43 resultados para 124-767A


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《高等断裂力学》系统论述断裂力学的基本概念、理论基础、力学原理、分析方法以及断裂力学的实验测定和工程应用。深入阐明了断裂力学各个重要发展阶段的新颖学术思想和原创性工作,同时融会贯通地介绍了国内学者在作者熟悉的若干领域内的创造性贡献。  《高等断裂力学》共14章。第1章介绍断裂力学的历史背景和发展脉络;第2~5章介绍线弹性断裂力学;第6~8章论述弹塑性断裂力学;第9及第10章分别介绍疲劳裂纹扩展和界面裂纹;第11~14章阐述裂纹体弹性动力学和裂纹动态扩展。  《高等断裂力学》适合从事断裂力学研究和应用的科技工作者及工程师使用和参考,也可供力学专业的高年级本科生和研究生阅读参考.

目录

丛书序
序言
第1章 引论
1.1 历史背景
1.2 工程意义
1.3 脆性破坏特征
1.4 断裂力学起源与发展
参考文献

第2章 线弹性断裂力学
2.1 裂纹尖端弹性应力场
2.2 应力强度因子理论
2.3 裂纹扩展能量原理
2.4 裂纹尖端塑性区
2.5 厚度对KC的影响
2.6 裂纹扩展阻力曲线
参考文献

第3章 应力强度因子分析方法
3.1 Williams级数展开与边界配置法
3.2 复变函数方法
3.3 权函数法
3.4 积分变换法
3.5 奇异积分方程
3.6 有限单元法
参考文献

第4章 平面应变断裂韧性
4.1 标准试样
4.2 试样取向与制备
4.3 测试仪器和有效性分析
4.4 KR曲线测试
参考文献

第5章 复合型裂纹的脆断理论
5.1 复合型裂纹变形特征
5.2 应力参数准则
5.3 分支裂纹应力强度因子
5.4 能量释放率准则
5.5 复合型裂纹脆断试验
5.6 理论与实验比较
5.7 塑性变形对金属材料复合型裂纹脆性断裂的影响
参考文献

第6章 弹塑性断裂力学
6.1 J积分原理
6.2 HRR奇性场
6.3 J积分准则
6.4 J控制扩展
6.5 断裂韧性JIC测试
6.6 Dugdale模型
6.7 带状颈缩区模型
6.8 裂纹张开位移准则
参考文献

第7章 裂纹顶端弹塑性高阶场
7.1 高阶场基本方程
7.2 一阶场和二阶场
7.3 高阶场前5项完整结果
7.4 J-Q双参数方法
7.5 J-k断裂准则
7.6 平面应力裂端弹塑性场
参考文献

第8章 理想弹塑性介质扩展裂纹尖端场
8.1 v=0.5时的裂尖渐近场
8.2 v<0.5时的裂尖场
8.3 理想弹塑性介质Ⅲ型扩展裂纹
8.4 扩展裂纹与J积分
参考文献

第9章 疲劳裂纹扩展
9.1 等幅载荷下裂纹扩展
9.2 影响疲劳裂纹扩展的因素
9.3 裂纹闭合效应
94疲劳裂纹扩展门槛值确定
95等幅载荷下疲劳裂纹寿命预测
96变幅载荷下疲劳寿命预测
97缺口根部的疲劳裂纹
参考文献

第10章 界面裂纹
101弹性界面力学
102界面裂纹弹性断裂力学
10.3 典型的界面断裂问题
10.4 界面断裂试验
参考文献

第11章 弹性动力学基本概念及方法
11.1 动态惯性效应
11.2 线弹性动力学基本方程
11.3 复变解析函数
11.4 Laplace变换
11.5 Wiener-Hopf分解
11.6 动态断裂的能量概念
参考文献

第12章 静止裂纹的弹性动力学基本解
121突加反平面剪切载荷
12.2 突加裂纹面正压力
12.3 突加平面内剪切应力情况
124有限长裂纹面突加载荷情况
12.5 动态载荷裂纹的起始扩展
参考文献

第13章 均匀材料中动态扩展裂纹
13.1 动态裂纹定常扩展
13,2裂纹面上集中剪切力
133黏结区模型
13.4 Broberg问题
13.5 对称扩展剪切裂纹
136时间无关载荷作用下裂纹扩展
13.7 时间相关载荷作用下裂纹扩展
13.8 II型超剪切波扩展裂纹
13.9 裂纹尖端超弹性区对I、II型裂纹速度的影响
参考文献

第14章 双材料界面动态裂纹扩展
14.1 准静态动态裂纹扩展
14.2 双材料界面裂纹含接触区跨音速扩展
14.3 界面裂纹的超音速扩展
参考文献
索引

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Space-resolved spectra of line-shaped laser-produced magnesium plasmas in the normal direction of the target have been obtained using a pinhole crystal spectrograph. These spectra are treated by a spectrum analyzing code for obtaining the true spectra and fine structures of overlapped lines. The spatial distributions of electron temperature and density along the normal direction of the target surface have been obtained with different spectral diagnostic techniques. Especially, the electron density plateaus beyond the critical surface in line-shaped magnesium plasmas have been obtained with a fitting technique applied to the Stark-broadened Ly-alpha wings of hydrogenic ions. The difference of plasma parameters between those obtained by different diagnostic techniques is discussed. Other phenomena, such as plasma satellites, population inversion, etc., which are observed in magnesium plasmas, are also presented.

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Experimental investigation of Talbot self-imaging effect of an amplitude grating under illumination of femtosecond laser pulse -- the FemtoTalbot effect is reported. Theoretical analyzed results show that Talbot images under illumination of femtosecond laser pulses are not the same as that under continuous wave illumination. Experimental results are in good agreement with the theoretical analysis. We believe that the experimental investigation of the FemtoTalbot effect is highly interesting for the enormous potential applications of Talbot effect.

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abstract {Proton induced X-ray emission (PIXE) technique is an effective method for the chemical composition analysis of ancient glass samples without destruction. Chemical composition of the ancient glass samples dated from the Warring States Period (770-476 B.C.) to the Six Dynasties Period (220-589 A.D.), which were unearthed in Sichuan area, was quantitatively determined by the PIXE technique. The results show that the glass Bi (disc) and the glass eye beads of the Warring States Period all belong to the PbO-BaO-SiO2 system. According to the composition and shape, we infer that these glass Bi and eye beads were made in China. Whereas, the chemical compositions of the glass ear pendants and beads of the Six Dynasties Period are varied, including K2O-CaO-SiO2, K2O-SiO2 and other glass systems. Based on the obtained results and those from literatures, some questions related to the technical propagation of the ancient Chinese glass are discussed.}

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玻璃是一种传统材料,通过利用外场对玻璃进行空间选择性的微结构调控,发挥微结构的协同效应、量子效应和干涉效应等,可以赋予玻璃高功能和全新性能。本文阐述了近年来发展迅速的飞秒激光与玻璃相互作用的特征,介绍了我们利用飞秒激光诱导折射率变化直写三维光波导、微光栅和光散射型光纤衰减器,进行活性离子(稀土、过渡和重金属离子)的价态操作及应用和发现的基于飞秒激光与玻璃非线性相互作用的偏振依赖的纳米光栅形成机制。

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There are two different effects to generate group delay dispersion by multilayer thin film mirrors: chirper effect and Gires-Tournois effect. Both effects are employed to introduce desired dispersion in the designed mirror. Thus the designed mirror provides large dispersion throughout broad waveband. Such mirror can be used for dispersion compensation in Ti:sapphire femtosecond lasers. Most group delay dispersion of a 5-mm Ti:sapphire crystal can be compensated perfectly with only four bounces of the designed mirror.

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A normal-incidence nonpolarizing guided-mode resonance filter is designed. There are two waveguide layers and one grating layer in the filter. By adjusting the distance between the two waveguide layers, the same resonance wavelength for both TE and TM polarization can be achieved. An antireflection design method is also used to decrease the sideband reflection of the filter. The results show that the filter has high reflection, more than 99.9% at 500 nm, and the FW-HMs of TE- and TM-polarized light are 2.16 and 0.15 nm, respectively. (C) 2009 Optical Society of America

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