交替行为对螺旋波影响的数值模拟研究

在离散可激发介质Greenberg-Hasting模型中引入交替(alternans)行为,研究了交替行为对螺旋波的影响.数值结果表明:在适当选择参数下,交替对螺旋波有很大影响,例如交替导致螺旋波的形状振荡,形成呼吸螺旋波,交替使螺旋波漫游、漂移,甚至使螺旋波漫游出系统的边界,交替使螺旋波破碎形成小螺旋波、反靶波和时空混沌等,首次在均匀介质中观察到交替导致传导障碍,使螺旋波破碎和消失,并对发生这些现象的机理进行了分析. 关键词： 离散可激发介质 螺旋波 靶波 漫游

Numerical simulation study on effects of alternans behavior on spiral waves

The alternans behavior is considered in the Greenberg-Hasting model of discrete excitable medium. The effect of the alternans behavior on spiral wave is investigated. The numerical results show that when the relevant parameters are appropriately chosen the alternans behavior has a significant influence on spiral waves. For example, the alternans behavior leads to the oscillation of the shape of the spiral wave and to the generation of the breathing spiral wave. The alternans behavior induces the meandering and the drifting of spiral waves, even causes spiral wave to move out of the system. Spiral wave can break up into multiple spiral waves, anti-target wave and spatiotemporal chaos due to the alternans behavior. The phenomena that the alternans behavior leads to the conduction barrier in homogeneous medium and causes spiral wave to break up or vanish, are observed for the first time. The physical mechanisms about these phenomena are briefly analyzed.