共查询到20条相似文献,搜索用时 31 毫秒
1.
Let X be a metric space andμa finite Borel measure on X. Let pμq,t and pμq,t be the packing premeasure and the packing measure on X, respectively, defined by the gauge (μB(x,r))q(2r)t, where q, t∈R. For any compact set E of finite packing premeasure the authors prove: (1) if q≤0 then pμq,t(E)=pμq,t(E);(2)if q>0 andμis doubling on E then pμq,t(E) and pμq,t(E) are both zero or neither. 相似文献
2.
陈传钟 《数学物理学报(B辑英文版)》2007,27(1):219-224
This article discusses the perturbation of a non-symmetric Dirichlet form,(ε, D(ε)), by a signed smooth measure μ, whereμ=μ1 -μ2 with μ1 and μ2 being smooth measures. It gives a sufficient condition for the perturbed form (εμ, D(εμ)) (for some αo ≥ 0) to be a coercive closed form. 相似文献
3.
Blow-up analysis for a system of heat equations with nonlinear flux which obey different laws 总被引:1,自引:0,他引:1
We consider a system of heat equations ut=Δu and vt=Δv in Ω×(0,T) completely coupled by nonlinear boundary conditions We prove that the solutions always blow up in finite time for non-zero and non-negative initial values. Also, the blow-up only occurs on ∂Ω with for p,q>0, 0≤α<1 and 0≤β<p. 相似文献
4.
Global existence and blow-up of solutions for a system of nonlinear viscoelastic wave equations with damping and source 总被引:1,自引:0,他引:1
In this paper we investigate the global existence and finite time blow-up of solutions to the system of nonlinear viscoelastic wave equations in Ω×(0,T) with initial and Dirichlet boundary conditions, where Ω is a bounded domain in . Under suitable assumptions on the functions gi(), , the initial data and the parameters in the equations, we establish several results concerning local existence, global existence, uniqueness and finite time blow-up property. 相似文献
5.
王阳 《数学物理学报(B辑英文版)》2007,27(2):274-282
This article consider, for the following heat equation ut/|x|s-△pu=uq,(x,t)∈Ω×(0,T), u(x,t)=0,(x,t)∈(?)Ω×(0,T), u(x,0)=u0(x),u0(x)≥0,u0(x)(?)0 the existence of global solution under some conditions and give two sufficient conditions for the blow up of local solution in finite time, whereΩis a smooth bounded domain in RN(N>p),0∈Ω,△pu=div(|▽u|p-2▽u),0≤s≤2,p≥2,p-1
相似文献
6.
We prove the Marcinkiewicz–Zygmund Strong Law of Large Numbers for U-statistics of strictly stationary, absolutely regular observations (ξi)i≥1. Under suitable moment conditions and conditions on the mixing rate, we show that for some γ≥0, in the non-degenerate case, and in the degenerate case. 相似文献
7.
Let be a bounded domain such that 0Ω. Denote by , the set of all complex polynomials of degree at most n. Let where . We relate the maximal polynomial range to the geometry of Ω. 相似文献
8.
In this paper, we will consider the following multipoint boundary value problem for the following second-order dynamic equations on time scales where :RR is an increasing homeomorphism and positive homomorphism and (0)=0. By using fixed point theorems, we obtain an existence theorem of positive solutions for the above boundary value problem, which includes and improve some related results in the relevant literature. As an application, an example to demonstrate our results is given. 相似文献
9.
Ivan Kiguradze Tariel Kiguradze 《Nonlinear Analysis: Theory, Methods & Applications》2008,69(7):1914-1933
In the rectangle Ω=[0,a]×[0,b] for the nonlinear hyperbolic equation the boundary value problems of the type are considered, where and are linear bounded functionals.Sufficient conditions of solvability and unique solvability of the general problem and its particular cases (Nicoletti type, Dirichlet, Lidstone and Periodic problems) are established. 相似文献
10.
Let F be any field. Let p(F) be the characteristic of F if F is not of characteristic zero, and let p(F)=+∞ otherwise. Let A1,…,An be finite nonempty subsets of F, and let with k{1,2,3,…}, a1,…,anF{0} and degg<k. We show that When kn and |Ai|i for i=1,…,n, we also have consequently, if nk then for any finite subset A of F we have In the case n>k, we propose a further conjecture which extends the Erdős–Heilbronn conjecture in a new direction. 相似文献
11.
This note shows that every positive solution to the following third order non–autonomous max-type difference equationwhen is a three-periodic sequence of positive numbers, is periodic with period three. The same result was proved for the following min-type difference equation 相似文献
12.
We consider the following nonlinear elliptic equation with singular nonlinearity: where α>β>1, a>0, and Ω is an open subset of , n2. Let uH1(Ω) with and be a nonnegative stationary solution. If we denote the zero set of u by we shall prove that the Hausdorff dimension of Σ is less than or equal to . 相似文献
13.
Stevo Stevi 《Chaos, solitons, and fractals》2009,40(5):2364-2369
In this paper, among others, we give a complete picture of the boundedness character of the positive solutions of the following nonlinear difference equationwhere the parameters A and p are positive real numbers. This is a natural extension of a difference equation equivalent to an equation arising in automatic control theory. We present some new methods for investigating the boundedness character of nonlinear difference equations. 相似文献
14.
In this paper we stochastically perturb the functional Kolmogorov-type system into the stochastic functional differential equation This paper studies existence and uniqueness of the global positive solution, and its asymptotic bound properties and moment average in time. These properties are natural requirements from the biological point of view. As the special cases, we discuss the various stochastic Lotka–Volterra systems. 相似文献
15.
In this article, the authors consider equation ut = div(ψ(Гu)A(|Du|2)Du) -(u- I), where ψ is strictly positive and Г is a known vector-valued mapping, A: R → R is decreasing and A(s) ~ 1/√a as s → ∞. This kind of equation arises naturally from image denoising. For an initial datum I ∈ BVloc ∩ L∞, the existence of BV solutions to the initial value problem of the equation is obtained. 相似文献
16.
J. Lang 《Journal of Approximation Theory》2006,140(2):141-146
Consider the Hardy-type operator T : Lp(a,b)→Lp(a,b),-∞a<b∞, which is defined byIt is shown thatwhere ρn(T) stands for any of the following: the Kolmogorov n-width, the Gel’fand n-width, the Bernstein n-width or the nth approximation number of T. 相似文献
17.
This paper gives upper and lower bounds of the Christoffel-type functions , for the m-orthogonal polynomials for a Freud weight W=e-Q, which are given as follows. Let an=an(Q) be the nth Mhaskar–Rahmanov–Saff number, φn(x)=max{n-2/3,1-|x|/an}, and d>0. Assume that QC(R) is even, , and for some A,B>1Then for xRand for |x|an(1+dn-2/3) 相似文献
18.
Dehong Ji Yu Tian Weigao Ge 《Nonlinear Analysis: Theory, Methods & Applications》2009,71(11):5406-5416
This paper deals with the existence of positive solutions for the one-dimensional p-Laplacian subject to the boundary value conditions: where p(s)=|s|p−2s,p>1. We show that it has at least one or two positive solutions under some assumptions by applying the fixed point theorem. The interesting points are that the nonlinear term f is involved with the first-order derivative explicitly and f may change sign. 相似文献
19.
Let be an orthonormal Jacobi polynomial of degree k. We will establish the following inequality:where δ-1<δ1 are appropriate approximations to the extreme zeros of . As a corollary we confirm, even in a stronger form, T. Erdélyi, A.P. Magnus and P. Nevai conjecture [T. Erdélyi, A.P. Magnus, P. Nevai, Generalized Jacobi weights, Christoffel functions, and Jacobi polynomials, SIAM J. Math. Anal. 25 (1994) 602–614] by proving thatin the region . 相似文献
20.
Let , with
-1=x0n<x1n<<xnn<xn+1,n=1