LAUSR

We study the processes of heterodiffusion of admixtures in the case of their cascade decay in a body with two ways of migration accompanied by the mass exchange between states. For the case of unbranched cascade decay, we formulate coupled cascade-type initial-boundary-value problems of heterodiffusion in which the solutions of the problem for a certain stage play the role of sources in the next stage. The solutions of the problems are constructed by using an iterative procedure with the help of Green functions. We obtain expressions for the diffusion fluxes of migrating admixtures through a given section of the body and the amounts of decaying substances passing through the layer for a certain time.