The collective Bamiltonian up to the fourth order for multi-O（4） model is derived based on the self-consistent collective-coordinate （SCC） method, which is formulated in the framework of the time-dependent Hartree...The collective Bamiltonian up to the fourth order for multi-O（4） model is derived based on the self-consistent collective-coordinate （SCC） method, which is formulated in the framework of the time-dependent Hartree-Bogoliubov （TDHB） theory. The validity of the collective Hamiltonian is checked in the two special cases of the multi-O（4） model： the case where the number of the shells is equal to one （a single j-shell case）, and the case where the Hartree-Bogoliubov equilibrium point is spherical （the spherical case）. The collective Hamiltonian constitutes a good starting point to study nuclear shape coexistence.展开更多
Based on the Eigen and Crow-Kimura models with a single-peak fitness landscape, we propose the fitness values of all sequence types to be Gausslan distributed random variables to incorporate the effects of the fluctua...Based on the Eigen and Crow-Kimura models with a single-peak fitness landscape, we propose the fitness values of all sequence types to be Gausslan distributed random variables to incorporate the effects of the fluctuations of the fitness landscapes （noise of environments） and investigate the concentration distribution and error threshold of quasispecies by performing an ensemble average within this theoretical framework. We find that a small fluctuation of the fitness landscape causes only a slight change in the concentration distribution and error threshold, which implies that the error threshold is stable against small perturbations. However, for a sizable fluctuation, quite different from the previous deterministic models, our statistical results show that the transition from quasi-species to error catastrophe is not so sharp, indicating that the error threshold is located within a certain range and has a shift toward a larger value. Our results are qualitatively in agreement with the experimental data and provide a new implication for antiviral strategies.展开更多
The relaxation property of both Eigen model and Crow-Kimura model with a single peak fitness landscape is studied from phase transition point of view. We first analyze the eigenvalue spectra of the replication mutatio...The relaxation property of both Eigen model and Crow-Kimura model with a single peak fitness landscape is studied from phase transition point of view. We first analyze the eigenvalue spectra of the replication mutation matrices. For sufficiently long sequences, the almost crossing point between the largest and seeond-largest eigenvalues locates the error threshold at which critical slowing down behavior appears. We calculate the critical exponent in the limit of infinite sequence lengths and compare it with the result from numerical curve fittings at sufficiently long sequences. We find that for both models the relaxation time diverges with exponent 1 at the error （mutation） threshold point. Results obtained from both methods agree quite well. From the unlimited correlation length feature, the first order phase transition is further confirmed. Finally with linear stability theory, we show that the two model systems are stable for all ranges of mutation rate. The Igigen model is asymptotically stable in terms of mutant classes, and the Crow-Kimura model is completely stable.展开更多
In the framework of the Hartree–Fock–Bogoliubov(HFB)approach with Skyrme interactions SLy5+T,SLy5+Tw and several sets of TIJ parametrizations,i.e.the Skyrme interaction parametrizations including the tensor terms,th...In the framework of the Hartree–Fock–Bogoliubov(HFB)approach with Skyrme interactions SLy5+T,SLy5+Tw and several sets of TIJ parametrizations,i.e.the Skyrme interaction parametrizations including the tensor terms,the proton density distribution in ^(34)Si and ^(46)Ar nuclei is calculated with and without the tensor force.It is shown that the bubble effect in ^(34)Si does not depend a great deal on the Skyrme parametrization and the proton density distribution in ^(34)Si is hardly influenced by the tensor force.As to ^(46)Ar,the SLy5+Tw parametrization favors the formation of the bubble structure due to the inversion between the 2s_(1/2) and 1d_(3/2) orbits(2s_(1/2)–1d_(3/2) inversion).The inversion mechanism induced by the SLy5+Tw interaction is analyzed based on the proton single−particle spectra obtained from the SLy5 and SLy5+Tw interactions as well as the wave functions of the 2s_(1/2) and 1d_(3/2) states.展开更多
Within the framework of the two-center shell model,the classically dynamical behaviour of a nucleon in heavy nuclei is investigated when nuclear shape parameters are changed systematically.It is found that there is a ...Within the framework of the two-center shell model,the classically dynamical behaviour of a nucleon in heavy nuclei is investigated when nuclear shape parameters are changed systematically.It is found that there is a good quantum-classical correspondence of nucleonic regular(chaotic)motion so that Bohigas,Giannoni and Schmit conjecture is confirmed once again.展开更多
基金supported by grants from the Natural Science Foundation of Hebei Province of China(C2013202192)The National Natural Science Foundation of China(11275271,11675265)Postdoctoral Merit Funding Project of Hebei Province(B2018003006)~~
基金The project supported by the Director Foundation from the Department of Nuclear Physics of China Institute of Atomic Energy under Grant Nos. 11SZZ200501 and 11SZZ200601 0ne of the authors （J.Z. Gu） is grateful to H. Aiba, K. Hagino, K. Matsuyanagi, S. Mizutori, F. Sakata, and Y.Z. Zhuo for valuable discussions on this subject. He also acknowledges support from Postdoctoral Fellowship for Foreign Researchers of the Japan Society for the Promotion of Science with thanks.
文摘The collective Bamiltonian up to the fourth order for multi-O（4） model is derived based on the self-consistent collective-coordinate （SCC） method, which is formulated in the framework of the time-dependent Hartree-Bogoliubov （TDHB） theory. The validity of the collective Hamiltonian is checked in the two special cases of the multi-O（4） model： the case where the number of the shells is equal to one （a single j-shell case）, and the case where the Hartree-Bogoliubov equilibrium point is spherical （the spherical case）. The collective Hamiltonian constitutes a good starting point to study nuclear shape coexistence.
基金The project supported by National Natural Science Foundation of China under Grant Nos. 10475008, 10675170, and 10435020, and the Department of Nuclear Physics of China Institute of Atomic Energy under Grant Nos. 11SZZ-200501 and 11SZZ-200601
文摘Based on the Eigen and Crow-Kimura models with a single-peak fitness landscape, we propose the fitness values of all sequence types to be Gausslan distributed random variables to incorporate the effects of the fluctuations of the fitness landscapes （noise of environments） and investigate the concentration distribution and error threshold of quasispecies by performing an ensemble average within this theoretical framework. We find that a small fluctuation of the fitness landscape causes only a slight change in the concentration distribution and error threshold, which implies that the error threshold is stable against small perturbations. However, for a sizable fluctuation, quite different from the previous deterministic models, our statistical results show that the transition from quasi-species to error catastrophe is not so sharp, indicating that the error threshold is located within a certain range and has a shift toward a larger value. Our results are qualitatively in agreement with the experimental data and provide a new implication for antiviral strategies.
基金Supported in part by the National natural Science Foundation of China under Grant No.10675170Major State Basic Research Developing Program under Gant No.2007CB815003
文摘The relaxation property of both Eigen model and Crow-Kimura model with a single peak fitness landscape is studied from phase transition point of view. We first analyze the eigenvalue spectra of the replication mutation matrices. For sufficiently long sequences, the almost crossing point between the largest and seeond-largest eigenvalues locates the error threshold at which critical slowing down behavior appears. We calculate the critical exponent in the limit of infinite sequence lengths and compare it with the result from numerical curve fittings at sufficiently long sequences. We find that for both models the relaxation time diverges with exponent 1 at the error （mutation） threshold point. Results obtained from both methods agree quite well. From the unlimited correlation length feature, the first order phase transition is further confirmed. Finally with linear stability theory, we show that the two model systems are stable for all ranges of mutation rate. The Igigen model is asymptotically stable in terms of mutant classes, and the Crow-Kimura model is completely stable.
基金Supported by the National Natural Science Foundation of China under Grant No.10975190the National Basic Research Program of China under Grant No.2007CB815003the Funds for Creative Research Groups of China under Grant No.11021504)。
文摘In the framework of the Hartree–Fock–Bogoliubov(HFB)approach with Skyrme interactions SLy5+T,SLy5+Tw and several sets of TIJ parametrizations,i.e.the Skyrme interaction parametrizations including the tensor terms,the proton density distribution in ^(34)Si and ^(46)Ar nuclei is calculated with and without the tensor force.It is shown that the bubble effect in ^(34)Si does not depend a great deal on the Skyrme parametrization and the proton density distribution in ^(34)Si is hardly influenced by the tensor force.As to ^(46)Ar,the SLy5+Tw parametrization favors the formation of the bubble structure due to the inversion between the 2s_(1/2) and 1d_(3/2) orbits(2s_(1/2)–1d_(3/2) inversion).The inversion mechanism induced by the SLy5+Tw interaction is analyzed based on the proton single−particle spectra obtained from the SLy5 and SLy5+Tw interactions as well as the wave functions of the 2s_(1/2) and 1d_(3/2) states.
基金Supported by the China Postdoctoral Science Foundation(1977-11)the National Natural Science Foundation of China under Grant No.19677203。
文摘Within the framework of the two-center shell model,the classically dynamical behaviour of a nucleon in heavy nuclei is investigated when nuclear shape parameters are changed systematically.It is found that there is a good quantum-classical correspondence of nucleonic regular(chaotic)motion so that Bohigas,Giannoni and Schmit conjecture is confirmed once again.
