一类具弱非线性耗散项粘弹性波方程解的能量衰减估计

通过运用扰动能量方法研究了一类具有弱非线性耗散项粘弹性波方程解的能量衰减性,其中耗散项显依赖于时间t,得到解的衰减率依赖于阻尼的增长速度和t的函数.     

三维Zakharov-Kuznetsov方程解的衰减性

考虑三维Zakharov-Kuznetsov方程的初值问题,证明了该初值问题解的指数衰减性.这个性质与加权Sobolev空间中解的持久性及该问题解的唯一连续性相关.     

变系数波动方程的边界镇定

应用Riemann几何方法和乘子方法,得到一定条件下变系数波动方程在线性边界反馈下能量的指数衰减性.     

一类带记忆边界条件波动系统解的长时间性态

研究一类带记忆边界条件波动系统解的长时间性态.在初边值满足一定条件时,利用Faedo-Galerkin近似方法得到了系统解的存在唯一性.使用扰动能量方法,证明了系统解的一致衰减性.     

具超音速边界可压Navier-Stokes方程解的指数衰减

考虑了二维空间上具超音速物理边界的可压Navier-Stokes方程的初边值问题.给定常数平衡态(ρ~*,0),得到了所考虑问题解的整体存在性.在平衡态附近的小扰动下,利用加权能量估计方法得到解的指数衰减性.     

带有一般线性耗散项的p-方程组解的衰减估计

该文主要研究带有一般的线性耗散项的p-方程组Cauchy问题解的衰减性.该文采用Fourier变换的方法,利用基本解方法构造Cauchy问题的解,证明了当初始值有紧支集、耗散项系数满足一定条件时p-方程组Cauchy问题的解任意阶导数具有衰减性.该文的讨论可以推广到更加一般的2×2带耗散项的双曲型方程组的情形.     

带非线性阻尼的粘弹方程解的整体存在性和一致衰减性

研究带有非线性阻尼的粘弹方程,得到了弱解整体存在性和一致指数衰减性.     

具时间依赖系数和耗散边界的非线性波方程的能量指数衰减性

利用能量法证明了具耗散边界条件和时间依赖系数的非线性波方程的能量指数衰减性.     

基于基样条局部逼近散乱数据拟合中的Shepard方法

本文针对散乱数据拟合的shepard方法,提出了一种局部逼近的新方法.该方法以局部三次基样条函数作为Shepard公式中的权函数,新的权函数具有良好的衰减性和二阶连续性,从而改进了传统方法的不足之处,使实际应用效果更好.     

一个带有阻尼项和耦合源项的波动方程组解的一般衰减估计

本文研究了一个具有弱阻尼项和耦合源项的粘弹性波动方程组的初边值问题.首先,在一定的初边值条件下,应用位势井理论证明了解的整体存在.其次,在松弛函数满足一定的条件下,利用能量扰动的方法结合微分不等式技巧证明了解能量的一般衰减性结果.     

BBM-Burgers方程解得衰减估计

本文研究了一维空间的BBM-Burgers方程.利用时频分解和能量估计等工具,在解整体存在的前提下,得到了本方程柯西问题解的某些衰减估计.     

一类具有Taylor阻尼的Klein-Gordon方程解的稳定性分析

研究了一类具有Taylor阻尼的Klein-Gordon方程解的稳定性.通过对松弛函数及初始值进行适当的限制,首先基于位势井理论,得到了整体解的存在性,然后构造新的能量函数,利用凸函数的性质及扰动能量方法,得到了显式的能量衰减估计.研究过程中弱化了对松弛函数的限制,同时得到了更广泛的能量衰减速率估计.     

On the decay of solutions to the 2D Neumann exterior problem for the wave equation

We consider the exterior problem in the plane for the wave equation with a Neumann boundary condition and study the asymptotic behavior of the solution for large times. For possible application we are interested to show a decay estimate which does not involve weighted norms of the initial data. In the paper we prove such an estimate, by a combination of the estimate of the local energy decay and decay estimates for the free space solution.     

A sharper decay rate for a viscoelastic wave equation with power nonlinearity

We consider a viscoelastic wave equation with power nonlinearity. First, we construct a local solution by the Faedo-Galerkin approximation scheme and contraction mapping theorem. Next, we continue the local solution to the global one by a priori estimates obtained from a decreasing energy. Finally, we discuss the decay rate of the global solution by assuming that the kernel function is convex.     

Energy decay estimates and infinite blow‐up phenomena for a strongly damped semilinear wave equation with logarithmic nonlinear source

This paper deals with the energy decay estimates and infinite blow‐up phenomena for a strongly damped semilinear wave equation with logarithmic nonlinear source term under null Dirichlet boundary condition. By constructing a new family of potential wells, together with logarithmic Sobolev inequality and perturbation energy technique, we establish sufficient conditions to guarantee the solution exists globally or occurs infinite blow‐up and derive the polynomial or exponential energy decay estimates under some appropriate conditions.     

A note on time decay for the nonlinear beam equation

In this note we obtain another form of Morawetz-type identity by Lagrange method and present a simple proof of the time decay estimates for the solution of the nonlinear beam equation, for a nonlinear term with repelling sign, as t→∞. As an immediate consequence, we also get the time-integrability of the local energy of the solution for the beam equation.     

Decay of the nematic liquid crystal system

In this paper, we study the time‐decay rates of the solution to the Cauchy problem for a nematic liquid crystals system via a refined pure energy method. In particular, the optimal decay rates of the higher‐order spatial derivatives of the solution are obtained. The negative Sobolev norms are shown to be preserved along time evolution and enhance the decay rates. Copyright © 2015 John Wiley & Sons, Ltd.     

Global existence and decay of solutions of a nonlinear system of wave equations

This work is concerned with a system of two wave equations with nonlinear damping and source terms acting in both equations. Under some restrictions on the nonlinearity of the damping and the source terms, we show that our problem has a unique local solution. Also, we prove that, for some restrictions on the initial data, the rate of decay of the total energy is exponential or polynomial depending on the exponents of the damping terms in both equations.     

Stoxes方程初边值问题的Phragmen－Lindelof二择性原理

本文对非定常的Ｓｔｏｋｅｓ方程的初边值问题证明了Ｐｈｒａｇｍｅｎ－Ｌｉｎｄｅｌｏｆ二择性原理，即证明Ｓｔｏｋｅｓ流函数的能量，随着与带状区域有限端距离的增加必定或者按指数率增长或者按指数率衰减．对能量衰减情况建立了Ｓｔｏｋｅｓ流速度的最大模的点点估计．并提出求全能量上界的方法．     

Optimal time decay of the Boltzmann equation with frictional force

In this paper, we use the combination of energy method and Fourier analysis to obtain the optimal time decay of the Boltzmann equation with frictional force towards equilibrium. Precisely speaking, we decompose the equation into macroscopic and microscopic partitions and perform the energy estimation. Then, we construct a special solution operator to a linearized equation without source term and use Fourier analysis to obtain the optimal decay rate to this solution operator. Finally, combining the decay rate with the energy estimation for nonlinear terms, the optimal decay rate to the Boltzmann equation with frictional force is established.