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

燃烧物理学基础

非平衡流模拟参数ρ_∞L有效性的数值分析

在非平衡流相似律现有研究成果的基础上,通过对化学反应特征时间、具体流场区域热化学状态、辐射输运方程的分析,并结合若干典型算例,讨论双体碰撞反应的非平衡尺度效应模拟参数ρ_∞L对高空高超声速飞行器全流场适用的条件.结果表明,当模拟参数ρ_∞L值低于一定范围时,在高超声速流场非平衡区中离解非平衡起主导作用,此时模拟参数ρ_∞L不仅对全流场的无量纲参数分布有效,而且对流场电离特性、模型气动热特性、分子光谱范围的驻点辐射谱强度都是有效的.模拟参数ρ_∞L的有效性与自由流速度、不同类物理量和流场不同区域均相关:当自由流速度增加时,对全场有效的ρ_∞L要求ρ_∞L值减小;与无量纲压力、密度和温度相比,对化学组元特别是离子组元分布有效的ρ_∞L所要求的ρ_∞L值更小;与模型头部区相比,在身部区有效的ρ_∞L所要求的ρ_∞L值更小.

Investigation of transient process and steady output of lasing without inversion

The transient evolution processes and steady outputs of continuous wave lasing without inversion (LWI) and self-pulsing LWI in a resonant open V type three-level system are studied. It was found that the two kinds of LWI have some obvious differences not only from the steady outputs but also from the transient evolution processes. The effects of the unsaturated gain coefficient, cavity loss coefficient, ratio of the atomic injection rates and atomic exit rate on the transient evolution processes and steady outputs are discussed.

XPM-induced pulse compression in birefringent dispersion decreasing fiber

The pulse compression induced by cross-phase modulation in birefringent dispersion decreasing fiber is discussed theoretically by solving the coupled Schrodinger equations which include the contribution of the high-order non-linear effects, and third-order dispersion. In particular, it is found that a high quality compressed signal pulse can be obtained by a pump pulse of low intense through the technique. The dependence of optimum compression on the non-linear factor N, time delay tau(d) and the dispersive ratio f is also discussed in detail. (c) 2005 Elsevier B.V. All rights reserved.

Effects of Yb concentration on the fluorescence spectra of Yb-doped YAlO3 single crystals

0.5 at.% Yb:YAlO3(YAP), 5 at.% Yb:YAP and 15 at.% Yb:YAP were grown using the Czochralski method. Their absorption and fluorescence spectra were measured at room temperature and their emission line shape was calculated using the method of reciprocity. It was observed that the fluorescence spectra changed appreciably with the increasing of Yb concentration. For 0.5 at.% Yb:YAP, the line shape of fluorescence is very similar with the calculated emission line shape; with the increasing of Yb doping concentration, the line shape of fluorescence is very different from the calculated emission line shape. These phenomena are caused by the strong self-absorption at 979 and 999 nm for Yb:YAP. (c) 2005 Elsevier B.V. All rights reserved.