局部相空间压缩实现对时空混沌和螺旋波的控制

采用相空间压缩方法研究时空混沌和螺旋波系统的抑制问题．以局部控制方式将系统变量的幅值限制在一定范围内，对CO在Pt（110）表面氧化模型（Filzhugh-Nagumo方程）与心肌组织模型（Panfilov方程）的数值研究表明：无论是否存在外界噪声，该方案都可以消除螺旋波和时空混沌；尤其是存在噪声时，相空间压缩控制暂态过程会更短，系统很快达到稳定均匀态（从几个到几十个时间单位）．     

Feedback control of wave segments in an excitable medium

Depending on the excitability of the medium, a propagating wave segment will either contract or expand to fill the medium with spiral waves. This paper aims to introduce a simple mechanism of feedback control to stabilize such an expansion or contraction. To do this, we lay out a feedback control system in a block diagram and reduce it into a bare, universal formula. Analytical and experimental findings are compared through a series of numerical simulations of the Barkley model.     

Effects of Periodic Forcing Amplitude on the Spiral Wave Resonance Drift

We study dynamics of spiral waves under a uniform periodic temporal forcing in an excitable medium. With a specific combination of frequency and amplitude of the external periodic forcing, a resonance drift of a spiral wave occurs along a straight line, and it is accompanied by a complicated ‘flower-like＇ motion on each side of this bifurcate boundary line. It is confirmed that the straight-line drift frequency of spiral waves is not locked to the nature rotation frequency as the forcing amplitude expends are further verified numerically for a simplified kinematical the range of the spiral wave frequency. These results model.     

三维可激发系统中Winfree湍流态的控制

三维可激发系统中的Winfree湍流态被认为与心室纤维性颤动可能有着密切的关系.如何快速而有效地消除Winfree湍流是理论工作者非常关心的问题.文章作者发展了两种可有效地控制三维楞可激发系统中Winfree湍流态的方法:(1)局域的周期刺激,即通过小区域内的周期刺激所产生的激发波来消除Winfree湍流;(2)全局的时空微扰,通过对参数的时空调制来消除Wnifree湍流.     

Dynamics of Vortex-Wave under a Travelling-Wave Modulation

The mechanism of destabilization is studied for the rotating vortices （scroll waves and spiral waves） in excitable media induced by a parameter modulation in the form of a travelling-wave. It is found that a rigid rotating spiral in the two-dimensional （2D） system undergoes a synchronized drift along a straight line, and a 3D scroll ring with its filament closed into a circle can be reoriented only if the direction of wave number of a travelling-wave perturbation is parallel to the ring plane. Then, in order to describe the behaviour of the synchronized drift of spiral wave and the reorientation of scroll ring, the approximate formulas are given to exhibit qualitative agreements with the observed results.