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Convolution theorems for the linear canonical transform and their applications 被引量:22
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作者 DENG Bing TAO Ran WANG Yue 《Science in China(Series F)》 2006年第5期592-603,共12页
As generalization of the fractional Fourier transform (FRFT), the linear canonical transform (LCT) has been used in several areas, including optics and signal processing. Many properties for this transform are alr... As generalization of the fractional Fourier transform (FRFT), the linear canonical transform (LCT) has been used in several areas, including optics and signal processing. Many properties for this transform are already known, but the convolution theorems, similar to the version of the Fourier transform, are still to be determined. In this paper, the authors derive the convolution theorems for the LCT, and explore the sampling theorem and multiplicative filter for the band limited signal in the linear canonical domain. Finally, the sampling and reconstruction formulas are deduced, together with the construction methodology for the above mentioned multiplicative filter in the time domain based on fast Fourier transform (FFT), which has much lower computational load than the construction method in the linear canonical domain. 展开更多
关键词 linear canonical transform convolution theorems sampling multiplicative filter.
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基于π定理的崩落法转充填法过渡采场顶柱尺寸研究 被引量:19
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作者 刘艳章 邓磊 +4 位作者 王其飞 赵卫 石志军 张群 张丙涛 《采矿与安全工程学报》 EI CSCD 北大核心 2015年第2期331-336,共6页
崩落法转充填法开采过程中,充填法过渡采场顶柱下方存在采空区,顶柱上部有大量崩落法开采留下的松散岩石,顶柱的稳定性对过渡段矿石的安全开采具有重要意义。过渡采场顶柱厚度与跨度之比即厚跨比r是影响过渡采场顶柱稳定性的重要因素之... 崩落法转充填法开采过程中,充填法过渡采场顶柱下方存在采空区,顶柱上部有大量崩落法开采留下的松散岩石,顶柱的稳定性对过渡段矿石的安全开采具有重要意义。过渡采场顶柱厚度与跨度之比即厚跨比r是影响过渡采场顶柱稳定性的重要因素之一,为了分析顶柱稳定性,采用π定理建立了充填法过渡采场顶柱厚跨比r和顶柱稳定性的关系模型,该模型选取顶柱的许用应变作为采场稳定性判断标准,根据许用应变得到合理的厚跨比。将此关系模型应用于程潮铁矿无底柱分段崩落法转充填法的试验过渡采场顶柱尺寸研究中。运用有限元法计算得出程潮铁矿过渡采场顶柱的最小厚跨比rmin,根据损失率约束得出最大的厚跨比rmax。通过计算厚跨比r的取值为1.24~1.45。试验采场按此厚跨比进行生产,顶柱未失稳。工程试验检验了此关系模型的有效性。 展开更多
关键词 顶柱尺寸 π定理 厚跨比 许用应变
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A Characterization of Continuous Module Homomorphisms on Random Semi—Normed Modules and Its Applications 被引量:12
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作者 TieXinGUO 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2003年第1期201-208,共8页
In this paper, a characterization of continuous module homomorphisms on random semi-normed modules is first given; then the characterization is further used to show that the Hahn-Banach type of extension theorem is st... In this paper, a characterization of continuous module homomorphisms on random semi-normed modules is first given; then the characterization is further used to show that the Hahn-Banach type of extension theorem is still true for continuous module homomorphisms on random semi-normed modules. 展开更多
关键词 Random semi normed modules Continuous module homomorphisms Extension theorems
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Radon-Nikodym property of conjugate Banach spaces and w*-equivalence theorems of w*-u-measurable functions 被引量:11
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作者 郭铁信 《Science China Mathematics》 SCIE 1996年第10期1034-1041,共8页
A deep representation theorem of random conjugate spaces and its several important applications are given. As an application of the representation theorem, the following basic theorem is also proved: let B* be the con... A deep representation theorem of random conjugate spaces and its several important applications are given. As an application of the representation theorem, the following basic theorem is also proved: let B* be the conjugate space of a Banach space B, be a given probability space. Then every B*-valued w*-u-measurable function defined on is w*-equivalent to a B*-valued u-measurable function defined on if and only if B* has the Radon-Nikodym property with respect to 展开更多
关键词 the Radon-Nikodym property MARTINGALES u-measurable functions w*-equivalence theorems random CONJUGATE spaces.
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Functional Limit Theorems for C-R Increments of k-Dimensional Brownian Motion in Holder Norm 被引量:11
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作者 Qicai Wei School fo Economics, Zhejiang University. Hangzhou 310028. P. R. China 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2000年第4期637-654,共18页
In this paper. based on large deviation formulas established in stronger topology generated by Hlder norm, we obtain the functional limit theorems for C-R increments of k-dimensional Brownian motion in Hlder norm
关键词 Large deviation formulas k-dimensional Brownian motion Functional limit theorems C-R increments Holder norm
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Polynomials,Higher Order Sobolev Extension Theorems and Interpolation Inequalities on Weighted Folland-Stein Spaces on Stratified Groups 被引量:10
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作者 Guozhen Lu Department of Mathematics,Wayne State University,Detroit,MI 48202,USA 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2000年第3期405-444,共40页
This paper consists of three main parts.One of them is to develop local and global Sobolev interpolation inequalities of any higher order for the nonisotropic Sobolev spaces on stratified nilpotent Lie groups.Despite ... This paper consists of three main parts.One of them is to develop local and global Sobolev interpolation inequalities of any higher order for the nonisotropic Sobolev spaces on stratified nilpotent Lie groups.Despite the extensive research after Jerison’s work[3]on Poincaré-type inequalities for Hrmander’s vector fields over the years,our results given here even in the nonweighted case appear to be new.Such interpolation inequalities have crucial applications to subelliptic or parabolic PDE’s involving vector fields.The main tools to prove such inequalities are approximating the Sobolev func- tions by polynomials associated with the left invariant vector fields on G.Some very useful properties for polynomials associated with the functions are given here and they appear to have independent interests in their own rights.Finding the existence of such polynomials is the second main part of this paper.Main results of these two parts have been announced in the author’s paper in Mathematical Research Letters[38]. The third main part of this paper contains extension theorems on anisotropic Sobolev spaces on stratified groups and their applications to proving Sobolev interpolation inequalities on(εδ)domains. Some results of weighted Sobolev spaces are also given here.We construct a linear extension operator which is bounded on different Sobolev spaces simultaneously.In particular,we are able to construct a bounded linear extension operator such that the derivatives of the extended function can be controlled by the same order of derivatives of the given Sobolev functions.Theorems are stated and proved for weighted anisotropic Sobolev spaces on stratified groups. 展开更多
关键词 Poincaré inequalities Extension theorems Interpolation inequalities Anisotropic Sobolev spaces A_p weights δ)domains Vector fields Polynomials on stratified groups
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一元不可微函数的局部分数阶定积分的问题 被引量:11
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作者 杨小军 李磊 杨然 《世界科技研究与发展》 CSCD 2009年第4期722-724,729,共4页
利用Jumarie的分数阶微积分理论推广了Kolwankar和Gangal的局部分数阶微积分,并且重新讨论了局部分数阶定积分,讨论了局部分数阶定积分的性质及其定理。
关键词 局部分数阶积分 局部分数阶定积分 局部分数阶导数 性质 定理
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Existence of Positive Solutions for Boundary Value Problem of Nonlinear Fractional <i>q</i>-Difference Equation 被引量:9
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作者 Liu Yang 《Applied Mathematics》 2013年第10期1450-1454,共5页
In this paper, we investigate the existence of positive solutions for a class of nonlinear q-fractional boundary value problem. By using some fixed point theorems on cone, some existence results of positive solutions ... In this paper, we investigate the existence of positive solutions for a class of nonlinear q-fractional boundary value problem. By using some fixed point theorems on cone, some existence results of positive solutions are obtained. 展开更多
关键词 Fractional q-Difference Equation Positive Solution Fixed Point theorems on Cone
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Multiplicity of Solutions for a Class of Kirchhoff Type Problems 被引量:9
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作者 Xiao-ming He Wen-ming Zou 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2010年第3期387-394,共8页
In this paper we apply the (variant) fountain theorems to study the symmetric nonlinear Kirch- hoff nonlocal problems. Under the Ambrosetti-Rabinowitz's 4-superlinearity condition, or no Ambrosetti- Rabinowitz's 4... In this paper we apply the (variant) fountain theorems to study the symmetric nonlinear Kirch- hoff nonlocal problems. Under the Ambrosetti-Rabinowitz's 4-superlinearity condition, or no Ambrosetti- Rabinowitz's 4-superlinearity condition, we present two results of existence of infinitely many large energy solutions, respectively. 展开更多
关键词 Kirchhoff nonlocal problems Multiple solutions Fountain theorems
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Representation theorems of the dual of Lebesgue-Bochner function spaces 被引量:8
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作者 郭铁信 《Science China Mathematics》 SCIE 2000年第3期234-243,共10页
By representing random conjugate spaces a general representation theorem on classical duals is proved. For application, we unify and improve many known important representation theorems of the dual of Lebesgue-Bochner... By representing random conjugate spaces a general representation theorem on classical duals is proved. For application, we unify and improve many known important representation theorems of the dual of Lebesgue-Bochner function spaces. 展开更多
关键词 random normed modules random coqjugate spaces representation theorems on classical duals LebesgueBochner function spaces
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RAZUMIKHIN-TYPE THEOREMS FOR ASYMPTOTIC STABILITY OF IMPULSIVE STOCHASTIC FUNCTIONAL DIFFERENTIAL SYSTEMS 被引量:8
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作者 Pei CHENG~1 Feiqi DENG~2 Xisheng DAI~3 Systems Engineering Institute,South China University of Technology,Guangzhou 510640,China 《Journal of Systems Science and Systems Engineering》 SCIE EI CSCD 2010年第1期72-84,共13页
In this paper, we investigate the pth moment uniformly asymptotic stability of impulsive stochastic ftmctional differential systems by extending some Razumikhin-type theorems. Based on the Lyapunov functions and Razum... In this paper, we investigate the pth moment uniformly asymptotic stability of impulsive stochastic ftmctional differential systems by extending some Razumikhin-type theorems. Based on the Lyapunov functions and Razumikhin techniques, some criteria are established and their applications to impulsive stochastic delay systems are proposed. An illustrative example shows the effectiveness of our results. 展开更多
关键词 Stochastic functional differential systems IMPULSE Razumiltial theorems Asymptotic stability
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Existence of Entire Solutions of a Singular Semilinear Elliptic Problem 被引量:8
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作者 Wei Jie FENG Xi Yu LIU 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2004年第6期983-988,共6页
In this paper, we obtain some existence results for a class of singular semilinear elliptic problems where we improve some earlier results of Zhijun Zhang. We show the existence of entire positive solutions without th... In this paper, we obtain some existence results for a class of singular semilinear elliptic problems where we improve some earlier results of Zhijun Zhang. We show the existence of entire positive solutions without the monotonic condition imposed in Zhang’s paper. The main point of our technique is to choose an approximating sequence and prove its convergence. The desired compactness can be obtained by the Sobolev embedding theorems. 展开更多
关键词 Singular semilinear elliptic problem Sobolev embedding theorems Maximum principle
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Unicity Theorems for Entire or Meromorphic Functions 被引量:8
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作者 Yi Hongxun Department of Mathematics Shandong University Jinan, 250100 China 《Acta Mathematica Sinica,English Series》 SCIE CSCD 1994年第2期121-131,共11页
In this paper, we deal with the problem of uniqueness of entire or meromorphic functions and obtain some results that are improvements over those of M. Ozawa, H. Ueda, K. Shibazaki and Yi Hongxun. An example shows tha... In this paper, we deal with the problem of uniqueness of entire or meromorphic functions and obtain some results that are improvements over those of M. Ozawa, H. Ueda, K. Shibazaki and Yi Hongxun. An example shows that the results in this paper are sharp. 展开更多
关键词 Unicity theorems for Entire or Meromorphic Functions
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CENTRAL LIMIT THEOREMS FOR A BRANCHING RANDOM WALK WITH A RANDOM ENVIRONMENT IN TIME 被引量:6
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作者 高志强 刘全升 汪和松 《Acta Mathematica Scientia》 SCIE CSCD 2014年第2期501-512,共12页
We consider a branching random walk with a random environment m time, in which the offspring distribution of a particle of generation n and the distribution of the displacements of its children depend on an environmen... We consider a branching random walk with a random environment m time, in which the offspring distribution of a particle of generation n and the distribution of the displacements of its children depend on an environment indexed by the time n. The envi- ronment is supposed to be independent and identically distributed. For A C R, let Zn(A) be the number of particles of generation n located in A. We show central limit theorems for the counting measure Zn (-) with appropriate normalization. 展开更多
关键词 Branching random walk random environment in time central limit theorems
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Symmetrical Fundamental Tensors, Differential Operators, and Integral Theorems in Differential Geometry 被引量:6
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作者 殷雅俊 吴继业 尹杰 《Tsinghua Science and Technology》 SCIE EI CAS 2008年第2期121-126,共6页
To make the geometrical basis for soft matters with curved surfaces such as biomembranes as simple as possible, a symmetrical analytical system was developed in conventional differential geometry. The conventional sec... To make the geometrical basis for soft matters with curved surfaces such as biomembranes as simple as possible, a symmetrical analytical system was developed in conventional differential geometry. The conventional second fundamental tensor is replaced by the so-called conjugate fundamental tensor. Because the differential properties of the conjugate fundamental tensor and the first fundamental tensor are symmetrical, the symmetrical analytical system including the symmetrical differential operators, symmetrical differential characteristics, and symmetrical integral theorems for tensor fields defined on curved surfaces can be constructed. From the symmetrical analytical system, the symmetrical integral theorems for mean curvature and Gauss curvature, with which the symmetrical Minkowski integral formulas are easily deduced just as special cases, can be derived. The applications of this symmetrical analytical system to biology not only display its simplicity and beauty, but also show its powers in depicting the symmetrical patterns of networks of biomembrane nanotubes. All these symmetrical patterns in soft matters should be just the reasonable and natural results of the symmetrical analytical system. 展开更多
关键词 gradient operators integral theorems tensor fields curved surfaces
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Approximation Theorems and Fixed Point Theorems for Various Classes of 1-set-contractive Mappings in Banach Spaces 被引量:3
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作者 Li Shan LIU 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2001年第1期103-112,共10页
In this paper, we will prove that Ky Fan’s Theorem (Math. Z. 112(1969), 234-240) is true for 1-set-contractive maps defined on a bounded closed convex subset K in a Banach space with int K≠ . This class of 1-set-con... In this paper, we will prove that Ky Fan’s Theorem (Math. Z. 112(1969), 234-240) is true for 1-set-contractive maps defined on a bounded closed convex subset K in a Banach space with int K≠ . This class of 1-set-contractive maps includes condensing maps, nonexpansive maps, semicontractive maps, LANE maps and others. As applications of our theorems, some fixed point theorems of non-self- maps are proved under various well-known boundary conditions. Our results are generalizations and improvements of the recent results obtained by many authors. 展开更多
关键词 Approximation theorems Fixed point theorems 1-set-contractive maps Semicontractive maps LANE maps
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Some pinching theorems for minimal submanifolds in S^m(1)×R 被引量:7
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作者 CHEN Hang CHEN GangYi LI HaiZhong 《Science China Mathematics》 SCIE 2013年第8期1679-1688,共10页
Let Mn be an n-dimensional compact minimal submanifolds in Sin(1)× R. We prove two pinching theorems by the Ricci curvature and the sectional curvature pinching conditions respectively. In fact, we characterize... Let Mn be an n-dimensional compact minimal submanifolds in Sin(1)× R. We prove two pinching theorems by the Ricci curvature and the sectional curvature pinching conditions respectively. In fact, we characterize the Clifford tori and Veronese submanifolds by our pinching conditions respectively. 展开更多
关键词 minimal submanifolds pinching theorems Ricci curvature sectional curvature
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Parametric Duality Models for Semi-infinite Discrete Minmax Fractional Programming Problems Involving Generalized (η,ρ)-Invex Functions 被引量:4
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作者 G.J.Zalmai 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2007年第3期353-376,共24页
A semi-infinite programming problem is a mathematical programming problem with a finite number of variables and infinitely many constraints. Duality theories and generalized convexity concepts are important research t... A semi-infinite programming problem is a mathematical programming problem with a finite number of variables and infinitely many constraints. Duality theories and generalized convexity concepts are important research topics in mathematical programming. In this paper, we discuss a fairly large number of paramet- ric duality results under various generalized (η,ρ)-invexity assumptions for a semi-infinite minmax fractional programming problem. 展开更多
关键词 Semi-infinite programming discrete minmax fractional programming generalized invex functions infinitely many equality and inequality constraints parametric duality models duality theorems
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GENERAL INTERPOLATION FORMULAS FOR SPACES OF DISCRETE FUNCTIONS WITH NONUNIFORM MESHES 被引量:5
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作者 Zhou Yu-lin(Institute of Applied Physics and Computational Mathematics, Beijing, China ) 《Journal of Computational Mathematics》 SCIE CSCD 1995年第1期70-93,共24页
The unequal meshsteps are unavoidable in general for scientific and engineering computations especially in large Scale computations. The analysis of difference schemes with nonuniform meshes is very rare even by use o... The unequal meshsteps are unavoidable in general for scientific and engineering computations especially in large Scale computations. The analysis of difference schemes with nonuniform meshes is very rare even by use of fully heuristic methods. For the purpose of the systematic and theoretical study of the finite difference method with nonuniform meshes for the problems of partial differential equations, the general interpolation formulas for the spaces of discrete functions of one index with unequal meshsteps are established in the present work. These formulas give the connected relationships among the norms of various types, such as' the sum of powers of discrete values, the discrete maximum modulo, the discrete Holder and Lipschitz coefficients. 展开更多
关键词 Discrete functions INTERPOLATION Mathematical constants Partial differential equations Difference quotients Real lines Finite difference methods Mathematical theorems Ratios Engineering
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NONSMOOTH CRITICAL POINT THEOREMS AND ITS APPLICATIONS TO QUASILINEAR SCHRDINGER EQUATIONS 被引量:5
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作者 李周欣 沈尧天 《Acta Mathematica Scientia》 SCIE CSCD 2016年第1期73-86,共14页
In this paper, the existence and nonexistence of solutions to a class of quasilinear elliptic equations with nonsmooth functionals are discussed, and the results obtained are applied to quasilinear SchrSdinger equatio... In this paper, the existence and nonexistence of solutions to a class of quasilinear elliptic equations with nonsmooth functionals are discussed, and the results obtained are applied to quasilinear SchrSdinger equations with negative parameter which arose from the study of self-channeling of high-power ultrashort laser in matter. 展开更多
关键词 nonsmooth critical point theorems quasilinear elliptic equations SchrSdingerequation
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