  Within the framework of Skyrme energy-density functional theory, the
nucleus-nucleus potential is calculated and potential energy surface is
obtained with different effective forces for accurately estimating the
formation cross sections of superheavy nuclei in massive fusion reactions. The
width and height of the potential pocket are influenced by the Skyrme effective
forces SkM, SkM$^{\ast}$, SkP, SIII, Ska and SLy4, which correspond to the
different equation of state for the isospin symmetry nuclear matter. It is
found that the nucleus-nucleus potential is associated with the collision
orientation and Skyrme parameters. More repulsive nuclear potential is
pronounced with increasing the incompressible modulus of nuclear matter. The
available data in the fusion-evaporation reaction of $^{48}$Ca+$^{238}$U are
nicely reproduced with the SkM$^{\ast}$ parameter by implementing into the
dinuclear system model.
