低功率泵浦Ti：Al2O3自锁模激光器

本文报道了低功率泵浦的Ｔｉ：Ａｌ２Ｏ３激光器实现了稳定的自锁模运转，锁模脉冲宽度为１８０ｆｓ。分析了激光器的结构及工作特性。     

医学超声研究的一些新进展

1991年12月在美国奥兰多(Orlando)召开的IEEE1991超声年会上有许多医学超声方面的研究报告,反映了当前医学超声研究的一些发展,本文选择几个方面的内容作一介绍。 一、超声背散射显微镜 目前常用的B型超声诊断仪使用的超声频率是3—10MHz,相应的分辨率是毫米级的。近年来许多研究单位研究开发20MHz以上直到100MHz的B型成像系统,其分辨率可达到20μm。由于人体组织     

Decomposition of the Two Lowest Lamb modes in a Bonded Plate

Based on the expression of the dispersion equation of Lame waves in an adhesive two-layered plate pressented in our proevious paper [Chin,Phys,Lett,18(2001)1483],the two lowest Lamb modes,the symmetric mode S0 and the antisymmetric mode A0 are successfully decomposed in the low-frequency regime,Relations between the rigidity of the bond and the velocity of the two Lamb modes are found,which lay a foundation for the estimation of the bond rigidity of the adhesive plate.The influence of the variations of the bond rigidity in terms of the stiffness constants KN and KT of the spring model on the velocity of the two Lamb modes in discussed and numerically evaluated.numerical results indicate that the deterioration of the bond rigidity causes the phase velocity decrease for Lamb modes of the two lowest order,thus having a possibility for the evaluation of the bonding state of the adhesive plate by using ultrasonic wave velocity measurement.     

平面数控抛光工艺优化技术

为了满足“神光”-Ⅲ装置对大批量大口径光学元件的需求，解决加工精度以及加工效率等方面的问题，对计算机控制光学表面成型技术（CCOS）进行了多方面的研究。在对平面数控软件进行了深入的研究工作后，结合高精度干涉检测手段，对数控工艺软件进行了大幅的改进。     

2003 International Powder／Bulk Conference ＆ Exhibition

Hosted by the Chinese Society of Particuology, China Powder Industry Association and Shanghai Science Technology Exhibition Company, with the sponsorship of Trans Tech Publications, Germany, and the organization of Worldwide Exhi-bitions Service Company, the above Conference/Exhibition, the largest of its kind in China, was held from Nov. 29 to Dec. 1 in Shanghai Mart, Shanghai. More than 100 professional equipment producers and market promotion agencies in powder/bulk handling and p…     

C60量子点与磁性电极的耦合

在磁电子学领域，自旋极化输运与分子器件的结合是一个热门研究方向．最近，来自美国康奈尔大学的Pasupathy等，采用纳米加工技术，将单个C60分子吸附在一对Ni电极之间，构成了“铁磁电极-C60量子点”器件．量子点的Kondo效应和铁磁性交换耦合，原本是相互排斥的，在Pasupathy的实验中，两者被首次结合在一个器件中并加以观察．研究结果表明，如果器件的质量能够保证两种效应之间的竞争得到有效控制，     

基于信息化平台的光学课程系统改革

一、问题提出 课程建设是高等学校教学改革工程的重要组成部分，是提高教学质量的重要途径。如何在课程建设中体现现代教育思想的先进性、科学性、综合性、开放性的特点，以及怎样合理运用现代教学技术、方法和手段，提高教学质量是当前课程建设中重点研究的问题。为此，从2000年开始，我们基于信息化平台系统地进行了光学课程的教学内容、教学手段和方法、     

工科数学教学中数学建模技术的嵌入式教学法

本介绍了在工科数学教育中引入数学建模技术的教学方法，教学组织及教学案例，是多年工科数学教学的经验总结。     

修饰聚合物液-固亲和萃取体系纯化大豆中的组氨酸

聚乙二醇(PEG)6000经亚氨基二乙酸(IDA)修饰后和CuSO4反应,形成PEG修饰聚合物PEG-(IDA-Cu)2 ,与吐温80、磷酸盐混合,构成液-固亲和萃取体系,直接从大豆蛋白匀浆中提取氨基酸.选定萃取条件为磷酸盐摩尔比n(K2HPO4)∶n(NaH2PO4)为4.8∶1,体系pH值 7.70,总盐浓度为1.60 mol·L-1;吐温80的体积分数为10.5%.结果表明该体系对大豆蛋白匀浆中氨基酸的二次萃取率为66.5%,用离子交换技术后继处理,得纯度较高的组氨酸.     

Damage and fracture evaluation of granular composite materials by digital image correlation method

This paper presents the applications of digital image correlation technique to the mesoscopic damage and fracture study of some granular based composite materials including steelfiber reinforced concrete, sandstone and crystal-polymer composite. The deformation fields of the composite materials resulted from stress localization were obtained by the correlation computation of the surface images with loading steps and thus the related damage prediction and fracture parameters were evaluated. The correlation searching could be performed either directly based on the gray levels of the digital images or from the wavelet transform (WT) coefficients of the transform spectrum. The latter was developed by the authors and showed higher resolution and sensitivity to the singularity detection. Because the displacement components came from the rough surfaces of the composite materials without any coats of gratings or fringes of optical interferometry, both surface profiles and the deformation fields of the composites were visualized which was helpful to compare each other to analyze the damage of those heterogeneous materials. The project supported by the National Natural Science Foundation of China (10125211 and 10072002), the Scientific Committee of Yunnan Province for the Program of Steel Fiber Reinforced Concrete, and the Institute of Chemical Materials, CAEP at Mianyang