MULTIDIMENSIONAL GOURSAT PSOBLEM FOR SEMILINEAR WAVE EQUATIONS

ＭＵＬＴＩＤＩＭＥＮＳＩＯＮＡＬＧＯＵＲＳＡＴＰＳＯＢＬＥＭＦＯＲＳＥＭＩＬＩＮＥＡＲＷＡＶＥＥＱＵＡＴＩＯＮＳＦＡＮＧＤＡＯＹＵＡＮＡｂｓｔｒａｃｔ：ＩｎｔｈｉｓｐａｐｅｒｗｅｓｔｕｄｙｔｈｅＧｏｕｒｓａｔｐｒｏｂｌｅｍｆｏｒｓｅｍｉｌｉｎｅａｒｗ...     

ON NEUMANN PROBLEM FOR SOMESEMILINEAR ELLIPTIC EQUATIONS INVOLVING CRITICAL SOBOLEV EXPONENTS

1IntroductionLetnbeaboundeddomaininRewithCIboundarytn23.Weconsidertheprobleminwhichp=ac,q=M,7denotestheunitoutwardnormaltoon,A>0,p20.Inthisp8Per,wesuppose(Al)a(z)eL"(n),a(z)50.(afl)op(2)EC(on),op(x)20,M==op(:).(op2)op(zo)=M,icEOf.InasmallneighborhoodUofic,thedoesnQliesononesideOfthetangentplaneOfonatic,andthe(n--l)principlecurvaturesofxo(withrespecttotheinnernormalOfon)arepositive.(gi)g(z,u)ismeasurablein2,continuousinu,sup{g(2,u)::En,0Su5an}< coforeveryfixedan>0andg(x,0)=0.(g2)!5op=0…     

具C^∞系数的非主型方程的Goursat问题

本文以逼近和正则化方法，对一类具Ｃ＾∞系数和数据的非主型方程的Ｇｏｕｒｓａｔ问题证明了Ｃ＾∞解的存在唯一性。     

一类奇异半线性反应扩散方程初值问题解的存在性

本文获得了如下的奇异半线性反应扩散方程初值问题{(e)u/(e)t-(1/tσ)△u=up+f(x),t＞0,x∈Rnlim t→0+ u (t,x)=0, x∈Rn广义解(mild solution)在L∞ loe[(0,∞);L∞(Rn)]中的存在性.其中σ＞0,0＜p＜1,f(x)非负且f(x)∈L∞(Rn).     

奇异半线性非局部反应扩散方程Cauchy问题局部解的存在性

本文讨论如下初值问题局部解的存在性 u/ t- (1/ tσ)Δu =(∫RNuλ(t,y) dy) p /λur + f (x) ,t>0 ,x∈ RNlimt→ 0 + u(t,x ) =0 ,　　　　　　　　　　　　　 x∈ RN其中σ>0 ,λ≥ 1,p≥ 0 ,r≥ 1,p+ r>1,f (x)连续有界非负但不恒等于零 ,Δ是 N维 L aplace算子 ,所得结论推广了文献 [2 ,3]的相应结果     

THE ASYMPTOTIC SOLUTION FOR A CLASS OF SINGULARLY PERTURBED PROBLEM FOR SEMILINEAR SINGULAR EQUATION

The singularly perturbed boundary value problem for a class of semilinearsingular equation is considered. Using a simple and special method the asym-ptotic behavior of solution is studied.     

SINGULAR PERTURBATION OF OPTIMAL CONTROL FOR SEMILINEAR INTEGRO-DIFFERENTIAL EQUATIONS

1 IlltroductionWe shall solve a problem Of optimal control consisting of the systemon the interval 0 5 t 5 1, with initial conditionsand the quadratic cost functionalwhich is to be minimized. Here the "T" denotes transposition; I = jot K(t, asx) fi are m-vectors; is gi are n-vectors, u is an r--vector, and the matrix R.is symmetric and positive definite, while the matrices Q and T are symmetricand positive semidefinite throughout 0 5 t S 1 for E > 0 small. fi, g2, 51 and6z are matrix functi…     

TRIPLE INTERACTIONS OF CONORMAL WAVES FOR HIGHER ORDER SEMILINEAR HYPERBOLIC EQUATIONS

The interaction of three conormal waves for send-linear strictly hyperbolic equations of third oeder is considered. Let ∑i:i = 1,2,3, be smooth characteristic surfaces for P = Di(D^2i-△) intersecting transversally at the origin. Suppose that the solution u to Pu = f(t, x, y, D^αu), |α| ≤2 is conormal to ∑i:i = 1, 2, 3, for t &lt; 0. The author uses Bony‘s second microlocalization techniques and commutator arguments to conclude that the new singularities a short time after the triple interaction lie on the surface of the light cone Γ over the origin plus the surfaces obtainedby flow-outs of the lines of intersection Γ （交集） ∑i and ∑i（交集） ∑j，i, j = 1, 2, 3.     

奇异半线性椭圆方程的非径向正整体解

研究如下N维奇异半线性椭圆方程△u+f(x,u)=0, x∈RN(N≥3),其中函数f:RN× R+→R+连续,在u=0有奇异性;采用上-下解方法给出该方程具有满足如下性质的有界正整体解u的条件: u∈C2+θloc(RN)使得lim |x|→∞ u(x)=0且u(x)≥εmin{1,|x|2-N},其中ε＞0是常数;并证明:若条件添加"f关于u单调不增"的限制,则这种解是唯一的.     

半线性方程周期边值问题

本文利用整体反函数理论，研究了半线性周期边值问题，给出存在唯一性的充分条件，推广和改进了现有的结果。     

AN EXISTENCE THEOREM OF SOLUTIONS FOR SEMILINEAR ELLIPTIC EQUATIONS ON R~N

1991MRSubjectClassification35C15,58E50ConsiderthesernilinearellipticdifferentialequationInthestudyofllollliliearSchrodingerequations,nonlinearequationsofKleili~Gordolltypeall(1reaction-diffusiollequatiolls,sollltionsof(1)correspolldtostalldingwavesolutions.stroll(lill~(ortraveling)wavesolutionsandsteadystatesofthesystem.Manypapersdealtwiththeautonomouscasewhere5andfareindependentofatorwiththeradiallysynlluetriccasewherebandfdependonfi](see[1-4]andtheirreferences).Recentlytheperiodiccaseand…     

拟线性积分微分方程系统的奇摄动边值问题

本文研究高维拟线性积分微分方程系统边值问题的奇摄动,在适当的条件下,利 用渐近分析方法和对角化技巧,证得解的存在性,同时给出解的渐近展开式及其相应的 余项估计.     

QUENCHING PROBLEM IN SOME SEMILINEAR WAVE EQUATIONS

This article proves a quenching result of the solutions for some semi-linear wave equations.     

MULTIDIMENSIONAL RELAXATION APPROXIMATIONS FOR HYPERBOLIC SYSTEMS OF CONSERVATION LAWS

We construct and implement a non-oscillatory relaxation scheme for multidimensional hyperbolic systems of conservation laws. The method transforms the nonlinear hyperbolic system to a semilinear model with a relaxation source term and linear characteristics which can be solved numerically without using either Riemann solver or linear iterations. To discretize the relaxation system we consider a high-resolution reconstruction in space and a TVD Runge-Kutta time integration. Detailed formulation of the scheme is given for problems in three space dimensions and numerical experiments are implemented in both scalar and system cases to show the effectiveness of the method.     

半线性抛物方程的时空有限元方法的误差估计

<正>1引言本文考虑如下半线性抛物方程(?)其中Ω∈R~2.函数f(u):C→C满足:(1)|f(u)|≤c|u|(?)u∈C(Ω)(2)Lipschitz条件,即     

环形域上半线性椭圆型方程径向正解的多重性

讨论如下的半线性方程：｛－△ｕ＝ｇ（│ｘ│）ｆ（ｕ） ｉｎΩ ｕ＝０ ｏｎδΩ这里Ω＝｛ｘ∈Ｒ＾Ｎ：Ｒ〈│ｘ│〈Ｒ｝ Ｎ≥２，０〈Ｒ〈Ｒ〈＋∞，在适当的条件下，运用变分方法我们得到了该方程存在两个非平凡径向正解。     

一类二阶退化半线性椭圆型方程边值问题的适定性及解的正则性

本文考虑一类二阶退化半线性椭圆型方程边值问题.由椭圆正则化方法建立能量不等式,利用紧性推理,Banach—Saks定理,弱解与强解一致性,解常微分方程,椭圆型方程正则性定理,迭代方法.极值原理和Fredholm—Riesz-Schauder理论,可得相应线性问题适定性及解的高阶正则性;再由Moser引理和Banach不动点定理可得半线性问题解的存在性.这类问题与几何中无穷小等距形变刚性问题密切相关,其高阶正则性解的存在性对几何应用尤为重要.     

多维拟线性退化抛物方程Cauchy问题解的唯一性和稳定性

本文证明了拟线性退化抛物方程■的Cauchy问题BV解的唯一性和稳定性.     

算子方程解的稠密性及半线性系统的近似可控性

本文利用Ｂａｎａｃｈ不动点定理和Ｓｃｈａｕｄｅｒ不动点定理研究如下算子方程解的稠密性：ｙ＝ｙ０＋ＬＦ（ｙ）＋ＬＨ（ｖ）（其中，Ｌ、Ｈ为线性算子，Ｆ为非线性算子），然后，利用所得结论讨论Ｂａｎａｃｈ空间内的半线性系统：ｘ＇（ｔ）＋Ａ（ｔ）ｘ（ｔ）＝ｆ（ｔ，ｘ（ｔ）＋Ｂｕ（ｔ）的近似可控性。     

A PRIORI BOUNDS FOR GLOBAL SOLUTIONS OF HIGHER-ORDER SEMILINEAR PARABOLIC PROBLEMS

In this paper, we derive a priori bounds for global solutions of 2m-th order semilinear parabolic equations with superlinear and subcritical growth conditions. The proof is obtained by a bootstrap argument and maximal regularity estimates. If n≥ 10/3m, we also give another proof which does not use maximal regularity estimates.