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1.
非自治退化抛物-双曲型方程可以描述许多自然现象.主要研究这类方程的柯西问题,建立了动力学公式,在对流函数、扩散函数适当光滑性的基础上,证明了该问题动力学解的存在唯一性.  相似文献   

2.
本文研究了Cauchy问题(1.1),(1.2)的可解性及解的性质,得到了为使问题(1.1),(1.2)存在局部解、初值u0应满足的可积性及增长性的充分和必要条件.此外,还讨论了一些临界情况和解的唯一性问题.  相似文献   

3.
4.
本文采用整体迭代法证明了带小初值的一阶非线性耗散偏微分方程组的Cauchy问题的整体经典解的存在性及指数衰减性质。  相似文献   

5.
带非线性边界条件的非线性抛物型方程组   总被引:1,自引:0,他引:1  
本文讨论带非线性边界条件的抛物型方程组ut=Δum,vt=Δvm,x∈Ω,t>0,un=vp,vn=uq,x∈Ω,t>0,u(x,0)=u0(x)δ>0,v(x,0)=v0(x)δ>0,x∈Ω(I)解的整体存在性和在有限时刻爆破问题.其中m,p,q>0,ΩIRN是有界光滑区域,δ>0可以充分小.  相似文献   

6.
Semidiscretization in space of nonlinear degenerate parabolic equations of nondivergent form is presented, under zero Dirichlet boundary condition. It is shown that semidiscrete solutions blow up in finite time. In particular, the asymptotic behavior of blowing-up solutions, is discussed precisely.  相似文献   

7.
This paper deals with the following semilinear parabolic equations with nonlinear boundary conditions u_t - Δu = f(u) - λu,x ∈ Ω, t > 0 \frac{∂u}{∂n} = g(u), \qquad x ∈ ∂Ω, t > 0 It is proved that every positive equilibrium solution is a threshold.  相似文献   

8.
本文研究了非线性抛物方程弱解的L2 衰减 ,证明了若u是非线性抛物方程的一个弱解 ,则u满足‖u‖L2 ≤C( 1 t) -n/ 4,其中C是常数且仅依赖于初始值u0 的范数 .  相似文献   

9.
姜朝欣 《东北数学》2007,23(5):464-470
This paper deals with blow-up criterion for a doubly degenerate parabolic equation of the form (un)t = (|ux|m-1ux)x up in (0, 1) × (0, T) subject to nonlinear boundary source (|ux|m-1ux)(1,t) = uq(1,t), (|ux|m-1ux)(0,t) = 0, and positive initial data u(x,0) = uo(x), where the parameters m, n, p, q > 0.It is proved that the problem possesses global solutions if and only if p ≤ n and q≤min{n, m(n 1)/ m 1}.  相似文献   

10.
This paper deals with blow-up criterion for a doubly degenerate parabolic equation of the form (un)t = (|ux|m-1ux)x up in (0, 1) × (0, T) subject to nonlinear boundary source (|ux|m-1ux)(1,t) = uq(1,t), (|ux|m-1ux)(0,t) = 0, and positive initial data u(x,0) = uo(x), where the parameters m, n, p, q > 0.It is proved that the problem possesses global solutions if and only if p ≤ n and q≤min{n, m(n 1)/ m 1}.  相似文献   

11.
This paper discusses the Cauchy problem of the equationu_t=▽·(▽_u~m|~(p-2)▽_u~m)-u~qwith initial datum a measure.Under the assumption of the parameters,one proves the existence andnou-existence of the non-negative generalized solution.  相似文献   

12.
This paper discusses the Cauchy problem of the equation
(1)
with initial datum a measure. Under the assumption of the parameters, one proves the existence and non-existence of the non-negative generalized solution. Member in Partner Group of MPI for Math. in Leipzig at AMSS. Supported by the Research Fund for Returned Overseas Chinese Scholars 20010107  相似文献   

13.
By means of the fixed point technique and integral estimation method, we study the solutions of periodic boundary value problem and initial value problem for the coupled nonlinear parabolic equations. The global classical solutions of the mentioned problems are shown to exists.  相似文献   

14.
In this paper, we provide a method to solve the Cauchy problem of systems of quasi‐linear parabolic equations, such systems can be transformed to the systems of linear parabolic equations with variable coefficients via the hodograph transformations. Our approach to solve the linear systems with variable coefficients is to use their fundamental solutions, which are constructed by using the Lie's symmetry method. In consequence, we can derive explicit solutions to the Cauchy problem of the quasi‐linear systems in terms of the solutions of the linear systems and the hodograph transformations relating to the quasi‐linear and the linear systems.  相似文献   

15.
In this paper, we obtain the necessary and sufficient conditions on the global existence of all positive (weak) solutions to a nonlinear degenerate parabolic equation with nonlinear boundary condition.  相似文献   

16.
In spaces of classical functions with power weight, we prove the existence and uniqueness of a solution of the Cauchy problem for nonuniformly parabolic equations without restrictions on the power order of degeneracy of the coefficients. We obtain an estimate for the solution of the problem in the corresponding spaces.  相似文献   

17.
We consider a free boundary problem connected with non-Newtonian fluid motion, i.e. the flow of power law fluids with the yield stress. We obtain the solution of the relevant approximation problem by means of a parabolic quasi-variational inequality, and then obtain the weak solution of the original problem after a passage to the limit. Finally, we study the regularity of the weak solution.  相似文献   

18.
In this paper, a class of parabolic systems with nonlinear boundary conditions is discussed. By introducing a complete metric space with decay of W^s_p-norm, we obiain the existence uniqueness of global weak solutions, our method is simpler than before. A decay estimate of the global weak solutions is obtained simultaneously.  相似文献   

19.
In this paper we study the decay estimate of global solutions to the initialboundary value problem for double degenerate nonlinear parabolic equation by using a difference inequality.  相似文献   

20.
In this paper, the local and global existence of solutions for the Cauchy problem of the critical and subcritical nonlinear Schrödinger equations in H^s (s ≥ 2) is studied by using the manner of formal differentiation with respect to time. Some conjectures posed by Cazenave and Weissler in [1] are verified.  相似文献   

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