An improved semi-empirical relationship for cluster radioactivity half-lives is proposed by introducing an accurate charge radius formula and an analytic expression of the preformation probability.Moreover,the cluster...An improved semi-empirical relationship for cluster radioactivity half-lives is proposed by introducing an accurate charge radius formula and an analytic expression of the preformation probability.Moreover,the cluster radioactivity half-lives for the daughter nuclei around ^(208)Pb or its neighbors and the ^(12)C radioactivity half-life of114Ba are calculated within the improved semi-empirical relationship.It is shown that the accuracy of the new relationship is improved significantly compared to its predecessor.In addition,the cluster radioactivity half-lives that are experimentally unavailable for the trans-lead and trans-tin nuclei are predicted by the new semi-empirical formula.These predictions might be useful for searching for the new cluster emitters of the two islands in future experiments.展开更多
To search for new candidates of the true and simultaneous two-proton(2 p)radioactivity,the 2 p decay energies(Q2 p)are extracted by the Weizs?cker–Skyrme-4(WS4)model,the finite-range droplet model(FRDM),the Koura–Ta...To search for new candidates of the true and simultaneous two-proton(2 p)radioactivity,the 2 p decay energies(Q2 p)are extracted by the Weizs?cker–Skyrme-4(WS4)model,the finite-range droplet model(FRDM),the Koura–Tachibana–Uno–Yamada(KTUY)model and the Hartree–Fock–Bogoliubov mean-field model with the BSk29 Skyrme interaction(HFB29).Then,the 2 p radioactivity half-lives are calculated within the generalized liquid drop model by inputting the four types of Q2 pvalues.By the energy and half-life constraints,it is found that the probable 2 p decay candidates are the nuclei beyond the proton-drip line in the region of Z≤50 based on the WS4 and KTUY mass models.For the FRDM mass model,the probable 2 p decay candidates are found in the region of Z≤44.However,the 2p-decaying candidates are predicted in the region of Z≤58 by the HFB29 mass model.It means that the probable 2 p decay candidates of Z>50 are only predicted by the HFB29 mass model.Finally,the competition between the true 2p radioactivity andα-decay for the nuclei above the N=Z=50 shell closures is discussed.It is shown that~(101)Te,~(111)Ba and~(114)Ce prefer to 2p radioactivity and the dominant decay mode of~(107)Xe and~(116)Ce isα-decay.展开更多
A unified fission model is extended to study two-proton radioactivity of the ground states of nuclei,and a good agreement between the experimental and calculated half-lives is found.The two-proton radioactivity half-l...A unified fission model is extended to study two-proton radioactivity of the ground states of nuclei,and a good agreement between the experimental and calculated half-lives is found.The two-proton radioactivity half-lives of the ground states of some probable candidates are predicted within this model by inputting the released energies taken from the AME2020 table.It is shown that the predictive accuracy of the half-lives is comparable to those of other models.Then,two-proton radioactivity of the excited states of^(14)O,^(17,18)Ne,^(22)Mg,^(29)S,and^(94)Ag is discussed within the unified fission model and two analytical formulas.It is found that the experimental half-lives of the excited states are reproduced better within the unified fission model.Furthermore,the two formulas are not suitable for the study of two-proton radioactivity of excited states because their physical appearance deviates from the mechanism of quantum tunneling,and the parameters involved are obtained without including experimental data from the excited states.展开更多
Magnetars are strong magnetized neutron stars which could emit quiescent X-ray, repeating burst of soft gamma ray, and even the giant flares. We investigate the effects of magnetic fields on the structure of isolated ...Magnetars are strong magnetized neutron stars which could emit quiescent X-ray, repeating burst of soft gamma ray, and even the giant flares. We investigate the effects of magnetic fields on the structure of isolated magnetars. The stellar structure together with the magnetic field configuration can be obtained at the same time within a self-consistent procedure. The magnetar mass and radius are found to be weakly enhanced by the strong magnetic fields. Unlike other previous investigations, the magnetic field is unable to violate the mass limit of the neutron stars.展开更多
基金Supported by the National Natural Science Foundation of China(U1832120,11675265)the Natural Science Foundation for Outstanding Young Scholars of Hebei Province of China(A2020210012,A2018210146)+1 种基金the Continuous Basic Scientific Research Project(WDJC-2019-13)the Leading Innovation Project(LC192209000701).
文摘An improved semi-empirical relationship for cluster radioactivity half-lives is proposed by introducing an accurate charge radius formula and an analytic expression of the preformation probability.Moreover,the cluster radioactivity half-lives for the daughter nuclei around ^(208)Pb or its neighbors and the ^(12)C radioactivity half-life of114Ba are calculated within the improved semi-empirical relationship.It is shown that the accuracy of the new relationship is improved significantly compared to its predecessor.In addition,the cluster radioactivity half-lives that are experimentally unavailable for the trans-lead and trans-tin nuclei are predicted by the new semi-empirical formula.These predictions might be useful for searching for the new cluster emitters of the two islands in future experiments.
基金supported by the National Natural Science Foundation of China(Grants No.U1832120 and No.11675265)the Natural Science Foundation for Outstanding Young Scholars of Hebei Province of China(Grants No.A2020210012 and A2018210146)+1 种基金the Continuous Basic Scientific Research Project(Grant No.WDJC-2019-13)the Leading Innovation Project(Grant No.LC 192209000701)。
文摘To search for new candidates of the true and simultaneous two-proton(2 p)radioactivity,the 2 p decay energies(Q2 p)are extracted by the Weizs?cker–Skyrme-4(WS4)model,the finite-range droplet model(FRDM),the Koura–Tachibana–Uno–Yamada(KTUY)model and the Hartree–Fock–Bogoliubov mean-field model with the BSk29 Skyrme interaction(HFB29).Then,the 2 p radioactivity half-lives are calculated within the generalized liquid drop model by inputting the four types of Q2 pvalues.By the energy and half-life constraints,it is found that the probable 2 p decay candidates are the nuclei beyond the proton-drip line in the region of Z≤50 based on the WS4 and KTUY mass models.For the FRDM mass model,the probable 2 p decay candidates are found in the region of Z≤44.However,the 2p-decaying candidates are predicted in the region of Z≤58 by the HFB29 mass model.It means that the probable 2 p decay candidates of Z>50 are only predicted by the HFB29 mass model.Finally,the competition between the true 2p radioactivity andα-decay for the nuclei above the N=Z=50 shell closures is discussed.It is shown that~(101)Te,~(111)Ba and~(114)Ce prefer to 2p radioactivity and the dominant decay mode of~(107)Xe and~(116)Ce isα-decay.
基金Supported by the National Natural Science Foundation of China (U1832120, 11675265)the Natural Science Foundation for Outstanding Young Scholars of Hebei Province of China (A2020210012, A2018210146)+1 种基金the Natural Science Foundation of Hebei Province of China (A2021210010)the Continuous Basic Scientific Research Project (WDJC-2019-13) and the Leading Innovation Project (LC 192209000701)
文摘A unified fission model is extended to study two-proton radioactivity of the ground states of nuclei,and a good agreement between the experimental and calculated half-lives is found.The two-proton radioactivity half-lives of the ground states of some probable candidates are predicted within this model by inputting the released energies taken from the AME2020 table.It is shown that the predictive accuracy of the half-lives is comparable to those of other models.Then,two-proton radioactivity of the excited states of^(14)O,^(17,18)Ne,^(22)Mg,^(29)S,and^(94)Ag is discussed within the unified fission model and two analytical formulas.It is found that the experimental half-lives of the excited states are reproduced better within the unified fission model.Furthermore,the two formulas are not suitable for the study of two-proton radioactivity of excited states because their physical appearance deviates from the mechanism of quantum tunneling,and the parameters involved are obtained without including experimental data from the excited states.
基金supported by the National Natural Science Foundation of China(Grant Nos.1140522311175219+4 种基金11275271 and 11435014)the National Program on Key Basic Research Project(Grant No.2013CB834405)the Knowledge Innovation Project of Chinese Academy of Sciences(Grant No.KJCX2-EW-N01)the Funds for Creative Research Groups of China(Grant No.11021504)the Youth Innovation Promotion Association of Chinese Academy of Sciences
文摘Magnetars are strong magnetized neutron stars which could emit quiescent X-ray, repeating burst of soft gamma ray, and even the giant flares. We investigate the effects of magnetic fields on the structure of isolated magnetars. The stellar structure together with the magnetic field configuration can be obtained at the same time within a self-consistent procedure. The magnetar mass and radius are found to be weakly enhanced by the strong magnetic fields. Unlike other previous investigations, the magnetic field is unable to violate the mass limit of the neutron stars.
