  With the quantum diffusion approach the behavior of capture cross sections
and mean-square angular momenta of captured systems are revealed in the
reactions with deformed and spherical nuclei at sub-barrier energies. With
decreasing bombarding energy under the barrier the external turning point of
the nucleus-nucleus potential leaves the region of short-range nuclear
interaction and action of friction. Because of this change of the regime of
interaction, an unexpected enhancement of the capture cross section is found at
bombarding energies far below the Coulomb barrier. This effect is shown its
worth in the dependence of mean-square angular momentum on the bombarding
energy. From the comparison of calculated capture cross sections and
experimental capture or fusion cross sections the importance of quasifission
near the entrance channel is demonstrated for the actinidebased reactions and
reactions with medium-heavy nuclei at extreme sub-barrier energies.
