EXISTENCE OF MULTIPLE POSITIVE PERIODIC SOLUTIONS TO A CLASS OF INTEGRO-DIFFERENTIAL EQUATION

In this paper,by the Avery-Henderson fixed point theorem,we investigate the existence of multiple positive periodic solutions to a class of integro-differential equation. Some suficient conditions are obtained for the existence of multiple positive periodic solutions.     

PERIODIC SOLUTIONS TO A KIND OF SECOND ORDER NEUTRAL LINARD EQUATIONS WITH A DEVIATING ARGUMENT

By means of continuation theorem of coincidence degree theory, some new results on the nonexistence, existence and uniqueness of T-periodic solutions to a kind of second order neutral Linard equations with a deviating argument are obtained.     

Birkhoff Normal Form for the Derivative Nonlinear Schrodinger Equation

This paper is concerned with the derivative nonlinear Schr?dinger equation with periodic boundary conditions.We obtain complete Birkhoff normal form of order six.As an application,the long time stability for solutions of small amplitude is proved.     

EXACT TRAVELLING WAVE SOLUTIONS TO BBM EQUATION

Abundant new travelling wave solutions to the BBM (Benjamin-Bona-Mahoni) equation are obtained by the generalized Jacobian elliptic function method. This method can be applied to other nonlinear evolution equations.     

Analytic intermediate dimensional elliptic tori for the planetary many-body problem

In our context,the planetary many-body problem consists of studying the motion of(n+1)-bodies under the mutual attraction of gravitation,where n planets move around a massive central body,the Sun.We establish the existence of real analytic lower dimensional elliptic invariant tori with intermediate dimension N lies between n and 3n-1 for the spatial planetary many-body problem.Based on a degenerate KolmogorovArnold-Moser(abbr.KAM)theorem proved by Bambusi et al.(2011),Berti and Biasco(2011),we manage to handle the difficulties caused by the degeneracy of this real analytic system.     

Quasi-periodic Solutions for the Derivative Nonlinear SchrÖdinger Equation with Finitely Differentiable Nonlinearities

The authors are concerned with a class of derivative nonlinear Schr¨odinger equation iu_t + u_(xx) + i?f(u, ū, ωt)u_x=0,(t, x) ∈ R × [0, π],subject to Dirichlet boundary condition, where the nonlinearity f(z1, z2, ?) is merely finitely differentiable with respect to all variables rather than analytic and quasi-periodically forced in time. By developing a smoothing and approximation theory, the existence of many quasi-periodic solutions of the above equation is proved.     

ENERGY DECAY OF SOLUTIONS TO A NONLINEAR EQUATION ARISING FROM ELASTIC WAVEGUIDE MODEL

In this paper, we study the asymptotic behavior of solutions to the initial boundary value problem for a nonlinear equation arising from an elastic waveguide model. We prove that under rather mild conditions the initial boundary value problem possesses global solutions which decay at an exponential rate.     

广义2+1维变系数非线薛定愕方程新的准确解(英文)

With the help of the variable-coefficient generalized projected Ricatti equation expansion method,we present exact solutions for the generalized(2+1)-dimensional nonlinear Schrdinger equation with variable coefficients.These solutions include solitary wave solutions,soliton-like solutions and trigonometric function solutions.Among these solutions,some are found for the first time.     

具有p-Laplacian算子的二阶微分方程Picard边值问题(英文)

Suffcient conditions for the existence of at least one solution of two-point boundary value problems for second order nonlinear differential equations {[φ（x（t））] ＋ kx（t） ＋ g（t,x（t）） = p（t）,t ∈（0,π） x（0） = x（π） = 0 are established,where [φ（x）] =（｜x ｜p-2x） with p 1.Our result is new even when [φ（x）] = x in above problem,i.e.p = 2.Examples are presented to illustrate the effciency of the theorem in this paper.     

Quasi-periodic Solutions of the General Nonlinear Beam Equations

In this paper,one-dimensional (1D) nonlinear beam equations of the form utt - uxx + uxxxx + mu = f(u)with Dirichlet boundary conditions are considered,where the nonlinearity f is an analytic,odd funct...     

On a Class of Solutions to the Generalized Derivative Schrödinger Equations

In this work we shall consider the initial value problem associated to the generalized derivative Schrödinger (gDNLS) equationsandFollowing the argument introduced by Cazenave and Naumkin we shall establish the local well-posedness for a class of small data in an appropriate weighted Sobolev space. The other main tools in the proof include the homogeneous and inhomogeneous versions of the Kato smoothing effect for the linear Schrödinger equation established by Kenig-Ponce-Vega.     

A KAM theorem for one dimensional Schrödinger equation with periodic boundary conditions

In this paper, one-dimensional (1D) nonlinear Schrödinger equation

     

KAM tori for higher dimensional beam equation with a fixed constant potential

In this paper, we consider the higher dimensional nonlinear beam equation:utt + △2u + σu + f(u)=0 with periodic boundary conditions, where the nonlinearity f(u) is a real-analytic function of the form f(u)=u3+ h.o.t near u=0 and σ is a positive constant. It is proved that for any fixed σ>0, the above equation admits a family of small-amplitude, linearly stable quasi-periodic solutions corresponding to finite dimensional invariant tori of an associated infinite dimensional dynamical system.     

Lower dimensional invariant tori with prescribed frequency for nonlinear wave equation

In this paper, one-dimensional (1D) nonlinear wave equation utt−uxx+mu+u³=0, subject to Dirichlet boundary conditions is considered. We show that for each given m>0, and each prescribed integer b>1, the above equation admits a Whitney smooth family of small-amplitude quasi-periodic solutions with b-dimensional Diophantine frequencies, which correspond to b-dimensional invariant tori of an associated infinite-dimensional dynamical system. In particular, these Diophantine frequencies are the small dilation of a prescribed Diophantine vector. The proof is based on a partial Birkhoff normal form reduction and an improved KAM method.     

Generalized Extended Tanh-Function Method for Traveling Wave Solutions of Nonlinear Physical Equations

In this paper, the generalized extended tanh-function method is used for constructing the traveling wave solutions of nonlinear evolution equations. We choose Fisher's equation, the nonlinear schrödinger equation to illustrate the validity and advantages of the method. Many new and more general traveling wave solutions are obtained. Furthermore, this method can also be applied to other nonlinear equations in physics.