共查询到20条相似文献,搜索用时 15 毫秒
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Let q be a positive integer. Recently, Niu and Liu proved that, if , then the product is not a powerful number. In this note, we prove (1) that, for any odd prime power ? and , the product is not a powerful number, and (2) that, for any positive odd integer ?, there exists an integer such that, for any positive integer , the product is not a powerful number. 相似文献
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In this paper, we consider the Cauchy problem for a two-phase model with magnetic field in three dimensions. The global existence and uniqueness of strong solution as well as the time decay estimates in are obtained by introducing a new linearized system with respect to for constants and , and doing some new a priori estimates in Sobolev Spaces to get the uniform upper bound of in norm. 相似文献
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In this paper, by using Picard–Fuchs equations and Chebyshev criterion, we study the upper bounds of the number of limit cycles given by the first order Melnikov function for discontinuous differential systems, which can bifurcate from the periodic orbits of quadratic reversible centers of genus one (r19): , , and (r20): , , and the periodic orbits of the quadratic isochronous centers , , and , . The systems (r19) and (r20) are perturbed inside the class of polynomial differential systems of degree n and the system and are perturbed inside the class of quadratic polynomial differential systems. The discontinuity is the line . It is proved that the upper bounds of the number of limit cycles for systems (r19) and (r20) are respectively and counting the multiplicity, and the maximum numbers of limit cycles bifurcating from the period annuluses of the isochronous centers and are exactly 5 and 6 (counting the multiplicity) on each period annulus respectively. 相似文献
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Carme Cascante Joan Fàbrega Joaquín M. Ortega 《Journal of Mathematical Analysis and Applications》2018,457(1):722-750
In this paper we characterize the boundedness of the bilinear form defined by in the product of homogeneous Sobolev spaces , . We deduce a characterization of the space of pointwise multipliers from to its dual in terms of trace measures. 相似文献
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Tristan Roy 《Journal of Differential Equations》2018,264(9):6013-6024
The purpose of this corrigendum is to point out some errors that appear in [1]. Our main result remains valid, i.e scattering of solutions of the loglog energy-supercritical Schrödinger equation , , , with , radial data but with slightly different values of , i.e if and if . We propose some corrections. 相似文献
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Quốc Anh Ngô 《Comptes Rendus Mathematique》2017,355(5):526-532
In this note, we mainly study the relation between the sign of and in with and for . Given the differential inequality , first we provide several sufficient conditions so that holds. Then we provide conditions such that for all , which is known as the sub poly-harmonic property for u. In the last part of the note, we revisit the super poly-harmonic property for solutions to and with in . 相似文献
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In this article we obtain positive singular solutions of
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where Ω is a small perturbation of the unit ball in . For we prove that if Ω is a sufficiently small perturbation of the unit ball there exists a singular positive weak solution u of (1). In the case of we prove a similar result but now the positive weak solution u is contained in and yet is not in for any . 相似文献
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Let be an isometric immersion from a Riemannian n-manifold into a Euclidean m-space. Denote by Δ and the Laplace operator and the position vector of M, respectively. Then M is called biharmonic if . The following Chen?s Biharmonic Conjecture made in 1991 is well-known and stays open: The only biharmonic submanifolds of Euclidean spaces are the minimal ones. In this paper we prove that the biharmonic conjecture is true for -ideal and -ideal hypersurfaces of a Euclidean space of arbitrary dimension. 相似文献