐磨合金钢中Ｎｉ、Ｃｒ、Ｍｏ、Ｖ、Ｗ、Ｚｎ、Ｃｏ、Ｌａ、Ｃｅ、Ｔｉ、Ｍｎ、Ｃｕ１２种元素的方法。试验了硫酸、磷酸用量对测定的影响和共存离子干扰，方法相对标准偏差为１．４０％—３．２２％，回收率为９６．０％—１０８．１％。对试样进行分析，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.