高效液相色谱法测定杀虫剂灭幼脲三号的含量

本文采用 Hypersil- ODS2 ( 4 .6mm× 2 50 mm,5μm)柱 ,乙腈 -水 - N,N-二甲基甲酰胺 ( 60∶ 4 0∶ 0 .1)为流动相 ,测定波长为 2 54nm,建立了测定灭幼脲三号的高效液相色谱法。该法线性范围为 2 .0— 80μg/m L,回归方程为 A=52 .4 1C+0 .1936,相关系数 r=0 .9987,精密度为 3.5% ( n=11,C=4 0μg/m L) ,检出限为 0 .0 5μg/m L。平均回收率在 96%— 10 4 %之间 ,已用于 2 5%水剂样品的测定 ,结果令人满意。     

DBC-偶氮胂分光光度法测定水样中钙

在 p H10 .9H3 BO3 - H3 PO4- HAc缓冲介质中 ,Ca2 +与 DBC-偶氮胂生成 1∶ 2蓝色络合物 ,最大吸收波长位于 6 2 0 nm处 ,表观摩尔吸光系数ε62 4nm=1.86× 10 4L· mol-1· cm-1,钙量在 0— 1.4μg/ m L范围内遵守比耳定律。本法用于水样中钙的测定 ,结果令人满意。     

原子吸收法测定三七中的铜、镉和锂

干法灰化、硝酸浸取盐分 ,原子吸收法同时测定三七中的铜、镉、锂。优化了仪器工作条件 ,对盐酸、高氯酸、硫酸、共存元素干扰进行了试验。该法对铜、镉、锂的检出限分别为 0 .0 0 2 3μg/ m L、0 .0 0 2 6μg/ m L和0 .0 0 2 0 μg/ m L;测定精密度分别为 2 .5 0 %、10 .0 8%和 9.0 2 % ;回收率分别在 96 %— 10 3%、92 %— 10 8%和 96 %— 10 4 %之间。     

中性红褪色光度法测定蒙药铜灰体系中产生的过氧化氢含量

在 p H=3.5的乙酸 -乙酸钠缓冲溶液中 ,用中性红褪色光度法测定了蒙药铜灰体系中产生的过氧化氢的含量。过氧化氢在 0— 5 0μg/ 2 5 m L范围内与 lg(A0 / A)值呈线性关系 ,线性回归方程为 lg(A0 / A) =2 .5× 10 -3+1.0 5× 10 -2 C双氧水 (μg/ 2 5 m L) ,r=0 .9999     

偶氮胂(Ⅲ)光度法测定催化剂中的镧

研究了分光光度法测定催化剂中的镧含量。在 p H=2 .8— 3.0条件下 ,镧与偶氮胂 ( )显色生成稳定络合物 ,最大吸收波长为 6 5 8nm,表观摩尔吸光系数 ε658=5 .2 3× 10 4L· mol-1· cm-1,线性范围为 0—5 0μg/2 5 m L ,相对标准偏差 <2 % ,加标回收率为 98%— 10 2 % ,方法准确、可靠。     

亚叶酸钙与对硝基酚荷移反应的研究

本文主要研究了在水溶液中亚叶酸钙与对硝基酚发生荷移反应生成稳定的 1∶ 1络合物 ,络合物的最大吸收波长为 4 0 2 .2 nm,表观摩尔吸光系数为 ε=5 .2 5 5× 10 2 L· mol-1· cm-1,线性范围为 5 0—12 0 0 μg/ m L。回收率为 99.5 8%— 10 2 .6 0 % ,相对标准偏差为 1.4 3%。方法简单、快速、准确度高 ,可用于亚叶酸钙制剂含量的测定。     

胶束增溶光度法测定土豆中微量铝

采用 Al( ) - CAS- CTMAB- OP胶束增溶分光光度法测定了土豆中的铝。实验表明 ,在 p H=6 .5的HAc- Na Ac缓冲溶液中 ,λmax=6 2 0 nm处 ,Al3 在 0— 0 .2 4 μg/ m L范围遵守朗伯 -比耳定律 ,回归方程、相关系数、回收率和 RSD分别为 :A=4 .773C- 0 .0 1 3、r=0 .9995 (n=4 )、98.8%— 1 0 2 %和 0 .5 3%。不同产地土豆样品中 Al含量为 :1号样品 1 6 8.8μg/ g,2号样品 1 6 7.0 μg/ g     

碘蓝分光光度法测定微量铬（Ⅳ）

基于在酸性介质中 ,重铬酸钾与碘化钾、淀粉的显色反应 ,建立了碘蓝分光光度法测定微量铬 ( )的方法。铬 ( )浓度在 0— 0 .6μg/ m L范围内有良好的线性关系 ,方法的相对标准偏差为 1.3% ,表观摩尔吸光系数为 5 .6 3× 10 4 L· mol- 1 · cm- 1 ,检出限为 2 .0× 10 - 3μg/ m L     

新显色剂四(4-甲氧基-4-磺酸基苯基)卟啉与Fe~(3+)的高灵敏反应的研究与应用

本文提出以四 (4 -甲氧基 - 4 -磺酸基苯基 )卟啉 (p- OCH3TPPS4 )为显色剂 ,在 p H=3.5— 5 .5的条件下测定痕量铁的新体系 ,络合物最大吸收波长为 4 4 6nm,表观摩尔吸收系数ε=2 .0× 10 4 L· mol-1· cm-1,Fe3+ 在 0— 10 μg/ 2 5 m L 范围内符合比耳定律 ,应用本法测定花生仁皮中铁 ,回收率可达 95 .0 %—10 8.4 %     

聚丙烯酸钠增敏抑制高碘酸钠氧化夜蓝褪色光度法测定痕量锡

建立了聚丙烯酸钠增敏抑制高碘酸钠氧化夜蓝褪色光度法测定痕量锡的新方法。该方法基于聚丙烯酸钠增敏锡 ( )抑制高碘酸钠氧化夜蓝褪色反应 ,在最佳条件下 ,锡 ( )的含量在 0 .2 0— 2 .0 μg/L范围内与 ΔA值呈线性关系 ,其校准曲线的回归方程 ΔA=0 .0 0 788+ 0 .10 9CSn( ) (μg/L) ,r=0 .9992 ,检出限(L D) =1.1× 10 -11g/m L。本方法用于测定人发样品和水样中的锡含量 ,其相应的回收率为 10 0 .3%和10 0 .0 %。相对标准偏差为 3.4 %和 3.2 %。     

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.