Abstract : the paper interprets alternant polarization phenomen on of even alternant hydrocarbons by discussing charge density on every position of even alternate when it is polarized using perturbational molecular orbitals ( pmo ) 文摘:本文用微扰分子轨道法( pmo )讨论了偶交替烃被极化时各位置上的电荷密度,解释了偶交替烃电荷的交替极化现象。