共查询到20条相似文献,搜索用时 28 毫秒
1.
It is shown that Bethe's exact solution for the finite Heisenberg ferromagnetic chain can be obtained via a direct Fourier transform. Unlike the Bethe ansatz approach, the latter is not confined to one space dimension and opens the possibility of obtaining exact solutions in higher dimensions. 相似文献
2.
Stotts SA Knobles DP Koch RA 《The Journal of the Acoustical Society of America》2011,129(5):EL172-EL178
Scattering from a rough ocean bottom is described numerically with a two-way coupled-mode formalism that contains scattering effects to all orders and provides an exact solution to the wave equation. Both scattered field and direct blast components are computed within the formalism framework. A comparison of the scattered component solution from the coupled mode with the Born approximation (BA) solution for scattering from a rough bottom Pekeris waveguide shows that the BA predicts correctly the scattered field levels but not detailed structure. The transition from direct blast to scattered field dominance is identified in the total field time series. 相似文献
3.
A certain critical two-soliton solution of the nonlinear Schroedinger equation 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《中国物理》网站下载免费的PDF全文](/ch/ext_images/free.gif)
An exact two-soliton solution of the nonlinear Schroedinger equation is derived by using the Hirota direct approach. This solution describes such a critical process that two still solitons separated infinitely approach and then pass through each other and keep straight on infinitely. 相似文献
4.
An exact direct perturbation theory of nonlinear Schrodinger equation with corrections is developed under the condition that the initial value of the perturbed solution is equal to the value of an exact multisoliton solution at a particular time. After showing the squared Jost functions are the eigenfunctions of the linearized operator with a vanishing eigenvalue,suitable definitions of adjoint functions and inner product are introduced. Orthogonal relations are derived and the expansion of the unity in terms of the squared Jost functions is naturally implied. The completeness of the squared Jost functions is shown by the generalized Marchenko equation. As an example,the evolution of a Raman loss compensated soliton in an optical fiber is treated. 相似文献
5.
The direct method of Clarkson and Kruskal is used to study the symmetry reductions of the Burgers equation with linear damping.
The classical similarity reductions reported previously is recovered. The new, nonclassical similarity reduction is obtained.
The new similarity solution is given, and it is also obtained by means of the singular manifold method. The nonclassical method
is used to demonstrate that the new exact solution is indeed a nonclassical similarity solution.
This work has been supported by the Postdoctoral Science Foundation of China. 相似文献
6.
Y.A. DUGUSHM. EISENBERGER 《Journal of sound and vibration》2002,254(5):911-926
The dynamic behavior of multi-span non-uniform beams transversed by a moving load at a constant and variable velocity is investigated. The continuous beam is modelled using Bernoulli-Euler beam theory. The solution is obtained by using both the modal analysis method and the direct integration method. The natural frequencies and mode shapes used in the solution of this problem are obtained exactly by deriving the exact dynamic stiffness matrices for any polynomial variation of the cross-section along the beam using the exact element method. The mode shapes are expressed as infinite polynomial series. Using the exact mode shapes yields the exact solution for general variation of the beam section in case of constant and variable velocity. Numerical examples are presented in order to demonstrate the accuracy and the effectiveness of the present study, and the results are compared to previously published results. 相似文献
7.
8.
M. N. Zhuravlev N. V. Ostrovskaya 《Journal of Experimental and Theoretical Physics》2004,99(2):427-442
The generalized moment method is applied to average the Ginzburg-Landau equation with quintic nonlinearity in the neighborhood of a soliton solution to the nonlinear Schrödinger equation. A qualitative analysis of the resulting dynamical system is presented. New soliton solutions bifurcating from a known exact soliton solution are obtained. The results of the qualitative analysis are compared with those obtained by direct numerical solution of the Ginzburg-Landau equation. 相似文献
9.
10.
The exact soliton solution with a good convergency for nonlinear problem which describes proton motion in a system with ice-like structure is obtained by using a renormalized condition of the expansion coefficients in addition to a direct algebraic method. 相似文献
11.
We report what we believe to be the first rigorous numerical solution of the two-dimensional Maxwell equations for optical propagation within, and scattering by, a random medium of macroscopic dimensions. Our solution is based on the pseudospectral time-domain technique, which provides essentially exact results for electromagnetic field spatial modes sampled at the Nyquist rate or better. The results point toward the emerging feasibility of direct, exact Maxwell equations modeling of light propagation through many millimeters of biological tissues. More generally, our results have a wider implication: Namely, the study of electromagnetic wave propagation within random media is moving toward exact rather than approximate solutions of Maxwell's equations. 相似文献
12.
In this study, we use the direct discontinuous Galerkin method to solve the generalized Burgers-Fisher equation. The method is based on the direct weak formulation of the Burgers-Fisher equation. The two adjacent cells are jointed by a numerical flux that includes the convection numerical flux and the diffusion numerical flux. We solve the ordinary differential equations arising in the direct Galerkin method by using the strong stability preserving Runge-Kutta method. Numerical results are compared with the exact solution and the other results to show the accuracy and reliability of the method. 相似文献
13.
Fedyukhin L. A. Gorchakov A. V. 《Journal of Experimental and Theoretical Physics》2020,131(5):689-695
Journal of Experimental and Theoretical Physics - We propose an original approach to analyzing the exact solution of the direct problem in the theory of reflection that allows an algorithm for... 相似文献
14.
F.X. Magrans 《Journal of sound and vibration》1984,96(1):13-21
In a recent article Kruzins and Fricke [1] applied the method of Markov chains to represent the “random walk” of phonons inside an enclosed space and to predict stationary state acoustic pressure levels, at sufficiently high frequencies, in geometrically complex spaces. In this paper it is demonstrated that with the same initial hypothesis the exact solution can be obtained directly by using the method of direct transference. Explicit expressions for the coefficients of the solution matrix are found, their physical significance is made evident, and a simple method for calculating the solution is presented. 相似文献
15.
A numerical analysis of wave propagation in one dimensional inhomogeneous media is presented in this paper, the first (Part I) of two companion papers. The aim is to provide a natural and physical basis for the solution of the inverse scattering problem in one dimension. The paper includes (i) a discussion of some aspects of the numerical solution of the direct problem, (ii) typical results of calculation and (iii) a comparison between exact solutions and forward scattering approximation (FSA) solutions of the direct problem. It is shown that the FSA allows accurate calculations of the reflected wave and thus constitutes a sound basis for the solution of the inverse problem treated in Part II. 相似文献
16.
Elastic analysis of an elliptic notch in quasicrystals of point group 10 subjected to shear loading
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Based on the stress potential and complex variable
function method, this paper makes an elastic analysis of an
elliptic notch subjected to uniform shear stress at infinity in
quasicrystals with point group 10. With the aid of conformal
transformation, an exact solution for the elliptic notch of the
quasicrystals is obtained. The solution of the mode {\rm II}
Griffith crack as a special case is constructed. The stress
intensity factor and energy release rate have been also obtained as
a direct result of the crack solution. 相似文献
17.
PENG Yan-Ze 《理论物理通讯》2004,41(5):669-670
A new multisoliton solution to the
(2+1)-dimensional KdV equation is obtained by means of the
truncated Painleve expansion method and a direct ansatz technique.
This new exact solution is periodic in the propagating direction
x and exponentially decaying in y and thus it is called
periodic solitons. A typical spatial structure of it is
illustrated by the figures. 相似文献
18.
Hongwu Fan Bingxi LiLidan Yang Ruzhu Wang 《Journal of Quantitative Spectroscopy & Radiative Transfer》2002,74(1):85-95
An inverse radiation analysis is presented for estimating the temperature and the heat load distributions of the heating surface from the temperature and the heat flux measurements of the heated object. The Monte Carlo method is employed to solve the direct radiation problem. The inverse radiation problem is solved using the conjugate gradient and singular value decomposition methods. The measured data are simulated by adding random errors to the exact solution of the direct problem. The effects of the measurement errors on the accuracy of the inverse analysis are investigated. The study shows that the heat load distribution of the heating surface can be estimated accurately for the exact and noisy data. And the conjugate gradient method is better than the singular value decomposition method since the former can obtain more accurate results if the measurement errors are the same. 相似文献
19.
Based on the general direct method developed by Lou et al. [J. Phys. A: Math. Gen. 38 (2005) L129], the symmetry group theorem is obtained,from that both the Lie point groups and the non-Lie symmetry groups of the Konopelchenko-Dubrovsky (KD) equation are obtained. From the theorem, some exact solutions of KD equation are derived from a simple travelling wave solution and a multi-soliton solution. 相似文献
20.
N-Soliton Solution in Wronskian Form for a Generalized Variable-Coefficient Korteweg--de Vries Equation
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We concentrate on finding exact solutions for a generalized variable-coefficient Korteweg-de Vries equation of physically significance. The analytic N-soliton solution in Wronskian form for such a model is postulated and verified by direct substituting the solution into the bilinear form by virtue of the Wronskian technique. Additionally, the bilinear auto-Backlund transformation between the ( N - 1)- and N-soliton solutions is verified. 相似文献