Comparison of the jump and electrodiffusion description of the movement of particles in thin membranes-I. Posing of the trouble. Steady transfer

The present communication is the first in a series of studies on comparative analysis of the jump (three-barrier) and electrodiffusion descriptions of the movements of particles in thin membranes. It considers the case of the steady transfer. It is shown that the three-barrier jump description is as good as the electrodiffusion for an inhomogeneous membrane with a high narrow barrier in the middle. The uniform electrodiffusion description is as good as the three-barrier jump only when the limiting stage is transfer across the boundary of the membrane or for small external fields.