Oscillatory clusters in the periodically illuminated, spatially extended Belousov-Zhabotinsky reaction
                                 Vanag VK, Zhabotinsky AM, Epstein IR
                                   PHYSICAL REVIEW LETTERS
                                     86 (3): 552-555 JAN 15 2001
Abstract:
Cluster-cluster transitions in the periodically illuminated photosensitive Belsusov-Zhabotinsky (BZ) reaction-diffusion system
exhibit the same scenario as in the autonomous BZ system with negative global feedback: two-phase clusters <-> three-phase
clusters <-> irregular clusters <-> localized clusters. Transitions induced by changing the dark (TD) or light (TL) phases of the
periodic external square wave illumination are dependent not only on the frequency of illumination at constant T-D/T-L, but also
on the ratio T-D/T-L at constant frequency (when T-D + T-L = const).

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