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。     

红霉素琥珀酸乙酯与茜素磺酸钠的荷移反应研究

研究了红霉素琥珀酸乙酯与茜素磺酸钠的荷移反应 ,建立了一种测定红霉素琥珀酸乙酯的方便、快捷的荷移分光光度法。红霉素琥珀酸乙酯与茜素磺酸钠在乙醇 -水介质中发生电荷转移反应 ,荷移络合物在波长 5 30 nm处有最大吸收 ,表观摩尔吸光系数为 7.90× 10 3 L· mol-1·cm-1,该络合物的组成为 1∶ 1,稳定常数是 1.3× 10 5。药物浓度在 10— 10 0 mg/L范围内服从比耳定律。当红霉素琥珀乙酯浓度为 5 0 mg/L时 ,6次测定结果的相对标准偏差为 1.33%。回收率 >98%。本法测定了红霉素琥珀酸乙酯片中有效成分的含量与药典法比较 ,二者结果吻合。     

琥乙红霉素与水杨基荧光酮的荷移配合物生成光度法分析

琥乙红霉素与水杨基荧光酮（SAF）在乙醇溶液中发生荷移反应,荷移络合物在522nm处有最大吸收,表观摩尔吸光系数ε为8.5×103L.mol^-1.cm^-1,荷移络合物的组成比为1∶1,稳定常数是105.2,药物浓度在1.724—129.3mg/L范围内服从比耳定律。当琥乙红霉素的浓度为68.96mg/L时,8次测定结果的相对标准偏差为0.52%。测定了琥乙红霉素片剂中有效成分的含量,并与药典法比较,结果基本吻合,回收率在98.3%以上。     

荷移分光光度法测定甲氧氯普胺

采用分光光度法研究了甲氧氯普胺与茜素红之间的荷移反应。确定了反应条件,建立了一种快速简便测定甲氧氯普胺的荷移分光光度法。实验表明,甲氧氯普胺与茜素红在乙醇—水介质中,室温条件下即可形成稳定的1：2型荷移络合物,该络合物的λmax=528nm,表观摩尔吸光系数为4.66×10^3L·mol^-1·cm^-1。甲氧氯普胺药物质量浓度在10-70mg/L范围内服从比耳定律,相关系数为0.9991。测定结果的相对标准偏差为1.08%（n=6）,回收率为98.2%—101.6%。     

琥乙红霉素与茜素的荷移反应及其测定

琥乙红霉素与茜素在水 -乙醇介质中反应 ,生成电荷转移络合物 ,最大吸收波长为 5 46 nm,表观摩尔吸光系数为 9.91× 10 3 L· mol-1·cm-1。以等摩尔连续变换法和斜率比法测得荷移络合物的组成比为1∶ 1,稳定常数是 1.6× 10 4。浓度在 0— 80 mg/ L范围内服从比耳定律。 6次测定结果的相对标准偏差为1.4 1%。测定了琥乙红霉素样品中有效成分的含量 ,与文献结果基本吻合 ,回收率在 97.0 %以上     

荷移分光光度法测定氧氟沙星及其分析应用

研究了氧氟沙星与茜素红在水系中发生的荷移反应。确定了最佳反应条件,建立了一种快速简便测定氧氟沙星的荷移分光光度法。结果表明,荷移络合物的最大吸收波长是522nm,表观摩尔吸光系数是8.64×103L.mol-1.cm-1,络合比为1∶1,氧氟沙星的浓度在0.5—25mg/L范围内服从比耳定律,相对标准偏差为0.8%,检出限为0.38mg/L。用于氧氟沙星片剂含量的测定,回收率在97.0%—101.0%以上。此方法简单、灵敏度较高、选择性较强,结果令人满意。     

克拉霉素与醌茜素的荷移反应及其测定

克拉霉素与醌茜素在乙醇 -水介质中发生电荷转移反应 ,形成 1∶ 1的电荷转移络合物。该络合物在5 80 nm处有最大吸收 ,表观摩尔吸光系数为 3.74× 1 0 3 L·mol-1· cm-1 ,稳定常数是 2 .6× 1 0 5。建立了一种快速测定克拉霉素的荷移分光光度法。药物浓度在 0— 1 0 0 mg/ L范围内服从比耳定律。本法测定了克拉霉素制剂中有效成分的含量 ,与文献法结果基本吻合。     

TCNQ分光光度法测定利福平

用分光光度法研究了利福平(Rifampicin)与7,7,8,8-四氰基对二次甲基苯醌(TCNQ)之间的荷移反应.实验表明,利福平与TCNQ间的反应在丙酮介质中进行,形成的络合物在744nm和844nm有两个吸收峰,表观摩尔吸光系数分别是2.38×104L·mol-1·cm-1和4.18×104L·mol-1·cm-1;药物浓度在1.65-57.6mg·L-1范围内服从比耳定律.用摩尔比法和等摩尔连续变化法测得荷移络合物中利福平与配体的摩尔比为1∶1.用所研究方法测定了药物中利福平的含量结果令人满意,相对标准偏差为0.57％(n=5),回收率在99.0％-99.4％之间.     

四氯苯醌荷移反应分光光度法测定洛美沙星

研究了在pH 6.86磷酸标准缓冲溶液中,电子给体洛美沙星与电子受体四氯苯醌之间的荷移反应产物的紫外光谱性质.用摩尔比法和平衡移动法测定络合物的组成比为1∶1.洛美沙星的浓度在0-17mg/L范围内符合比耳定律,r=0.9999.在测定波长336nm处,络合物的表观摩尔吸光系数为1.22×104L·mol-1·cm-1.方法用于洛美沙星胶囊的测定,其回收率为99.1％-102.3％,6次测量相对标准偏差为1.5％-2.1％.     

氟罗沙星荷移络合物在胶束体系中的紫外光谱特性及应用

采用紫外光谱法研究了π电子受体四氯对苯醌(TCBQ)与电子供体氟罗沙星的荷移反应,结果表明,氟罗沙星与TCBQ在十二烷基硫酸钠(SDS)胶束体系中能形成稳定的荷移反应络合物,使其吸光度明显增强。据此建立了氟罗沙星简单、快速、准确和灵敏的分析方法。氟罗沙星浓度在0. 6～24 mg·L-1范围内符合比尔定律。r= 0.999 3。荷移络合物在326 nm处的表观摩尔吸光系数为3.3×104 L·mol-1·cm-1。本方法用于片剂中氟罗沙星含量的测定, 其回收率为99.3%～99.8%, 相对标准偏差为0.9%～2.3%。     

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.