弹性散射

On the basis of the frequency domain Born approximation theory of the scattering of two dimentional elastic waves, the time domain Born approximate solution to the scattering of elastic wave s with arbitrary frequencies is derived.

在二维弹性波散射频域Bron近似解的基础上，通过Fourier变换，推导了任意频率平面P波组合的脉冲波入射二维散射系统时，散射场的时域Born近似解。

The changes of the electron transverse momentum are the basic factors of electron and photon scattering, and their differential scattering sections are decreased with increasing of the quantity of photons which are active with an electron at the same time, and they are quickly decreased with the increasing of the inelastic scattering composition, but their change are slower than that in the situation dominated by laser field.

电子横向动量的变化是引起电子和光子散射的根本原因，其微分散射截面随与一个电子同时作用的光子数的增大而减小，随散射非弹性成分的增大而迅速减小，但比激光场中的情况来得慢一些。

We fit the anisotropic interaction potential based on the Murrell-Sorbie potential function for He-HCl system by applying the interaction energy data, which are calculated at the theoretical level of the single and double excitation coupled-cluster method with noniteractive perturbation treatment of triple excitation CCSD. The new potential model is compared with other potential models. The differential scattering cross sections for collisions between He atoms and HCl molecules are calculated by using CC (Close-Coupling) method. Furthermore, the changing regularity of the inelastic differential scattering cross sections is summed up.

根据在CCSD/aug-cc-pVQZ理论水平下计算的He-HCl相互作用能数据，作者采用Murrell-Sorbie势函数形式拟合了He原子与HCl分子相互作用的各向异性势，并与其它势模型进行了比较；然后采用公认的精确度较高的CC近似方法计算了He-HCl碰撞体系的微分散射截面，总结了非弹性微分散射截面的变化规律。

This paper reviews the applications of singular integral equation to the scattering problems of elastic waves by cracks, especially by interface cracks, which were made during past two decades.

结合20多年来国内外的研究成果，评述奇异积分方程在裂纹体弹性波散射问题中的应用，特别是在界面裂纹散射问题中的应用。

The results show that the angular distribution of the total differential cross section at zero degree increases and the position of oscillation minimum of the same order gradually shift towards small scattering angle along with the increase of the incident isotope He atom mass at identical collision energy. And crossing angle between the elastic and total inelastic DCS gradually decreases and the total inelastic DCS gradually increases.

结果表明：在相同碰撞能量时，随着同位素氦原子质量的增加，总微分截面在0°时的角分布逐渐增大，同一级衍射振荡极小值位置逐渐向小散射角方向移动；弹性与总非弹性截面交界角逐渐减小，总非弹性截面逐渐增加。

Vadim Backman, PhD, a professor of biomedical engineering at Northwestern University in Evanston, Illinois, and colleagues, recently developed the 2 complementary optical techniques that were used in the study. The 4-dimensional elastic light-scattering spectroscopy (4D-ELF) and low-coherence enhanced backscattering spectroscopy use the elastic light-scattering signals from tissue that exhibit characteristic structure-dependent signatures in wavelength and scattering angle, explain the researchers in their paper.

伊利诺斯州埃文斯顿西北学的Vadim Backman生物医学工程博士与其同事，在此研究中应用最近发展的两项互补式光学技术，四维弹性光散射光谱（4D-ELF）与低相干散射增强光谱，运用组织中特殊结构表现的波长、与散射角度的弹性光散射信号来解释这项研究。

Vadim Backman, PhD, a professor of biomedical engineering at Northwestern University in Evanston, Illinois, and colleagues, recently developed the 2 complementary optical techniques that were used in the study. The 4-dimensional elastic light-scattering spectroscopy (4D-ELF) and low-coherence enhanced backscattering spectroscopy use the elastic light-scattering signals from tissue that exhibit characteristic structure-dependent signatures in wavelength and scattering angle, explain the researchers in their paper.

伊利诺斯州埃文斯顿西北大学的Vadim Backman生物医学工程博士与其同事，在此研究中应用最近发展的两项互补式光学技术，四维弹性光散射光谱（4D-ELF）与低相干散射增强光谱，运用组织中特殊结构表现的波长、与散射角度的弹性光散射信号来解释这项研究。

As same as the above-mentioned reason, because theconditions at the inside straight boundary of the binarycomposite material can not be easily satisfied, here, anelastic circular inclusion with large radius is used to replacethe upper half space of the binary composite material, so the〓mary binary composite mater ial problem can be changed〓the scattering problem of a circular elastic inclusion andto the scattering problem of a circular eastic inclusion and〓circular cavity in an infinite space to the steady incident〓wave.

与前面两个问题的理由一样，同样，由于问题中双质复合材料的内部直边界上的边界条件不易解析满足，为此，本文采用了一个半径很大的弹性实夹杂来代替问题中双质复合材料的上半空间部分，而将原来的双质复合材料问题转化成了无限大空间中一圆形弹性夹杂和一圆孔对稳态P波的共同散射问题，根据该问题的特点写出了弹性夹杂内外波场中波函数的一般形式解，利用该问题中夹杂和圆孔处的位移和应力的连续条件，并采用复数傅立叶级数展开技术将其化为一个仅包含问题波函数中未知系数的无穷线性代数方程组，在满足一定计算精度的前提下，通过有限项截断进行近似求解，进而讨论了双质复合材料中圆孔边界处的动应力集中系数随不同入射角、圆孔的不同位置、以及入射波的不同无量纲波数的变化和分布情况。

"Compton effect: Change in wavelength of X rays and other energetic forms of electromagnetic radiation when they collide with electrons. It is a principal way in which radiant energy is absorb ed by matter,"

康普顿效应：电子对X射线和其它高能电磁辐射的弹性散射引起波长增大的现象；这是物质吸收辐射能的一种主要方式。

"Compton effect: Change in wavelength of X rays and other energetic forms of electromagnetic radiation when they collide with electron s. It is a principal way in which radiant energy is absorbed by matter,"

康普顿效应：电子对X射线和其它高能电磁辐射的弹性散射引起波长增大的现象；这是物质吸收辐射能的一种主要方式。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了