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排序方式: 共有2242条查询结果,搜索用时 11 毫秒
281.
We are concerned with the following nonlinear Schrödinger equation where , . For small enough and a class of , we show the uniqueness of the positive ground state under certain assumptions on asymptotic behavior of and its first derivatives. Here our results are suitable for a kind of which has different increasing rates at different directions. 相似文献
282.
Mourad E. H. Ismail 《The Ramanujan Journal》2006,11(3):349-353
We give short elementary proofs of a formula of Ramanujan as interpreted by Bradley, and a companion formula originally proved
by W. Chu. We also give an elementary proof of a generalization of an identity originally proved using modular functions and
used to study a generating function for the number of partitions with specified crank.
Research partially supported by NSF grant DMS 99-70865.
2000 Mathematics Subject Classification Primary—39A70, 11P83; Secondary—33C20 相似文献
283.
利用初等方法以及取整函数的性质研究了Fibonacci数列三次倒数的求和问题,获得了该和式倒数取整后的确切值,也就是给出了一个包含Fibonacci数列有趣的恒等式. 相似文献
284.
本文研究了一个二阶微分方程的解及其振动性质,利用它获得了一般二阶自共轭方程的振动性判别准则,特别对其中一类二阶微分方程的振动性给出了定量的判别方法.推广了E.Hille的工作,使E.Hille的研究结论成为本文结果的极特殊的情形,同时对一类具有“积分小”系数或可化为具有“积分小”系数的二阶微分方程的振动性与非振动性给出了简便、精确的判别方法. 相似文献
285.
THE IMPROVED FOURIER SPLITTING METHOD AND DECAY ESTIMATES OF THE GLOBAL SOLUTIONS OF THE CAUCHY PROBLEMS FOR NONLINEAR SYSTEMS OF FLUID DYNAMICS EQUATIONS 下载免费PDF全文
Linghai Zhang 《应用数学年刊》2016,32(4):396-417
Consider the Cauchy problems for an n-dimensional nonlinear system of fluid dynamics equations. The main purpose of this paper is to improve the Fourier splitting method to accomplish the decay estimates with sharp rates of the global weak solutions of the Cauchy problems. We will couple together the elementary uniform energy estimates of the global weak solutions and a well known Gronwall''s inequality to improve the Fourier splitting method. This method was initiated by Maria Schonbek in the 1980''s to study
the optimal long time asymptotic behaviours of the global weak solutions of the nonlinear system of fluid dynamics equations. As applications, the decay estimates with sharp rates of the global weak solutions of the Cauchy problems for $n$-dimensional incompressible Navier-Stokes equations, for the $n$-dimensional magnetohydrodynamics equations
and for many other very interesting nonlinear evolution equations with dissipations can be established. 相似文献
286.
Jingzhu Wu Xiuzhi Xing Xianguo Geng 《Mathematical Methods in the Applied Sciences》2016,39(14):3925-3931
Based on a general isospectral problem of fractional order, a fractional bilinear form variational identity, the new integrable coupling of fractional L‐hierarchy and the Hamiltonian structures of the integrable coupling of fractional L‐hierarchy are obtained. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
287.
Let , , , , be the usual operators on classes of rings: and for isomorphic and homomorphic images of rings and , , respectively for subrings, direct, and subdirect products of rings. If is a class of commutative rings with identity (and in general of any kind of algebraic structures), then the class is known to be the variety generated by the class . Although the class is in general a proper subclass of the class for many familiar varieties . Our goal is to give an example of a class of commutative rings with identity such that . As a consequence we will describe the structure of two partially ordered monoids of operators.
288.
Gaiane Panina 《Central European Journal of Mathematics》2006,4(2):270-293
Hyperbolic virtual polytopes arose originally as polytopal versions of counterexamples to the following A.D.Alexandrov’s uniqueness
conjecture: Let K ⊂ ℝ3
be a smooth convex body. If for a constant C, at every point of ∂K, we have R
1 ≤ C ≤ R
2
then K is a ball. (R
1
and R
2
stand for the principal curvature radii of ∂K.)
This paper gives a new (in comparison with the previous construction by Y.Martinez-Maure and by G.Panina) series of counterexamples
to the conjecture. In particular, a hyperbolic virtual polytope (and therefore, a hyperbolic hérisson) with odd an number
of horns is constructed.
Moreover, various properties of hyperbolic virtual polytopes and their fans are discussed. 相似文献
289.
Siddhartha Sahi 《Annals of Combinatorics》2006,10(2):255-269
We describe a connection between discrete birth process and a certain family of multivariate interpolation polynomials. This
enables us to compute all asymptotic moments of the birth process, generalizing previously known results for the mean and
variance.
Received July 15, 2004 相似文献
290.
Cilanne E. Boulet 《The Ramanujan Journal》2006,12(3):315-320
We present a new partition identity and give a combinatorial proof of our result. This generalizes a result of Andrews in
which he considers the generating function for partitions with respect to size, number of odd parts, and number of odd parts
of the conjugate.
2000 Mathematics Subject Classification Primary—05A17; Secondary—11P81 相似文献