双节奏和三重稳定性现象的一个自催化反应模型

远离平衡的化学反应系统即使在恒温和均相条件下也能产生各种各样复杂的动力学现象。从理论和实际应用的角度来说,其中的多重稳定性现象,尤其是双节奏现象和三重稳定性现象特别引起人们的兴趣。最近,这类现象已经在某些简单的恒温反应系统中观察到,一个代表性的例子是BrO_3~--ClO_2~--I~-系统。然而迄今还没有一个简单的恒温反应模型可以模拟这类现象。

AN AUTOCATALYTIC REACTION MODEL FOR BIRHYTHUM AND TRISTABILITY

An autocatalytic reaction model X+2Y→3Y, Y+Z→2Z, Y→P, in a CSTR is put forward to model the phenomena of birhythum and tristability in isothermal, homogeneous chemical systems. Numerical simulations show that, under the proper values of the parameters, system may evolve to and remain at two or three different asymptotic states under same parameter's values but different initial values of X, Y and Z. In some cases, two of these asymptotic states are oscillatory, as shown in Fig.1. This is the phenomenon of birhythum. The stability of these asymptotic states are discussed. Some of them are not strickly stable but might be observed experimentally in chemical systems. It′s implications to the problem of biological evolution is also discussed.