993 resultados para 204-1247B
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Parte 1 - Atos do Poder Legislativo.
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本书共有16篇论文,论述了国内外有关复合材料及其结构力学等方面新近进展的情况。如:复合材料及其结构的粘弹性力学、三相模型下复合材料的细观力学性质等。
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内容简介
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第三章 动态松弛法及其在复合材料叠层板壳非线性分析中的应用&黄小清 范赋群
第四章 单向复合材料损伤本构模型的细观分析&夏源明 袁建明 杨报昌
第四节 单向复合材料冲击拉伸过程的Monte Carlo数值模拟
第五章 短纤维复合材料的弹性与弹塑性行为的理论研究&陈浩然 杨庆生
第七章 半解析数值法在复合材料及其结构力学问题中的应用&洪志泉 方赤峰
第九章 超高模聚乙烯纤维增强复合材料的力学性能和微观结构&冼杏娟
第十一章 复合材料离散加筋曲板在面内载荷作用下用于屈曲分析的有限条法&童贤鑫 B・盖尔
第十二章 在湿热环境下碳纤维/树脂复合材料结构强度的研究…………
第十五章 复合材料机翼在气动弹性和强度约束下的设计剪裁研究&丁惠梁
第十六章 复合材料梁的强度、冲击和疲劳性能的研究&薛元德 陈心爽 刘壮健
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内容简介
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量纲分析是一门非常值得研究和学习的知识,它是探讨科学规律,解决科学和工程的一个有效的工具。熟练掌握量纲分析应当是科学和技术工作者应有的基本训练。
本书内容包括:量纲分析的基本概念;量纲分析在熟知的力学现象中的应用;量纲分析在某些经典的力学问题中的应用以及郑哲敏先生的研究集体近三四十年中在爆炸力学诸多的应用实例等几个部分。
写在前面
第1章 结论
1.1 量纲分析是分析和研究问题的有力手段和方法
1.2 物理量的度量
1.3 量纲:有量纲量和元量纲量
1.4 基本量和导出量
1.5 单摆
1.6 量纲分析的实质
1.7 量纲分析的简史
第2章 基本原理
2.1 量纲的幂次表示
2.2 II定理
2.3 自变量和基本量的选择
2.4 相似律
2.5 运用II的定理的注意点
第3章 流体力学问题
3.1 典型流动
3.2 流体力学问题中的相似准数[13]
3.3 其他相似准数
3.4 流体运动的分类
第4章 固体力学问题
4.1 弹性体的应力分析和简单结构的稳定性分析
4.2 弹性体的振动和波动
4.3 弹塑性体的应力分析
4.4 固体的拉伸断裂
第5章 固体中的热传导与热应力
5.1 固体中的热传导
5.2 弹性体内的热应力
第6章 流固耦合问题
6.1 水击
6.2 弹性和轴承
6.3 机翼的颤振
6.4 热交换器的气激振动
第7章 流体弹塑性模型
7.1 流体弹塑性体模型
7.2 化学炸药的爆炸效应问题中的相似参数
7.3 高速冲击问题中的相似参数
第8章 爆炸相似律
8.1 空中爆炸波和水中爆炸波
8.2 爆炸加工
8.3 爆破
第9章 冲击相似律
9.1 杆式穿甲弹
9.2 破甲——聚能射流的形成及其对装甲的侵彻
9.3 碎甲层裂
9.4 超高速冲击
9.5 金属射流与薄板的高速扩张断裂
9.6 煤与瓦斯突出——两相耦合介质动力学现象
第10章 数学模拟规整化
参考文献
主题索引
外国人名索引
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水动力学讲义手稿》是1958年钱学森先生在清华大学给第一届力学研究班学员讲授《水动力学》课程用的备课笔记。钱先生选材简赅精切,遴的内容具有基础性、经典性,整个手稿清晰耐读,详略得体,推演细腻,覆盖全面。
《水动力学讲义手稿》可供科技人员、教研人员及广大师生研究和学习之用。
目录
基本方程式
平面波
在深水中驻波
进行波
第二讲 表面波(续)
另一研究行波的方法
群速度
在有限深度液体中的波
在空气与水交界面上的波
风力生波的问题
第三讲 波阻
波的能量
能量的转移
波阻
在自由面下的旋
第四讲 水面滑行的平板
作用在自由面上的力F
以仰角α运行的平板
船舶造波阻力的计算
第五讲 浅水中的长波
基本方程式
写成气动力学的形式
高速气流的水流模型
特征线解法
水跃
第六讲 河流水动力学
河道和明渠中的流动
定常流、合流问题
洪峰、不定常流
特征线法
第七讲 空化
空泡、空蚀现象
局部的空蚀
完全的空泡情况
完全空泡中的平板(任意攻角)
正迎水流的平板
正迎水的平板(另一推演)
第八讲 非线性自由面及交界问题
基本方程式
自由面问题
一种转换
异重流
水库的异重流问题
第九讲 泥沙问题
渠道中泥沙的输移
悬沙浓度的分布
浅水情况下的沙涟波长
注释与说明
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Baltic Sea herring is a traditional raw material for the German fish processing industry and the fresh fish market. This applies also for the spring herring of the spawning population of the waters around the island of Rügen. Reduction of the fat content to about 5 % during the spawning cycle limits the processing possibilities of mature herring from this area. Failures in taste and odour (tainting), a common problem of the past have not been detected in the last 3 years. Infestation by nematodes are comparable to other herring stocks and contamination levels of organic and inorganic contaminants are well below allowable limits. The annual German fishing quota of about 85000 t of Baltic Sea herring is now utilised only to 10 %. For a stronger utilization of this stock as in the 70th and 80th , there are scarcely prerequisites. The project of a central processing plant on the island Rügen for about 50000 t of herring as raw material is not realistic. The answer to the question asked at the beginning of this article, whether Baltic Sea herring represents a raw material for the German fish processing industry, is YES, dispite some restrictions.
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Traz atualizado o texto do Marco Civil Brasileiro da Internet, a Lei nº 12.965, de 23 de abril de 2014.
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The paper discusses the status of the Tiga Reservoir Fishery pre-and Clupeid transplantation. This was achieved by examining the species diversity, abundance and distribution with mitigating factors. It concludes with a verdict on the achievement of the transplantation exercise
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DNA is nature’s blueprint, holding within it the genetic code that defines the structure and function of an organism. A complex network of DNA-binding proteins called transcription factors can largely control the flow of information from DNA, so modulating the function of transcription factors is a promising approach for treating many diseases. Pyrrole-imidazole (Py-Im) polyamides are a class of DNA-binding oligomers, which can be synthetically programmed to bind a target sequence of DNA. Due to their unique shape complementarity and a series of favorable hydrogen bonding interactions that occur upon DNA-binding, Py-Im polyamides can bind to the minor groove of DNA with affinities comparable to transcription factors. Previous studies have demonstrated that these cell-permeable small molecules can enter cell nuclei and disrupt the transcription factor-DNA interface, thereby repressing transcription. As the use of Py-Im polyamides has significant potential as a type of modular therapeutic platform, the need for polyamides with extremely favorable biological properties and high potency will be essential. Described herein, a variety of studies have been performed aimed at improving the biological activity of Py-Im polyamides. To improve the biological potency and cellular uptake of these compounds, we have developed a next-generation class of polyamides bearing aryl-turn moieties, a simple structural modification that allows significant improvements in cellular uptake. This strategy was also applied to a panel of high-affinity cyclic Py-Im polyamides, again demonstrating the remarkable effect minor structural changes can have on biological activity. The solubility properties of Py-Im polyamides and use of formulating reagents with their treatment have also been examined. Finally, we describe the study of Py-Im polyamides as a potential artificial transcription factor.
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A theoretical investigation is carried out into the effect of spontaneously generated coherence on the Kerr nonlinearity of general three-level systems of Lambda, ladder, and V-shape types. It is found, with spontaneously generated coherence present, that the Kerr nonlinearity can be clearly enhanced. In the Lambda- and ladder-type systems, the maximal Kerr nonlinearity increases and at the same time enters the electromagnetically induced transparency window as the spontaneously generated coherence intensifies. As for the V-type system, the absorption property is significantly modified and therefore enhanced Kerr nonlinearity without absorption occurs for certain probe detunings. We attribute the enhancement of Kerr nonlinearity mainly to the presence of an extra atomic coherence induced by the spontaneously generated coherence.