超重核292-310122同位素链的α衰变和自发裂变的竞争

基于推广的液滴模型(GLDM) 理论框架,计算了292-310122 同位素链的 衰变和自发裂变的半衰期。计算时的基本输入量为两子核的质量数和电荷数以及反应Q 值。GLDM能很好地描述重核和超重核的 衰变和自发裂变过程。计算结果表明,A < 308 时在同位素链上N = 176~184 的区域α衰变为主要衰变模式。A > 308 时在同位素链上自发裂变为主要衰变模式。308122 是α衰变和自发裂变的分界点,暗示着N = 184 为中子幻数。Based on the framework of the Generalized Liquid Droplet Model (GLDM), alpha decay and spontaneous fission half-lives for 292-310122 isotopes are studied. The calculation of the basic inputs which only need the two fragmentmass numbers, charge numbers and the Q value. GLDM can describe alpha decay and spontaneous fission the nuclei. It is found that the alpha decay is the dominant mode of decay for isotopes with mass number A < 308, and for those with A > 308 spontaneous fission is dominant. The demarcation between alpha decay and spontaneous fission is at 308122, which shows the presence of a spherical neutron shell closure at N = 184.     

Basic characteristics of nuclear landscape by improved Weizs?cker-Skyrmetype nuclear mass model

Atomic Mass Evaluation(AME2016) has replenished the latest nuclear binding energy data. Other physical observables, such as the separated energies, decay energies, and the pairing gaps, were evaluated based on the new mass table. An improved Weizs?cker-Skyrme-type(WS-type) nuclear mass model with only 13 parameters was presented, including the correction from two combinatorial radial basis functions(RBFs), where shell and pairing effects are simultaneously dealt with using a Strutinsky-like method. The RBFs code had 2267 updated experimental binding energies as inputs, and their correspondent root-mean square(rms) deviations dropped to 149 keV. For the training of other mass models by RBFs correction, rms deviations are clustered between 100 keV to 200 keV. Compared with other experimental quantities, the rms deviations calculated within the improved WS-type model falls between 100 keV and 250 keV. We extrapolate the binding energies to 12435 nuclei, which covers the ranges 8 ≤ Z ≤ 128 and 8 ≤ N ≤ 251 in the framework of the WS-type model with RBFs correction. Simultaneously, the ground state deformations β_(2,4,6) and all parts in the WS-type mass formula are presented in this paper. Finally, we tabulated all calculated characteristics within the improved formula and linked them to https://github.com/lukeronger/Nuclear Data-LZU: nuclear binding energies, one-nucleon and two-nucleon separation energies(S_(n,p,2n,2p)), and β-decay energies( Q_α and Q_(β-,β+,EC)), and the pairing gap ?_n and ?_p.     

推广的液滴模型及其应用

简单介绍了近年来在研究重核和超重核衰变性质及熔合反应方面取得的理论成果和面临的挑战,着重阐述推广的液滴模型(GLDM) 理论框架及其应用。基于原子核的质量数、质子数以及反应Q 值,GLDM考虑了质量和电荷的不对称性、形状演化、亲近势和温度等,很好地描述了重核和超重核的质子放射性、 衰变、重离子放射性、自发裂变的半衰期和重离子熔合反应截面,同时也研究了原子核的粒子(质子、 、重离子) 放射性与自发裂变的竞争。Recent theoretical achievements and challenges about the fusion and decay properties of heavy and superheavy nuclei are generally introduced. Especially, the Generalized Liquid Drop Model(GLDM) as well as its application are emphatically described. Based on the mass number, proton number and the reaction Q value, the GLDM has taken the mass and charge asymmetry, the shape evolution, the proximity potential, as well as the temperature of nucleus into account, well described the proton radioactivity, the decay, the heavy particle radioactivity, the half life of spontaneous fission of heavy nuclei and superheavy nuclei, and the cross-sections of heavy ion fusion. The competitions between the spontaneous fission and other decay modes such as proton and heavy particle radioactivity, the alpha decay, and so on are also studied.     

高压CO~2对反胶束溶解蛋白质性质的影响

在308.15K下,研究了表面活性剂琥珀酸二(2-乙基己基)酯磺酸钠(Aerosol-Ot,简称AOT)的浓度和水的含量不同时,溶解的CO~2对反胶束溶解牛血清蛋白(BSA)的性质和异辛烷中AOT反胶束稳定性的影响。实验表明,在适当条件下,CO~2可以使反胶束溶液中的蛋白质全部析出。本研究对有关机理进行了初步分析。