超重核的生成和衰变

简单介绍了近年来在超重核研究方面所取得的成就和理论方面所面临的挑战.着重介绍推广的液滴模型和准分子形状机制,它们的优点是考虑了精确的核半经、质量和电荷的不对称性、形变、亲和力和温度等.推广的液滴模型和准分子形状机制能很好地描述重核和超重核的裂变、衰变及完全熔合反应.The progress and challenge on studies of superheavy elements both experiments and theories has been briefly introduced. It is emphasis to introduce a generalized liquid drop model, including the proximity effects, the asymmetry, an accurate nuclear radius, and quasi molecular shapes. The α decay half lives of 373 nuclei and superheavy elements have been calculated in the generalized liquid drop model and compared with the available experimental data. The deformed energies have also been obtained ...     

Ground-State Properties of Ca Isotopes and the Density Dependence of the Symmetry Energy

A relativistic mean field model is used to study the ground-state properties of neutron-rich nuclei in Ca isotopes. An additional isoscalar and isovector nonlinear coupling has been introduced in the relativistic mean field model, which could soften the symmetry energy, while keep the agreement with the experimental data. The sensitivity of proton and neutron density distributions and single particle states in Ca isotopes to the additional isoscalarisovector nonlinear coupling term is investigated. We found that the binding energies, the density distributions of single particle levels are strongly correlated with the density dependence of the symmetric energy in nuclear matter.     

27,28P+28Si总反应截面增强及可能相关的机制

测量了27,28P和相应同中子异位素在28Si靶上的中能反应截面.测得N=12和13同中子异位素的反应截面在Z=15处突然增大.对Z≤14同中子异位素和28P的实验数据结果可以用改进的光学极限近似的Glauber理论很好地描述.28P的反应截面能够用扩大核芯以改进的Glauber理论来解释.但是,用改进光学极限和少体近似的Glauber理论却低估了27P的实验数据.理论分析表明,扩大的核芯加质子晕可能是响应27P+28Si反应截面增强的机制. The reaction cross sections of~(27,28)P and the corresponding isotones on Si target were measured at intermediate energies. The measured reaction cross sections of the N=12 and 13 isotones show an abrupt increase at Z=15. The experimental results for the isotones with Z≤14 and~(28)P can be described well by the modified Glauber theory of the optical limit approach. The enhancement of the reaction cross section for~(28)P could be explained by the modified Glauber theory with an enlarged core. Theoretical ana...     

N-N关联和有限核相对论平均场方法

密度有关的核子-介子相互作用耦合常数是在相对论平均场近似下用核物质的相对论Brueckner-Hartree-Fock近似计算的自能参数化得到的.这种密度有关的相互作用考虑了介质中N-N关联效应,用这种密度有关的相互作用来研究有限核的基态性质,如单粒子能级,平均结合能,电荷均方根半径,与实验值较好地符合,同时还与其它模型的结果进行了比较.     

用相对论Brueckner-Bethe-Goldstone方程研究相对论微观光学位

本文用相对论Brueckner-Bethe-Goldstone(RBBG)方程研究核子-核的相对论微观学学势.核子的复有效质量是通过入射能量为200MeV的质子-⁴⁰Ca散射数据来确定,由此进一步研究了质子对不同靶核:¹⁶O,⁴⁰Ca,⁹⁰Zr,²⁰⁸Pb能量范围从160—800MeV的相对论微观光学位.我们用这种微观光学位研究入射能量为200MeV质子与⁴⁰Ca的弹性散射,并与唯象相对论光学位计算得到的截面,自旋可观测量进行了比较.     

N－N关联和有限核相对论平均场方法

密度有关的核子－介子相互作用耦合常数是在相对论平均场近似下用核物质的相对论Ｂｒｕｅｃｋｎｅｒ－Ｈａｒｔｒｅｅ－Ｆｏｃｋ近似计算的自能参数化得到的．这种密度有关的相互作用考虑了介质中Ｎ－Ｎ关联效应，用这种密度有关的相互作用来研究有限核的基态性质，如单粒子能级，平均结合能，电荷均方根半径，与实验值较好地符合，同时还与其它模型的结果进行了比较。     

Systematic studies on α-decay half-lives for super heavy nuclei

Radioactive decay of super heavy nuclei via the emission of α-particles has been studied theoretically in the preformed cluster model （PCM）. The nucleus-nucleus （NN） potential is obtained by double folding the density distributions of the α-particle and the daughter nucleus with a realistic effective interaction. The M3Y effective interaction, supplemented by a zero-range pseudo-potential for exchange term, is used to calculate the NN potential. The α decay half-lives for 317 nuclei at Z=102 120 are performed in the PCM framework with the theoretical Q values extracted from the MSller-Nix-Kratz and Liran-Marinov-Zeldes mass tables and are compared with the experimental data. The calculated results are also compared with those obtained by using Q values from the Muntian-Hofmann-Patyk-Sobiczewski and Myers-Swiatecki mass estimates.     

丰质子核性质的研究

用相对论平均场理论研究了2sld壳丰质子核及其镜核的性质,理论计算结果与实验数据很好地符合.     

低密度、弱束缚核结构研究

讨论了用平均场理论研究低密度、弱束缚核性质中的主要物理问题,着重研究在同位旋极端条件下的核子的有效相互作用、平均场和同位旋相关性.     

稳定和不稳定核巨共振性质的相对论研究

在相对论平均场的基态上自洽的相对论无规位相近似(RRPA)理论框架下,研究稳定核和不稳定核的巨共振性质.研究了稳定核²⁰⁸Pb,¹⁴⁴Sm,¹¹⁶Sn,⁹⁰Zr,⁴⁰Ca,¹⁶O和不稳定核Ca同位素链同位旋标量和同位旋矢量集体巨共振激发,并讨论了Dirac海负能核子态和矢量介子空间分量对核的巨共振性质的影响.研究的结果表明,Dirac海负能核子态和矢量介子空间分量对同位旋标量激发有贡献,特别是对重核,而对轻核它的贡献减弱,对于同位旋矢量激发的贡献可忽略.几组常用的相对论平均场非线性模型参量,不仅能成功的描述有限核的基态性质,也能很好地描述核的巨共振激发.对于N/Z极端情况下,同位旋矢量巨偶极激发模式存在低能集体激发,它是由于费密面附近弱束缚核子的激发和同位旋混杂效应 关键词： 相对论无规位相近似 核巨共振