The results indicate that the effects of the dirac sea states are pronounced in the collective multipole excitations for nuclei , especially on the isoscalar giant modes , but become weaker for light nuclei , while the contributions on the isovector modes are negligible 在核的同位旋標量激發(fā)模式中, dirac海負能核子態(tài)在不同的共振模式中的貢獻程度不一。對于同一種激發(fā)模式, dirac海負能核子態(tài)的貢獻隨著核子數(shù)的減少而變?nèi)酢?