两个空间之间复合映射的不动点集和Reidemeister数

设X,Y为拓扑空间,f:X→Y,g:y→X．该文证明了下列结论:对每一自然数n, (1)f(Fix((g o,f)n))=Fix((f o g)n),g(Fix((f og )n))=Fix(g o f)n),且#Fix((g o f)n)= #Fix((f o g)n);(2)R((g o f)n)=R((f o g)n)．     

Crystal packing of 8,9,10,12-tetrafluoro-<Emphasis Type="Italic">o</Emphasis>-carborane: H...F versus H...H contacts

Detailed study of the crystal packing of 8,9,10,12-tetrafluoro-o-carborane by the topological analysis of the electron density distribution function was performed and the competing between the F...H and H...H interactions in the crystal was investigated.     

ON THE SHEAF OF GENERALIZED FUNDAMENTAL GROUP AND COVERING SPACE

ＯＮ ＴＨＥ ＳＨＥＡＦ ＯＦ ＧＥＮＥＲＡＬＩＺＥＤ ＦＵＮＤＡＭＥＮＴＡＬ ＧＲＯＵＰ ＡＮＤ ＣＯＶＥＲＩＮＧ ＳＰＡＣＥ￥ＧＡＮＤＡＮＹＡＮＡｂｓｔｒａｃｔ：Ｔｈｅａｕｔｈｏｒｃｏｎｓｔｒｕｃｔｓｔｈｅｓｈｅａｆｏｆｇｅｎｅｒａｌｉｚｅｄｆｕ...     

Cohomological aspects of gauge theories: superfield formalism

Some of the key cohomological features of the two (1 + 1)-dimensional (2D) free Abelian- and self-interacting non-Abelian gauge theories (having no interaction with matter fields) are briefly discussed first in the language of symmetry properties of the Lagrangian densities and the same issues are subsequently addressed in the framework of superfield formulation on the four (2 + 2)-dimensional supermanifold. Special emphasis is laid on the on-shell- and off-shell nilpotent (co-)BRST symmetries that emerge after the application of (dual) horizontality conditions on the supermanifold. The (anti-)chiral superfields play a very decisive role in the derivation of the on-shell nilpotent symmetries. The study of the present superfield formulation leads to the derivation of some new symmetries for the Lagrangian density and the symmetric energy-momentum tensor. The topological nature of the above theories is captured in the framework of superfield formulation and the geometrical interpretations are provided for some of the topologically interesting quantities.     

Attractor minimal sets for cooperative and strongly convex delay differential systems

We study the skew-product semiflow induced by a family of convex and cooperative delay differential systems. Under some monotonicity assumptions, we obtain an ergodic representation for the upper Lyapunov exponent of a minimal subset. In addition, when eventually strong convexity at one point is assumed and there exist two completely strongly ordered minimal subsets K₁?_CK₂, we show that K₁ is an attractor subset which is a copy of the base. The long-time behaviour of every trajectory strongly ordered with K₂ is then deduced. Some examples of application of the theory are shown.     

拓扑度计算与应用

本文运用锥理论计算一类全连续场的拓扑度,极大地减弱了非线性算子下方 有界的条件, 因而本质上改进和推广了现有结果. 最后,把抽象结果应用于研究超线 性Hammerstein积分方程非平凡解的存在性.     

Periodic solutions of a predator-prey system with stage-structures for predator and prey

By using the continuation theorem of coincidence degree theory, the existence of a positive periodic solution for the predator-prey system with stage-structures for predator and prey is established.     

向量场的Nielsen数

对于紧致流形M上的任意一个向量场X，定义了一个由向量场X确定的自映射fX：M→M，使得向量场X的奇异点均为fX的不动点．证明了向量场的Nielsen数是不依赖于向量场选取的量．     

Equicontinuity and Sensitivity of Group Actions*

Let(X, G) be a dynamical system(G-system for short), that is, X is a topological space and G is an infinite topological group continuously acting on X. In the paper,the authors introduce the concepts of Hausdorff sensitivity, Hausdorff equicontinuity and topological equicontinuity for G-systems and prove that a minimal G-system(X, G) is either topologically equicontinuous or Hausdorff sensitive under the assumption that X is a T₃-space and they provide a classification of transitive d...     

Observability and topological dynamics

Using methods of topological dynamics, we study sufficiency conditions for observability of a given dynamical system (X, T) by a continuous output function. In particular, we show that ifX has either finite topological or covering dimension andT does not have infinitely many periodic points with same period, then (X, T) admits an observable. The paper also gives a partial survey of various related results and improves some of them.Dedicated to the memory of Douglas McMahon.