富氧空气-乙炔火焰原子吸收光谱法测定钡

于试样溶液中加入0．25％镧和0．5％氯化钾，在富氧空气－乙炔火焰的条件下，可有效地降低干扰及电离效应，具有较高的原子化效率，方法的检出限为0．001μg/mL，灵敏度为0．12μg/mL，可用于矿泉水中钡的测定。     

富氧空气-乙炔火焰原子吸收光谱法测定钨

试样在2％磷酸介质中，加入0．5％过硫酸钾，在富氧空气－乙炔火焰的条件下用原子吸收光谱测定钨，可有效地抑制干扰，具有较高的原子化效率，方法的检出限为0．23μg/mL，灵敏度为2．4μg/mL。     

流动注射化学发光法测定头孢氨苄

基于头孢氨苄（CEX）降解产物中有还原性的巯基（SH）基团，在0．2mol/L的H2SO4介质中，能与Ce(Ⅳ）产生化学发光反应，罗丹明6G可敏化其发光强度，结合流动注射技术，考察了本体系的化学发光条件，建立了一种测定头孢氨苄的化学发光新方法。该法线性范围为0．05－10．0μg/mL，相关系数r=0.9984,检出限为0．02μg/mL，对1．0μg/mL的头孢氨苄标准溶液进行连续9次平行测定，相对标准偏差为1．4％。     

荧光素汞荧光熄灭法测定海带中微量碘

本文研究表明，在pH=6.0-11的磷酸协缓冲溶液中，碘离子对荧光素汞的荧光具有熄灭作用，据此建立了碘离子的荧光熄灭测定新方法。碘离子浓度在0．0768－4．365μg/mL范围内具有良好的线性关系，检出限为0．038μg/mL。该方法操作简单，灵敏度高，选择性好，可用于海带中碘含量的测定。     

铟(Ⅲ)-8-羟基喹啉-核酸三元荧光体系的研究与应用

基于核酸对铟(Ⅲ）-8-羟基喹啉配合物的荧光增强作用，应用铟(Ⅲ)-8-羟基喹啉为荧光探针，研究了铟(Ⅲ)-8-羟基喹啉与核酸的作用，建立了新的核酸测定方法。在最佳条件下，ctDNA、hsDNA、smDNA和yRNA的线性范围分别为0．20-1．40μg／mL、0．20-1．60μg／mL、0．10—1．40μg／mL、0．20—1．20μg／mL。检出限(3o／K)分别为0．004μg／mL，0．002μg／mL，0．002μg／mL，0．002μg／mL；测定实际样品，回收率为90．9％-103．5％。     

富氧空气-乙炔火焰原子吸收光谱法测定地质样品中钛

向钛的标准系列溶液中加入200μg／mL的AlCl3溶液，在富氧空气-乙炔高温火焰中有效地提高了钛化合物的原子化效率，还能较好地克服共存元素的化学干扰。在优化的测定条件下，直接测定了地质样品中的钛。方法的检出限CL(K=3)为0．25μg／mL，对GBW 07302管理样品测定6次，RSD为3．81％。     

超声提取-反相高效液相色谱法测定牛膝中蜕皮甾酮

比较了超声提取与回流提取法在提取牛膝中活性成分蜕皮甾酮的提取效率，在频率为1100kHz时超声提取40min可获得稳定的提取效率。采用Shim-Pack CLC-ODS色谱柱，甲醇：水＝40：60（V／V，％）为流动相，在波长248nm下，测定牛膝中蜕皮甾酮，线性范围为2－200μg/mL（r=0．9998），检出限为0．052μg/mL（S/n=3），加标加收率为98．3％－103％。     

荧光法直接测定环境水中痕量苯酚

研究了荧光分光光度通过控制酸度直接测定环境水中苯酚的新方法。在pH＝1时，直接测定苯酚的含量，波长为λex／λem＝270／297nm，检出限为4．0g/mL，线性范围为0－3．2μg/mL。回收率为99％－101％。     

苦瓜中维生素C含量的测定

建立苦瓜中维生素C含量直接测定新方法。以10%盐酸溶液为溶剂,采用紫外分光光度法测定含量。维生素C在0—10μg/mL浓度范围内与吸光度呈良好的线性关系,回归方程为：y=0.04746C＋0.00109,r=0.9997。检出限为0.023μg/mL,加标回收率在94.8%—101.1%之间。该法操作简单,干扰离子少,结果准确,测量快速、准确度和灵敏度高,可应用于维生素C含量的测定。     

考马斯亮蓝催化分光光度法测定微量甲醛

在H3PO4溶液中,甲醛强烈催化KB rO3氧化考马斯亮蓝褪色,确定了反应最佳条件,测定了反应级数、表观速率常数和表观活化能,确立了反应速率方程,探讨了反应机理,建立了一种测定甲醛的新方法。该方法的检出限为0.091μg/mL,线性范围为0—2.1μg/mL。方法选择性好,直接用于废水中甲醛的测定,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.