共查询到20条相似文献,搜索用时 62 毫秒
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一类修正的Navier-Stokes方程的长时间性态 总被引:3,自引:0,他引:3
该文主要讨论,Rn上一类修正的 Navier-Stokes 方程弱解的长时间性态, 通过进一步改进Fourier分解方法, 得到了当初速度u0∈ L2 ∩L1时其弱解在L2 范数下的最优衰减率为 (1+t)n/4 同时该文也给出了修正的Navier-Stokes 方程与经典Navier-Stokes 方程的误差估计. 相似文献
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设μ是非双倍测度且||μ|=∞, 多重线性奇异积分是从L1(μ)×L1(μ)到L1/2,∞(μ)有界的,则由多重线性奇异积分和由Tosla定义的正规有界振动函数生成的交换子是在Lebesgue空间有界的. 相似文献
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研究与强奇异Calderón-Zygmund 算子和Lipschitz函数b∈Λ8729;β0(Rn)相关的Toeplitz型算子Tb(f)从 Lp(Rn)到Lq(Rn) 的有界性和 Lp(Rn)到F8729;β0,∞ p的有界性,1/q=1/p-β0/n. 得到了广义Toeplitz型算子Θbα0 是 Lp(Rn)到Lq(Rn)有界的,1/q=1/p-(α0+β0)/n.上述结果包含了相应的交换子的有界性.同时还得到了与强奇异Calderón-Zygmund 算子和BMO函数b相关的 Toeplitz型算子 Tb(f)的Lp(Rn)有界性, 1ápá∞ . 相似文献
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积域上奇异积分算子的Lp有界性 总被引:1,自引:0,他引:1
用旋转法证明了对于Ω∈ L(log+L)2 (Sn-1×Sm-1),Ω(x′,y′)dσ(x′)= 0(y′∈Sm-1), Ω(x′,y′)dσy′)=0(x′∈Sn-1),带核函数K(u,v)= Ω(u′,v′)|u|-n|v|-m的奇异积分算子T是Lp(Rn×Rm)有界的,其中1<p<∞. 相似文献
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郑兆娟 《数学物理学报(A辑)》2008,28(6):1206-1217
Cq:=Cq[x±11, x±12] 为复数域上的量子环面, 其中q≠ 0是一个非单位根, D(Cq) 为Cq的导子李代数. 记Lq 为Cq ㈩ D(Cq)的导出子代数. 该文研究李代数Lq的自同构群, 泛中心扩张和导子李代数. 相似文献
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In the present paper, we obtain a sequence of positive linear operators which has a better rate of convergence than the Szász-Mirakian Durrmeyer and Baskakov Durrmeyer operators and their Voronovskaya type results. 相似文献
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Harun Karsli 《Mathematical Methods in the Applied Sciences》2019,42(16):5190-5198
The concern of this paper is to continue the investigation of convergence properties of nonlinear approximation operators, which are defined by Karsli. In details, the paper centers around Urysohn‐type nonlinear counterpart of the Bernstein operators. As a continuation of the study of Karsli, the present paper is devoted to obtain Voronovskaya‐type theorems for the Urysohn‐type nonlinear Bernstein operators. 相似文献
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Lucian Coroianu Bogdan D. Opris Sorin Trifa 《Numerical Functional Analysis & Optimization》2017,38(3):327-343
By analogy with Feller’s general probabilistic scheme used in the construction of many classical convergent sequences of linear operators, in this paper, we consider a Feller-kind scheme based on the possibilistic integral, for the construction of convergent sequences of nonlinear operators. In particular, in the discrete case, all the so-called max-product Bernstein-type operators and their qualitative convergence properties are recovered. Also, discrete nonperiodic nonlinear possibilistic convergent operators of Picard type, Gauss–Weierstrass type and Poisson–Cauchy type are studied and the possibility of introduction of discrete periodic(trigonometric) nonlinear possibilistic operators of de la Vallée–Poussin type, of Fejér type and of Jackson type is mentioned as future directions of research. 相似文献
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王健 《数学年刊A辑(中文版)》2011,32(1):33-50
利用Levy型算子积分微分型表示形式和拟微分型表示形式,以寻求Levy型算子生成的马氏过程各种稳定性的精确且可验证的充分条件.给出了由符号函数直接判定的Levy型过程非爆炸的充分条件,这个条件包括了扩散过程非爆炸的线性增长条件;当Levy型算子生成马氏过程对应半群的符号函数已知时,得到了由该符号函数直接表达的常返性充分条件,它推广了关于Levy过程经典的Chung-Fuchs常返性准则. 相似文献
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The present paper deals with the study of the rate of convergence of the integrated Baskakov-Durrmeyer type operators in simultaneous approximation. We also mention some of the improvements on the recent paper of Deo [N. Deo, Direct results on exponential type operators, Applied Mathematics and Computation 204(1) (2008) 109-115]. 相似文献
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Jesús de la Cal Javier Cárcamo 《Journal of Mathematical Analysis and Applications》2007,334(2):1106-1115
As a consequence of Jensen's inequality, centered operators of probabilistic type (also called Bernstein-type operators) approximate convex functions from above. Starting from this fact, we consider several pairs of classical operators and determine, in each case, which one is better to approximate convex functions. In almost all the discussed examples, the conclusion follows from a simple argument concerning composition of operators. However, when comparing Szász-Mirakyan operators with Bernstein operators over the positive semi-axis, the result is derived from the convex ordering of the involved probability distributions. Analogous results for non-centered operators are also considered. 相似文献
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Ana Maria Acu Tuncer Acar Carmen‐Violeta Muraru Voichia Adriana Radu 《Mathematical Methods in the Applied Sciences》2019,42(16):5551-5565
Starting with the well‐ known Bernstein operators, in the present paper, we give a new generalization of the bivariate type. The approximation properties of this new class of bivariate operators are studied. Also, the extension of the proposed operators, namely, the generalized Boolean sum (GBS) in the Bögel space of continuous functions is given. In order to underline the fact that in this particular case, GBS operator has better order of convergence than the original ones, some numerical examples are provided with the aid of Maple soft. Also, the error of approximation for the modified Bernstein operators and its GBS‐type operator are compared. 相似文献
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A.S. Mohamed 《Applicable analysis》2013,92(3-4):179-184
In this paper, we study conditions under which Schrodinger type operators with a matrix potential is separated and Schrodinger equation has a unique solution in the weighted space L2,k(Rn)l, where l is any natural number and k ε C1(Rn) is a positive function 相似文献
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Alessia Elisabetta Kogoj Ermanno Lanconelli 《Proceedings of the American Mathematical Society》2007,135(7):2019-2030
We study a notion of link of Lie groups suggested by the structure of the partial differential operators of Kolmogorov type. As an application of our link procedure we construct explicit examples of stratified Lie groups, with dimension and step arbitrarily large. We also give a set of examples of hypoelliptic second-order operators which are left translation invariant and homogeneous of degree two on the previous groups.
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Vishnu Narayan Mishra Prashantkumar Patel Lakshmi Narayan Mishra 《Numerical Functional Analysis & Optimization》2013,34(12):1265-1277
AbstractIn the present paper, we discuss the approximation properties of Durrmeyer-Stancu type variant of Jain operators with the modified forms of the Beta basis functions. We establish some direct results, which include the asymptotic formula, the error estimation in terms of the modulus of continuity and weighted approximation. Also, we construct a King modification of these operators which preserves the test functions e0 and e1. 相似文献