【摘要】 由于实际系统中噪声不可避免 ,噪声使得同步混沌吸引子A变成具有一定生存时间 <τ >的准稳态吸引子A′.以加性噪声作用下的二维耦合映射混沌同步系统为例 ,给定系统实验时间长度T ,解析发现 :仅当 <τ >>2T时准稳态同步混沌吸引子的筛形吸引域才可被定性观察到 ;而当 <τ><2T时则不复存在 ,此时 ,根据原无噪声时的筛形吸引域特征的不同 ,筛形域不仅可以转变成时变筛形结构 ,还可以转变成分形结构 .同时利用数值模拟作了进一步验证 .该结果对于二维耦合映射混沌同步系统具有普遍意义 .更多还原

【Abstract】 In real systems, because of the inevitable noise, a chaotic synchronized attra ctor A will turn into a metastable attractor A′ with an average lifetim e <τ>. We analyze a two-dimensional coupled map with additive noises and find analytically that the riddled basin of A′ will disappear when <τ><2 T and can only be observed qualitativel y when <τ>>2T, where T is the duration of an experiment. According to the characters o f the riddled basin without noises, it is found that the riddled basin will tu rn into not only a temporal riddled basin but also a regular fractal basin. This re sult is universal in two-dimensional coupled chaotic synchronized maps, and the further numerical calculations can also confirm this point.更多还原