In this paper, we develop a new path search algorithm which considers all the degrees of freedom and apply it on our calculated five-dimensional potential energy surface(PES) of^(236) U. Asymmetric and symmetric fissi...In this paper, we develop a new path search algorithm which considers all the degrees of freedom and apply it on our calculated five-dimensional potential energy surface(PES) of^(236) U. Asymmetric and symmetric fission paths and barriers are obtained.展开更多
A relativistic Weizsacker mass model is proposed based on the single-particle levels and ground state deformations obtained in axial deformed relativistic mean field theory.The density functional of relativistic mean ...A relativistic Weizsacker mass model is proposed based on the single-particle levels and ground state deformations obtained in axial deformed relativistic mean field theory.The density functional of relativistic mean field theory is chosen as DD-LZ1,which can partially remove spurious shell closures.Compared with the fourth Weizsacker-Skyrme mass model,the proposed model provides shell correction energies that exhibit wide spreading,and the root-mean-square mass deviation is 1.353 MeV.Further improvement is in progress.展开更多
α decay energies of 323 heavy nuclei with Z ≥82 are evaluated with a macroscopic-microscopic model. In this model, the macroscopic part is treated by the continuous medium model and the microscopic part consists of ...α decay energies of 323 heavy nuclei with Z ≥82 are evaluated with a macroscopic-microscopic model. In this model, the macroscopic part is treated by the continuous medium model and the microscopic part consists of shell and pairing corrections based on the Nilsson potential. α decay half-lives are calculated bY Viola-Seaborg formula. The results of α decay energies and half-lives are compared with experimental values and satisfactory agreement is found. The recoiling effect of the daughter nucleus on α decay half-life is also discussed.展开更多
The potential energy surfaces of the even-even 68-92Se, 112-150Ba, and 208-230Ra isotopes are calculated using the macroscopic-microscopic method in a multidimensional space {αλ,μ} including quadrupole （λ=2, μ=0...The potential energy surfaces of the even-even 68-92Se, 112-150Ba, and 208-230Ra isotopes are calculated using the macroscopic-microscopic method in a multidimensional space {αλ,μ} including quadrupole （λ=2, μ=0, 2） and octupole （λ=3, μ=0, 1, 2, 3） degrees of freedom. The calculated results show that the even-even isotopes 92Se, 112,114,144-150Ba and 220-228Ra can exhibit the coexistence of triaxial and octupole deformations, thereby leading to simultaneous chiral and reflected symmetry breaking. Therefore, chirality-parity quartet bands are expected in these and their neighboring odd-A/odd-odd nuclei.展开更多
The ground state properties of superheavy nuclei are systematically calculated by the macroscopic-microscopic (MM) model with the Nilsson potential.The calculations well produced the ground state binding energies,α-d...The ground state properties of superheavy nuclei are systematically calculated by the macroscopic-microscopic (MM) model with the Nilsson potential.The calculations well produced the ground state binding energies,α-decay energies,and half lives of superheavy nuclei.The calculated results are systematically compared with availableexperimental data.The calculated results are also compared with theoretical results from other MM models and fromrelativistic mean-field model.The calculations and comparisons show that the MM model is reliable in superheavy regionand that the MM model results are not very sensitive to the choice of microscopic single-particle potential.展开更多
The global nuclear mass based on the macroscopic-microscopic model was studied by applying a newly designed multi-task learning artificial neural network(MTL-ANN). First, the reported nuclear binding energies of 2095 ...The global nuclear mass based on the macroscopic-microscopic model was studied by applying a newly designed multi-task learning artificial neural network(MTL-ANN). First, the reported nuclear binding energies of 2095 nuclei(Z ≥ 8, N ≥ 8) released in the latest Atomic Mass Evaluation AME2020 and the deviations between the fitting result of the liquid drop model(LDM)and data from AME2020 for each nucleus were obtained.To compensate for the deviations and investigate the possible ignored physics in the LDM, the MTL-ANN method was introduced in the model. Compared to the single-task learning(STL) method, this new network has a powerful ability to simultaneously learn multi-nuclear properties,such as the binding energies and single neutron and proton separation energies. Moreover, it is highly effective in reducing the risk of overfitting and achieving better predictions. Consequently, good predictions can be obtained using this nuclear mass model for both the training and validation datasets and for the testing dataset. In detail, the global root mean square(RMS) of the binding energy is effectively reduced from approximately 2.4 MeV of LDM to the current 0.2 MeV, and the RMS of Sn, Spcan also reach approximately 0.2 MeV. Moreover, compared to STL, for the training and validation sets, 3-9% improvement can be achieved with the binding energy, and 20-30% improvement for S_(n), S_(p);for the testing sets, the reduction in deviations can even reach 30-40%, which significantly illustrates the advantage of the current MTL.展开更多
The structure properties for even–even nuclei around^(230)U,located on the hexadecapoledeformation island,are investigated using the potential-energy-surface calculation within the framework of the macroscopic-micros...The structure properties for even–even nuclei around^(230)U,located on the hexadecapoledeformation island,are investigated using the potential-energy-surface calculation within the framework of the macroscopic-microscopic model.The impact of different deformation degrees of freedom(including axial and nonaxial quadrupole and hexadecapole deformations)on total energy,shell,and pairing contributions is analyzed,based on the projected energy maps and curves.The single-particle structure is presented and briefly discussed.To a large extent,a much better agreement with experimental data and other theoretical results is obtained if the hexadecapole deformations,especially the axial one,are taken into account.These results could provide useful insights into understanding the effects of different quadrupole and hexadecapole deformations.展开更多
基金Supported by the Major Research plan of National Natural Science of China under Grant No.11790324the National Key Research and Development Program of China under Grant Nos.2016YY0200804 and 2017YFF0206205+1 种基金the National Magnetic Confinement Fusion Science Program of China under Grant Nos.2013GB106004 and 2012GB-101003the National Natural Science Foundation of China under No.1179320013
文摘In this paper, we develop a new path search algorithm which considers all the degrees of freedom and apply it on our calculated five-dimensional potential energy surface(PES) of^(236) U. Asymmetric and symmetric fission paths and barriers are obtained.
基金Supported by the Open Project of Guangxi Key Laboratory of Nuclear Physics and Nuclear Technology(NLK2021-01)the National Natural Science Foundation of China(U2032141)+2 种基金Natural Science Foundation of Henan Province(202300410480,202300410479)the Foundation of Fundamental Research for Young Teachers of Zhengzhou University(JC202041041)the Physics Research and Development Program of Zhengzhou University(32410217)。
文摘A relativistic Weizsacker mass model is proposed based on the single-particle levels and ground state deformations obtained in axial deformed relativistic mean field theory.The density functional of relativistic mean field theory is chosen as DD-LZ1,which can partially remove spurious shell closures.Compared with the fourth Weizsacker-Skyrme mass model,the proposed model provides shell correction energies that exhibit wide spreading,and the root-mean-square mass deviation is 1.353 MeV.Further improvement is in progress.
基金National Natural Science Foundation of China (10475003, 10435010, 10705014, 10575036)Major State BasicResearch Development Program of China (2007CB815000)Knowledge Innovation Project of Chinese Academy of Sciences(KJCX3-SYW-N02, KJCX2-SW-N17)
文摘α decay energies of 323 heavy nuclei with Z ≥82 are evaluated with a macroscopic-microscopic model. In this model, the macroscopic part is treated by the continuous medium model and the microscopic part consists of shell and pairing corrections based on the Nilsson potential. α decay half-lives are calculated bY Viola-Seaborg formula. The results of α decay energies and half-lives are compared with experimental values and satisfactory agreement is found. The recoiling effect of the daughter nucleus on α decay half-life is also discussed.
基金Supported by Natural Science Foundation of China(11705102,11622540,11675094)the Shandong Natural Science Foundation(ZR2017PA005,JQ201701)+1 种基金the China Postdoctoral Science Foundation(2017M612254)the Young Scholars Program of Shandong University,Weihai(2015WHWLJH01)
文摘The potential energy surfaces of the even-even 68-92Se, 112-150Ba, and 208-230Ra isotopes are calculated using the macroscopic-microscopic method in a multidimensional space {αλ,μ} including quadrupole （λ=2, μ=0, 2） and octupole （λ=3, μ=0, 1, 2, 3） degrees of freedom. The calculated results show that the even-even isotopes 92Se, 112,114,144-150Ba and 220-228Ra can exhibit the coexistence of triaxial and octupole deformations, thereby leading to simultaneous chiral and reflected symmetry breaking. Therefore, chirality-parity quartet bands are expected in these and their neighboring odd-A/odd-odd nuclei.
基金National Natural Science Foundation of China under Grant Nos.10125521 and 10535010the State Key Basic Research and Development Program of China under Grant Nos.G2000077400 and 2007CB815004+1 种基金the CAS Knowledge Innovation Project under Grant No.KJCX2-SW-N02the Fund of the Education Ministry of China under Grant No.20010284036
文摘The ground state properties of superheavy nuclei are systematically calculated by the macroscopic-microscopic (MM) model with the Nilsson potential.The calculations well produced the ground state binding energies,α-decay energies,and half lives of superheavy nuclei.The calculated results are systematically compared with availableexperimental data.The calculated results are also compared with theoretical results from other MM models and fromrelativistic mean-field model.The calculations and comparisons show that the MM model is reliable in superheavy regionand that the MM model results are not very sensitive to the choice of microscopic single-particle potential.
基金supported by the National Natural Science Foundation of China(Nos.1187050492,12005303,and 12175170).
文摘The global nuclear mass based on the macroscopic-microscopic model was studied by applying a newly designed multi-task learning artificial neural network(MTL-ANN). First, the reported nuclear binding energies of 2095 nuclei(Z ≥ 8, N ≥ 8) released in the latest Atomic Mass Evaluation AME2020 and the deviations between the fitting result of the liquid drop model(LDM)and data from AME2020 for each nucleus were obtained.To compensate for the deviations and investigate the possible ignored physics in the LDM, the MTL-ANN method was introduced in the model. Compared to the single-task learning(STL) method, this new network has a powerful ability to simultaneously learn multi-nuclear properties,such as the binding energies and single neutron and proton separation energies. Moreover, it is highly effective in reducing the risk of overfitting and achieving better predictions. Consequently, good predictions can be obtained using this nuclear mass model for both the training and validation datasets and for the testing dataset. In detail, the global root mean square(RMS) of the binding energy is effectively reduced from approximately 2.4 MeV of LDM to the current 0.2 MeV, and the RMS of Sn, Spcan also reach approximately 0.2 MeV. Moreover, compared to STL, for the training and validation sets, 3-9% improvement can be achieved with the binding energy, and 20-30% improvement for S_(n), S_(p);for the testing sets, the reduction in deviations can even reach 30-40%, which significantly illustrates the advantage of the current MTL.
基金the National Natural Science Foundation of China(No.11975209,No.U2032211,and No.12075287)the Physics Research and Development Program of Zhengzhou University(No.32410017)the Project of Youth Backbone Teachers of Colleges and Universities of Henan Province(No.2017GGJS008)
文摘The structure properties for even–even nuclei around^(230)U,located on the hexadecapoledeformation island,are investigated using the potential-energy-surface calculation within the framework of the macroscopic-microscopic model.The impact of different deformation degrees of freedom(including axial and nonaxial quadrupole and hexadecapole deformations)on total energy,shell,and pairing contributions is analyzed,based on the projected energy maps and curves.The single-particle structure is presented and briefly discussed.To a large extent,a much better agreement with experimental data and other theoretical results is obtained if the hexadecapole deformations,especially the axial one,are taken into account.These results could provide useful insights into understanding the effects of different quadrupole and hexadecapole deformations.
