Anomalous Kinetics in A + B --, C with Initially-Separated Reactants

We review mcent deve~o~~nts in the study of the diffusion reaction system of the type A+ B -+ C in which the reactants are initially separated. We consider the case where the A and B particles are initially placed uniformly in Euclidean space at x > 0 and 2 < 0 respectively. We find that whereas for d > 2 a single scaling exponent characterizes the width of the reaction zone, a multiscaling approach is needed to describe the one-~~~ion~ system. We also present analytical and numerical results fur the reaction rate on fractais and percolation systems.