The effects of ion screening in stellar core collapses are investigated based on a new progenitor star model. Simulation results show that ion screening slightly affects the leptons and decreases explosion energy, which is a negative factor for energy transfer supernova explosions. We also investigate the effect on type II-supernova explosions of neutrino-nucleus elastic scattering based on the new progenitor star model. It is shown that, compared with the previously calculated results,

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... s-nucleus elastic scattering in stellar core collapses is more severe, leading to an obvious reduction of the neutrino leakage energy loss and an increase of supernova explosion energy.