Analysis of properties of anamolous diffusion processes based on a comb model

The model for investigation diffusion of particles in fractal environments is presented in this article. Earlier it was established that at random walk on fractals nature of diffusion significantly changes. This phenomenon was named abnormal diffusion. Unusual power-law dependence of mean square displacement is abnormal. For studying of abnormal diffusion on the percolation clusters the microscopic model of comb structure has been used. Application of the differential equations of the fractional order to anomalous diffusion problem has been considered. The formalism of such approach isn''t supported with the physical contents. Regardless of the fact that research of abnormal diffusion is quite widespread and was conducted rather long ago, there is still a set of unresolved questions. The question of asymptotic behavior of function of particles distribution at abnormal diffusion is actual. For example, in connection with a problem of radioactive burials reliability, at transfer of radionuclide in the geological environment the shape of tails (asymptotic distribution of concentration at long distances) matters. Asymptotic solutions in different limiting cases have been obtained.