5-Br-PADAP光度法测定磷铁中的钒

本文研究了在H2O2存在下，用5－Br-PADAP光度法，测定磷铁中钒的条件及配合物组成。配合物在波长590nm处有最大吸收，其摩尔吸光系数ε＝5.43×10^4L·mol^-1·cm^-1；钒量在2－20μg/25mL范围内符合比耳定律；钒与5－Br-PADAP的配合比为1：2。     

钒（V）—7—碘—8—羟基喹啉—5—磺酸显色体系测定钢样中的钒

研究了7－碘－8－羟基喹啉－5－磺酸（H2QSI）在乙醇存在下分光光度法测定钒（V）的最佳条件。在乙醇存在下pH4的硫酸介质中，（H2QSI）与V（V）形成了红棕色配合物，最大吸收位于506nm处，表观摩尔吸光系数εmax=2.9×10^3L·mol^-1·cm^-1，有色配合物组成为V（V）：（H2QSI）＝1：3。钒（V）在0－14μg/25mL符合比耳定律。本法用于钢样中的测定，结果满意。H2QSI是光度分析中的一种显色剂，近年来，8－羟基喹啉类试剂用于钒（V）的测定尚未见报道。本文研究了V（V）与H2QSI的显色反应条件及组成，在pH4的乙醇介质中，V（V）与H2QSI生成红棕色配合物，ε506nm=2.910^3L·mol^-1·cm^-1。本方法用于低碳合金钢中钒的测定，结果满意。     

新显色剂PMNHA的合成、分析鉴定及其在分光光度测定钒中的应用

用1－甲基－2－萘甲酰基替换N－苯甲酰苯基羟胺（BPHA）的苯甲酰基，合成了一种新显色剂N－苯基－1－甲氧基－2－萘甲酰氧肟酸（N-phenyl-1-methoxy-2-naphthoyl hydroxamic acid，缩写为PMNHA）。根据元素分析、差热分析、质谱分析、核磁共振、红外光谱分析，确定PMNHA的组成和结构为 。该试剂的三氯甲烷溶液能很快从2.25-4.50mol/L HCl中萃取钒（V）的紫色配合物，其配合物最大吸收在540nm，很多外来离子，特别是大量的钛不干扰钒的测定，钒含量在0－28μg·g^-1范围遵守比耳定律。我们建立了一个高选择性和简便的用显色剂PMNHA分光光度测定钒的方法。     

4-(2-吡啶偶氮)-间苯二酚光度法测定煤灰中钒

在 0 .6 mol· L-1的硫酸介质中 ,钒 - PAR-羟胺生成红色络合物 ,最大吸收波长为 5 5 0 nm,摩尔吸光系数ε=1.91× 10 4L· mol-1· cm-1,钒含量在 0— 80μg/ 2 5 m L范围内符合比耳定律。本方法灵敏、简便 ,用于测定煤灰中的钒 ,结果满意     

邻硝基苯基荧光酮-钛-吐温-40体系分光光度研究及硅铁合金中钛的测定

系统研究邻硝基苯基荧光酮与钛的显色反应，试验多种表面活性剂对体系的作用及相应的光度性质，从而确定Ti(Ⅳ）－ONPF－Tween－40为较佳体系，在0.084-0.15mol/L HCl介质中形成紫红色配合物，其波长在530nm处的表观摩尔吸光系数ε为1.79×10^5L·mol^-1·cm^-1，配合物组成中Ti:ONPF＝1：4，钛浓度在0－1.2μg/10mL范围内服从比耳定律。应用于直接测定硅铁合金中钛，结果满意。     

5—Br—PADAP测定地下水中钒

本文研究了ＨＣｌ－ＫＣｌ缓冲体系中钒（Ｖ）与５－Ｂｒ－ＰＡＤＡＰ形成配合物的条件及配合物的带电性质。提出一个灵敏、简便、快速测定钒的分光光度法。配合物的表观摩尔吸光系数为３．８×１０＾４，最大吸收波长为５８８ｎｍ，钒（Ｖ）与５－Ｂｒ－ＰＡＤＡＰ的配合比为１：１。含钒量在０－２０μｇ／２５ｍＬ范围内符合比尔定律。分析季地下水中钒，结果满意。     

银－2－羧基－4－溴苯基重氮氨基偶氮苯－Triton X－100－SDS显色体系的研究及应用

新三氮烯类试剂之一，２－羧基－４－溴苯基重氮氨基偶氮苯，在ｐＨ１１．０的Ｎａ_２Ｂ_４Ｏ_７－ＮａＯＨ缓冲介质中，有非离子表面活性剂ＴｒｉｔｏｎＸ－１００及阴离子表面活性剂ＳＤＳ的共同存在下，可与Ａｇ（Ⅰ）生成稳定的２∶１红色配合物，红色配合物的λ_（ｍａｘ）＝５４０ｎｍ，表观摩尔吸光系数ε_（５４０）＝１．１０×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）。Ａｇ量在０－１０μｇ／２５ｍＬ符合比尔定律。方法用于工业废水中痕量Ａｇ的测定，结果满意。     

5－Br－PADAP测定地下水中钒

本文研究了ＨＣｌ－ＫＣｌ缓冲体系中钒（Ⅴ）与５－Ｂｒ－ＰＡＤＡＰ形成配合物的条件及配合物的带电性质。提出一个灵敏、简便、快速测定钒的分光光度法。配合物的表观摩尔吸光系数为３．８×１０~４，最大吸收波长为５８８ｎｍ，钒（Ⅴ）与５－Ｂｒ－ＰＡＤＡＰ的配合比为１：１。含钒量在０—２０μｇ／２５ｍＬ范围内符合比尔定律。分析了地下水中钒，结果满意。     

磷钨钒杂多酸-TMBPS电荷转移配合物光度法测定钒

提出了一种基于形成磷钨钒杂多酸 3,3′,5 ,5′ 四甲基联苯胺 -丙磺酸 (TMBPS)电荷转移配合物的分光光度法测定钒 (Ⅴ )的新方法 ,其最大吸收波长为 45 0nm ,摩尔吸光系数 2 74× 10 4 L·mol-1·cm-1,线性范围 0 0 2～ 1μg·mL-1。采用浮选反萃取分光光度法 ,可提高测定灵敏度 ,其表观摩尔吸光系数增至 3 10×10 5L·mol-1·cm-1。     

钒(Ⅴ)-5-Br-PADAP-H2O2-吐温-80显色体系的研究与应用

研究了在非离子表面活性剂吐温 - 80存在下 ,钒 ( )与 2 - [(5 -溴 - 2 -吡啶 ) -偶氮 ]- 5 -二乙氨基苯酚 (5 -Br- PADAP)及 H2 O2 的显色反应。实验表明 :在 p H1.5— 4 .0范围内 ,钒 ( )与 5 - Br- PADAP、H2 O2 形成稳定的配合物 ,最大吸收峰位于 5 95 nm处 ,表观摩尔吸光系数为 6 .2× 10 4L· mol-1· cm-1,配合物组成比为钒 ( )∶ 5 - Br- PADAP∶ H2 O2 =1∶ 1∶ 1。钒含量在 0— 15μg/ 2 5 m L范围内服从比耳定律。该方法灵敏度较高 ,用于合成水样中钒的测定 ,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.