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31.
Leonid I. Manevitch Mercedes Mane Lawrence A. Bergman 《International Journal of Non》2011,46(1):247-252
We present a novel type of an energy trap providing targeted energy transfer in a system of weakly coupled pendulums. Our approach is based on the analogy we revealed between the behavior of two weakly coupled classical parametric pendulums (in linear approximation) and the nonadiabatic Landau-Zener tunneling in a two-state quantum system. This analogy leads us to the prediction of an efficient irreversible transfer of vibration energy from one subsystem to another, when the eigenfrequency of at least one of them changes in time, so that the coupled subsystems pass through an internal resonance. The existence of such a phenomenon is not restricted to coupled pendulums, but is inherent to a wide class of both linear and nonlinear parametric oscillatory systems. This opens up the possibility of designing new types of energy traps and absorbers for the dynamic protection of various mechanical systems. 相似文献
32.
一类一阶常微分方程初值问题的无穷多解性 总被引:1,自引:0,他引:1
应用分离变量法,得到了一类一阶微分方程初值问题u′(t)=b(t)f(u(t)),t0,u(0)=0存在无穷多个解的充分必要条件.并给出了全部解. 相似文献
33.
Thomas Chen Younghun Hong Nataša Pavlović 《Annales de l'Institut Henri Poincaré (C) Analyse Non Linéaire》2018,35(2):393-416
In this paper, we study the dynamics of a system of infinitely many fermions in dimensions near thermal equilibrium and prove scattering in the case of small perturbation around equilibrium in a certain generalized Sobolev space of density operators. This work is a continuation of our previous paper [11], and extends the important recent result of M. Lewin and J. Sabin in [19] of a similar type for dimension . In the work at hand, we establish new, improved Strichartz estimates that allow us to control the case . 相似文献
34.
35.
Trevor D. Wooley 《Compositio Mathematica》1998,111(2):149-165
Let p be a rational prime number. We refine Brauer's elementary diagonalisation argument to show that any system of r homogeneous polynomials of degree d, with rational coefficients, possesses a non-trivial p-adic solution provided only that the number of variables in this system exceeds (rd
2)2d-1. This conclusion improves on earlier results of Leep and Schmidt, and of Schmidt. The methods extend to provide analogous conclusions in field extensions of Q, and in purely imaginary extensions of Q. We also discuss lower bounds for the number of variables required to guarantee local solubility. 相似文献
36.
具有通用机的n组工件的排序问题 总被引:4,自引:0,他引:4
本文讨论了具有n台速度相同的专用机,一台同速度的通用机的n组工件的Cmax问题,提出了改进的LPT算法,得到了近似算法的一个估计. 相似文献
37.
A. M. Mathai 《Annals of the Institute of Statistical Mathematics》1982,34(1):591-597
Summary Consider mutually independent inputsX
1,...,X
n onn different occasions into a dam or storage facility. The total input isY=X
1+...+X
n. This sum is a basic quantity in many types of stochastic process problems. The distribution ofY and other aspects connected withY are studied by different authors when the inputs are independently and identically distributed exponential or gamma random
variables. In this article explicit exact expressions for the density ofY are given whenX
1,...,X
n are independent gamma distributed variables with different parameters. The exact density is written as a finite sum, in terms
of zonal polynomials and in terms of confluent hypergeometric functions. Approximations whenn is large and asymptotic results are also given. 相似文献
38.
In this paper certain correspondences have been shown among various formulations of coupled-cluster theories for many electron
closed-shell systems. Specifically it is shown that (i) the energy functional using unitary ansatz of the form exp (T−T
+) is exactly sameorder by order inT with the size-consistent energy functional 〈ψ|H|ψ〉/〈ψ|ψ〉 recently obtained by us in coupled-cluster framework; (ii) in the framework of unitary ansatz of the form exp (T−T
+), both non-variational and variational approaches lead to identical equations upto any given order inT andT
+ inT∼T
2 approximation; (iii) variational procedure using our size-consistent energy functional or using the functional obtained in
the framework of unitary ansatz (as envisaged by Kutzelnigg) leads to energy in both cases, inT∼T
2 approximation, for a total of quadratic powers inT andT
+, same as Cizek’s linearised coupled pair many electron theory energy; (iv) in case of practical calculation of the energy
through the variational procedures using our size-consistent energy functional and the functional in unitary ansatz framework,
there is a loss of upper bound. 相似文献
39.
We study the limit properties of solutions to one class of systems of differential equations as the number of equations and some parameters tend to infinity. We establish a close connection between solutions to these systems and differential equations with retarded argument. Our convergence theorems provide a new method for approximation of solutions to nonlinear differential equations with retarded argument.Original Russian Text Copyright © 2005 Demidenko G. V. and Likhoshvai V. A.The authors were supported by the Russian Foundation for Basic Research (Grants 03-01-00328, 03-04-48506, 03-04-48829, 03-07-96833, 04-01-00458, 05-04-49068, and 05-07-90274), the Integration Grant of the Siberian Branch of the Russian Academy of Sciences (No. 119 and 148), the Program Development of the Scientific Potential of Higher School of the Ministry for Education of the Russian Federation (Grant 8273), and NSF:FIBR (Grant EF-0330786).__________Translated from Sibirskii Matematicheskii Zhurnal, Vol. 46, No. 3, pp. 538–552, May–June, 2005. 相似文献
40.
The extensivity property of entropy is clarified in the light of a critical examination of the entropy formula based on quantum
statistics and the relevant thermodynamic requirement. The modern form of the Gibbs paradox, related to the discontinuous
jump in entropy due to identity or non-identity of particles, is critically investigated. Qualitative framework of a new resolution
of this paradox, which analyses the general effect of distinction mark on the Hamiltonian of a system of identical particles,
is outlined. 相似文献