  Within the framework of the dinuclear system (DNS) model, the production
cross sections of superheavy nuclei Hs (Z=108) and Z=112 combined with
different reaction systems are analyzed systematically. It is found that the
mass asymmetries and the reaction Q values of the combinations play a very
important role on the formation cross sections of the evaporation residues.
Both methods by solving the master equations along the mass asymmetry degree of
freedom (1D) and along the proton and the neutron degrees of freedom (2D) are
compared each other and with the available experimental results.
