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1.
关于Fujita型反应扩散方程组的Cauchy问题   总被引:5,自引:1,他引:5  
张凯军  王亮涛 《数学学报》1997,40(5):717-732
本文研究Fujita型反应扩散方程组ut-Δu=α1|u|q1-1u+β1|v|p1-1v,(x∈RN,t>0),vt-Δv=α2|u|q2-1u+β2|v|p2-1v,u(x,0)=u0(x)0,v(x,0)=v0(x)0,(x∈RN)Lp解的整体存在性和有限时间Blow up问题.这里qi>1,pi>1(i=1,2),α10,α2>0,β1>0,β20,1p+∞.  相似文献   

2.
梁保松  叶耀军 《数学季刊》1999,14(2):97-101
§1. IntroductionandResultInthisarticleweareconcernedwiththedecayofglobalsolutionoftheinitial-boundaryvalueproblemforthefollowingnonlinearhyperbolicequationutt+Au+|ut|αut=f(x,t)     inΩ×R+,(1)u(x,0)=u0(x),ut(x,0)=u1(x)  x∈Ω,(2)u(x,t)=0            (x,t…  相似文献   

3.
徐中海 《数学研究》1999,32(2):179-183
研 究如下第一边值 问题u t = div(| Du m |p - 2 Dum ) + f (x ,u)u (x ,t) = 0u (x ,0) = u0  0      (x ,t) ∈ Q T = Ω× (0, T)(x ,t) ∈ Ω× (0, T)x ∈ Ω解的极限性质 (t → ∞),推 广了文献[1 ~ 7] 的结果  相似文献   

4.
本文讨论下述非齐次Kirchhof方程的Cauchy问题utt-m∫Rn|Δu|2dxΔu=f(t,x),u(0,x)=u0(x),ut(0,x)=u1(x),其中m(r)∈C1[0,+∞)且m(r)>0.在初值和右端项“小”的条件下,我们获得了此问题整体解的存在唯一性  相似文献   

5.
本文研究非线性薛定鄂方程的初始值和边界值问题 iu_t=u_(xx)-g|u|~(p-1)u。0<x,t<∞,这里 g> 0, p> 3; u(x,0)= h(x).假设 h(x)∈ H(IR~+), Q(t),R(t) E C(IR~+).对于二类不同的边界值(狄里克莱型u(0,t)=Q(t)和鲁宾型u_x(0,t)+au(0,t)=R(t);这里a是实数)本文证明古典解。 u∈ C~1(L~2)∩ L~2(H~2)的存在性,唯一性和全局性.  相似文献   

6.
命题 设直线l:Ax+By+C=0(A,B不同时为零),⊙O:(x-a)2+(y-b)2=R2,则l与⊙O有交点|Aa+Bb+C|A2+B2≤R.本文举例说明这一命题在解题中的巧用.一、用于求最值(或值域)例1 如果实数x,y满足等式(x-2)2+y2=3,求u=yx的最大值.(1990年高考试题)解 由u=yx得ux-y=0,点(x,y)在直线ux-y=0以及圆(x-2)2+y2=3上.∴2u-01+u2≤1-3≤u≤3,∴umax=3.例2 求函数u=2x-1+5-2x的最大值.解 点(…  相似文献   

7.
对于如下一类奇异非线性抛物型方程:tu(t,x)=Δu(t,x)-uβ(t,x),x∈B(0,a),u(0,x)=0,u(t,x)|x|→a-→∞,t>0,这里,1≤β≤2,B(o,a)表示以o为中心,以a为半径的Rd中的闭球,利用超过程的理论,给出了它的概率解法,从而推广了文[1]相应的结论  相似文献   

8.
一类拟线性二阶微分方程解的振动与非振动的判定   总被引:4,自引:0,他引:4  
杨小京 《数学学报》2001,44(2):311-318
本文讨论了拟线性微分方程(p(x'))'+q(t)p(x)=0,t≥t0,q(t)≥0(这里 p(u)=|u|p-1u,p>0是常数)的解的振动与非振动条件,并改进了文献[2]的结果.  相似文献   

9.
考虑包含测度μ的椭圆型方程-divA(x,u,u)+B(x,u,u)=μ,在G内,ξ·A(x,u,ξ)|ξ|p-f0(x),1<p<n,|A(x,u,ξ)|κ|ξ|p-1+f1(x),κ1,|B(x,u,ξ)|c(x)|ξ|γ+f2(x),p-1γp在γ=p-1的情况,为证有界解的Hlder连续性,只需c(x)∈Ln(G)  相似文献   

10.
赵云  王术 《数学季刊》1999,14(2):102-107
§1. IntroductionThispaperdealswiththefollowinginitialvalueproblemut=Δu+vp1(0,t)vr1(x,t),vt=Δv+up2(0,t)ur2(x,t),u(x,0)=u0(x),v(x,0)=v0(x),  x∈RN,t>0,x∈RN,t>0,x∈RN,(1)whereN1,pi>0,ri1,i=1,2,u0(x)0andv0(x)0arenonnegativecontinuous,andboundedfunction…  相似文献   

11.
12.
Schr(o)dinger operator is a central subject in the mathematical study of quantum mechanics.Consider the Schrodinger operator H = -△ V on R, where △ = d2/dx2 and the potential function V is real valued. In Fourier analysis, it is well-known that a square integrable function admits an expansion with exponentials as eigenfunctions of -△. A natural conjecture is that an L2 function admits a similar expansion in terms of "eigenfunctions" of H, a perturbation of the Laplacian (see [7], Ch. Ⅺ and the notes), under certain condition on V.  相似文献   

13.
14.
正Applied Mathematics-A Journal of Chinese Universities,Series B(Appl.Math.J.Chinese Univ.,Ser.B)is a comprehensive applied mathematics journal jointly sponsored by Zhejiang University,China Society for Industrial and Applied Mathematics,and Springer-Verlag.It is a quarterly journal with  相似文献   

15.
正Journal overview:Journal of Mathematical Research with Applications(JMRA),formerly Journal of Mathematical Research and Exposition(JMRE)created in 1981,one of the transactions of China Society for Industrial and Applied Mathematics,is a home for original research papers of the highest quality in all areas of mathematics with applications.The target audience comprises:pure and applied mathematicians,graduate students in broad fields of sciences and technology,scientists and engineers interested in mathematics.  相似文献   

16.
A cumulative-capacitated transportation problem is studied. The supply nodes and demand nodes are each chains. Shipments from a supply node to a demand node are possible only if the pair lies in a sublattice, or equivalently, in a staircase disjoint union of rectangles, of the product of the two chains. There are (lattice) superadditive upper bounds on the cumulative flows in all leading subrectangles of each rectangle. It is shown that there is a greatest cumulative flow formed by the natural generalization of the South-West Corner Rule that respects cumulative-flow capacities; it has maximum reward when the rewards are (lattice) superadditive; it is integer if the supplies, demands and capacities are integer; and it can be calculated myopically in linear time. The result is specialized to earlier work of Hoeffding (1940), Fréchet (1951), Lorentz (1953), Hoffman (1963) and Barnes and Hoffman (1985). Applications are given to extreme constrained bivariate distributions, optimal distribution with limited one-way product substitution and, generalizing results of Derman and Klein (1958), optimal sales with age-dependent rewards and capacities.To our friend, Philip Wolfe, with admiration and affection, on the occasion of his 65th birthday.Research was supported respectively by the IBM T.J. Watson and IBM Almaden Research Centers and is a minor revision of the IBM Research Report [6].  相似文献   

17.
Résumé On décrit toutes les feuilles des laminations minimales dont un ensemble résiduel de feuilles ont 2 bouts.   相似文献   

18.
We develop a theory of downward sets for a class of normed ordered spaces. We study best approximation in a normed ordered space X by elements of downward sets, and give necessary and sufficient conditions for any element of best approximation by a closed downward subset of X. We also characterize strictly downward subsets of X, and prove that a downward subset of X is strictly downward if and only if each its boundary point is Chebyshev. The results obtained are used for examination of some Chebyshev pairs (W,x), where ∈ X and W is a closed downward subset of X  相似文献   

19.
In this paper, the author establishes the boundedness of multilinear operators on weighted Herz spaces and Herz-type Hardy spaces. The author also obtains their weak estimates on endpoints. As a special case, the conclusions may lead to the weighted estimates for multilinear Calderon-Zygmund operators.  相似文献   

20.
In this paper we present a generalized quantitative version of a result due to M. Revers concerning the exact convergence rate at zero of Lagrange interpolation polynomial to f(x) = |x|α with on equally spaced nodes in [-1, 1].  相似文献   

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