  The heavy-ion fusion reactions with 16O bombarding on 62Ni, 65Cu, 74Ge,
148Nd, 180Hf, 186W, 208Pb, 238U are systematically investigated with the
improved quantum molecular dynamics (ImQMD) model. The fusion cross sections at
energies near and above the Coulomb barriers can be reasonably well reproduced
by using this semi-classical microscopic transport model with the parameter
sets SkP* and IQ3a. The dynamical nucleus-nucleus potentials and the influence
of Fermi constraint on the fusion process are also studied simultaneously. In
addition to the mean field, the Fermi constraint also plays a key role for the
reliable description of fusion process and for improving the stability of
fragments in heavy-ion collisions.
