Experimental and theoretical study on numerical density evolution of short fatigue cracks

Fatigue testing was performed using a kind of triangular shaped specimen to obtain the characteristics of numerical density evolution for short cracks at the primary stage of fatigue damage. The material concerned is a structural alloy steel. The experimental results show that the numerical density of short cracks reaches the maximum value when crack length is slightly less than the average grain diameter, indicating grain boundary is the main barrier for short crack extension. Based on the experimental observations and related theory, the expressions for growth velocity and nucleation rate of short cracks have been proposed. With the solution to phase space conservation equation, the theoretical results of numerical density evolution for short cracks were obtained, which were in agreement with our experimental measurements.

A finite-element analysis of viscoelastically damped sandwich plates

A finite element analysis associated with an asymptotic solution method for the harmonic flexural vibration of viscoelastically damped unsymmetrical sandwich plates is given. The element formulation is based on generalization of the discrete Kirchhoff theory (DKT) element formulation. The results obtained with the first order approximation of the asymptotic solution presented here are the same as those obtained by means of the modal strain energy (MSE) method. By taking more terms of the asymptotic solution, with successive calculations and use of the Padé approximants method, accuracy can be improved. The finite element computation has been verified by comparison with an analytical exact solution for rectangular plates with simply supported edges. Results for the same plates with clamped edges are also presented.

Regimento Interno da Câmara dos Deputados : Resolução nº 30, de 31 de outubro de 1972

Texto consolidado em 1978 e alterado pelas Resoluções de nº 1, 37, 42, 54/79, 13 e 15/81.

不同形状微管道中的气体流动

不同形状微尺度管道（圆形、六边形、半圆形、不同宽高比的矩形）中的气体流动特性是微机电系统设计最为关心的问题之一．文中利用信息保存（IP）方法和直接模拟Monte Carlo（DSMC）方法进行研究，给出两种方法的计算结果相互符合，并与其它研究者的BGK模型方程计算结果进行了比较．对于微尺度管道中关心的低Mach数流动，IP方法的统计收敛效率明显优于DSMC方法,通过拟合IP和DSMC结果，给出了圆形、六边形、半圆形、不同宽高比的矩形截面情况下无量纲质量流率与等效Knudsen数的关系．

激波风洞中超声速燃烧现象的初步实验研究

介绍了启用激波风洞进行超燃研究所作的改造和得到的初步实验结果。实验除测量常规流场参数和模型表面的动态参数外，主要使用二维实验模型，利用高温气体的自发光和燃烧伴随的发光现象，采用高速摄影技术来观测燃烧现象，记录到高焓流场中叠加燃料喷射和燃烧的流场，观察到自由边界条件下扩散控制的超声速燃烧现象。结果表明激波风洞用于超声速燃烧研究的一些必要的技术问题已基本解决。

纪念谈镐生先生诞辰九十周年暨基础力学学术会议介绍

2006年12月1日是国际著名的力学家、应用数学家谈镐生院士诞辰九十周年纪念日．为纪念谈先生在力学学科的卓越贡献，缅怀他对推动我国力学基础研究和培养科技人才所作出的杰出贡献，中科院力学所于这天上午在所礼堂隆重举行“纪念谈镐生先生诞辰九十周年暨基础力学学术会议”．会前举行了《谈镐生先生文集》首发式，该文集由胡文瑞院士主持编辑，科学出版社出版，收录了谈镐生先生在流体力学、稀薄气体动力学和应用数学研究领域的论文和研究报告26篇，谈先生倡导和推行力学基础研究的有关文章和论述21篇，谈先生的学术活动和生活图片多幅，简介了谈先生生平.

"Nicotiana tabacum" L. cv Xanthi como sistema heterólogo para la producción de lactógeno placentario humano (hPL)

152 p. : il., col.

Os atores-chave no processo decisório no âmbito das comissões permanentes

Descreve os atores-chave no processo decisório no âmbito das comissões permanentes da Câmara dos Deputados, a partir de uma análise de como influenciam na tomada de decisões naqueles órgãos. Essa análise parte de três variáveis: poder de agenda, poder de veto (veto player) e capacidade de influenciar na decisão final do colegiado. Para tanto, o método utilizado foi de levantar as atribuições regimentais de cada um dos atores definidos em comparação com os poderes dos demais parlamentares. Concluiu-se que a concentração de poderes em determinados atores pode influenciar na tomada de decisões

Ejes estratégicos para el sector del cordero de raza latxa en el País Vasco

El sector ovino de raza Latxa en el País Vasco debe hacer frente a numerosos problemas que derivan en una pérdida importante de competitividad y en una disminución del consumo. Ante esta situación el presente trabajo trata de impulsar actuaciones innovadoras, tanto desde una perspectiva estratégica como operativa, que contribuyan a subsanar esta situación. Para ello, se lleva a cabo un análisis DAFO del sector y posteriormente, tomando como base dicha información, se establecen siete ejes estratégicos con una serie de líneas de actuación en cada uno de ellos. Estas propuestas deben servir como punto de partida para llevar a cabo acciones coordinadas entre todos los agentes del sector.

Piezoelectricity of ZnO films prepared by sol-gel method

ZnO piezoelectric thin films were prepared on crystal substrate Si(111) by sol-gel technology, then characterized by scanning electron microscopy, X-ray diffraction and atomic force microscopy (AFM). The ZnO films characterized by X-ray diffraction are highly oriented in (002) direction with the growing of the film thickness. The morphologies, roughness and grain size of ZnO film investigated by AFM show that roughness and grain size of ZnO piezoelectric films decrease with the increase of the film thickness. The roughness dimension is 2.188-0.914 nm. The piezoelectric coefficient d(33) was investigated with a piezo-response force microscope (PFM). The results show that the piezoelectric coefficient increases with the increase of thickness and (002) orientation. When the force reference is close to surface roughness of the films, the piezoelectric coefficient measured is inaccurate and fluctuates in a large range, but when the force reference is big, the piezoelectric coefficient d(33) changes little and ultimately keeps constant at a low frequency.

Collecção das Leis da Republica dos Estados Unidos do Brazil de 1902

Parte 1 - Atos do Poder Legislativo

板壳断裂力学

本书阐明了板壳断裂理论的基础。论证了Reissner型板壳断裂理论的科学性、经典板壳断裂理论的缺陷及在一定范围内仍具有的实用价值；介绍了作者所创意的研究Reissner型板壳断裂纹尖端场的方法等。

目录