对硝基酚荷移分光光度法测定甲氧苄啶的含量

在水溶液中甲氧苄啶与对硝基酚发生反应生成 1∶ 1的荷移络合物。络合物最大吸收波长 4 0 2 .4 nm,线性范围 2— 2 5 μg/ m L,表观摩尔吸光系数为 ε=8.4 6 8× 10 3 L· mol-1· cm-1,回收率为99.6 7%— 10 0 .4 % ,相对标准偏差为 1.3% (n=5 )。本法测定甲氧苄啶药物制剂含量 ,结果令人满意。     

可变误差多面体分光光度法同时测定联磺甲氧苄啶片三组分的含量

以可变误差多面体法处理多波长分光光度数据同时测定联磺甲氧苄啶片中三组分的含量 ,模拟样品中磺胺甲口恶唑、磺胺嘧啶、甲氧苄啶的回收率分别为 98.89%— 10 1.36 %、98.18%— 10 0 .89% ,98.86 %—10 1.75%相对标准偏差分别为 0 .81%、0 .2 3%、0 .94 %。对 3个批号实际样品的测定结果与药典方法的测定结果吻合。     

甲氧苄啶与茜素红的荷移反应及其测定

建立了一种测定甲氧苄啶的荷移分光光度法。甲氧苄啶与茜素红在水-乙醇溶液中发生电荷转移反应,荷移络合物在528nm处有最大吸收,表观摩尔吸光系数是5.71×103L·mol-1·cm-1,该络合物的组成是1∶1,稳定常数是1.4×105。药物浓度在0—50mg/L范围内服从比耳定律。当甲氧苄啶浓度为25mg/L时,6次测定结果的相对标准偏差为0.86%。利用本法测定了甲氧苄啶制剂中有效成分的含量,并与文献法进行比较,二者结果吻合,回收率在97%以上。     

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 %     

多波长线性回归-零吸收分光光度法在复方制剂中的应用

本文建立一种全新的光谱分析方法 ,多波长线性回归 -零吸收分光光度法 ,并应用于复方新诺明片剂的含量测定。样品经乙醇溶解稀释后 ,不需分离 ,直接在选定波长组 ( n=5 )下 ,分别测定一组吸光度值 ,经线性回归处理后计算出磺胺甲口恶唑与甲氧苄啶含量。二组分的平均回收率分别为 10 1.4± 0 .9%和 97.3± 0 .4 %。本法测量误差小 ,优于传统的双波长分光光度法 ,可用于未经分离的双组分和多组分混合体系的含量测定。     

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。     

CPA矩阵分光光度法同时测定复方磺胺甲噁唑片两组分含量

应用 CPA矩阵分光光度法 ,不经分离直接测定复方磺胺甲唑片中两组分含量。选取 2 2 0、2 2 8、2 5 4、2 6 0、2 6 1nm5个波长作为 CPA矩阵程序的最佳波长点 ,磺胺甲唑的平均回收率和相对标准偏差分别为 :99.7%和 0 .85 % ;甲氧苄氨嘧啶为 99.9%和 1.1%。     

Pd(Ⅱ)-p-NBR-CTMAB分光光度法测定微量钯

在 (1+ 10 )的盐酸介质中 ,CTMAB存在下 ,Pd( )与新试剂 5 - (p-硝基苄叉 )若丹宁 (p- NBR)反应生成 1∶ 2黄色稳定的络合物 ,λmax=4 5 0 nm,ε=6 .0 5× 10 4L· mol-1· cm-1,钯的含量在 0— 18μg/ 2 5 m L范围内符合比耳定律。方法用于以碳为载体的钯催化剂中微量钯的测定 ,结果令人满意     

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。     

磷钼杂多酸-结晶紫分光光度法测定高纯氯化铯中微量磷

以 4 -叔丁基 - 2 (α-甲苄基 )苯酚 (t- BAMBP)萃取分离基体铯 ,磷钼杂多酸与结晶紫染料生成离子缔合物 ,在聚乙烯醇存在下 ,在水溶液中显色。在波长 5 45 nm处 ,其摩尔吸光系数可达 2 .0 1× 10 5L· mol-1·cm-1。方法的回收率为 97%— 10 1% ,相对标准偏差为 0 .8%— 2 .7%。     

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.