在三通道α-螺旋蛋白质中传递生物能量的孤子的特性

用庞小峰先生提出的生物能量传递的新理论和 Runge-Kutta数值模拟方法,研究了三通道α-螺旋蛋白质中激发的孤子的动力学特性,求出在0K和300K温度下该孤子稳定地沿蛋白质链传递.由此可见,它能担任在蛋白质分子中传递生物能量的功能.从而再次证实了新理论的可利用性.     

乳腺癌组织中蛋白质与核酸分子氢键特征的研究

正常乳腺组织与乳腺癌组织的红外光谱之间存在明显而规律的差异,其中包括蛋白质与核酸等生物分子的氢键缔合方式和程度上的不同。光谱的变化主要表现在：（1）蛋白质的酰胺Ⅰ带,N－H基团和某些氨基酸残基上C－O（H）基团的振动谱带;（2）核酸分子中磷酸二酯的反对称伸缩振动谱带和配对的碱基N－H基团振动等谱带上。氢键是维系和促进蛋白质与核酸高级结构形成的重要作用力,癌变时氢键的变化与癌细胞的特殊生物学行为密切相关,因此有可能利用氢键的这些光谱特征作为乳腺癌诊断和预测癌变可能性的指标。     

氢化富勒烯能否解释天文光谱中的21μm辐射特征?（英文）

目前在天文环境中探测到了C_(60)、C_(70)、C_(60)~+,极大地刺激了对星周包层中富勒烯衍生物的研究.原行星状星云是富勒烯在天文环境下的可能形成源,其红外光谱中具有丰富的、还未能认证的特征谱带,其中在21μm处的一条谱带尤为神秘.当富勒烯被氢化,分子的对称性被破坏,能够激活新的红外振动谱,这有可能部分解释天文光谱中的红外谱带.本文对氢化富勒烯的理论振动谱进行研究,考查了氢化富勒烯能否作为21μm辐射的载体,详细讨论了各种支持和反对的证据,并且推测了可能贡献21μm特征的氢化富勒烯的氢化程度.     

红外夜视技术及其军事应用

 红外线是人眼看不见的一种光波,它是由物质内部的分子、原子的运动所产生的电磁辐射,是一种电磁波,波长比红光更长,其突出的特点是热作用。“红外线”也称“红外辐射”,波长在0.75～1000μm,是个相当宽的区域,且这种辐射都载有物体的特征信息,这就为探测和识别各种目标提供了客观基础。红外线具有与可见光类似的特性,如反射、折射、干涉、衍射和偏振,同时,又具有粒子性,即它可以以光量子的形式发射和吸收,这已在康普顿散射、光电效应等实验中得到了充分的证明。不同波长的红外线在传输过程中能量衰减程度有很大的差别,能透过大气的红外线主要有3 个波段,即1～2.5μm、3～5μm 和8～14 μm,这3 个波段称为“大气窗口”,所有红外仪器都工作在这3 个波段内。     

固体的光散射讲座第二讲 分子振动及其喇曼光谱

分子的振动能量是量子化的,这些不连续的能量可用对应的一组振动量子数表示.当光和分子相互作用时,分子从一个振动量子态跃迁到另一个量子态所产生的光谱(喇曼谱和红外谱),我们称它为分子振动光谱.喇曼谱与红外谱,都是用来研究分子振动、分子碰撞所导致的能级跃迁、分子与光子以及其他粒子之间的相互作用等物理过程,从而提供对分子或固体的某些信息并推断分子或固体的空间构型及其对称性.喇曼光谱术已成为分析分子振动和晶格振动的重要实验手段.振动喇曼谱的理论是分子光谱学的一个重要方面. 激光出现以后,大大推动了喇曼光谱实验和理论研究…     

钩藤中异钩藤碱在TLC原位的FT-SERS研究

本文报道了将薄层色谱（TLC）与傅里叶变换表面增强拉曼散射（FT－SERS）联用，获得了中草药钩藤中的异钩藤碱光谱研究的新方法。研究表明，在薄层原位，2.5μg钩藤总碱可将异钩藤碱等8种生物碱完全分离。应用薄层原位的薄层色谱傅里叶变换表面增强拉曼散射（TLC－FT－SERS）技术，获得异钩藤碱分子的特征振动谱带，进而阐述了样品分子在银胶表面的吸附模式，异钩藤碱以分子中氧化吲哚基团上N原子的孤子电子对和吲哚环π电子共同吸附于银晶体微粒表面,1.615cm^-1与芳环骨架振动和氧化吲哚N－H变形振动相关的峰获得最大增强。说明TLC－FT－SERS对中草药化学成分进行高灵敏度示踪指纹检测的可靠性和优越性。     

羟基磷灰石-碳酸钙-BSA水溶性复合物中蛋白质微观结构的研究

利用傅里叶变换红外光谱，结合二阶导数谱、退卷、积和曲线拟合等计算机解析方法，对牛血清白蛋白（BSA）－羟基磷灰灰石－碳酸钙水溶性复合物中BSA的二级结构进行了研究。结果表明，BSA的α－螺旋结构的含量增加，蛋白质结构趋于有序化；紫外光谱和紫外二阶导数谱的研究发现，BSA的芳香族氨基酸残基的微环境受到扰动，在生物体内，正是蛋白质结构的这些变化导致生物矿化过程的发生和进行。     

连续与脉冲两功能CO_2 调谐激光器

如果一台CO2调谐激光器,能同时具有连续和脉冲(调Q)两种工作方式,将其用做其它仪器的激励源,如红外激光光声光谱仪的激光源,亚毫米波激光器的泵浦源等,将是十分方便的.在实现脉冲工作方式时,采用了转镜调Q方法,它具有制作简单、易于调节重复频率的优点.一　　基本原理与实验装置 CO2激光器是分子激光器,CO2分子由振动能级(0　0°1)向(1　0°0)与(0　2°0)的跃迁,分别输出中心波长为10.6μm与9.6μm的红外激光.由于分子转动能级的存在,将使谱线扩展为 10 P、10 R、9 P和9 R四支光谱带,从9.1#m到 11.2 urn共 120条谱线.但非调谐激光器,一…     

热氢原子碰撞导致的CO_2(ν_3)的高振动激发(英文)

用时间分辨 傅里叶变换红外发射光谱研究了热的氢原子与CO2 分子间高效率的平动 振动 (T V)能传递 .热的氢原子由ArF激光光解H2 S得到 ,这种氢原子的平动能为 2 2 3kJ/mol .实验中观察到了从 2 130cm-1到2 4 0 0cm-1的红外发射谱带 ,它归属于高振动激发的CO2 分子的非对称伸缩振动 (ν3 ) .对这一发射谱带的光谱拟合显示CO2 的非对称伸缩振动被激发到了较高的振动态 ,振动量子数达到了v =7.并且有 5 5 80cm-1的能量经传能过程由氢原子到达了CO2 的ν3 模 .实验条件下氢原子与CO2 的T V传能效率为 0 .30 .实验结果与Schatz等人的用 3D半经典计算预测的碰撞截面符合的很好 .     

蛋白质分子中生物能量传输基本方程椭圆波解的讨论

在庞小峰关于蛋白质分子能量传输基本方程的基础上,求出了该方程的另一类解析解－－椭圆皮解。并验证了孤子解的存在性。还获得了椭圆波解的质量、动量和能量表达工。     

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.     

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.     

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.     

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.     

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.