原子核形变中的动力学效应I.172Os核高自旋态的形变

利用我们最近提出的Hill-Wheeler方程的一种数值解法,考虑动力学效应计算了¹⁷²Os核转晕态的形状随转动频率的变化.所得结果比通常的总罗斯量面(TRS)计算的形变值更符合于实验测量值.这表明,至少对于像¹⁷²Os这样的过渡核,核形变的动力学效应是不能忽略的.     

原子的超精细能级与光谱超精细结构

 原子是由原子核和核外电子构成的,原子核和核外电子都处在运动状态,具有能量.根据实验(例如光谱实验和夫兰克-赫兹实验等)和量子论研究表明,原子中电子(原子核也一样)的能量不是任意的,只能取一些不连续定值,即是量子化的.这些不连续的能量状态就是原子能级.     

Pre-formation Probability of ^5He Cluster in Pre-equilibrium Mechanism

The possibility of ^5He cluster emission has been affirmed theoretically. In order to describe the emission probability of SHe cluster, the pre-formation probability of ^5He cluster in pre-equilibrium emission process is needed to be established. In terms of Iwamoto-Harada model, the theoretical formula of pre-formation probability of ^5He cluster including lp shell nucleon in pre-equilibrium mechanism has been established and calculated. In the case of low incident energies, the configuration of [1, m] for ^5He cluster is the dominant part in the nuclear reaction. The calculated results indicate that pre-formation probability of configuration [1, m] for the unstable SHe duster is much smaller than those of d, t, ^3He, and ^4He, i.e. the light stable composite particles, which are consisted of only ls shell nucleons. However, it is propitious to the emission of ^5He from the point of view on threshold energies, since the binding energies of ^5He are generally lower than that of 3He in compound nucleus. The corresponding model formula has been given in this paper for described pre-formation probability of ^5He cluster in pre-equilibrium mechanism.     

Pairing Field and Moments of Inertia of Superdeformed Nuclei

We have systematically analysed the dynamic moments of inertia of the experimental superdeformed(SD)bands observed in the A=190,150 and 60-80 mass regions as functions of rotational frequency,By combining the different mass regions,the dramatic features of the dynamic moments of inertia were found and explained based on the calculations of the pairing fields of SD nuclei with the anisotropic harmonic oscillator quadrupole pairing Hartree-Fock-Bogoliubov model.     

Lifetimes of Excited Levels in ^131Ce

The fusion-evaporation reaction ^116Sn (^19F, p3n)^131 Ce at projectile energy of 95 MeV is used to populate high spin states in ^131Ce. The de-exciting γ-rays are detected in γ-γ coincidence measurement with Compton-suppressed BGO-HPGe detectors. Level lifetimes of ^131 Ce were determined by using the Doppler shift attenuation method.The experimental results indicate that collectivity of ^131 Ce is reduced relative to that of ^130Ce and it follows that deformation decreases with increase of the neutron number on the basis of systematic comparison of transition quadrupole moments for the light cerium isotopes.     

在极端相对论性原子核碰撞中奇异粒子的演化

在本文中我们用相对论流体力学方程描述了一个膨胀的夸克-胶子等离子体的演化.在此基础上考虑了相变和相变引起的温度效应后,用弛豫方程计算了不同初始温度的奇异粒子的时空分布以及总的奇异粒子数随时间的演化规律,分判定在极端相对论原子核碰撞中是否产生了夸克物质提供了一种理论依据.