  We present a model of diffusion in heterogeneous environment, which
qualitatively reflects the transport properties of a polymeric membrane with
carbon nanotubes. We derived Fokker-Planck equation from system of stochastic
equations, responding diffusion regime in polymer and ballistic regime in
nanotube areas. We show how probability density function is changed in presence
of nanotube areas. Hereupon nonlinear time dependence of mean square
displacement is observed, that indicates anomalous diffusion regime. Thus, the
model explains mechanism of appearance of anomalous diffusion for
diffusion-ballistic regime. Our approach does not suppose any type of
distributions and using fractional differentiate apparatus.
