Ott–Sudan–Ostrovskiy equation on a half-line

We consider the initial-boundary value problem for the Ott-Sudan-Ostrovskiy equation on a half-line. We study traditionally important problems of the theory of nonlinear partial differential equations, such as global in time existence of solutions to the initial-boundary value problem and the asymptotic behavior of solutions for large time.     

A Neumann problem for the KdV equation with Landau damping on a half-line

We consider the initial-boundary value problem on a half-line for the KdV equation with Landau damping. We study traditionally important problems of the theory of nonlinear partial differential equations, such as global in time existence of solutions to the initial-boundary value problem and the asymptotic behavior of solutions for large time.     

Asymptotic bounds of solutions for a periodic doubly degenerate parabolic equation

This paper is concerned with a doubly degenerate parabolic equation with logistic periodic sources. We are interested in the discussion of the asymptotic behavior of solutions of the initial-boundary value problem. In this paper, we first establish the existence of non-trivial nonnegative periodic solutions by a monotonicity method. Then by using the Moser iterative method, we obtain an a priori upper bound of the nonnegative periodic solutions, by means of which we show the existence of the maximum periodic solution and asymptotic bounds of the nonnegative solutions of the initial-boundary value problem. We also prove that the support of the non-trivial nonnegative periodic solution is independent of time.     

On an unstable thin-film equation in multi-dimensional domains

We study the existence of weak and strong solutions to the initial-boundary value problem for a thin-film type equation with unstable diffusion in multi-dimensional domains. Depending on the initial data and the parameter values, we prove local and global in time existence of nonnegative weak and strong solutions.     

The behavior of a finite difference approximation to a singular initial boundary value problem

We develop difference approximations to a singular parabolic initial-boundary value problem and its corresponding steady-state problem. A critical value for the existence of nonnegative solutions to the discrete steady state system is established. Convergence of the computed critical values is obtained. The long time behavior for the approximated solution of the parabolic problem is investigated. It is shown that the behavior of the discrete system is consistent with that of the continuous one     

On the nonexistence of global solutions of some initial-boundary value problems for the Korteweg-de Vries equation

We consider the problem of finite-time blow-up of solutions of a class of initial-boundary value problems for the Korteweg-de Vries equation. By using the method of optimal test functions corresponding to the boundary conditions, we obtain blow-up conditions for local (with respect to t > 0) solutions and estimate the blow-up time.     

Blow up of solutions of pseudoparabolic equations

We obtain sufficient conditions for the blow up of solutions of the initial-boundary value problem for nonlinear pseudoparabolic equation involving nonlinear convective term.     

Asymptotic behavior of the solution of the first initial-boundary value problem for equations of the Sobolev type from the viewpoint of oscillations

We study the large-time behavior of solutions of the first initial-boundary value problem for partial differential equations of the Sobolev type. We find conditions under which the derivatives of solutions are either oscillating or stabilize to zero.     

Study of Solvability of a Thermoviscoelastic Model Describing the Motion of Weakly Concentrated Water Solutions of Polymers

We study the problem of existence of a weak solution to the initial-boundary value thermoviscoelasticity problem for the model describing the motion of weakly concentrated water solutions of polymers.     

具变指数非线性拟抛物方程弱解的存在性

虑一类变指数的非线性拟抛物方程的初值问题.在一些初值的假定下,基于时间离散化方法构造逼近解.通过对逼近解的一致性估计,证明了弱解的存在性.     

On Solvability of Some Initial-Boundary Problems for Mathematical Models of the Motion of Nonlinearly Viscous and Viscoelastic Fluids

In the paper, the settings of initial-boundary and initial value problems arising in a number of models of movement of nonlinearly viscous or viscoelastic incompressible fluid are considered, and existence theorems for these problems are presented. In particular, the settings of initial-boundary value problems appearing in the regularized model of the movement of viscoelastic fluid with Jeffris constitutive relation are described. The theorems for the existence of weak and strong solutions for these problems in bounded domains are given. The initial value problem for a nonlinearly viscous fluid on the whole space is considered. The estimates on the right-hand side and initial conditions under which there exist local and global solutions of this problem are presented. The modification of Litvinov's model for laminar and turbulent flows with a memory is described. The existence theorem for weak solutions of initial-boundary value problem appearing in this model is given.     

On the well-posedness of entropy solutions to conservation laws with a zero-flux boundary condition

We study a zero-flux type initial-boundary value problem for scalar conservation laws with a genuinely nonlinear flux. We suggest a notion of entropy solution for this problem and prove its well-posedness. The asymptotic behavior of entropy solutions is also discussed.     

Global existence for a quasi-linear evolution equation with a non-convex energy

We establish the existence of global in time weak solutions to the initial-boundary value problem related to the dynamics of coherent solid-solid phase transitions in viscoelasticity. The class of the stored energy functionals includes the double well potential, and a general convolution damping term is considered.

     

Characteristic Symmetric Hyperbolic Systems with Dissipation: Global Existence and Asymptotics

We consider the initial-boundary value problem for quasi-linear symmetric hyperbolic systems with dissipation and characteristic boundary of constant multiplicity. We investigate the global existence and decay property of small regular solutions in suitable functions spaces which take into account the loss of regularity in the normal direction to the characteristic boundary. We also show the existence, uniqueness and stability of the time periodic solutions. © 1997 by B. G. Teubner Stuttgart–John Wiley & Sons Ltd.     

Existence and Uniqueness of Weak Solutions to the $p$-Biharmonic Parabolic Equation

We consider an initial-boundary value problem for a $p$-biharmonic parabolic equation. Under some assumptions on the initial value, we construct approximate solutions by the discrete-time method. By means of uniform estimates on solutions of the time-difference equations, we establish the existence of weak solutions, and also discuss the uniqueness.     

A sixth order degenerate equation with the higher order <Emphasis Type="Italic">p</Emphasis>-laplacian operator

We consider a initial-boundary value problem for a sixth order degenerate parabolic equation. Under some assumptions on the initial value, we establish the existence of weak solutions by the time-discrete method. The uniqueness, asymptotic behavior and the finite speed of propagation of perturbations of solutions are also discussed.     

Global solutions for initial-boundary value problem of quasilinear wave equations

This work investigates the existence of globally Lipschitz continuous solutions to a class of initial-boundary value problem of quasilinear wave equations. Applying the Lax's method and generalized Glimm's method, we construct the approximate solutions of initial-boundary Riemann problem near the boundary layer and perturbed Riemann problem away from the boundary layer. By showing the weak convergence of residuals for the approximate solutions, we establish the global existence for the derivatives of solutions and obtain the existence of global Lipschitz continuous solutions of the problem.     

三维空间中带非线性阻尼项的等熵欧拉方程组轴对称解的爆破

研究了三维空间中带非线性阻尼项的可压缩等熵欧拉方程组Dirichlet初边值问题.采用泛函方法,定义几种不同的泛函,当初始速度足够大时分别得到了经典解在某一时间内必定爆破的结论.由于出现了非线性阻尼项,较之线性阻尼的情形,经典解爆破的难度随之增加.     

Extinction for a quasilinear parabolic equation with a nonlinear gradient source and absorption

We deal with the extinction, non-extinction and decay estimates of the non-negative nontrivial weak solutions of the initial-boundary value problem for the quasilinear parabolic equation with nonlinear gradient source and absorption.     

The Phase Field Equations and Gradient Flows of Marginal Functions

We prove existence of solutions to the initial-boundary value problem for the quasistationary phase field equations with a multidimensional order parameter. We show that these solutions satisfy the entropy maximum principle and the entropy production minimum principle. We obtain a new selection theorem for differential inclusion with multifunctions generated by weak differentials of marginal functions.