盐酸川芎嗪的荧光光谱研究及应用

在 p H6— 10的水溶液中 ,盐酸川芎嗪产生稳定的荧光。最佳激发波长与发射波长分别为 2 95nm和335nm,当盐酸川芎嗪浓度为 5.0× 10 -6— 5.0× 10 -5mol/ L时 ,荧光强度与浓度有良好的线性关系。据此建立了荧光光度法直接测定盐酸川芎嗪注射液中盐酸川芎嗪含量的方法 ,该方法的相对标准偏差为3.51% ,检出下限为 1.0× 10 -6mol/ L。     

钙黄绿素-Pd2+荧光光度法测定甲基对硫磷

报道了甲基对硫磷的荧光光度测定方法.在pH=7.4的缓冲溶液中钙黄绿素有荧光,Pd2+与其反应使其荧光消失.由于甲基对硫磷与Pd2+形成的配合物比钙黄绿素-钯配合物更稳定,加入后可使钙黄绿素游离出来而重显荧光,激发波长和发射波长分别位于492nm和512nm,测得游离的钙黄绿素荧光强度与甲基对硫磷浓度在1.0×10-7-1.2×10-6mol/L范围内呈良好的线性关系,检出限为5×10-8mol/L,空白样品加标回收率为87%-108%,相对标准偏差小于4%.     

邻苯二甲醛的荧光光度法测定

在 p H11.0的缓冲介质中 ,邻苯二甲醛与 l-组氨酸形成的复合物在 5 4 0 nm处发射出强烈荧光 ,由此建立了邻苯二甲醛的荧光光度分析新方法 ,并系统的研究了邻苯二甲醛与 l-组氨酸结合的反应条件。本法检出限为 1.2× 10 -8mol/ L,荧光强度与浓度在 4 .0× 10 -8— 4 .0× 10 -6 mol/ L范围内呈良好的线性关系。将该法用于消毒剂中邻苯二甲醛的测定 ,回收率为 95 .8%— 10 6.5 %。     

Meso-5,10,15,20-四(4-甲氧基苯基)卟啉荧光熄灭法测定铅

基于铅对荧光试剂 Meso- 5 ,10 ,15 ,2 0 -四 (4 -甲氧基苯基 )卟啉 (TMOPP)的荧光熄灭 ,建立了测定微量铅的荧光分析方法。在 p H9.5的 Tris- HCl缓冲体系中 ,最大激发波长和发射波长分别为 4 2 4 nm和6 5 7nm,测定铅浓度的线性范围为 5 .5 0× 10 -7— 7.5 0× 10 -5mol/ L,检出限为 8.5 0× 10 -8mol/ L。用于环境水样中铅含量的分析 ,结果满意。     

微量元素对B族维生素同步荧光分析法影响的研究

本文探讨了钙、镁、铜等 7种微量元素对维生素 B1、B2 、B6的同步荧光光谱的影响。实验结果表明 ,当Ca2 + 的浓度为 1.0× 10 -3mol/ L时 ,VB2 、VB6的同步荧光光谱有显著的增强作用 ;而其他微量元素对VB1、VB2 、VB6的同步荧光有不同程度的猝灭或增强作用。利用 Ca2 + 对 3种维生素荧光强度的增敏作用 ,可以有效地提高同步荧光分析法同时测定 VB1、VB2 、VB6的灵敏度 ,VB1、VB2 、VB6的校准曲线的线性范围分别为 2 .4× 10 -7— 9.0× 10 -6、1.1× 10 -7— 4 .6× 10 -6、7.1× 10 -7— 2 .0× 10 -6mol/ L。采用本方法测定混合样品 ,样品不需分离 ,操作简便、快速     

5-甲氧基色醇-酸性高锰酸钾-甲醛化学发光体系研究与应用

在甲醛的存在下 ,5 -甲氧基色醇 (5 - ML)与高锰酸钾在高氯酸介质中发生化学反应 ,能产生很强的化学发光。本文据此采用流动注射技术研究其发光行为 ,对影响化学发光强度的实验因素进行优化 ,建立了快速灵敏测定 5 - ML的化学发光新方法 ,测定方法的线性范围为 2 .0× 10 -8mol/ L— 4 .0× 10 -5mol/ L,检出限为 7.9× 10 -9mol/ L(S/ N=3) ,相对标准偏差为 2 .4 % (5 .7× 10 -7mol/ L5 - ML;n=10 )。该方法应用于脑脊液样品中 5 - ML含量测定 ,回收率达到 86 .0 %— 97.2 %。文中还对体系的化学发光反应机理进行探讨     

表面活性剂对HPTS荧光的单分子猝灭及胶束作用

研究了各种表面活性剂存在下,8-羟基-1,3,6-三磺酸芘钠盐(HPTS)的荧光光谱,结果表明、表面活性剂对其荧光特性的影响可分为两种类型:单分子猝灭(CMC以下)和胶束作用(CMC以上)。它们分别服从相应的Stern-Volmer稳态猝灭和溶质-胶束作用线性方程。按导出方程对应作图,求得CTMAB的单分子猝灭常数K=2.4×10~5L/mol;CTMAB胶束和TX100胶束对HPTS的键合常数分别为7.4×10~5L/mol和7.0×10~3L/mol。阴离子表而活性剂十二烷基硫酸钠,由于其电性与HPTS阴离子电性的不相容性,对HPTS荧光未见明显影响。     

光泽精化学发光体系的研究与应用

对光泽精化学发光体系的动力学性质、荧光光谱、化学发光光谱及化学发光机理进行研究和探讨。详细研究了光泽精 - H2 O2 - Co( )流动注射化学发光体系的最佳分析条件。结果表明 ,当光泽精 (L c)为 2 .5×10 - 5mol/L、H2 O2 为 0 .5 mol/L、Na OH为 0 .4 mol/L、CTMAB为 2 .0× 10 - 5mol/L时 ,测定 Co( )的校准曲线线性范围为 0 .0 5— 2 0 0μg/m L ,检出限为 0 .0 1μg/m L。对 10μg/m L Co( )连续测定 7次 ,相对标准偏差为 1.7%。     

测定抗坏血酸的流动注射化学发光新体系

基于在酸性介质中甲醛存在下 ,抗坏血酸与高锰酸钾直接化学发光反应 ,建立了测定抗坏血酸的流动注射化学发光的方法 ,该法测定抗坏血酸的线性范围为 3.0× 10 -8— 2 .0× 10 -5mol/ L,检出限为 1.0×10 -8mol/ L ,相对标准偏差为 2 .5 % (1.0× 10 -5mol/ L抗坏血酸 ,n=11)。该法应用于测定维生素 C针剂及片剂中抗坏血酸的测定 ,结果令人满意。     

邻苯二酚荧光光谱法测定铁(Ⅲ)的研究

基于铁(Ⅲ)对荧光试剂邻苯二酚的荧光熄灭,建立了测定微量铁的荧光分析方法.在0.3mol/L的HCl介质中,最大激发与发射波长分别为277nm和313nm,铁的荧光强度与浓度呈良好的线性关系,测定铁浓度的线性范围为1.59×10-5-1.26×10-3mol/L,检出限为7.14×10-6mol/L,常见的共存离子不干扰测定.本方法用于环境水中铁(Ⅲ)的测定,结果满意.     

Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide

Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·10⁴ Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.     

Femtosecond Transform-Limited Pulse Generation by Compensating for the Linear Chirp of SPM Spectra in Dispersion Shifted Fibers

A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.     

Measurement of nonlinear coefficient of optical fiber based on small chirped soliton transmission

We measure the waveform and phase curves of short optical pulses before and after transmission over different lengths of fibers by use of the pulse analyzer with the frequency-resolved optical gating (FROG),and numerically simulate pulse evolution under the experimental conditions.The nonlinear coefficient of the fiber is given by comparing the experimental results with the numerical ones.Difference between the experiment and numerical simulation is analyzed.     

Resonance scattering of canonical elastic shells in absorbing fluid medium

Resonance scattering of elastic spherical shell and cylindrical shell while the surrounding fluid medium has absorption is studied. The normal mode solution derived using exact elastic theory and the separation of variables is still applicable. However, the scattering form function has to be modified for the absorbing medium, otherwise the unreasonable result would be obtained. The backscattering form function in the absorbing medium is redefined, and the form function of elastic spherical and cylindrical shell with vacuum or solid matter filled is calculated in various absorption conditions. The results show that the absorption of surrounding fluid leads to notable attenuation of the coincidence resonances in the mid-frequency, but it has a little influence on the low-frequency resonance scattering induced by the filler inside the shell.     

Single-beam self-referenced phase-sensitive surface plasmon resonance sensor with high detection resolution

A versatile and low-cost single-beam self-referenced phase-sensitive surface plasmon resonance(SPR)sensing system with ultra-high resolution performance is presented.The system exhibits a root-mean-square phase fluctuation of ±0.0028.over a period of 45 min.i.e.a resolution of±5.2×10-9 refractive index units.The enhanced performance has been achieved through the incorporation of three design elements:a true single-beam configuration enabling complete self-referencing so that only the phase change associated with SPR gets detected,a differential measurement scheme to eliminate spurious signals not related to the sensor response,and the elimination of retardation drifts by incorporating temperature stabilization in the liquid crystal phase modulato .Our design should bring the detection sensitivity of non-labeling SPR biosensing closer to that achievable by conventional fluorescence-based techniques.     

Influences of SiO2 protective layers and annealing on the laser-induced damage threshold of Ta2O5 films

Ta2O5 films are prepared on BK7 substrates with conventional electron beam evaporation deposition.The effects of SiO2 protective layers and annealing on the laser-induced damage threshold (LIDT) of the films are investigated.The results show that SiO2 protective layers exert little influence on the electric field intensity(EFI)distribution,microstructure and microdefect density but increase the absorption slightly.Annealing iS effective on decreasing the microdefect density and the absorption of the films.Both SiO2 protective layers and annealing are beneficial to the damage resistance of the films and the latter is more effective to improve the LIDT.Moreover,the maximal LIDT of Ta2O5 films is achieved by the combination of SiO2 protective layers and annealing.     

A stereo matching algorithm using multi-peak candidate matches and geometric constraints

Gray cross correlation matching technique is adopted to extract candidate matches with gray cross correla- tion coefficients less than some certain range of maximal correlation coefficient called multi-peak candidate matches. Multi-peak candidates are extracted corresponding to three closest feature points at first. The corresponding multi-peak candidate matches are used to construct the model polygon. Correspondence is determined based on the local geometric relations between the three feature points and the multi-peak candidates. The disparity test and the global consistency checkout are applied to eliminate the remaining ambiguous matches that are not removed by the local geometric relational test. Experimental results show that the proposed algorithm is feasible and accurate.