非均匀可激介质中的螺旋波

Spiral wave in an inhomogeneous excitable medium

以Barkley模型为对象,研究了可激介质的非均匀性对螺旋波斑图形成的影响.该模型中各参数与可激介质的属性密切相关,通过参数涨落的正态分布来刻画非均匀性,数值研究了单参数以及多参数涨落的正态分布情形下螺旋波斑图的形成.研究表明,可激介质的非均匀性对于螺旋波波纹的粗细及疏密程度有较大影响.参数涨落分布的方差越大,形成的螺旋波波纹越粗糙.对于两参数均匀分布的极端情形,当参数分布大于某一范围,无法形成螺旋波.这些都与螺旋波旋转的角频率密切相关.螺旋波旋转的角频率越大,螺旋波波纹越粗,同时波纹越密集;反之,螺旋波旋转角频越小,螺旋波波纹越细,同时波纹越稀疏.

Using a Barkley model as an example,the pattern formation of spiral waves in inhomogeneous excitable medium is investigated.The normal distribution of parameters fluctuations is introduced to depict the inhomogeneous medium.It is found that the parameter fluctuations play an important role in the formation of spiral pattern.For a larger variance of the parameter fluctuations,the spiral waves are rough.In the case of the uniform distribution of fluctuations in two parameters,spiral wave cannot be observed for fluctuations beyond a certain range.It is conjectured that these results are induced by the rotating frequency of spiral wave for different parameters.For the larg rotating frequency,the spiral wave pattern is finely crowded,while it is sparse for small frequencies.