Stochastic resonance in the absence and presence of external signals for a chemical reaction

摘要

A catalytic reduction of NO with CO on Pt(100) surface is adopted to study its response under random perturbation. Noise-induced oscillations and noise-induced frequency shifts have been observed when the system works in the vicinity of the oscillatory region and meanwhile is subjected to random modulation of its feeding speed. Stochastic resonance behavior can be recognized from the noise-induced peak in the power spectrum even though in the absence of external signals. The numerical results have been obtained near supercritical Hopf bifurcation points, but are not confined to the classification of bifurcation. When the system falls into bistable regions, noise can help an external weak signal to induce state-to-state transitions and also shows a stochastic resonance behavior except for the case that the system has an isolated bifurcation scheme.