Phase instabilities generated by parametric modulation in reaction   diffusion systems
  Effect of external periodic force on an oscillatory order in a reaction diffusion system (Gierer Meinhardt model) has been investigated. The 2:1 resonance situation is found susceptible for the generation of a band of phase instabilities. These phase instabilities, captured on multiple time scales, produces a mismatch between the oscillation frequency of reacting species. 
A.Bhattacharyay and J.K.Bhattacherjee