催化动力学分光光度法测定痕量双酚A

在盐酸介质中,双酚A对溴酸钾氧化罗丹明B具有促进作用,据此建立了动力学分光光度测定痕量双酚A的方法。方法的线性范围是0.1—0.4mg·L-1,检出限为0.01mg·L-1,回收率在84.0%—115.0%之间。该方法用于塑料包装杯、地表水中双酚A的测定,结果满意。     

环境样品中痕量铝的现代光度分析研究新进展

论文综述和评论了近年来环境样品中痕量铝的光度分析研究新进展。重点论述了现代光度分析法测定环境样品中铝的研究新进展 ,内容包括 :胶束增溶分光光度法、双波长分光光度法、导数分光光度法、催化光度法、固相光度法、流动注射光度法。对普通光度法和胶束增溶光度法的反应体系、测定条件、摩尔吸收系数 (ε)或检出限、线性范围及其应用进行了归纳总结 ,评述了各种光度法测定的优劣 ,展望了光度法测定痕量铝的发展前景     

发酵过程中菌液浓度的检测

采用分光光度测量发酵菌液浓度,选择波长215nm,首先测定样品中菌液的吸光度,再根据校准曲线获得菌体浓度。该法设备简单,操作方便、快速,测量相对误差小于3%,相对标准偏差小于2%,精密度高,准确度好,适合于生产监控。     

分光光度法测定丙烯中的痕量硫

建立了分光光度法测定丙烯中痕量硫的方法,当样品中硫质量分数在0-1 mg/kg内,样品中硫含量与吸光度呈良好的线性关系,检出限为0.1 mg/kg.该方法适用于丙烯中痕量硫的测定.     

工作场所空气中磷化氢测定方法的改进

对工作场所空气中磷化氢的钼酸铵分光光度测定方法进行了改进.试验表明,改进的方法准确、稳定性好、操作简便,与钼酸铵分光光度法结果吻合良好.将本法应用于实际样品的测定,结果满意.     

分光光度法测定桔皮中橙皮苷含量

用分光光度法测定桔皮中橙皮苷的含量 ,显色体系最大吸收波长在 4 2 2 nm处 ,表观摩尔吸光系数ε=4 .2 1× 10 4 L· mol-1· cm-1,橙皮苷含量在 0— 60μg/ m L范围内符合比耳定律。该法简便可靠 ,可获得满意的分析结果     

荷移-UV分光光度法测定杨树桑黄提取物总黄酮含量

建立了荷移-UV分光光度法测定杨树桑黄提取物中总黄酮含量的方法.以芦丁为对照品,AlCl3为受电子试剂,408.2nm处测定荷移复合物吸光度.杨树桑黄提取物总黄酮浓度在8-40μg·mL-1范围内线性良好,RSD为1.48％,平均回收率为98.44％.该方法稳定、简便、快速,适用于杨树桑黄中黄酮类物质含量测定.     

紫外分光光度法测定岩盐中的硝酸盐

沸水溶解岩盐样品,过滤除去水不溶物,紫外分光光度法分别测定滤液在220nm和275nm处的吸光度值,计算出样品中NO3-含量。结果表明,3种不同类型岩盐样品中NO-3的回收率为98.0%—102.0%,相对标准偏差为1.03%—2.92%（RSD,n=5）。与百里酚分光广度法和离子色谱法相比,紫外分光光度法简单快速,准确度、灵敏度、精密度高,适用于岩盐样品中硝酸盐含量的快速检测。     

血液中碳氧血红蛋白饱和度的双波长分光光度简便测定法

本文报道血液中碳氧血红蛋白基于吸光度差值的双波长分光光度检测方法,检血用含有Na2S2O4的溶液释得到HbCO和Hb的双组分溶液,Hb有相同吸光度的双波长处的吸光度差值只反映HbCO的浓度,HbCO有相同吸光度的双波长处的光度差值只反映Hb的浓度,测定了这此吸光度差值可以利用约定的公式计算出检血的HbCO%.进行比较实验,当检出是由HbCO和Hb溶液混合制备时,本方法测定值与理论值严格一致,当检血是中毒案件检血时,本方法测定值与可靠方法的测定值严格一致.     

非线性偏最小二乘导数分光光度法同时测定复方新诺明中二组分的含量

构造了导数光谱与多组分浓度间的非线性模型 ,以偏最小二乘法估计模型参数 ,建立了同时测定两组分的非线性偏最小二乘导数分光光度法 ,方法用于复方新诺明中磺胺甲唑SMZ(Sulfamethoxazole)和甲氧苄啶TMP(Trimethoprim)含量的测定 ,10份模拟样中SMZ ,TMP的回收率分别为 99 8%和 10 0 1% ,RSD分别为 1 3%和 1 6 %。结果明显好于线性偏最小二乘导数分光光度法。用该法测定复方新诺明片中的二组分含量测定结果与药典方法一致 ,该法为复方制剂的分光光度分析提供了更为理想的新途径。     

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.