Boundary conditions at a thin membrane for the normal diffusion equation which generate subdiffusion

We consider a particle transport process in one-dimensional system with thin membrane, described by normal diffusion equation. two boundary conditions at the membrane that are linear combinations of integral operators, time dependent kernels, which act on functions and their spatial derivatives define both surfaces. show how change temporal evolution first second moments position distribution (the Green's function) is solution to As these kind diffusion, an appropriate choice generates characteristic for subdiffusion. The interpretation based random walk model subdiffusion effect caused anomalously long stays membrane.