Experimental Study of Wave Propagation in the Belousov-Zhabotinsky Reaction

主要研究结果如下：1）建立了一种通过起搏器强度控制靶模式波长的实验方法。从一般的反应扩散系统的简化方程定性地解释了控制的机制。利用货车der Pol方程，通过数值计算再现了这一现象。从实验的角度来看，能够以如此简单的方式控制目标图案的波长是值得注意的。2）观察到目标图案的塌陷。最初是在一个目标斑图形成的时候偶然发现的，由于坍缩发生得非常剧烈，整个斑图在几秒钟内就消失了，因此不能确定这一现象是否可以用通常的反应扩散系统来解释。3）数值上发现了新的波类型。其中一种波是所谓的“测量蠕虫波”，它的波面不是光滑的，而是以规则的间隔不连续地运动。4）最后我们给出了混沌反应扩散系统的数值结果。当频率低于外部介质的频率时，在扩散耦合Rossler系统中观察到目标图案。当系统中加入小扰动时，该模式被证实是稳定的。

Results are summarized as follows :1) an experimental method was developed to control wavelength of a target pattern by strength of the pacemaker. The mechanism of the control is qualitatively explained by a reduced equation from a general reaction-diffusion system. The phenomena can be reproduced by numerical computation by using the van der Pol equation.From the experimental point of view, it is remarkable to be able to control the wavelength of the target pattern in such a simple way.2) collapse of target patterns was observed. At first it was found by chance when a target pattern was forming.Since the collapse occurs very drastically and the whole pattern disappears in a few seconds, it is not certain whether the phenomena can be interpreted within the framework of the usual reaction-diffusion system or not.3) new types of waves are found numerically. One of the waves is so-called a 'measuring worm wave', whose wave surface does not move smoothly but discontinuously at regular intervals.4) finally we mention the numerical results of chaotic reaction-diffusion system. Target patterns are observed in a diffusion-coupled Rossler system when the frequency is lower than that of the outer medium. The pattern is confirmed to be stable when small perturbaitons are added to the system.