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一种磁场拓扑分离面的计算方法
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作者 李碧强 宋慕陶 《紫金山天文台台刊》 北大核心 1995年第4期261-268,共8页
本文介绍了一种计算太阳活动区磁场拓扑界面所具体数值方法。它对于寻找耀斑及物质抛射的可能发生位置提供了十分有效的手段。
关键词 太阳活动区 磁场 拓扑分离 计算法
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基于分离拓扑结构的直流电压平衡控制策略
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作者 常卫花 陈智娟 《电力电子技术》 CSCD 北大核心 2021年第2期65-69,93,共6页
针对严重不平衡条件导致的级联H桥电力电子变压器(PET)中高压侧和低压侧直流电压不平衡问题,提出了一种基于分离拓扑结构的级联H桥PET独立直流电压平衡控制。该策略通过调节流经隔离级和输出级有功功率来分别平衡高压直流链路和低压直... 针对严重不平衡条件导致的级联H桥电力电子变压器(PET)中高压侧和低压侧直流电压不平衡问题,提出了一种基于分离拓扑结构的级联H桥PET独立直流电压平衡控制。该策略通过调节流经隔离级和输出级有功功率来分别平衡高压直流链路和低压直流链路。首先,详细讨论了不同PET调整策略的最大调整有功功率,并与所提策略进行电压平衡能力对比。然后详细描述了所提策略的控制框图,最后通过实验对在严重不平衡条件下各策略的电压平衡能力进行比较。实验验证了所提策略的有效性,结果表明:该策略具备最大调整有功功率以及在严重不平衡条件下优良的电压平衡能力,此外所提策略具备通用性。 展开更多
关键词 电力电子变压器 分离拓扑结构 高/低压直流链路
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基于依参数分离算子的鲁棒可靠滤波器设计 被引量:1
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作者 欧阳高翔 倪茂林 孙承启 《自动化学报》 EI CSCD 北大核心 2008年第3期225-232,共8页
针对凸面体不确定系统并考虑传感器发生故障的情况,基于二次型分离算子进行了鲁棒可靠滤波器设计的研究.利用不确定系统鲁棒镇定时的拓扑解释,采用分离算子将不含故障描述的系统矩阵与故障描述矩阵进行解耦,从而获得对故障不敏感的鲁棒... 针对凸面体不确定系统并考虑传感器发生故障的情况,基于二次型分离算子进行了鲁棒可靠滤波器设计的研究.利用不确定系统鲁棒镇定时的拓扑解释,采用分离算子将不含故障描述的系统矩阵与故障描述矩阵进行解耦,从而获得对故障不敏感的鲁棒可靠滤波器.为进一步降低设计的保守性,文中还给出了一种依参数分离算子的滤波器存在条件,并将滤波器设计转化为线性矩阵不等式(LMIs)表述的凸优化问题.仿真实例验证了文中所提出设计方法的有效性. 展开更多
关键词 鲁棒可靠滤波器 拓扑分离 依参数分离算子 线性矩阵不等式
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拓扑空间的“一点紧化”新定理
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作者 彭声羽 《九江师专学报》 1992年第5期6-7,共2页
本文得到了下述较为整齐的结论:当拓扑空间X是T_i空间(i=2,2 1/2,3,3 1/2,4,5,6)、直至度量空间时,X的“一点紧化”空间都是T_(1 1/2)空间,且这里r的T_(1 1/2)不能改进为T_1。
关键词 拓扑空间 拓扑分离 “一点紧化”空间 度量空间 T11/2空间 有限子覆盖
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组播业务发展思路(the blueprint to develop multicast service)
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作者 郭锋 《计算机与网络》 2003年第9期42-43,共2页
组播核心技术介绍 许多城市的城域网接入到核心各个部分都实现了宽带化,架构了以IP为基础的无阻塞数据承载平台。网络的宽带化让人们在宽阔的信息高速公路上更顺畅地进行通信,人们已经不再局限于传统点到单点的交流,更渴望多点之间的沟... 组播核心技术介绍 许多城市的城域网接入到核心各个部分都实现了宽带化,架构了以IP为基础的无阻塞数据承载平台。网络的宽带化让人们在宽阔的信息高速公路上更顺畅地进行通信,人们已经不再局限于传统点到单点的交流,更渴望多点之间的沟通。组播技术为多点通信业务的开展提供了良好的技术支撑。 多点通信业务可以应用传统的单播技术实现。 展开更多
关键词 组播业务 组播路由协议 组播通信模型 组播拓扑分离协议 信源管理 组播安全控制
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SEPARATED FRAMES
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作者 张凤玲 StraussDona 《Transactions of Tianjin University》 EI CAS 1998年第1期76-79,共4页
In this paper we shall offer a separation axiom for frames inspired by the Hausdorff separation axiom for topological spaces. We call it separated condition. This is a condition on topology OX equivalent to the ... In this paper we shall offer a separation axiom for frames inspired by the Hausdorff separation axiom for topological spaces. We call it separated condition. This is a condition on topology OX equivalent to the T O space X being Hausdorff. The class of separated frames includes that of strong Hausdorff frames and that of S frames. We shall show that the class of separated frames is a class closed under the formation of coproducts and subspaces, and the space Fil( L ) is Hausdorff for any separated frame L . Therefore there is a contravariant adjunction between the category TOP 2 of Hausdorff topological spaces and the category FRAM 2 of separated frames. 展开更多
关键词 FRAME separated frame Hausdorff topological space adjunction between categories
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T_2 Separation Subsets and T_2 Separateness in L-fuzzy Topological Spaces 被引量:3
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作者 孟广武 《Chinese Quarterly Journal of Mathematics》 CSCD 1997年第2期11-18, ,共8页
The concept of α-CT2 separation L-fuzzy subsets in L-fuzzy topological spaces is presented by taking the stratiform structure of L-fuzzy subsets as the point of departure,and its basic characterizations and some topo... The concept of α-CT2 separation L-fuzzy subsets in L-fuzzy topological spaces is presented by taking the stratiform structure of L-fuzzy subsets as the point of departure,and its basic characterizations and some topological properties are discussed,and the relation between it and other separateness is exposed,and the action is studied of α-CT2 separateness in N-compact spaces and N-paracompact spaces. 展开更多
关键词 fuzzy topological space α-CT_2 separation subset fuzzy lattice stratiform structure
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Diagonal Invariant Ideals of Topologically Graded C~*-algebras 被引量:2
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作者 XU Qing-xiang ZHANG Xiao-bo 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2005年第4期338-341,共4页
We study diagonal invariant ideals of topologically graded C*-algebras over discrete groups. Since all Toeplitz algebras defined on discrete groups are topologically graded, the results in this paper have improved the... We study diagonal invariant ideals of topologically graded C*-algebras over discrete groups. Since all Toeplitz algebras defined on discrete groups are topologically graded, the results in this paper have improved the first author's previous works on this topic. 展开更多
关键词 Fell bundle topologically graded C*-algebra diagonal invariant ideal
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Separation Properties of Bitopological Space
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作者 田利钦 《Chinese Quarterly Journal of Mathematics》 CSCD 1995年第2期109-110,共2页
In this paper we study a bitopological space with a fuzzy topological space,and examine the relation between various fuzzy and bitopological separation axioms.
关键词 fuzzy lattice MOLECULE fuzzy topology bitopological
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Separateness in Topological Molecular Lattices
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作者 李雷 《Chinese Quarterly Journal of Mathematics》 CSCD 1996年第2期17-20,共4页
In this paper,we discuss the separateness in topological molecular lattices (TML) by the molecular stratums given in [1] and [2],deal with the relationship between the compactness and separateness.
关键词 TML molecutar stratum SEPARATENESS COMPACTNESS
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Recent progress in random metric theory and its applications to conditional risk measures 被引量:18
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作者 GUO TieXin 《Science China Mathematics》 SCIE 2011年第4期633-660,共28页
The purpose of this paper is to give a selective survey on recent progress in random metric theory and its applications to conditional risk measures.This paper includes eight sections.Section 1 is a longer introductio... The purpose of this paper is to give a selective survey on recent progress in random metric theory and its applications to conditional risk measures.This paper includes eight sections.Section 1 is a longer introduction,which gives a brief introduction to random metric theory,risk measures and conditional risk measures.Section 2 gives the central framework in random metric theory,topological structures,important examples,the notions of a random conjugate space and the Hahn-Banach theorems for random linear functionals.Section 3 gives several important representation theorems for random conjugate spaces.Section 4 gives characterizations for a complete random normed module to be random reflexive.Section 5 gives hyperplane separation theorems currently available in random locally convex modules.Section 6 gives the theory of random duality with respect to the locally L0-convex topology and in particular a characterization for a locally L0-convex module to be L0-pre-barreled.Section 7 gives some basic results on L0-convex analysis together with some applications to conditional risk measures.Finally,Section 8 is devoted to extensions of conditional convex risk measures,which shows that every representable L∞-type of conditional convex risk measure and every continuous Lp-type of convex conditional risk measure(1 ≤ p < +∞) can be extended to an L∞F(E)-type of σ,λ(L∞F(E),L1F(E))-lower semicontinuous conditional convex risk measure and an LpF(E)-type of T,λ-continuous conditional convex risk measure(1 ≤ p < +∞),respectively. 展开更多
关键词 random normed module random inner product module random locally convex module random conjugate space L0-convex analysis conditional risk measures
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Topological evolution of laminar juncture flows under different critical parameters 被引量:1
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作者 YOUNIS Muhammad Yamin ZHANG Hua +1 位作者 HU Bo MEHMOOD Saqib 《Science China(Technological Sciences)》 SCIE EI CAS 2014年第7期1342-1351,共10页
Horseshoe vortex topological structure has been studied extensively in the past,traditional"saddle of separation"and new"attachment saddle point"topologies found in literature both have theoretical... Horseshoe vortex topological structure has been studied extensively in the past,traditional"saddle of separation"and new"attachment saddle point"topologies found in literature both have theoretical basis and experimental and computational evidences for support.The laminar incompressible juncture flows at low Reynolds numbers especially are observed to have new topology.Studies concerning the existence of the new topology though found in literature,the topological evolution and its dependency on various critical flow parameters require further investigation.A Particle Image Velocimetry based analysis is carried out to observe the effect of aspect ratio,?*/D and shape of the obstacle on laminar horseshoe vortex topology for small obstacles.Rise in aspect ratio evolves the topology from the traditional to new for all the cases observed.The circular cross section obstacles are found more apt to having the new topology compared to square cross sections.It is noted that the sweeping effect of the fluid above the vortex system in which horseshoe vortex is immersed plays a critical role in this evolution.Topological evolution is observed not only in the most upstream singular point region of horseshoe vortex system but also in the corner region.The corner vortex topology evolves from the traditional type to new one before the topological evolution of the most upstream singular point,resulting in a new topological pattern of the laminar juncture flows"separation-attachment combination".The study may help extend the understanding of the three-dimensional boundary layer separation phenomenon. 展开更多
关键词 horseshoe vortex saddle of attachment saddle of separation topological evolution sweeping effect
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Solutions to two problems of G.J.Wang
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作者 赵彬 王三民 《Science China Mathematics》 SCIE 2001年第7期889-894,共6页
The problem as to whether the sub-T0 separation and complete regularity are invariant under homeomorphism is answered negatively.And,the problem of multiplicativity of the complete regularity in general L-fuzzy topolo... The problem as to whether the sub-T0 separation and complete regularity are invariant under homeomorphism is answered negatively.And,the problem of multiplicativity of the complete regularity in general L-fuzzy topological spaces is also answered negatively. 展开更多
关键词 L-fuzzy topological space Sub-T0 separation Complete regularity HOMEOMORPHISM
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Separation axioms under crossover operator and its generalized
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作者 M. M. El-Sharkasy M. Shokry 《International Journal of Biomathematics》 2016年第4期169-191,共23页
The purpose of this work is to construct a new crossover operator using the properties of DNA and RNA by using topological concepts in constructing flexible mathematical models in the field of biomathematics. Also, we... The purpose of this work is to construct a new crossover operator using the properties of DNA and RNA by using topological concepts in constructing flexible mathematical models in the field of biomathematics. Also, we investigate and study topological prop- erties of the constructed operators and the associated topological spaces of DNA and RNA. Finally we use the process of exchange for sequence of genotypes structures to construct new types of topological concepts to investigate and discuss several examples and some of their properties. 展开更多
关键词 DNA and RNA GENOTYPES TOPOLOGY (To T1 T2)-crossover space.
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