  The detailed analysis of wide excitation function of nuclear stopping has
been studied within a transport model, Isospin-dependent Quantum Molecular
Dynamics model (IQMD) and an overall good agreement with the INDRA and FOPI
experimental data has been achieved. It is found that mean value of isotropy in
central Heavy-Ion Collision (HIC) reaches a minimum near Fermi energy and
approaches a maximum around 300 - 400$A$ MeV. This suggests that, in
statistical average, the equilibration is far from being reached even in
central HIC especially near Fermi energy. A hierarchy in stopping of fragments,
which favors heavy fragments to penetrate, provides a robust restriction on the
global trend of nuclear stopping and could serve as a probe for nuclear
equation of state.
