各向异性非线性强度条件下的边坡稳定性

解释了土体强度各向异性、非线性的物理本质,结合常规直剪试验、三轴试验结果,在前人工作基础上建立了边坡稳定性分析中强度各向异性、非线性的描述方法,其中特别提出了一个各向异性函数.基于Janbu普遍条分法(GPS),运用SPREADSHEET模板程序,提出了一个能将各向异性、非线性强度准则逐点等效到Mohr-Coulomb直线强度准则处理上的迭代方法,准确方便地获得了非线性强度下的边坡稳定性分析.最后的算例展示了方法的使用过程.

Time-Frequency Analysis of Nonlinear Systems: The Skeleton Linear Model and the Skeleton Curves

The joint time-frequency analysis method is adopted to study the nonlinear behavior varying with the instantaneous response for a class of S.D.O.F nonlinear system. A time-frequency masking operator, together with the conception of effective time-frequency region of the asymptotic signal are defined here. Based on these mathematical foundations, a so-called skeleton linear model (SLM) is constructed which has similar nonlinear characteristics with the nonlinear system. Two skeleton curves are deduced which can indicate the stiffness and damping in the nonlinear system. The relationship between the SLM and the nonlinear system, both parameters and solutions, is clarified. Based on this work a new identification technique of nonlinear systems using the nonstationary vibration data will be proposed through time-frequency filtering technique and wavelet transform in the following paper.

也谈力学──基础和前沿

也谈力学──基础和前沿谈庆明（中国科学院力学研究所北京１０００８０）最近一个时期常听见对力学的两种评价：一种是力学过时了，没什么好研究了；另一种是力学不解决问题，时髦的说法是不能转化为生产力。不论哪一种都是力学无用论，因此，力学要被排除在基础学科之外...

推动交叉学科研究 促进生命与医学科学的发展

<正>基础研究是国家科技发展的原动力,学科的交融与渗透已经成为当今科学发展的重要趋势,促进交叉学科的健康成长是目前科学界普遍关心的问题之一。分析近百年来获得诺贝尔自然科学奖的300多项成果中,近一半的项目是多学科合作的研究成果,对170多位生理学或医学诺贝尔奖获得者及他们的原创性成果的统计研究发现,具有跨学科知识

双模式高精度可调超分辨光瞳滤波器

基于双折射波片的特性，提出了一种具有双调节模式的连续可调超分辨光瞳滤波器。该滤波器通过两种调节模式实现超分辨，且在一定范围内连续可调。在横向旋转模式下，该滤波器为复振幅型光瞳滤波器，纵向倾斜模式下为纯相位型超分辨滤波器。通过对超分辨参量的分析，得到最佳设计参量，可以实现大的视场角，大的超分辨范围、高的调节精度。这种滤波器为实际应用提供了更多的方便。

The effect of the group delay ripple of chirped fiber grating on composite second-order in optical fiber CATV system

The effect of group delay ripple of chirped fiber gratings on composite second-order (CSO) performance in optical fiber CATV system is investigated. We analyze the system CSO performances for different ripple amplitudes, periods and residual dispersion amounts in detail. It is found that the large ripple amplitude and small ripple period will deteriorate the system CSO performance seriously. Additionally, the residual dispersion amount has considerable effect on CSO performance in the case of small ripple amplitude and large ripple period. (c) 2004 Elsevier B.V. All rights reserved.

Anomalous behaviour of photorefractive grating erasure owing to existence of both negative and positive carriers

In LiNbO3:Fe, anomalous behaviour of grating erasure is observed with different wavelenghts, i.e. rapid grating erasure in the short wavelength range, which deviates from the results predicted by the electron transport band model. The deviation is related to the coexistance of electrons and holes in photorefraction, and charge-transfer process including electrons and hole has been proposed. The electron and hole contributions to photo-excitation coefficient S of the Fe centre on the wavelength.

The association of the Arabidopsis actin-related protein (ARP) 2/3 complex with cell membranes is linked to its assembly status but not its activation

国科图

饱食因子及其制备方法和其基因

本发明涉及一种饱食因子及其制备方法和其基因，属于生物医学领域。该饱食因子为从中国两栖类动物大蹼铃蟾(Bombina maxima)皮肤分泌物中分离得到的由28个氨基酸组成的一种单链多肽，分子量3229.57，等电点7.7，多肽氨基酸全序列一级结构为：Asp Met Tyr Glu Ile Lys Gln Tyr Lys The Ala HisGly Arg Pro Pro Ile Cys Ala Pro Gly Glu Gln Cys Pro Ile Trp Val-AMIDATION。制备方法是收集大蹼铃蟾皮肤分泌物，离心去除沉淀、冷冻干燥后，经凝胶过滤、离子交换柱层析、高压液相反相柱层析分离纯化后即得到。编码饱食因子的基因由1041个核苷酸组成，其中编码成熟饱食因子为第835-918位核苷酸。具有抑制进食，增强缓激肽生物效应的作用，作为制备肥胖症治疗药物，心血管系统疾病治疗药物的应用。

黄鳝DEAD-box家族PL10基因的克隆与序列分析

通过PCR克隆的方法,从黄鳝(Monopterus albus)中得到两个PL10 基因的cDNA片段Mo PL10A和Mo PL10B,长度均为1.127 kb,推测其编码375个氨基酸的蛋白片段.结合其他PL10类同源物序列,对这两条cDNA进行了分析和初步的功能推测.根据此片段的氨基酸序列构建的系统发育树与形态分类结果一致.在不同组织中的RT PCR结果表明Mo PL10A和Mo PL10B的mRNA在各组织中的分布有差异.

香港米浦基围塘中有机氯农药和多氯联苯在微型生物群落中的积累

分别在 2 0 0 1年和 2 0 0 2年用国家标准《水质 -微型生物群落监测 -PFU法》在香港米浦自然保护区的基围塘和红树林中监测水质 .在 3个基围塘中共鉴定出 91种原生动物 ,为香港地区的首次记录 .同时在群落级水平上分析了4种生态结构参数和 5种功能参数 .用化学的方法成功地监测出在此 3个基围塘的PFU挤出液中 pp′-DDE和PCB的浓度 ,并且获得两年一致性的结果 .本文化学和生物学结合的研究结果为测定水中超痕量持久性有机污染物 (POPs)的环境暴露与生态毒性提供了一种新的尝试 .图