双轴应力状态下正交异性动态光弹性应力——光性定律研究

基于静态下Ｈｙｅｒ和Ｌｉｕ表述的正交异性应力－光性定律，在前文中，提出了正交异性光弹性复合材料的动态应力－光性定律并证明了其在单轴应力状态下的正确性。本文旨在进一步考察在双轴应力状态下正交异性动态应力－光性定律的适用性，采用的方法是对纤维增强光弹性复合材料制作的平板模型施加冲击荷载，加载方向与材料纤维方向分别成０°、９０°及４５°角，同时进行正交异性动态光弹性实验和动态应变测量，另外，对该模型进行相应的各向异性介质时域边界元计算。把动态应变测量推算出的应力分量以及时域边界元计算出的应力分量分别代入正交异性动态应力－光性定律，得到随时间变化的双折射条纹级数历程，将其与正交异性动态光弹性实验的结果进行比较。实验及计算结果表明，在三个加载方向下，由这三种方法得到的双折射条纹级数历程均吻合良好，从而证明了前文提出的正交异性动态应力－光性定律在双轴应力状态下的正确性。     

彩色光弹性干涉影像分析系统

自行开发的“彩色光弹性干涉影像分析系统”首先利用CCD成像和图像采集设备,将光弹图像以数字图像的形式存储到计算机,然后通过对存储的光弹图像进行处理,得到物体边界、等差线、等倾线等数据。最后根据这些数据,绘制出主应力迹线,并进行二维的和三维的应力分析。本文着重介绍了系统整体设计以及系统研制的难点问题(彩色光弹图像处理、主应力迹线的绘制等)。系统可以通过对彩色图像进行分解,应用目前已经比较成熟的灰度光弹图像处理技术,来完成彩色图像的处理;也可以直接应用彩色信息来确定条纹级数,进行相关处理。彩色图像能够比灰度图像提供更精确的图像信息,以满足高精度测量的要求。     

沉桩问题的光弹性模拟研究

实现了桩身直接贯入的沉桩光弹性模拟方法。应用这一方法研究了沉桩过程中桩周土体中的弹性应力场及其影响区域，指出Ｖｅｓｉｃ土体扩孔理论的适用范围     

回旋行波管的全固态Marx高压脉冲调制器设计

为回旋行波管设计了全固态近方波Marx高压脉冲调制器,设计参数:输出电压70kV,输出电流15A,工作频率0~2kHz可调,脉宽200μs可调,功率容量可以达到百kW级。设计利用串联IGBT作为控制开关,利用FPGA通过光纤传输的方式对IGBT进行逻辑控制、电路保护和监测,补偿单元利用FPGA控制IGBT自动补偿的方式对顶部压降进行补偿,使得输出电压平顶度达到±1%。对电路各个部分进行仿真及测试。结果验证此设计方案的可行性,可以提高回旋管电源的稳定性和工作频率,减小调制器体积及维护成本,并为高压测试提供了实验基础。     

Parameterization of Org27569: An allosteric modulator of the cannabinoid CB1 G protein‐coupled receptor

The cannabinoid CB₁ receptor is a class A G protein‐coupled receptor (GPCR) that is the most widely expressed GPCR in the brain. Many GPCRs contain allosteric binding sites for endogenous and/or synthetic ligands, which are topographically distinct from the agonist‐binding site that is known as the orthosteric site. While both endogenous and synthetic ligands that act at the CB₁ orthosteric site have been known for some time, compounds that act at a CB₁ allosteric site have only recently been discovered. The most studied of these is 5‐chloro‐3‐ethyl‐1H‐indole‐2‐carboxylic acid [2‐(4‐piperidin‐1‐ylphenyl)ethyl]amide (Org27569). Because allosteric ligands are thought to act through conformational changes in the receptor that are transmitted from the allosteric to the orthosteric site, computational studies of the structural and dynamic interactions of Org27569 with the CB₁ receptor are crucial to achieve a molecular level understanding of the basis of action of this important new class of compounds. To date, such computational studies have not been possible due to the lack of a complete set of molecular mechanics force field parameters for Org27569. Here, we present the development of missing CHARMM force field parameters for Org27569 using previously published methods and the validation and application of these new parameters using normal mode analysis and molecular dynamics simulations combined with experimental infrared measurements. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011     

基于Franz-Keldysh效应的倏逝波锗硅电吸收调制器设计

本文设计了一种基于Franz-Keldysh (FK) 效应的GeSi电吸收调制器. 调制器集成了脊形硅单模波导. 光由脊形硅波导以倏逝波形式耦合进锗硅吸收层. 在硅基锗二极管FK效应实验测试的基础上, 有源区调制层锗硅中的硅组分设计为1.19%, 从而使得器件工作在C (1528–1560 nm) 波段. 模拟结果显示该调制器的3 dB带宽可达64 GHz, 消光比为8.8 dB, 而插损仅为2.7 dB. 关键词： 锗硅 调制器 电光集成     

Capability of a Liquid-Crystal Adaptive Optics System Based on Feedback Interferometry for Retinal Imaging

A modified arrangement of the adaptive optical retinal imaging system that we described previously is proposed to reduce the intensity loss in the system, so that it works properly even when the intensity of light incident on the eye is very weak. Experiments to verify the system performance were conducted using a conventional artificial eye with a specular reflector as a model retina. We observed that an image of a test target (mimicking a retina) blurred by an aberration plate (mimicking the ocular aberrations) was successfully restored in the adaptive optics fashion even when the intensity of the incident light probing the aberration of the eye became about 1.5% of that required in the previous system. Effect of a more realistic artificial eye with a scattering object as a model retina was also examined experimentally. We found that not only the ocular aberrations, but also the retinal scattering cause the wave-front deformations and that our adaptive optics system compensates for both of them simultaneously.     

Proposition of Single Molecular Orientation Determination Using polarization Controlled Beam by Liquid Crystal Spatial Light Modulators

We have proposed a method to control the three-dimensional electric field in the focus of an optical microscope using two non-twisted liquid crystal spatial light modulators, and to detect the molecular orientation of a single molecule. The three-dimensional electric field is generated by focusing the beam with two dimensional spatial distribution of polarization. The possibility of detection of three-dimensional single molecular orientation was shown by numerical calculations. © 2005 The Optical Society of Japan     

Full-Field Determination of Principal-Stress Directions Using Photoelasticity with Plane-Polarized RGB Lights

In this paper, we propose a new three-wavelength method for automatic measurement of principal-stress directions over an entire model on the basis of four-step phase shift method. This method uses four fringe patterns captured by a color charge-coupled devices (CCD) camera corresponding to four angular position arrangements of polaroids in a dark-field plane polariscope. The principal-stress directions can be determined by a single calculation. The method is applied to a circular disc under compression. The principal-stress direction distributions obtained from the proposed method are compared with those obtained from a conventional method and theory. It can be obviously seen that the proposed method accurately yields the principal-stress directions compared with the conventional method.     

没有热效应的新型磁光测试装置

介绍了一种新型的磁光测试装置.根据法拉第磁致旋光效应,使用永磁片代替以往通电螺线圈产生磁场,不会产生热量,可以消除热效应对磁光介质费尔德常量的影响.通过实验测出这种磁场的分布特点,给出该装置的调节方法,并测出292 K温度下LaK2,LaK3,Tb20,Tb25,ZF6玻璃的费尔德常量.本实验为地磁成像技术提供了实验数据,并推动了该研究的进展.