通过用QMD模型研究晕核 11Be + 2 0 8Pb的近垒熔合反应 ,发现晕核引起的熔合反应中 ,并存着两种相互竞争的机制 :一方面当入射晕核 11Be靠近靶核时 ,由于 11Be是弱束缚体系 ,与靶核的相互作用可使其很容易破裂或少数核子被靶核俘获形成核子转移反应 ,从而对于熔合表现出压制 ;另一方面当 11Be的少数中子进入靶核并与靶核相互作用而使得靶核有些激发 ,而使局部半径增大 ,导致熔合势垒降低 ,熔合截面增强 .用QMD模型计算出的熔合截面与实验值基本符合 ,垒附近表现出增强效应 By using the QMD model to study the near-base fusion reaction of nucleus 11Be + 208Pb, we find that there are two competing mechanisms in the fusion reaction caused by nucleus-nucleus: on the one hand, Is a weak bound system, the interaction with the target can make it very easy to crack or a small number of nuclei were captured by the target nucleus to form a nuclear transfer reaction, which showed suppression of fusion; the other hand, a few neutrons 11Be into the target nucleus and The target nucleus interacts to make the target nuclei have some excitation and the local radius increases, which leads to the reduction of the fusion barrier and the increase of the fusion cross section. The fusion cross section calculated by the QMD model basically conforms to the experimental value, and the enhancement effect