胡麻卵磷脂鉴别检查与紫外吸收光谱定量分析

对精制胡麻卵磷脂进行了化学反应鉴别,反应呈阳性;并进行了酸值、碘值、丙酮不溶物、乙醇可溶物等项目的检查,结果表明各项指标达到国家标准.扫描胡麻卵磷脂样品和磷脂酰胆碱标准品红外光谱,结果表明样品与标准品在官能团区及指纹区吸收峰峰形及峰位置吻合.紫外光谱扫描发现胡麻卵磷脂样品207nm波长处有最大吸收,采用紫外吸收光谱法及校准曲线法,测定了样品中磷脂酰胆碱的含量;结果表明,在0.0102-0.0512mg/mL浓度范围内,磷脂酰胆碱吸光度与浓度呈现良好的线性关系(r=0.9904),平均回收率为99.09％(RSD=0.84％),样品中磷脂酰胆碱含量为88.6％ (RSD-0.36％).该方法具有良好的重现性和稳定性,为卵磷脂样品中磷脂酰胆碱含量的快速测定提供了参考依据.     

双波长薄层扫描法测定刺山柑不同部位盐酸水苏碱的含量

采用双波长薄层扫描法测定刺山柑不同部位盐酸水苏碱的含量。展开剂:正丁醇-盐酸-乙酸乙酯(8∶3∶1);波长分别为λS=525nm,λR=700nm。结果表明,盐酸水苏碱点样量在2.03—16.24μg范围内线性关系良好,平均回收率为96.83%,RSD=2.00%。刺山柑植株中盐酸水苏碱的含量从高到低依次为:根、花蕾、果实、茎及叶。该方法简便、准确、重现性好,可用于刺山柑不同部位盐酸水苏碱含量的测定。     

HPLC-ELSD测定不同厂家中/长链脂肪乳注射液中的溶血磷脂酰胆碱

采用高效液相色谱-蒸发光散射检测器(HPLC-ELSD)测定不同厂家中/长链脂肪乳注射液中溶血磷脂酰胆碱(LPC)的含量。采用Lichrospher Diol色谱柱(250mm×4.6mm,5μm),以正己烷-异丙醇-水(29.5:59:11.5,V/V/V)为流动相A,正己烷-异丙醇(43:57,V/V)为流动相B,进行梯度洗脱,流速1mL/min,漂移管温度85℃,气体流速2.7L/min。结果溶血磷脂酰胆碱在0.299—2.99mg/mL浓度范围内线性关系良好(r=0.9999),平均回收率为99.62%,RSD为0.89%。不同厂家产品中溶血磷脂酰胆碱的含量为0.92—1.34mg/mL。方法准确、方便,可以准确测定中/长链脂肪乳注射液中溶血磷脂酰胆碱的含量。     

基于荧光光谱的脂质体制备与稳定性的研究

利用L-α-磷脂酰胆碱和胆固醇分子制备脂质体体系,通过监测脂质体内部包裹的对pH变化敏感的荧光指示剂8-羟基芘-1,3,6-三磺酸三钠盐的荧光强度变化实现对脂质体稳定性的表征。研究发现,在脂质体磷脂膜中引入一定比例的胆固醇分子有助于提高脂质体的稳定性(L-α-磷脂酰胆碱∶胆固醇=4∶1)。利用温水浴-液氮多次冻融循环,在强烈外界温差作用条件下,L-α-磷脂酰胆碱和胆固醇形成的贴壁薄膜重组成内外两侧均为亲水头部而疏水尾部均指向脂双层膜内部的稳定脂质体,在10min内稳定性高达99%,9 200s内稳定性依然可以达到92%。基于以上研究成果,我们在脂质体的外部环境中引入K+载体缬氨霉素,结果表明缬氨霉素可以成功的插入至磷脂双分子层膜中并高效运输K+。     

花生中黄酮的荧光分光光度法测定

研究了花生中黄酮的荧光分光光度法测定条件,用芦丁为标准样品,在荧光激发波长λex=265nm,发射波长λem=331nm处测定了花生中黄酮的含量,回归方程为y=5.0775x＋46.716,相关系数r=0.9994,精密度（RSD）为0.28%（n=5）,加标回收率为93.75%—115.00%,该方法用于测定花生中黄酮的含量结果准确。     

高效薄层色谱法测定棉籽油中游离棉酚含量

利用高效薄层色谱法测定棉籽油中游离棉酚的含量.自动点样仪、自动展开仪、扫描仪均采用瑞士卡玛薄层色谱系统;使用含0.5%CMC-Na的硅胶G高效薄层板;以甲苯-甲酸乙酯-甲酸-丁酮(体积比50:8∶1.5∶1)为展开剂;饱和三氯化锑氯仿溶液为显色剂;扫描方式:双波长紫外反射法;检测波长:550nm,参比波长:750nm....     

荧光法直接测定环境水中邻羟基苯甲酸和苯酚混合物的含量

本文研究了用荧光分光光度法测定环境水中苯酚和邻羟基苯甲酸的含量,在pH＞11时直接测定邻羟基苯甲酸的含量,波长为λex/λem=289/338nm,检出限为3.4ng/mL,线性范围0-6.0μg/mL.在pH=6,波长为λex/λem=270/297nm测得苯酚含量,检出限为4.0ng/mL,线性范围在0-0.85μg/mL,回收率为98%-101%,结果满意.     

荧光分光光度法测定红丝线提取物中的紫蓝素

建立了荧光分光光度法测定红丝线提取物中紫蓝素含量的方法.在pH值为8.0的条件下,荧光激发波长λex=590nm,发射波长λem=625nm处测定样品中紫蓝素的含量.回归方程为y=515.81x+59.496,相关性系数r=0.9996,精密度(RSD)为0.46％(n=7),加标回收率为95.0％-99.4％.该方法用于测定红丝线提取物中紫蓝素的含量结果准确.     

紫外-可见分光法定量测定谷氨酸的比较

用紫外-可见分光光度法测定低浓度谷氨酸溶液:以λ=207nm为测定波长,谷氨酸浓度在0.02-0.12g/L范围内有很好的线性;以λ=401nm和λ=568nm为测定波长,茚三酮衍生后的谷氦酸溶液在0.02-0.07g/L范围内有很好的线性.此方法快速简便,结果准确,适合不同成分的产品分析与样品含量检测.     

薄层扫描法测定消渴丸中葛根素的含量

以氯仿-甲醇-乙酸乙酯-水（3∶3∶4∶1）为展开剂,在硅胶GF254薄层板分离葛根素,采用薄层扫描法,以254 nm为检测波长测定消渴丸中葛根素的含量.结果表明葛根素在2.0-10.0μg范围内呈良好的线性关系,y=1064x＋ 16290,r=0.9949,平均回收率为101.1％,RSD=1.7％（n=5）.该法简便、准确、重现性好,可作为消渴丸质量控制的方法.     

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.     

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.     

Fiber Modal Index Measurements Based on Fiber Gratings

A novel method based on fiber gratings for measuring the effective indices of fiber modes is proposed. The effective index difference between the core mode and a cladding mode was obtained by analyzing the interference fringe of a pair of cascaded long-period fiber gratings. In order to extract the core mode index from the measured index difference, an index matching oil immersion method is proposed. By analyzing the interaction between the cladding mode and the oil applied on the cladding surface, the mode order and the effective index of the involved cladding mode might be calculated. Experimental results about the interference fringe shifts induced by the oil index and the oil-applied length are also presented.     

Optical Pulse Compression Schemes That Use Nonlinear Bragg Gratings

Nonlinear optical pulse compression of picosecond pulses typically requires long lengths of optical fiber and multiple components. Periodic structures, such as fiber Bragg gratings, are highly dispersive at wavelengths outside of the photonic bandgap. This implies that such gratings can be used as very short all-fiber compressors. In this paper a number of such compression schemes are reviewed involving uniform and nonuniform fiber Bragg gratings, relying on both soliton and nonsoliton compression principles. Experimental results supporting the corresponding underlying theory are also presented. Finally, an extension of one of the compression schemes is shown, which allows the generation of adjustable high-repetition rate soliton trains.