A Zakharov-Shabat inverse scattering problem with a polynomial spectral dependence in the potential

The inverse scattering problem for the Zakharov-Shabat system , is considered. It is solved by reduction to the inverse scattering problem for two coupled Zakharov-Shabat systems in a 4n-dimensional space: . This work has been done as part of the program ‘Recherche Coopérative sur Programme No. 264: Etude interdisciplinaire des problèmes inverses’. Physique Mathématique et Théorique, Equipe de recherche associée au CNRS, No. 154.     

A new approach to the inverse scattering and spectral problems for the Sturm-Liouville equation

New proofs of the known uniqueness theorems for the one-dimensional inverse spectral and scattering problems are given. Proof of the invertibility of all of the steps in the inversion procedures of Gelfand-Levitan and Marchenko is given. The proposed method of investigation yields some new results, for example, a Marchenko-type equation at x = 0 which holds on the whole axis, rather than on a half-axis, as usual for the scattering theory on half-axis. It also yields a new method, shorter and simpler than earlier published, for proving that the potential in the class L_1,1, obtained by the Marchenko reconstruction procedure, generates the scattering data from which it was reconstructed.     

Direct and inverse problems of the scattering of modes in a waveguide with rough boundaries

Leningrad Technological Institute for the Refrigeration Industry. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 34, No. 6, pp. 694–706, June, 1991.     

Intensity dependence of a laser-initiated emission current from a metal surface

Numerical calculation of the current density at the nonlinear photoelectric effect from the metal surface has been performed. A self-consistent heating of the electron gas is taken into account.     

KDP晶体拉曼散射角度特性

利用群理论详细分析了磷酸二氢钾(KDP)晶体的拉曼振动模式,得出了其拉曼振动模的归类?并采用拉曼光谱仪测量了Z切退火KDP晶体X(ZZ)X,Z(XY)Z和Y(XY)X三种散射配置和未退火KDP晶体Z(XY)Z配置下的拉曼光谱?根据拉曼选择定则得出X(ZZ)X,Z(XY)Z和Y(XY)X散射配置下的拉曼峰分别对应A1,B2(LO)?B2(TO)对称类振动模,但在Z(XY)Z配置下的拉曼光谱中除了B2模,还观察到了A1模,而在Y(XY)X配置下的拉曼光谱中只有B2模,且退火和未退火晶体Z(XY)Z配置下的拉曼光谱无明显差别,此结果表明KDP晶体的对称性降低,在背向散射时A1模也具有角度特性,但与晶体的内应力无关,这是由KDP晶体内部结构决定的?     

KDP晶体拉曼散射角度特性

利用群理论详细分析了磷酸二氢钾(KDP)晶体的拉曼振动模式,得出了其拉曼振动模的归类。并采用拉曼光谱仪测量了Z切退火KDP晶体X(ZZ)珡X,Z(XY)珚Z和Y(XY)X三种散射配置和未退火KDP晶体Z(XY)珚Z配置下的拉曼光谱。根据拉曼选择定则得出X(ZZ)珡X,Z(XY)珚Z和Y(XY)X散射配置下的拉曼峰分别对应A1,B2(LO),B2(TO)对称类振动模,但在Z(XY)珚Z配置下的拉曼光谱中除了B2模,还观察到了A1模,而在Y(XY)X配置下的拉曼光谱中只有B2模,且退火和未退火晶体Z(XY)珚Z配置下的拉曼光谱无明显差别,此结果表明KDP晶体的对称性降低,在背向散射时A1模也具有角度特性,但与晶体的内应力无关,这是由KDP晶体内部结构决定的。     

Neutralization of charged fullerenes during grazing scattering from a metal surface

The neutralization of C(60)(+) and C(60)(2+) fullerenes with keV energies is studied for grazing scattering from a clean and flat Al(001) surface. From the measured shifts between the angular distributions for scattered projectiles of different incident charge, we derive image-charge interaction energies, which relate to the distances of electron transfer for C(60)(+) and C(60)(2+). These neutralization distances are in accord with a classical over-the-barrier model taking into account the image-charge effects of the Al target and the polarization of the fullerene.     

Orientation dependence in the dissociative scattering of hydrogen molecules from metal surfaces

We investigate the molecular orientation dependence of the dissociation probability of neutral molecular hydrogen scattered from metal surfaces. The probability distributions are calculated in the cases when positive and negative hydrogen ions (ion pair) are formed and when two neutral hydrogen atoms are formed. On the basis of numerical results, it is found that a parallel orientation preference of probability distributions shows a tendency to be suppressed in the case when an ion pair is formed as compared with the case when two neutral hydrogen atoms are formed.     

群体雾粒子散射模型及散射角谱研究

如何提高制导精度是研制制导系统所要关心的问题,在有雾的天气情况下,群体雾粒子的散射是影响制导精度的重要因素之一。在Mie理论的基础上,从单个球形粒子的散射效率因子出发,得到了1～6μm群体粒子的散射系数。根据布格尔定律导出了群体粒子对激光束的散射光强表达式,然后在接收器视场角范围内,模拟了散射光强的分布情况。结果表明,沿着激光束的传播方向,散射光强存在比较大的起伏,并且越靠近接收器的视场中轴线,散射光强有减少的趋势。     

群体雾粒子散射模型及散射角谱研究

 如何提高制导精度是研制制导系统所要关心的问题,在有雾的天气情况下,群体雾粒子的散射是影响制导精度的重要因素之一。在Mie理论的基础上,从单个球形粒子的散射效率因子出发,得到了1～6μm群体粒子的散射系数。根据布格尔定律导出了群体粒子对激光束的散射光强表达式,然后在接收器视场角范围内,模拟了散射光强的分布情况。结果表明,沿着激光束的传播方向,散射光强存在比较大的起伏,并且越靠近接收器的视场中轴线,散射光强有减少的趋势。     

A unified model for diffractive and inelastic scattering of a light atom from a solid surface

A simple model for gas-surface scattering is presented which permits treatment of inelastic effects in diffractive systems. This model, founded on an impulsive collision assumption, leads to an intensity distribution which is just a sum of contributions from n-phonon scattering events. Furthermore, by using a convenient form for the repulsive interaction potential, analytic expressions are obtained for the elastic and one-phonon intensities that are in qualitative agreement with experimental results.     

Pseudopotentials and the inverse scattering problems of the generalized Korteweg-de vries equation

The algebraic prolongation structure approach of Wahlquist and Estabrook is used to determine the various forms of inverse scattering equations known for the generalized Korteweg-de Vries equation.     

Size dependence of the surface energy and surface tension of metal nanoparticles

The specific surface energy of small nanoclusters of transition fcc metals is calculated using the many-particle tight-binding potential and its earlier analog, the Gupta potential. The calculations are performed using both a theoretical model and computer simulations based on the Monte Carlo method. The equimolecular surface is considered as the dividing surface. It is found that at short radii of the nanoclusters, the surface energy and surface tension grow linearly as the particle radius increases. The values of the coefficient of proportionality in the dependence of the specific surface energy on the radius of a nanocluster are compared to the available literature data, experimental and otherwise.