强CO_2激光退火时离子注入Si的光学性质

本文测量了砷离子(As~+)注入的Si在连续CO_2激光辐照下光的椭圆偏振参数、反射率、表面薄层电阻率随时间的变化。从(?)、△、R、ρ的变化看出Si注入层的激光退火是在一定的时间、温度条件下迅速完成的。

随机振动

<正> 随机振动作为一门学科正式出现,还是五十年代初期的事情,它是随着科学技术的发展,特别是电子计算机的广泛应用而迅速发展起来的一门新兴学科。今天,可以毫不夸张地说,在现代科学中,差不多已经没有什么领域不存在随机振动问题。

FORTRAN语言的非数值应用

<正> 1.系统设计 利用高速计算机,进行微分方程公式的推导是数学研究工作的一个新的尝试,它将影响今后微分方程研究工作的现代化。 微分方程程序系统(Differential Equation Program System,简称DEPS)的主要用途是

Some comments on the stability theory of mhd shock waves

The stability (evolutionarity) problem for a kind of MHD shock waves is discussed in this paper. That is to solve the interaction problem of MHD shock waves with (2-dimensional) oblique incident disturbances. In other words, the result of gasdynamic shocks is generalized to the case of MHD shocks. The previous conclusion of stability theory of MHD shock waves obtained from the solution of interaction problem of MHD shock wave with (one-dimensional) normal shock wave is that only fast and slow shocks are stable, and intermediate shocks are unstable. However, the results of this paper show that when the small disturbances are the Alfven waves a new stability condition which is related to the parameters in front of and behind the shock wave is derived. When the disturbances are entropy wave and fast and slow magneto acoustic waves the stability condition is related to the frequency of small disturbances. As the limiting ease, i. e. when a normal incident (reflection, refraction) is consid...更多ered, the fast and slow shocks are unstable. The results also show that the conclusion drawn by Kontorovich is invalid for the stability theory of shock waves.

激光微弯曲成形机理的数值研究

利用自行研制的含热传导、冲击动力学大、变形有限元程序，模拟了小尺寸梁在脉冲激光加热条件下的变形过程。在此基础上，利用商用程序模拟了冷却及残余应力的产生，研究了激光参数（强度及分布）等对于微弯曲的影响。数值模拟结果与文献中的实验观察相吻合。

水平管段塞流持液率的试验统计分析

对水平管段塞流持液率进行了试验研究。通过对试验结果的统计分析可以得出:①可以利用段塞流持液率的波动情况来确定液塞频率。②在段塞流动中,当气相折算速度和液相折算速度相差不大时,持液率概率密度函数呈双峰分布;当液相折算速度不变时,随着气相折算速度的增大,持液率概率密度函数第2峰值逐渐减小,直至消失而变为单峰分布;利用这一特征可初步确定段塞流动中气、液相流量相对大小。③折算速度的变化会引起液塞持液率的变化,液塞持液率随气相折算速度的增大而减小,随液相折算速度的增大而增大。

2002年度非线性力学国家重点实验室学术年会简介

<正> 2002年度非线性力学国家重点实验室(LNM)第14届学术年会于2002年12月21—22日在中国科学院力学研究所隆重举行.本次年会受到了所内外学术同行的广泛关注和重视,有10余个单位的近200人参加了本次LNM学术年会.

中国科学院国家微重力实验室简介

微重力科学是随着当今载人航天技术的发展而发展起来的前沿学科．微重力环境为诸多科学问题的研究提供了机遇，蕴育着自然科学的重大突破，并正在培育新一代高技术产业，是空间科学研究的热点．为适应我国空间科学发展的需要，1995年9月4日由总装备部和中国科学院共同投资建设中国科学院国家微重力实验室， 2003年4月通过全面验收，成为我国微重力科学研究基地．实验室主任为中科院院士、国际宇航科学院院士胡文瑞研究员．依托单位是中科院力学所．

El bosque guipuzcoano en la Edad Moderna: aprovechamiento, ordenamiento legal y conflictividad

[ES]En este libro se analiza la evolución tanto del bosque guipuzcoano como del aprovechamiento, el ordenamiento legal y la conflictividad en torno al mismo, entre los siglos XV al XVIII.

The response of porous Al2O3 probed to nanoindentation

The response of porous Al2O3 to nanoindentation was investigated at microscopic scales (nm-mu m) and under ultra-low loads from 5 to 90 mN with special attention paid to the dependence of the load-depth behaviour to sample porosity. It was found that the load-depth curves manifest local responses typical of the various porous structures investigated. This is particularly clear for the residual deformation after load removal. Similarly, the limited mean pressure of the sample containing small grains and interconnected pores is consistent with its porous structure. By comparison, the samples with larger grain size and various porous structures exhibit higher pressures and smaller residual deformations that can be attributed to the mechanical response of the solid phase. (C) 2007 Elsevier B.V. All rights reserved.

Transvases y discurso histórico: traducción/adaptación en la Edad Media

Eterio Pajares, Raquel Merino y José Miguel Santamaría (eds.)

Emendas ao PLOA : aumento do número das emendas individuais e inclusão da Bancada Feminina no rol de autores

O presente estudo foi motivado pelas Solicitações de Trabalho nos 285/12 e 328/12, por meio das quais a deputada Janete Rocha Pietá propõe, respectivamente, a alteração do número de emendas individuais ao projeto de lei orçamentária anual e a inclusão da bancada feminina como legítima autora de emendas à referida proposição