1-羟基-5-十二烷氧基-萘LB膜结构和取向的光谱研究

用红外透射,反射光谱及紫外可见吸收光谱方法研究了１－羟基－５－十二烷基－萘ＬＢ膜及溶液状态下的结构,分子取向。研究结果表明分子在溶液中主要是以单体形式存在;在ＬＢ膜中是以聚集体形式存在。     

聚酰亚胺LB膜上液晶表面锚定的研究

通过测试光延迟研究了聚酰亚胺ＬＢ膜的光学各向异性，分析了在ＬＢ膜成膜过程中成膜分子的流动取向特性，并研究了液晶的表面锚定能，分析了ＬＢ膜上液晶的取向机制．聚酰亚胺ＬＢ膜的链段的取向程度较强摩擦情形的聚酰亚胺表面的链段取向要差．强摩擦的聚酰亚胺会比聚酰亚胺ＬＢ膜具有更好的排列液晶分子的能力．ＬＢ膜的流动取向模式使得聚酰亚胺成膜分子沿拉伸方向形成一定的有序排列，并诱导液晶分子定向排列，液晶和聚合物分子相互作用是液晶表面排列的主要动力 关键词：     

1—苄基—9—氢富勒烯—60LB多层膜的制备及其光学非线性性质

利用π－Ａ等温线，小角Ｘ射线衍射和光学测量方法研究了一种取代富勒烯ＬＢ膜的结构特性。纯Ｃ６０－Ｂｅ分子以体相的形式存在于气－液界面上。氮冠分子作为隔层材料，与Ｃ６０－Ｂｅ分子相混合可以制备性能优良的ＬＢ膜。     

卟啉LB膜的分子取向,形貌和膜厚度研究

研究了５，１０，１５，２０－四（对－山嵛酸乙酯－α－氧代苯基）卟啉分子在气液罪肌的成膜性，制备了该化合物的多层ＬＢ膜，研究了分子中不同的基团在ＬＢ膜中的取向，观测了ＬＢ膜的形貌和厚度，利用偏振ＵＶ－Ｖｉｓ和偏振ＦＴ－ＩＲ谱测定了分子内卟啉环和脂链取代基的取向，结果表明卟啉面法线和脂缝线与载片线间的夹角分别为３７°和２７°，利用ＴＥＭ观测了ＬＢ膜的形貌和厚度，结果表明ＬＢ膜表面均匀，单层厚度大约为２     

酞菁铜固态薄膜的红外光谱

利用红外透射光谱，偏振透射光谱、掠角反射光谱研究了三－２，４－二特戊基苯氧基８－喹啉氧基酞菁铜ＬＢ膜和蒸镀膜的结构。确认在ＬＢ膜中，（１）取代基的碳链是以六方晶系或假六方晶系方式堆积的；（２）用偏振红外可以区别苯环上的两个ＣＨ２的伸缩振动带。在蒸镀膜中分子基本呈现无序状态。     

荧蒽／硬脂酸混合LB膜的时间分辨荧光研究

荧光法比吸光度法灵敏，更适用于超薄膜系如ＬＢ膜的表征。拉制了荧蒽和苯并［ｂ］荧蒽镶嵌在硬脂酸基质中的ＬＢ膜，探讨了它们的稳态和时间分辨荧光性质。实验表明，两种分子以单体形式存在于ＬＢ膜中。     

二茂铁衍生物L—B膜修饰铂电极的电化学性能

本文研究了单取代硬脂酸二茂铁酯、双取代亚麻酸二茂铁酯、单二茂铁酸十八酯和双二茂铁酸十八酯四种二茂铁衍生物Ｌ－Ｂ膜修饰铂电极的循环伏安行为，用理论模型模拟了归一化峰面积，峰电位差随扫描速度变化的规律，以及分子相互作用能与半高宽的关系，将实验结果与理论模型的模拟结果进行比较，求得了Ｌ－Ｂ膜的层间电荷转移速度常数，Ｌ－Ｂ膜与电极之间的电荷转移速度常数，分子作用能及半峰电位等参数，并比较了四种二茂铁衍生物     

LB膜混合聚集体中极性基团相互作用对光学非线性的影响

通过紫外－可见吸收光谱、压力－面积等温线、二次谐波的测量，研究了不同活性分子混合聚集体的形成对ＬＢ膜光学性质的影响。分子极性基团间的相互作用，使激发态能量及平均偶极矩发生变化，导致ＬＢ膜的光学非线性明显地增强或减弱。     

5,10,15,20-四-(4-十六烷基吡啶基)卟啉LB膜结构的研究

研究了两亲性卟啉５,１０,１５,２０－四－（４－十六烷基吡啶基）卟啉溴化物在气－液界面上的成膜性能,制备了其ＬＢ膜。用扫描隧道显微镜和ＵＶ－Ｖｉｓ光谱,荧光光谱,小角Ｘ射线衍射等实验方法研究了ＬＢ膜的形貌和卟啉大环分子在ＬＢ膜中的排列、取向和分子间的相互作用。结果表明,制备的ＬＢ膜结构均匀,性能稳定,在ＬＢ膜内,脂肪链并不是直立的,卟啉分子大环几乎平躺在基片上。     

聚合物LB膜定向铁电液晶的特性

利用新近合成的聚酰亚胺ＬＢ膜定向铁电液晶分子,通过原子力显微镜对经不同亚胺化温度处理的聚酰亚胺ＬＢ膜进行扫描探测,发现相应的ＬＢ膜具有不同的形貌结构,认为高温亚胺化的ＬＢ膜可以提高较高的势垒,这为铁电液晶双稳记忆性的出现提供了可能,而ＬＢ膜的超薄特性有利于开关过程中表面聚积电荷的中和与释放,保证了器件优良的双稳记忆性的最终获得以及微秒量级快速响应的实现。     

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.     

Theoretical analysis and simulation of conjugate heights for dual-conjugate AO system in lidar

A multi-conjugate adaptive optics （MCAO） can offer a possibility of widening field of view （FOV） characterized by the isoplanatic angle, and the choose of conjugate height becomes a basic problem for MCAO, which influences the size of iosplanatic angle. Considering the application of lidar, the isoplanatic angle＇s expressions of two deformable mirrors （DMs） MCAO for uplink and downlink are deduced. The effects of conjugate heights for dual-conjugate AO are thoughtfully discussed, and the isoplanatic angles are further analyzed. The results show that the isopanatic angle varies with the conjugate height and reaches the maximum as the conjugate height is at the optimal altitude. Moreover, the optimal conjugate height changes with the propagation distance.     

Quick single-photon detector with many avalanche photo diodes working on the time division

Due to the limit of response speed of the present single-photon detector, the code rate is still too low to come into practical use for the present quantum key distribution (QKD) system.A new idea is put up to design a quick single-photon detector.This quick single-photon detector is composed of a multi-port optic-fiber splitter and many avalanche photo diodes (APDs).Au of the ports with APDs work on the time division and cooperate with a logic discriminating and deciding unit driven by the clock signal.The operation frequency lies on the number N of ports, and can reach N times of the conventional single-photon detector.The single-photon prompt detection can come true for high repetition-rate pulses.The applying of this detector will largely raise the code rate of the QKD, and boost the commercial use.     

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.