| Popis: |
A hierarchy of generalized Nernst-Einstein relations is derived that gives relations among the higher-order transport coefficients that describe nonlinear mobility and non-Fickian diffusion. The results are valid for the case where the transported species is present in only trace concentration, but are otherwise general. In particular, the relations are independent of the density of the medium and of the form of the molecular interactions. Both a phenomenological derivation and a more rigorous one based on a linear kinetic equation are given. Some additional relations are also obtained for the special case of gaseous ions interacting according to the Maxwell model, which may be approximately valid for gaseous ions having more general interactions. |
