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1.
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   

2.
This note shows that every positive solution to the following third order non–autonomous max-type difference equation
when 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   

3.
In this article, the dependent steps of a negative drift random walk are modelled as a two-sided linear process Xn =-μ ∞∑j=-∞ψn-jεj, where {ε, εn; -∞< n < ∞}is a sequence of independent, identically distributed random variables with zero mean, μ>0 is a constant and the coefficients {ψi;-∞< i <∞} satisfy 0 <∞∑j=-∞|jψj| <∞. Under the conditions that the distribution function of |ε| has dominated variation and ε satisfies certain tail balance conditions, the asymptotic behavior of P{supn≥0(-nμ ∞∑j=-∞εjβnj) > x}is discussed. Then the result is applied to ultimate ruin probability.  相似文献   

4.
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   

5.
We consider the problem of deciding whether a given rational function has a power series expansion with all its coefficients positive. Introducing an elementary transformation that preserves such positivity we are able to provide an elementary proof for the positivity of Szegö's function
which has been at the historical root of this subject starting with Szegö. We then demonstrate how to apply the transformation to prove a 4-dimensional generalization of the above function, and close with discussing the set of parameters (a,b) such that
has positive coefficients.  相似文献   

6.
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   

7.
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   

8.
A Gaussian trend for humidity versus temperature is confirmed by a theoretical fit, i.e., 
where T0 and H0 are the experimental values of the temperature and humidity, respectively and K is a constant.  相似文献   

9.
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   

10.
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   

11.
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   

12.
In this paper we consider differential inclusion problem involving the p(x)-Laplacian of the type
Applying a version of the non-smooth three-critical-points theorem we obtain the existence of three solutions of the problem in .  相似文献   

13.
In this paper, the existence of a positive solution of the boundary value problem of the following fourth-order nonlinear differential equation:
is discussed.  相似文献   

14.
In this work the existence of a global solution for the mixed problem associated to the nonlinear equation
is proved in a Hilbert space framework by using Galerkin method.  相似文献   

15.
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   

16.
We prove several weighted inequalities involving the Hilbert transform of a function f(x) and its derivative. One of those inequalities,
is used to show finite time blow-up for a transport equation with nonlocal velocity.  相似文献   

17.
Oscillation criteria for damped half-linear PDE via the integral operator   总被引:1,自引:0,他引:1  
By using the integral operator, we establish some oscillation criteria for the damped half-linear PDE
The results are extensions of integral averaging technique of Kamenev and include earlier results of Usami, Xu and Xing.  相似文献   

18.
A family of orthonormal polynomials on the unit ball Bd of with respect to the inner product
where Δ is the Laplace operator, is constructed explicitly.  相似文献   

19.
Let be a bounded Lipschitz domain, a suitably quasiconvex integrand and consider the energy functional
over the space of measure preserving maps
In this paper we discuss the question of existence of multiple strong local minimizers for over . Moreover, motivated by their significance in topology and the study of mapping class groups, we consider a class of maps, referred to as twists, and examine them in connection with the corresponding Euler–Lagrange equations and investigate various qualitative properties of the resulting solutions, the stationary twists. Particular attention is paid to the special case of the so-called p-Dirichlet energy, i.e., when .  相似文献   

20.
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 that
in the region .  相似文献   

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