共振瑞利散射法测定环境水样中痕量砷(Ⅲ)

建立了一种测定环境水中痕量砷(Ⅲ)的共振瑞利散射(RRS)新方法.在pH=6.6 KH2PO4-Na2HPO4(PBS)缓冲溶液中和聚乙烯醇(PVA)存在时,I-3与结晶紫(CV)能生成稳定的离子缔合物,导致共振瑞利散射增强.当加入微量As(Ⅲ)时,碘能定量氧化As(Ⅲ),导致共振瑞利散射减弱.在0.1-3.0 μg/25mL浓度范围内,体系的共振瑞利散射改变值△IRRS与As(Ⅲ)浓度呈线性关系,方法检出限为1.0μg/L.已用于环境水样中痕量As(Ⅲ)的测定,结果令人满意.     

偶氮胭脂红B共振瑞利光散射技术测定人血清中的总蛋白

在0.1mol/LH2SO4介质中,偶氮胭脂红B(ACB)与蛋白质结合形成的复合物在599nm处产生强烈的共振瑞利光散射信号.在最佳反应条件下,建立了共振瑞利光散射技术测定蛋白质的新方法.该方法对牛血清白蛋白(BSA)、人血清白蛋白(HSA)及免疫球蛋白(IgG)测定的线性范围分别为0.25-20.0、0.25-20.0及0.25-25.0μg/mL,检出限均小于0.20μg/mL,且大量存在的常见金属离子、氨基酸等共存物质不干扰测定,用于人血清样品中总蛋白质的测定,结果满意.     

氯酚红共振瑞利散射法测定残留氯霉素

建立了测定残留氯霉素的共振瑞利散射法.在pH 9.25的Tris-HCl缓冲溶液中,氯霉素与氯酚红相互作用后,共振瑞利散射显著增强,在407nm处呈现最高散射强度.氯霉素的质量浓度在0.030-0.260μg/mL范围内与ΔⅠRRS成正比,检出限(3Sb/S)为0.0020μg/mL.该法简便、快速、灵敏,可用于虾及奶粉中氯霉素残留测定.     

共振光散射法测定环境水样中痕量锡

基于在Tris-HCl介质中,痕量锡对氯酚红-人血白蛋白-十二烷基硫酸钠体系的共振散射光谱有明显的猝灭作用;考察了它们的光谱特征、影响因素和适宜的反应条件;确定了散射光强度与Sn2 的关系,从而建立了测定痕量锡的共振光散射新方法.该法在室温下进行,操作方便,灵敏度高和选择性好.其线性范围为0.2-4.0μg/L,检出限0.12μg/L,用于环境水样中痕量Sn2 的测定,相对标准偏差小于3.1%,加标回收率为95.5%-100.5%,效果良好.     

新型吖啶染料-蛋白质光散射体系

研究了四磺酸钠-1,6-己二胺二吖啶(TSHDA)与蛋白质的共振光散射增强作用,建立了一种新的蛋白质共振光散射分析体系.实验考察了吖啶探针浓度、缓冲体系pH对体系共振散射光的影响.在pH=3.0的酸性溶液中,蛋白质分子与TSHDA发生结合作用,共振光散射明显增强,最大散射波长位于460nm,体系散射强度随着探针浓度的增加而增大,蛋白质测定线性范围为0.2-1.2μg/mL,检出限9.7ng/mL.分析了血清蛋白合成样品,浓度为0.4-0.8μg/mL的样品测定回收率为97.5%-103.3%,相对标准偏差1.2%-2.6%.     

火焰原子吸收光谱法测定化妆品中痕量汞

建立了火焰原子吸收光谱法间接测定痕量汞,并对铜(Cu)与汞(Hg)发生置换反应的条件及仪器的操作条件分别进行了优化.该方法中,汞在0.05-4.0μg/mL范围内线性良好,平均回收率在85.1%-100.7%之间,RSD为0.6%-2.2%.     

荧光共振能量转移增敏法测定锌

以巯基乙酸为稳定剂合成了CdTe量子点,并利用其与牛血清白蛋白(BSA)组成了荧光共振能量转移体系,考察BSA(供体)和CdTe量子点(受体)之间的荧光共振能量转移的最佳条件,建立了荧光共振能量转移增敏法测定Zn2+的新方法.在pH 7.4的Tris-HCl缓冲溶液中,Zn2+能对能量转移体系中CdTe量子点增敏从而测定锌的含量.Zn2+浓度在0.49-4.88μg/mL浓度范围内与CdTe量子点荧光强度呈现良好线性关系(r=0.9996),检出限为0.13μg/mL,RSD为3.2％,平均回收率为99.5％(n=5).方法适用于果汁饮料中微量锌的测定.     

激光诱导荧光光度法测定食品中的锌

本文利用自行组装的激光诱导荧光 CCD阵列检测器 计算机联用装置 ,建立了一种测定食品中锌的灵敏方法。在乙酸 乙酸铵 ( pH =4 )缓冲溶液中 ,Zn(Ⅱ )与SCN、罗丹明B(RhB)反应生成Zn SCN RhB配合物 ,经乙醚萃取后 ,以YAG激光二倍频 5 32nm为激发波长 ,在 5 80nm处测定荧光强度 ,优化了反应及食品样品的处理条件 ,用于食品试样中锌的测定 ,获得了满意的结果 ,方法检出限 4ng/mL ,加标回收率90 0～ 1 1 0 0 % ,相对标准偏差为 2 0～ 9 7%。     

铅（Ⅱ）-碘化物-溴化十四烷基吡啶三元络合体系的共振瑞利散射光谱及其分析应用研究

在pH4.O-6.0的BR缓冲溶液中,Pb(Ⅱ)与过量的I-形成的络离子[PbI2]2-可与阳离子表面活性剂溴化十四烷基吡啶发生作用形成离子缔合物,引起溶液共振瑞利散射(RRS)显著增强,并出现新的RRS光谱,其最大RRS峰位于308nm.在0.008-6ug/10mL范围内Pb(Ⅱ)的浓度与散射强度成正比,方法简洁灵敏,对Pb(Ⅱ)的检出限(3σa/K)为0.78ng/mL.据此建立了一种简便、快速测定Pb(Ⅱ)的新方法,并成功用于环境水样中Pb(Ⅱ)含量的测定.     

微波消解-火焰原子吸收光谱法测定蒙药乌兰-3中铁和锌

以微波消解系统处理传统蒙药乌兰-3,火焰原子吸收光谱法在选定的仪器工作条件下测定了其中的Fe和Zn.测定Fe和Zn的特征浓度分别为0.18和0.051μg/mL/1%;回收率分别为98.5%-101.3%和98.0%-102.5%;RSD分别为0.40%和1.60%;方法简便、结果令人满意.     

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.