一类奇异p-Laplace微分方程正解的存在性与不存在性

In this paper we give a necessary and sufficient condition for the existence of positive solutions for the one-dimensional singular p-Laplacian differential equation. The methods used to show existence rely on upper-lower solutions method and compactness techniques, while the methods used to prove nonexistence are based on monotone techniques and scaling arguments.     

六阶对流Cahn-Hilliard方程解的整体适定性

In this paper,we consider the global well-posedness of smooth solutions for the Cauchy problem of a sixth order convective Cahn-Hilliard equation with small initial data.We first construct a local smooth solution,then by combining some a priori estimates,continuity argument,the local smooth solution is extended step by step to all t>0 provided that the L1 norm of initial data is suitably small and the smooth nonlinear functions f(u)and g(u)satisfy certain local growth conditions at some fixed point■.     

NOTE ON AN OPEN PROBLEM OF HIGHER ORDER NONLINEAR EVOLUTION EQUATIONS

In view of a new idea on initial conditions,an open problem of nonlinear evolution equations with higher order,which was given by J.L.Lions,is solved.Effect of our results is shown on an example.     

基于欧姆加热模型的一类非局部双曲方程解的渐近性态

In this paper,the asymptotic behavior of a non-local hyperbolic problem modelling Ohmic heating is studied.It is found that the behavior of the solution of the hyperbolic problem only has three cases:the solution is globally bounded and the unique steady state is globally asymptotically stable;the solution is infinite when t→∞;the solution blows up.If the solution blows up,the blow-up is uniform on any compact subsets of(0,1] and the blow-up rate is lim t → T*-u(x,t)(T*-t)1/α+βp-1=(α+βp-1/1-α)1/1-α-βp,where T* is the blow-up time.     

一类带非线性边界条件的非经典扩散方程解的爆破

In this article,under suitable conditions on the internal term f(·)and the bound-ary nonlinear term g(·),we prove blow-up results for a class of nonclassical diffusion equations with nonlinear boundary condition.     

一类非线性双曲型方程解的整体存在性和破裂问题

对这样一类非线性双曲型方程的柯西问题这里F、h、g都是其变量的足够光滑的函数,且F满足当|Du|,|DD_xu|充分小时,p是>1的整数。我们要讨论f(t)对“小初值”柯西问题(h,g在某种意义下适当小)解的整体存在性的影响。本文就f(t)=O(e~(-t))、f(t)=O((1+t)~m),f(t)=O(e~t)(t→+∞)几种情形进行讨论。当f(t)=O(1)时的结论已由Klainerman、Shatah得到。     

非线性分数微分方程边值问题正解的存在性(英文)

In this paper,we study a Dirichlet-type boundary value problem（BVP） of nonlinear fractional differential equation with an order α∈(3,4],where the fractional derivative D^α_o⁺is the standard Riemann-Liouville fractional derivative.By constructing the Green function and investigating its properties,we obtain some criteria for the existence of one positive solution and two positive solutions for the above BVP.The Krasnosel’skii fixedpoint theorem in cones is used here.We also give an example to illustrate the applicability of our results.     

A Remark on Persistence of Regularity for the Nonlinear Boussinesq System in Dimension Two

This paper investigates the Cauchy problem for the nonlinear Boussinesq system in dimension two, and prove that for any initial data(u_0, θ_0) in H~(1+s)×H~(1+s), where s ∈(0, 1),the persistence of regularity holds.     

PRECISE SMOOTHING EFFECTS OF HOMOGENEOUS LANDAU EQUATION IN SOBOLEV SPACES＊

In this work,we study the smoothing effect of Cauchy problem in Sobolev space for the spatially homogeneous Landau equation in the Maxwellian case.We obtain a precise estimate with respect to time vari...     

一类非线性双曲方程整体弱解的存在性与不存在性

讨论了一类非线性双曲方程uu-a1△u-a2n∑i=1 / xi(｜uxi｜^-1)-a3△ut=0的初边值问题整体弱解的存在性与不存在性和指数衰减。     

具材料阻尼的非线性双曲型方程整体解的不存在性

考虑了一类具材料阻尼的非线性双曲型方程初边值问题整体解的不存在性．分别采用能量方法、Jensen不等式和凹性方法证明了该问题整体解的不存在性定理．作为主要结果的应用,给出了3个例子．     

一非线性双曲型方程解的爆破

本文应用压缩映射原理证明一非线性双曲型方程的初边值问题存在唯一局部广义解，并给出此问题的广义解爆破的充分条件。     

一具有阻尼非线性双曲型方程初边值问题整体解的不存在性

本文证明一具有阻尼非线性双曲型方程初边值问题局部广义解的存在性和唯一性,并给出此问题解爆破的充分条件.     

一类具边界耗散的高阶非线性双曲方程整体解的不存在性

本文利用广义凸性方法证明了边界耗散的非线性四阶方程初边值问题整体解的不存在性     

The Nonexistence of the Solutions for the Non-Newtonian Filtration Equation with Absorption

The paper proves the nonexistence of the solution for the following Cauchy problem\begin{align*}\begin{cases}u_{t} ={\rm div}\left(\left|\nabla u^{m} \right|^{p-2} \nabla u^{m} \right)-\lambda \; u^{q},&\qquad \left(x,t\right)\in S_{T} ={\mathbb{R}}^N \times \left(0,T\right), \\u\left(x,\; 0\right)=\delta \left(x\right), &\qquad x\in {\mathbb{R}}^,\end{cases}\end{align*}under some conditions on \textit{m,p,q},$\lambda$, where $\delta $ is Dirac function.     

On the Decay of Solution of Some Nonlinear Hyperbolic Equation

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Initial Boundary Value Problem for a Damped Nonlinear Hyperbolic Equation

In the paper, the existence and uniqueness of the generalized global solution and the classical global solution of the initial boundary value problems for the nonlinear hyperbolic equation u_{tt} + k_1u_{xxxx} + k_2u_{xxxxt} + g(u_{xx})_{xx} = f(x, t) are proved by Galerkin method and the sufficient conditions of blow-up of solution in finite time are given.     

一类高阶非线性双曲型方程Cauchy问题解的爆破

本文研究一类高阶非线性双曲型方程utt-uxx+μuxxx-αuxxtt+βuxxxxtt=f(ux)x的Cauchy问题,证明问题解的存在性与唯一性,并给出解在有限时刻爆破的充分条件.     

一类N维非线性波动方程的Cauchy问题

证明下列非线性波动方程的Cauchy问题v_(tt)-α△v_(tt)-Δv=g(v)-αΔg(v),x∈R~N,t>0,(1)v(x,0)=v_0(x),v_t(x,0)=v_1(x),x∈R~N(2)在空间C~2([0,∞);H~s(R~N))(s>N/2)中存在唯一整体广义解v和在空间C~2([0,∞);H~s(R~N))(s>2+N/2N)中存在唯一整体古典解v,即u∈C~2([0,∞);C_B~2(R~N)).还证明Cauchy问题(1),(2)在C~3([0,∞);W~(m,p)(R~N)∩L~∞(R~N))(m≥0,1≤p≤∞)中有唯一整体广义解v和在C~3([0,∞);W~(m,p)(R~N)∩L~∞(R~N))(m>2+N/P)中有唯一整体古典解v,即v∈C~3([0,∞);C~2(R~N)∩L~∞(R~N)).