NONLINEAR PSEUDOPARABOLIC EQUATIONS IN ARBITRARY DIMENSIONS

1.IntroductionAsiswellknownthenonlinearpseudoparabolicequationsweresuggestedandstudiedinconnectionwithmanypracticalproblemsatthebeginningofthe1970s.AmongthemtheBBMequationat box~abet~0(1'1)isthemostimportant,itwassuggestedinconnectionwiththepropagationoflongwavesinnonlineardispersivesystemsbyT.B.Benjaminetallljin1972.In1977,L.A.Medeirosetall2]studiedtheweaksolutionoftheinitialboundaryvalueproblemforageneralizedformof(1.1)RevisedJanuary,25,1995.*ThisworkissupportedbytheNationalScienceFOun…     

一类半线性双温度热传导方程整体强解的存在性

给出了一类半线性双温度热传导方程的初边值问题整体强解的存在条件,利用位势井方法证明了整体强解的存在性定理,且证明了方程的解或解对X的某些导数的L^2模估计式．     

GLOBAL EXISTENCE AND BLOW-UP OF SOLUTIONS FOR GENERALIZED POCHHAMMER-CHREE EQUATIONS

In this article,we study the initial boundary value problem of generalized Pochhammer-Chree equation u_(tt)-u_(xx)-u_(xxt)-u_(xxtt)=f(u) xx,x ∈Ω,t 0,u(x,0) = u0(x),u t(x,0)=u1(x),x ∈Ω,u(0,t) = u(1,t) = 0,t≥0,where Ω=(0,1).First,we obtain the existence of local W k,p solutions.Then,we prove that,if f(s) ∈ΩC k+1(R) is nondecreasing,f(0) = 0 and |f(u)|≤C1|u| u 0 f(s)ds+C2,u 0(x),u 1(x) ∈ΩW k,p(Ω) ∩ W 1,p 0(Ω),k ≥ 1,1 p ≤∞,then for any T 0 the problem admits a unique solution u(x,t) ∈ W 2,∞(0,T;W k,p(Ω) ∩ W 1,p 0(Ω)).Finally,the finite time blow-up of solutions and global W k,p solution of generalized IMBq equations are discussed.     

方程u_(tt)=u_(xxt)+σ(u_x)_x的初边值问题、周期边界问题与初值问题

本文用Galerkin方法研究了方程的初边值问题,周期边界问题及初值问题,在σ(Z)∈C~1,σ'(Z)下方有界的条件下,得到了整体强解的存在和唯一性,而在σ及初值函数满足一定的光滑性条件下,得到强解的相应的光滑性;最后讨论了解的渐近性质。     

一类半线性热方程整体解的存在性与非存在性

本文研究半线性热方程的初值问题u_t－△u＝u~γ＋cu,（γ＞1）;u（x,0）=（x）非负整体L~P解的存在性与非存在性．首先证明,若C＞0,则不存在非负整体解．而后,对C＜0情形给出了解的整体存在与非存在的充分条件,特别证明了,若P＞（γ一1）或,则当。充分小时存在非负整体L~P解.最后,对系数C和初值（x）得到无穷多个门槛结果．     

任意维数的强阻尼非线性波动方程（Ⅰ）—初边值问题

本文研究任意维数的强阻非线性波动方程ｕｔｔ－ａΔｕｔ－Δｕ＝ｆ（ｕ）具第一类齐边界条件的初值问题，设ｆ∈Ｃ＾１，ｆ＾１（ｕ）上方有界，且当ｎ≥４时存在常数Ａ，Ｂ和ｐ，使｜ｆ＾１（ｕ）｜≤Ａ｜ｕ｜＾ｐ＋Ｂ，其中０＜ｐ≤４／（ｎ－４）（ｎ＞４）：０＜ｐ＜∞（ｎ＝４），得到唯一整体强解，从而改进和推广了已知结果。