GLOBAL ATTRACTIVITY IN A CLASS OF NONLINEAR DIFFERENCE EQUATIONS

Considerkth(k22)orderdifferenceequationxn l=axn f(x.-bx.-1-x.-k),n=k,k 1,'')(1)wherexo1x1)'',xkaregivenrealnumbers,aand5arerealconstantswithoSa<1,andf:R-Risarealfunction-Equation(1)issaidtohaveglobalattractivityiftherearerealnumberssandtwithsosuchthatxnE[s,t]foralln2m.Globalattractivityindifferenceequationsinoneofthemostimportantglobalbehaviorsofdifferenceequationsandhasmuchsignificance…     

关于区间上的Lorenz映射

本文引进了变换ζ．首先，用比文［４］简捷的方法证明了Ｌｏｒｅｎｚ映射的Ｓａｒｋｏｖｓｋｉ定理并更正了文［４］中的一个错误，还得到了扩张的Ｌｏｒｅｎｚ映射中周期点的存在性与其扩张常数之间的关系．其次，证明了Ｌｏｒｅｎｚ映射与其在变换ζ的像具有相等的捏制行列式．此外，给出了广义的Ｌｏｒｅｎｚ映射的周期点的存在性适合Ｓａｒｋｏｖｓｋｉ序关系的一个充分条件     

A Note on Topological Entropy of Maps

For a given collection of subsets of a compact metric space X which cover X,the entropies,hm(f)and hi(f),are introduced for a continuous map f of X to itseif. Also the concept of shadowing property with same end point (SPSEP for short) is introduced. The main results are,(1)H(f)≤hi(f)+hm(f)and,(2)h(f)=hm(f)whenever f has SPSEP,where h(f) is the topological entropy of f. Moreover,several corollaries are obtained.     

一类高阶有理差分方程解的收敛性(英文)

本文考查下列高阶有理差分方程xn+1=(α+B1xn-1+B3xn-3+…+B2k+1xn-2k-1)/(A+B0xn+B2xn-2+…+B2kxn-2k,),n=0,1,…,其中k是非负整数,参数α,A,Bi,i=0,1,2,…,2k+1和初始值x-2k-1,x-2k,x-2k+1,…,x0是非负实数.给出充分条件,在此条件下当且仅当∑k+1i=1B2i-1=A时,方程的每个解收敛于方程的一个二周期解.     

广义树映射的吸引中心和ω-极限集空间

设D是广义树(即具有有限个分支点的树突(dendrite)),f是D上的连续自映射.用P(f)、R(f)、SA(f)、Γ(f)、UΓ(f)、ω(x,f)和?(f)分别表示f的周期点集、回归点集、特殊α-极限点集、γ-极限点集、单侧γ-极限点集、x的ω-极限集和非游荡集.对任意A?D,记ω(A)=∪_(x∈A)ω(x,f).对任意的自然数n≥2,记ω~n(f)=ω(ω~(n-1)(f)),其中ω(f)=∪_(x∈D)ω(x,f).本文证明:对任意的正整数n,有ω~(n+2)(f)=ω~2(f)=ω(?(f))=ω(SA(f))=ω(Γ(f))=ω(P(f)∪(∪_(n=0)~∞f~n(UΓ(f))))=ω(P(f))=ω(R(f)∪UΓ(f))=P(f)∪(∪_(n=0)~∞f~n(UΓ(f)))?P(f).此外,本文还构造了一个只有一个分支点的广义树D和D上的一个连续自映射f,使得{ω(x,f):x∈D}在Hausdorff度量下不是闭的.     

图映射拓扑序列熵的可交换性

主要研究图上连续自映射拓扑序列熵的可交换性,证明了对任意无界的正整数递增序列A=(ai)∞i=1和任意的连续图映射f,g都有hA(fog):hA(g of).解决了Balibrea F等人在相关文献中提出的一个猜想.     

单峰扩张映射的捏制序列

设Ｐ及ＡＣ均是准素序列并满足ｍｉｎ｛Ｐ，ＡＣ｝ＲＬＲ∞，ρ（Ｐ）及ρ（ＡＣ）分别是Ｐ及ＡＣ的特征值．设ｆ∈Ｃ０（Ｉ，Ｉ）是个单峰扩张映射并具有扩张常数λ，ｍ是个非负整数．本文证明了若λ（ρ（Ｐ））１／２ｍ，则ｆ的捏制序列Ｋ（ｆ）（ＲＣ）ｍＰ；若λ＞（ρ（ＡＣ））１／２ｍ，则对任极大序列Ｅ，Ｋ（ｆ）＞（ＲＣ）ｍＡＣＥ．（ρ（Ｐ））１／２ｍ及（ρ（ＡＣ））１／２ｍ均是下述意义下的最佳值，即若其中任一个被较小的值代替，则相应的结论便不成立．     

PARTIAL LYAPUNOV STABILITY AND PARTIAL LIPSCHITZ STABILITY IN FLOWS

１ＩｎｔｒｏｄｕｃｔｉｏｎＤｅｎｏｔｅｂｙＲ，Ｒ＋ａｎｄＲ－ｔｈｅｓｅｔｏｆｒｅａｌｎｕｍｂｅｒｓ，ｏｆｎｏｎｎｅｇａｔｉｖｅｎｕｍｂｅｒｓａｎｄｏｆｎｏｎｐｏｓｉｔｉｖｅｎｕｍｂｅｒｓ，ａｎｄｂｙＺ，Ｚ＋ｔｈｅｓｅｔｏｆｉｎｔｅｇｅｒｓ，ａｎｄｎｏ...     

树映射的ω-极限集

Let T be a tree and f be a continuous map form T into itself.We show mainly in this paper that a point x of T is an ω-limit point of f if and only if every open neighborhood of x in T contains at least nx 1 points of some trajectory,where nx equals the number of connected components of T/{x}.Then,for any open subset Gω(f) in T,there exists a positive integer m=m(G) such that at most m points of any trajectory lie outside G.This result is a generalization of the related result for maps of the interval.