核对称能是当前核物理领域的一个热点问题。不同理论得到的对称能密度依赖行为差别很大，而实验和理论对比给出的约束还不够理想，即使是目前比较确定的饱和密度区域对称能也存在不小的不确定性。这一方面源于实验数据不足，另一方面是由于微观输运模型对观测量的描述具有很强的模型依赖。本申请项目将从原子核反应及原子核结构两方面研究饱和密度附近及亚饱和密度下对称能密度依赖行为。核反应方面，采用微观输运模型模拟中能核子、轻核诱发重离子核反应，与现有的实验数据比较，获取低密条件下的对称能信息，并尝试寻找模型依赖程度小的对称能敏感观测量。核结构方面，利用原子核质量公式，研究远离β稳定线的原子核性质，从中提取饱和密度附近的对称能信息。通过从中低能核反应与原子核结构两方面获取的对称能信息相互比对印证，期望提高饱和密度附近及亚饱和密度区域下对称能的约束精度。

The nuclear symmetry energy is a hot topic in the nuclear domain. The behaviors of density dependence of symmetry energy given by various theories are quite different, and the density dependence of symmetry energy has not yet been constrained quite well by the comparison between experiments and theories, even for the symmetry energy at saturation density which is determined rather well, there still exists a certain uncertainty. This is due, on one hand, to the insufficient of experimental data, on the other hand, to the strong model dependence of microscopic transport model using to describe the experimental data. This proposal plans to study the density dependence of symmetry energy around and below saturation density from both nuclear reactions and nuclear structures. On the side of nuclear reaction, by using the microscopic transport model, the nucleon and light nuclei induced reactions on heavy nuclei will be simulated. By comparing the calculation results to the experimental data, the symmetry energy at low density will be extracted. And we will try to seek the observable sensitive to the symmetry energy with weak model dependence. On the side of nuclear structure, by using the nuclear mass formula, the properties of nuclei far away from the β stability line will be investigated to extract the symmetry energy around saturation density. We expect to improve the accuracy of constraint on the nuclear symmetry energy around saturation density and sub-saturation density through the comparison and verification between the information of symmetry energy extracted from nuclear reactions and nuclear structure.