The back bending phenomenon observed in ^(87)Nb is interpreted very well within the approach of the triaxial cranking shell model(CSM)with the deformations determined by a total routhian surface calculation which incl...The back bending phenomenon observed in ^(87)Nb is interpreted very well within the approach of the triaxial cranking shell model(CSM)with the deformations determined by a total routhian surface calculation which includes the deformation drive of the high j quasiparticle orbits.It is suggested that the CSM is still valid for slightly deformed transitional nuclei if the configuration dependence of deformations is taken into account properly.展开更多
The properties of the Superdeformed giant dipole resonance(SDGDR)in rotating 146-152Dy even nuclei are studied based on the linear response theory with the self-consistently determined,superdeformed mean field.The obt...The properties of the Superdeformed giant dipole resonance(SDGDR)in rotating 146-152Dy even nuclei are studied based on the linear response theory with the self-consistently determined,superdeformed mean field.The obtained features may serve as the criteria of observing the SDGDR.展开更多
The new striking feature of anomalously low second band crossing frequency observed in 163Lu is interpreted as the shape variation with,the quasiparticle(q.p.)configurations as a resuft of the deformation driving of t...The new striking feature of anomalously low second band crossing frequency observed in 163Lu is interpreted as the shape variation with,the quasiparticle(q.p.)configurations as a resuft of the deformation driving of the rotating g.p.high-j orbits・On the assumption that the crossing frequency is basically determined by an average over deformations before and after tke crossing,tke experimental data is reproduced very well by tke present model calculation.展开更多
We briefly reviewed the experimental study onβ-delayed proton decays near the proton drip line published by our group during the period of 1996-2004, namely the first observation of theβ-delayed proton decays of 9 n...We briefly reviewed the experimental study onβ-delayed proton decays near the proton drip line published by our group during the period of 1996-2004, namely the first observation of theβ-delayed proton decays of 9 new nuclides in the rare-earth region (Fig.1)and the new measurements ofβ-delayed proton decays of 5 nuclides in the mass≈90 region near the N = Z line (Fig. 2) with the aid of the 'p-γ'展开更多
The lifetimes for the states of magnetic dipole band in106Ag have been measured using the Doppler-shift attenuation method via the reaction of100Mo(11B,5n)106Ag at a beam energy of 60 MeV.The reduced transition streng...The lifetimes for the states of magnetic dipole band in106Ag have been measured using the Doppler-shift attenuation method via the reaction of100Mo(11B,5n)106Ag at a beam energy of 60 MeV.The reduced transition strengths of the magnetic dipole band,the B(M1)/B(E2)ratios together with the signature of the level energy as a function of angular momentum for the positive parity states of106Ag show that a drastic change of excitation mode,that is,from electric rotation to magnetic rotation,occurs within one unit of spin at around Iπ=12+.Theoretical calculations based on the triaxial projected shell model consistently reproduce the experimental data and provide an explanation on the nature of observed phenomena such that the dynamical drift of the rotational axis suddenly from the principal axis to the tilted one,along the positive parity bands of106Ag.展开更多
The heavy elements in the Universe are formed during the s- and r-processes mainly in AGB stars and supernovae, respectively. Simulation of s- and r-nucleosynthesis critically depends on the neutron capture and weak d...The heavy elements in the Universe are formed during the s- and r-processes mainly in AGB stars and supernovae, respectively. Simulation of s- and r-nucleosynthesis critically depends on the neutron capture and weak decay rates for all the nuclei on the reaction chain. The present work analyzes systematically the neutron capture rates (cross sections) for the s-process nuclei, including ～3000 rates on ～200 nuclei. The network calculations for the constant temperature s-process have been performed using the different data sets selected as the nuclear inputs to investigate the uncertainties in the predicted s-abundances. We show that the available cross sections of neutron capture on many s-process nuclei still carry large uncertainties, which lead to low accuracy in the determination of s-process isotope abundances. We analyze the neutron capture cross section data for the same unique isobar nucleus accorded by year from previous work. Such an analysis indicates that the s-process has been studied for more than fifty years and there exist two research stages around 1976 and 2002, respectively. The needs and opportunities for future experiments and theoretical tools are highlighted to remove the existing shortcomings in the neutron capture rates.展开更多
The projected total energy surface(PTES)approach has been developed based on the triaxial projected shell model(TPSM)hybridized with the macroscopic–microscopic method.The total energy of an atomic nucleus is decompo...The projected total energy surface(PTES)approach has been developed based on the triaxial projected shell model(TPSM)hybridized with the macroscopic–microscopic method.The total energy of an atomic nucleus is decomposed into macroscopic,microscopic and rotational terms.The macroscopic and microscopic components are described with the liquid drop model and Strutinsky method,respectively,and the rotational energy is given by the TPSM,the term beyond the mean field.To test theory,the PTES calculations have been carried out for the yrast states of the well deformed rare earth nucleus172W,and the theoretical results are in good agreement with the experimental data.By using the equilibrium quardrupole deformations(ε2andγ)determined by the PTES,the calculation of the transition quardrupole moment(Qt)in function of spin also reproduces the experimental data.A comparison between the PTES and TRS methods has been made for theoretical and application uses.展开更多
基金Supported by the National Natural Science Foundation of China.
文摘The back bending phenomenon observed in ^(87)Nb is interpreted very well within the approach of the triaxial cranking shell model(CSM)with the deformations determined by a total routhian surface calculation which includes the deformation drive of the high j quasiparticle orbits.It is suggested that the CSM is still valid for slightly deformed transitional nuclei if the configuration dependence of deformations is taken into account properly.
基金Project supported by the National Science Foundation of China.
文摘The properties of the Superdeformed giant dipole resonance(SDGDR)in rotating 146-152Dy even nuclei are studied based on the linear response theory with the self-consistently determined,superdeformed mean field.The obtained features may serve as the criteria of observing the SDGDR.
文摘The new striking feature of anomalously low second band crossing frequency observed in 163Lu is interpreted as the shape variation with,the quasiparticle(q.p.)configurations as a resuft of the deformation driving of the rotating g.p.high-j orbits・On the assumption that the crossing frequency is basically determined by an average over deformations before and after tke crossing,tke experimental data is reproduced very well by tke present model calculation.
基金Supported by the National Natural Science Foundation of China (10375078 and 10475002)
文摘We briefly reviewed the experimental study onβ-delayed proton decays near the proton drip line published by our group during the period of 1996-2004, namely the first observation of theβ-delayed proton decays of 9 new nuclides in the rare-earth region (Fig.1)and the new measurements ofβ-delayed proton decays of 5 nuclides in the mass≈90 region near the N = Z line (Fig. 2) with the aid of the 'p-γ'
基金supported by the NationalNatural Science Foundation of China(Grant Nos.10975191,10775184,10775182,10675171,10575133,11021504,11175258 and 11275068)the Chinese Major State Basic Research Development Program(Grant No.2007CB815005)
文摘The lifetimes for the states of magnetic dipole band in106Ag have been measured using the Doppler-shift attenuation method via the reaction of100Mo(11B,5n)106Ag at a beam energy of 60 MeV.The reduced transition strengths of the magnetic dipole band,the B(M1)/B(E2)ratios together with the signature of the level energy as a function of angular momentum for the positive parity states of106Ag show that a drastic change of excitation mode,that is,from electric rotation to magnetic rotation,occurs within one unit of spin at around Iπ=12+.Theoretical calculations based on the triaxial projected shell model consistently reproduce the experimental data and provide an explanation on the nature of observed phenomena such that the dynamical drift of the rotational axis suddenly from the principal axis to the tilted one,along the positive parity bands of106Ag.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11021504, 11175258, 11275068 and 11175001)the Major State Basic Research Development Program of China (Grant No.2013CB834406)
文摘The heavy elements in the Universe are formed during the s- and r-processes mainly in AGB stars and supernovae, respectively. Simulation of s- and r-nucleosynthesis critically depends on the neutron capture and weak decay rates for all the nuclei on the reaction chain. The present work analyzes systematically the neutron capture rates (cross sections) for the s-process nuclei, including ～3000 rates on ～200 nuclei. The network calculations for the constant temperature s-process have been performed using the different data sets selected as the nuclear inputs to investigate the uncertainties in the predicted s-abundances. We show that the available cross sections of neutron capture on many s-process nuclei still carry large uncertainties, which lead to low accuracy in the determination of s-process isotope abundances. We analyze the neutron capture cross section data for the same unique isobar nucleus accorded by year from previous work. Such an analysis indicates that the s-process has been studied for more than fifty years and there exist two research stages around 1976 and 2002, respectively. The needs and opportunities for future experiments and theoretical tools are highlighted to remove the existing shortcomings in the neutron capture rates.
基金supported by the National Natural Science Foundation of China (Grant Nos.11047171,11301508,11175258,11021504 and 11275068)the Knowledge Innovation Project of the Chinese Academy of Sciences (Grant No.KJCX2-SW-N02)the Key Project of Science and Technology Research of Education Ministry of China (Grant No.209053).
文摘The projected total energy surface(PTES)approach has been developed based on the triaxial projected shell model(TPSM)hybridized with the macroscopic–microscopic method.The total energy of an atomic nucleus is decomposed into macroscopic,microscopic and rotational terms.The macroscopic and microscopic components are described with the liquid drop model and Strutinsky method,respectively,and the rotational energy is given by the TPSM,the term beyond the mean field.To test theory,the PTES calculations have been carried out for the yrast states of the well deformed rare earth nucleus172W,and the theoretical results are in good agreement with the experimental data.By using the equilibrium quardrupole deformations(ε2andγ)determined by the PTES,the calculation of the transition quardrupole moment(Qt)in function of spin also reproduces the experimental data.A comparison between the PTES and TRS methods has been made for theoretical and application uses.
