Global chaos in a periodically forced, linear system with a dead-zone restoring force

The Poincare mapping and the corresponding mapping sections for global motions in a linear system possessing a dead-zone restoring force are introduced through switching planes pertaining to two constraints. The global periodic motions based on the Poincare mapping are determined, and the eigenvalue analysis for the stability and bifurcation of periodic motion is carried out. Global chaos in such a system is investigated numerically from the unstable global periodic motions analytically determined. The bifurcation scenario with varying parameters is presented. The mapping structures of periodic and chaotic motions are discussed. The Poincare mapping sections for global chaos are given for illustration. The grazing phenomenon embedded in chaotic motion is observed in this investigation.     

Inheritance principle in dynamical systems

We suggest an “inheritance principle” according to which local properties are inherited by the global shift mapping. The principle is based on the notions of roughness and semigroup. When analyzing general competition models, key inherited properties (sign-invariant structures etc.) are determined. This approach is used to prove the global stability of periodic modes in a number of nonlinear nonautonomous ecological models.     

拓扑定理及其在超线性脉冲方程中的应用

本文研究一类含脉冲的非保守超线性方程的周期振动问题.通过详细刻画跳跃映射的角度函数,并应用相平面分析方法,本文证明方程的Poincaré映射有无穷多个不动点,而这些不动点对应了方程的无穷多个2π周期解.由于本文考虑的Poincaré映射不是同胚,所以,本文重新构造并证明了一个拓扑定理用于替代经典的Poincaré-Birkhoff扭转不动点定理.     

A periodic single species model with intermittent unilateral diffusion in two patches

In this paper, we consider a periodic single species model with intermittent unilateral diffusion in two patches. By using analytic method, Poincare mapping, Lyapunov function approach, sufficient and necessary conditions on the existence, uniqueness and global attractivity of positive periodic solution and the extinction of species for the considered system are established. Two examples and numerical simulations are presented to validate our theoretical results.     

非线性微分系统的Poincare映射与周期解

采用一种新方法-反射函数法,建立了非线性非自治微分系统的Poincare映射, 给出了这些微分系统周期解存在及稳定的充要条件．     

Inheritance principle in dynamical systems and an application in ecological models

To analyze arbitrary nonautonomous models, we develop a general principle of inheritance of a number of local properties by the Poincaré period map: if some local property is rough and semigroup, then the global period map has the same property. In particular, for competition models, we specify key inherited properties (sign-invariant matrices etc.). This approach is used to prove the global stability of periodic modes for various nonlinear ecological models.     

Global periodic conservative solutions of a periodic modified two-component Camassa-Holm equation

In the paper, we first show the existence of global periodic conservative solutions to the Cauchy problem for a periodic modified two-component Camassa-Holm equation. Then we prove that these solutions, which depend continuously on the initial data, construct a semigroup.     

Global analysis of a three-dimensional delayed Michaelis-Menten chemostat-type models with pulsed input

In this paper, a new three-dimensional Michaelis-Menten type chemostat model with time delay and pulsed input nutrient concentration is considered. By means of a fixed point in Poincare map for the discrete dynamical system, we obtain a semi-trivial periodic solution, further, we establish the sufficient conditions for the global attractivity of the semi-trivial periodic solution. By use of new computational techniques for impulsive and delayed differential equation, we prove that the system is permanent under appropriate conditions. Our results show that time delays are “profitless”. The results are further substantiated by numerical simulation.     

Almost Periodic Solutions to a Stochastic Differential Equation in Hilbert Spaces

In this paper, we prove the existence and uniqueness of quadratic mean almost periodic mild solutions for a class of stochastic differential equations in a real separable Hilbert space. The main technique is based upon an appropriate composition theorem combined with the Banach contraction mapping principle and an analytic semigroup of linear operators.     

Global attractor for a nonlinear viscoelastic model

In this paper we establish the existence of global attractors of a semiflow and a semigroup for a nonlinear 1-d viscoelasticity in two frameworks. We exploit the properties of the analytic semigroup to show the compactness for the semiflow and semigroup generated by the weak global solutions.     

具有全局中心的三次Hamilton系统的Poincaré分支

本文讨论一类具有全局中心的三次:Hamilton系统的Poincare分支,证明了 其Poincare分支最多可以产生两个极限环,而且可以产生两个极限环.     

Means, homomorphisms, and compactifications of weighted semitopological semigroups

We consider some almost periodic type function algebras on a weighted semitopological semigroup, and using the set of multiplicative means on each of these algebras, we define their corresponding weighted semigroup compactifications. This will constitute an effective tool for investigating the properties of the function algebras concerned. We also show that these compactifications do not retain all the nice properties of the ordinary semigroup compactifications unless we impose some restrictions on the weight functions.     

Varieties and Nilpotent Extensions of Permutative Periodic Semigroups

We investigate certain semigroup varieties formed by nilpotent extensions of orthodox normal bands of commutative periodic groups. Such semigroups are shown to be both structurally periodic and structurally commutative, and are therefore structurally inverse semigroups. Such semigroups are also shown to be dense semilattices of structurally group semigroups. Making use of these structure decompositions, we prove that the subvariety lattice of any variety comprised of such semigroups is isomorphic to the direct product of the following three sublattices: its sublattice of all structurally trivial semigroup varieties, its sublattice of all semilattice varieties, and its sublattice of all group varieties. We conclude, therefore, that to completely describe this lattice, we must first describe completely the lattice of all structurally trivial semigroup varieties, since the other two are well known lattices.     

Approximate solutions and chaotic motions of a piecewise nonlinear–linear oscillator

A global symmetric period-1 approximate solution is analytically constructed for the non-resonant periodic response of a periodically excited piecewise nonlinear–linear oscillator. The approximate solutions are found to be in good agreement with the exact solutions that are obtained from the numerical integration of the original equations. In addition, the dynamic behaviour of the oscillator is numerically investigated with the help of bifurcation diagrams, Lyapunov exponents, Poincare maps, phase portraits and basins of attraction. The existence of subharmonic and chaotic motions and the coexistence of four attractors are observed for some combinations of the system parameters.     

THE POINCAR BIFURCATION OF QUADRATIC SYSTEMS HAVING A REGION CONSISTING OF PERIODIC CYCLES BOUNDED BY A HYPERBOLA AND AN ARC OF EQUATOR

The usual bifureation problems oeeurred in the study of the Planar differential systems having a region eonsisting of Periodie eycles are as follows:15 there any closed orbit whieh generates limit eyeles after a small perturbation?How many limit eyel     

一类三维Lotka-Volterra方程和Poincaré标准型及有关参数的讨论

讨论了一类三维Lotka-Volterra方程和Poincaré标准型问题.在给出方程出现周期解分歧现象的条件和确定重要参数中有广泛应用的一个级数的基础上,进一步讨论了与之相关的Poincaré标准型及确定若干个重要参数的表达式问题,并给出了参数的计算方法.     

The structure of L*-inverse semigroups

The concepts of L*-inverse semigroups and left wreath products of semigroups are introduced. It is shown that the L*-inverse semigroup can be described as the left wreath product of a type A semigroupΓand a left regular band B together with a mapping which maps the semigroupΓinto the endomorphism semigroup End(B). This result generalizes the structure theorem of Yamada for the left inverse semigroups in the class of regular semigroups. We shall also provide a constructed example for the L*-inverse semigroups by using the left wreath products.     

数理金融模型中Abel方程与Bernoulli方程周期问题的等价性

近年来随机微分方程在数理金融中的应用越来越得到人们的重视,而微分方程的周期性研究对经济模型也越来越重要,Abel(阿贝尔)、Bernoulli(伯努利)方程的周期性具有一定的指导性,但周期性问题的研究常具有一定的难度,为了解决这个问题,采用Mironenko发明的反射函数理论,通过构造与Abel方程、Bernoulli方程共同特征的更一般的方程,得到它们的反射函数,研究了Abel方程与Bernoulli方程的等价性,通过Poincare映射得出了它们相同的周期解问题.     

一类三维系统的次调和解与不变环面的分支

讨论一类三维自治系统的闭轨在周期扰动下的分支问题.利用Poincare映射与积分流形定理,得到扰动系统存在次调和解和不变环面的条件,以及次调和解的鞍结点分支.     

可换序半群的分式扩张

In this paper we extend the construction of the field of rational numbers from the ring of integers to an arbitrary commutative ordered semigroup.We first construct a fractional ordered semigroup and a homomorphism ψs:R→S-1R.Secondly,we characterize the commutative ordered semigroup so constructed by a universal mapping property.