期刊文献+
共找到291篇文章
< 1 2 15 >
每页显示 20 50 100
About Compact and Sequentially Compact Coincide in Topological Groups with the Axiom (A_1) 被引量:1
1
作者 Lina 《Northeastern Mathematical Journal》 CSCD 2004年第3期271-274,共4页
This paper is concerned with the relation between the compactness and sequential compactness in a topological space or a topological group, and show that the compactness and sequential compactness coincide in a topolp... This paper is concerned with the relation between the compactness and sequential compactness in a topological space or a topological group, and show that the compactness and sequential compactness coincide in a topolpgical group with the axiom (A1). 展开更多
关键词 topological space topological group COMPACT sequential compactness
下载PDF
Two Notes on Topological Groups
2
作者 ZHANG Ke-xiu LIU Xin TANG Zhong-bao 《Chinese Quarterly Journal of Mathematics》 2016年第1期82-86,共5页
In this short paper, we firstly give a short proof of Birkhoff-Kakutani Theorem by Moore metrizable Theorem. Then we prove that G is a topological group if it is a paratopological group which is a dense G_δ-set in a ... In this short paper, we firstly give a short proof of Birkhoff-Kakutani Theorem by Moore metrizable Theorem. Then we prove that G is a topological group if it is a paratopological group which is a dense G_δ-set in a locally feebly compact regular space X. 展开更多
关键词 topological group first-countable paratopological group locally feebly compact METRIZABLE
下载PDF
THE MAXIMUM OF THE γ-MAX-SUBADDITIVE FUNCTIONALS ON A CLASS OF TOPOLOGICAL GROUPS
3
作者 定光桂 《Acta Mathematica Scientia》 SCIE CSCD 1998年第3期310-314,共5页
It is shown that if a 'max-subadditive funtional' p(x) defined on some symmetric neighborhood U0 of zero vector θ in a 'b.f.-toplological group' X is 'upper semi-cotinuous' at a point x0 ∈ U0... It is shown that if a 'max-subadditive funtional' p(x) defined on some symmetric neighborhood U0 of zero vector θ in a 'b.f.-toplological group' X is 'upper semi-cotinuous' at a point x0 ∈ U0, or 'lower semi-continuous' in some neighborhood V(x0) U0 and X is of second category; then p(x) can attain its supremum in U0. And there is a similar conclusion for the γ-max-subadditive functional when its supremum is 0 and if U0 is 'pseudo-bounded' set in X. 展开更多
关键词 γ-max-subadditive functional Binary fissionable topological group Pseudo bounded set.
下载PDF
Topological Dynamics in Tandem with Permutation Groups
4
作者 Isaac Kwame Dontwi William Obeng-Denteh +1 位作者 Stephen K. Manu Richard Nyarko Yeboah 《Advances in Pure Mathematics》 2013年第2期292-296,共5页
The purpose of this study was to delve into the aspects of abstract algebra that has a link with topological dynamics in terms of permutation and symmetric groups. This would aid users to appreciate the role it plays ... The purpose of this study was to delve into the aspects of abstract algebra that has a link with topological dynamics in terms of permutation and symmetric groups. This would aid users to appreciate the role it plays in the theory and application of topological dynamics. The usage of matlab programming to carry out the permutations was carried out. The study contributes to the literature by providing candid explanation and usage of data-based evidence documenting the extent to which topological dynamics operates. 展开更多
关键词 PERMUTATION groups RECURRENCE topological Dynamics Matlab Code FLOWS
下载PDF
Relative Property (T) for Topological Groups
5
作者 Jicheng Tao Wen Yan 《Applied Mathematics》 2014年第19期2988-2993,共6页
In this paper, we investigate Kazhdan’s relative Property (T) for pairs , where is a topological group and is any subset of . We show that the pair has Property (FH) and every function conditionally of negative type ... In this paper, we investigate Kazhdan’s relative Property (T) for pairs , where is a topological group and is any subset of . We show that the pair has Property (FH) and every function conditionally of negative type on is X-bounded if the pair has relative Property (T). We also prove that has Property (T) whenis a s -compact locally compact group generated by its subgroups and the pair has relative Property (T) for all . 展开更多
关键词 RELATIVE PROPERTY (T) of topological group Function Conditionally of NEGATIVE Type PROPERTY (FH)
下载PDF
Stability of the topological quantum critical point between multi-Weyl semimetal and band insulator
6
作者 杨兆昆 王景荣 刘国柱 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第5期131-140,共10页
One could tune a topological double-Weyl semimetal or a topological triple-Weyl semimetal to become a topologically trivial insulator by opening a band gap.This kind of quantum phase transition is characterized by the... One could tune a topological double-Weyl semimetal or a topological triple-Weyl semimetal to become a topologically trivial insulator by opening a band gap.This kind of quantum phase transition is characterized by the change of certain topological invariant.A new gapless semimetallic state emerges at each topological quantum critical point.Here we perform a renormalization group analysis to investigate the stability of such critical points against perturbations induced by random scalar potential and random vector potential.We find that the quantum critical point between double-Weyl semimetal and band insulator is unstable and can be easily turned into a compressible diffusive metal by any type of weak disorder.The quantum critical point between triple-Weyl semimetal and band insulator flows to a stable strong-coupling fixed point if the system contains a random vector potential merely along the z-axis,but becomes a compressible diffusive metal when other types of disorders exist. 展开更多
关键词 topological quantum critical points Weyl semimetal DISORDER renormalization group
下载PDF
ALMOST PERIODICITY AND EQUICONTINUITY OF THE TOPOLOGICAL TRANSFORMATION GROUP 被引量:1
7
作者 Li Zhicong Li Juntao 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2006年第4期467-472,共6页
In this paper, a characterization of almost periodicity of topological transformation groups on uniform spaces is given. By searching the appropriate base for uniform structure, it is shown that the topological transf... In this paper, a characterization of almost periodicity of topological transformation groups on uniform spaces is given. By searching the appropriate base for uniform structure, it is shown that the topological transformation group is topologically equivalent to an isometric one if it is uniformly equicontinuous. 展开更多
关键词 uniform space topological transformation group EQUICONTINUITY almost periodicity compactly almost periodicity.
下载PDF
Almost Fuzzy Compactness in L-fuzzy Topological Spaces
8
作者 Li Hong-yan Cui Wei Lei Feng-chun 《Communications in Mathematical Research》 CSCD 2015年第3期267-273,共7页
In this paper, the notion of almost fuzzy compactness is dened in L-fuzzy topological spaces by means of inequality, where L is a completely distributiveDeMorgan algebra. Its properties are discussed and many characte... In this paper, the notion of almost fuzzy compactness is dened in L-fuzzy topological spaces by means of inequality, where L is a completely distributiveDeMorgan algebra. Its properties are discussed and many characterizations of it arepresented. 展开更多
关键词 l-fuzzy topological space l-fuzzy almost compactness l-fuzzy compactness almost fuzzy compactness
下载PDF
Topological超共形代数的Leibniz中心扩张 被引量:1
9
作者 法焕霞 李军波 王伟 《数学年刊(A辑)》 CSCD 北大核心 2010年第4期411-418,共8页
通过计算得到了Topological N=2超共形代数T的Leibniz二上同调群,从而确定了此代数的Leibniz中心扩张.
关键词 topological N=2超共形代数 Leibniz二上同调群 Leibniz中心扩张
下载PDF
Lower bounds of the topological entropy for nonautonomous dynamical systems 被引量:2
10
作者 ZHANG Jin-lian CHEN Lan-xin 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2009年第1期76-82,共7页
In this paper, lower bounds of the topological entropy for nonautonomous dynamical systems are given via the growths of topological complexity in fundamental group and in degree.
关键词 nonautonomous dynamical system topological entropy fundamental group DEGREE
下载PDF
H_∞ couple-group consensus of stochastic multi-agent systems with fixed and Markovian switching communication topologies 被引量:1
11
作者 Muyun Fang Cancan Zhou +2 位作者 Xin Huang Xiao Li Jianping Zhou 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第1期313-322,共10页
The paper addresses the issue of H_∞ couple-group consensus for a class of discrete-time stochastic multi-agent systems via output-feedback control. Both fixed and Markovian switching communication topologies are con... The paper addresses the issue of H_∞ couple-group consensus for a class of discrete-time stochastic multi-agent systems via output-feedback control. Both fixed and Markovian switching communication topologies are considered. By employing linear transformations, the closed-loop systems are converted into reduced-order systems and the H_∞ couplegroup consensus issue under consideration is changed into a stochastic H_∞ control problem. New conditions for the mean-square asymptotic stability and H_∞ performance of the reduced-order systems are proposed. On the basis of these conditions, constructive approaches for the design of the output-feedback control protocols are developed for the fixed communication topology and the Markovian switching communication topologies, respectively. Finally, two numerical examples are given to illustrate the applicability of the present design approaches. 展开更多
关键词 multi-agent system couple-group CONSENSUS output feedback control switching topologIES
下载PDF
The Unitary Group in Its Strong Topology
12
作者 Martin Schottenloher 《Advances in Pure Mathematics》 2018年第5期508-515,共8页
The goal of this paper is to confirm that the unitary group U(H) on an infinite dimensional complex Hilbert space is a topological group in its strong topology, and to emphasize the importance of this property for app... The goal of this paper is to confirm that the unitary group U(H) on an infinite dimensional complex Hilbert space is a topological group in its strong topology, and to emphasize the importance of this property for applications in topology. In addition, it is shown that U(H) in its strong topology is metrizable and contractible if H is separable. As an application Hilbert bundles are classified by homotopy. 展开更多
关键词 UNITARY OPERATOR Strong OPERATOR topology topological group Infinite Dimensional LIE group CONTRACTIBILITY Hilbert BUNDLE Classifying Space
下载PDF
Endpoints of Multi-Valued Weak Contractions on the Metric Space of Partially Ordered Groups
13
作者 Congdian Cheng 《Advances in Pure Mathematics》 2022年第11期638-651,共14页
The present work considers the endpoint in the abstract metric space. It firstly introduces the metric space of partially ordered groups and the metric space of partially ordered modules, respectively;and defines the ... The present work considers the endpoint in the abstract metric space. It firstly introduces the metric space of partially ordered groups and the metric space of partially ordered modules, respectively;and defines the convergence of sequences and the multi-valued weak contractions, etc., on the introduced space. And then, with the methods of functional analysis and abstract algebra, it successively establishes an endpoint theorem for the metric space of partially ordered groups and an endpoint theorem for the metric space of partially ordered modules. The contributions of this article extend the theory of cone metric space constructed by Huang and Zhang (2007) and some recent results on the fixed point and endpoint theory, such as the endpoint theorem given by Amini-Harandi (2010). 展开更多
关键词 Fixed Point Endpoint Metric Space Valued in Partially Ordered group topological Structure Weak Contraction
下载PDF
On Inverse Limits and Direct Limits for Fuzzy Topological Spaces
14
作者 A.Behera J.K.Sahu 《模糊系统与数学》 CSCD 北大核心 2010年第1期45-50,共6页
Li has introduced the concepts of inverse system and direct system for fuzzy topological spaces and studied inverse limits and direct limits on such spaces by presenting the explicit constructions of these limits.In t... Li has introduced the concepts of inverse system and direct system for fuzzy topological spaces and studied inverse limits and direct limits on such spaces by presenting the explicit constructions of these limits.In this paper some important concepts of fuzzy topology,such as,product fuzzy topology,quotient fuzzy topology,fuzzy continuity etc.,are used for further study of inverse limits and direct limits for fuzzy topological spaces. 展开更多
关键词 模糊拓扑 逆向极限 方向极限 代数
下载PDF
成组立模成型机模板结构优化设计研究
15
作者 蔡安江 梅浩鹏 于海滨 《机械设计与制造》 北大核心 2024年第4期379-383,共5页
混凝土预制构件成组立模成型机(简称成组立模)是一种新型的生产混凝土预制构件的设备。为了提高成组立模台面的振动效果和承载能力,本研究以成组立模模板结构为研究对象,提出了一种拓扑优化新兴设计与响应面法结合的优化设计理论。首先... 混凝土预制构件成组立模成型机(简称成组立模)是一种新型的生产混凝土预制构件的设备。为了提高成组立模台面的振动效果和承载能力,本研究以成组立模模板结构为研究对象,提出了一种拓扑优化新兴设计与响应面法结合的优化设计理论。首先,基于变密度法对成组立模模板结构加强筋布局进行拓扑优化设计,得到了加强筋最佳的材料分布形式,以此对成组立模模板结构进行了结构优化设计。为得到最佳的加强筋设计参数,采用中心组合试验设计,建立模板结构最大位移、最大等效应力的响应面模型。利用多目标遗传算法对响应面模型进行优化求解,得出加强筋各参数最优的组合方案。有限元分析结果表明:与初始方案相比,优化设计方案提高了台面的刚度和强度,同时改善了模板结构的振动特性,并提高了混凝土预制构件的成型质量。该研究为进一步推进成组立模的研究提供了理论指导。 展开更多
关键词 成组立模 加强筋布局 拓扑优化 结构优化设计 响应面法 有限元分析
下载PDF
指数有界n阶α次积分C群的紧性
16
作者 赵华新 刘娟娟 贺凯丽 《沈阳大学学报(自然科学版)》 CAS 2024年第3期267-272,共6页
利用指数有界n阶α次积分C群及其次生成元的定义,并借助经典算子理论的研究方法,给出了指数有界n阶α次积分C群紧的定义,从而推导出指数有界n阶α次积分C群的紧性的一些性质。
关键词 指数有界 n阶α次积分C群 次生成元 紧性 拓扑连续
下载PDF
L-Fuzzy 拓扑群范畴 被引量:1
17
作者 周相泉 《烟台大学学报(自然科学与工程版)》 CAS 1998年第2期85-90,共6页
介绍了LFuzy拓扑群范畴.引入了两个函子,构造了它们的右伴随函子,证明了分明拓扑群范畴和诱导LFuzy拓扑群范畴都是LFuzy拓扑群范畴的余反射子范畴,引入了一个遗忘函子,并通过构造其左右伴随揭示了分明群范畴... 介绍了LFuzy拓扑群范畴.引入了两个函子,构造了它们的右伴随函子,证明了分明拓扑群范畴和诱导LFuzy拓扑群范畴都是LFuzy拓扑群范畴的余反射子范畴,引入了一个遗忘函子,并通过构造其左右伴随揭示了分明群范畴与LFuzy拓扑群范畴之间的内在联系. 展开更多
关键词 范畴 函子 LF拓扑群 LF拓扑空间 拓扑群
下载PDF
基于以太网的列车灵活编组技术实现及研究 被引量:1
18
作者 王作禹 王翔 刘景利 《工业控制计算机》 2024年第2期41-42,45,共3页
灵活编组功能是配合铁道车辆灵活运用的网络技术,不仅响应复杂变化的运维条件,而且提高了轨道交通装备网络配置的效率。基于以太网的灵活编组技术通过IEC61375-2-5协议中的网络初运行、列车拓扑发现协议实现,对于解决列车网络系统的应... 灵活编组功能是配合铁道车辆灵活运用的网络技术,不仅响应复杂变化的运维条件,而且提高了轨道交通装备网络配置的效率。基于以太网的灵活编组技术通过IEC61375-2-5协议中的网络初运行、列车拓扑发现协议实现,对于解决列车网络系统的应用问题具有较高的参考价值。 展开更多
关键词 灵活编组 ETB初运行 列车拓扑发现协议 拓扑锁定 拓扑解锁
下载PDF
基于PSD-BPA数据的ADPSS大电网电磁暂态转换建模方法与软件实现
19
作者 徐树文 卓谷颖 +2 位作者 李壮 刘敏 穆清 《中国电力》 CSCD 北大核心 2024年第8期182-189,共8页
随着新能源、直流、柔性交流输电系统等电力电子类设备入网规模越来越大,新型大电网的运行特性发生巨大改变,电磁暂态精细化仿真成为未来电力系统仿真的重要手段。但电磁暂态建模困难严重制约了电磁暂态仿真的工程应用,针对这一难题,提... 随着新能源、直流、柔性交流输电系统等电力电子类设备入网规模越来越大,新型大电网的运行特性发生巨大改变,电磁暂态精细化仿真成为未来电力系统仿真的重要手段。但电磁暂态建模困难严重制约了电磁暂态仿真的工程应用,针对这一难题,提出了一种基于BPA数据快速生成ADPSS电磁暂态模型的技术解决方案,研发了相应转换建模软件,通过分组建模控制、映射建模、用户自定义建模、拓扑优化布局等技术手段,实现BPA数据到ADPSS模型的快速自动化转换建模。基于BPA区域电网数据,利用该软件完成了算例规模超过5000个三相节点的某省级电网的全电磁暂态建模,建模效率得到很大提升,校核结果验证了转换建模软件的有效性。 展开更多
关键词 电磁暂态仿真 分组建模控制 映射建模 用户自定义建模 拓扑优化布局
下载PDF
一类Kirchhoff-Poisson系统在Heisenberg群上解的存在性
20
作者 郭加超 索洪敏 安育成 《南昌大学学报(理科版)》 CAS 2024年第1期1-13,共13页
在Heisenberg群上研究了一类临界的Kirchhoff-Poisson系统。由于存在临界和非局部项,导致空间嵌入不紧,在非线性项适当的假设下,通过变分方法克服了空间的紧性并且得到该系统至少存在一个解。在此基础上,借助形变引理和拓扑度理论,证明... 在Heisenberg群上研究了一类临界的Kirchhoff-Poisson系统。由于存在临界和非局部项,导致空间嵌入不紧,在非线性项适当的假设下,通过变分方法克服了空间的紧性并且得到该系统至少存在一个解。在此基础上,借助形变引理和拓扑度理论,证明了该解是一个变号解。 展开更多
关键词 HEISENBERG群 Kirchhoff-Poisson系统 变分方法 形变引理 拓扑度理论
下载PDF
上一页 1 2 15 下一页 到第
使用帮助 返回顶部