The ErCo2 compound is prepared by arc-melting and its entropy changes are calculated using Maxwell relation. Its entropy change reaches 38 J/（kg·K） and its refrigerant capacity achieves 291 J/kg at 0-5 T. The m...The ErCo2 compound is prepared by arc-melting and its entropy changes are calculated using Maxwell relation. Its entropy change reaches 38 J/（kg·K） and its refrigerant capacity achieves 291 J/kg at 0-5 T. The mean field approximation is used to calculate the magnetic entropy of ErCo2 compound. Results estimated by using the Maxwell relation deviate from mean field approximation calculations in ferrimagnetic state; however, the data obtained by the two ways are consistent in the vicinity of phase transition or at higher temperatures. This indicates that entropy changes are mainly derived from magnetic degree of freedom, and the lattice has almost no contribution to the entropy change in the vicinity of phase transition but its influence is obvious in the ferrimagnetic state below TC.展开更多
Magnetic properties and magnetocaloric effect in TbCo2-xFex compounds are studied by DC magnetic measurement. With increasing content of Fe, the entropy changes decrease slightly, though the Curie temperature is tuned...Magnetic properties and magnetocaloric effect in TbCo2-xFex compounds are studied by DC magnetic measurement. With increasing content of Fe, the entropy changes decrease slightly, though the Curie temperature is tuned from 231 K （x = 0） to 303 K （x = 0.1）. Magnetic entropies of TbCo2 compound are calculated by using mean field approximation （MFA）. Results estimated by using Maxwell relation are consistent with that of MFA calculation. It is shown that the entropy changes are mainly derived from the magnetic entropy changes. The lattice has almost no contribution to the entropy change in the vicinity of phase transition.展开更多
The proton radioactivity half-lives are investigated theoretically within a hybrid method.The potential barriers preventing the emission of protons are determined in the quasimolecular shape path within a generalized ...The proton radioactivity half-lives are investigated theoretically within a hybrid method.The potential barriers preventing the emission of protons are determined in the quasimolecular shape path within a generalized liquid drop model(GLDM). The penetrability is calculated with the WentzelKramers-Brillouin(WKB) approximation. The spectroscopic factor has been taken into account in halflife calculation, which is obtained by employing the relativistic mean field(RMF) theory combined with the Bardeen-Cooper-Schrieffer(BCS) method. The half-lives within the present hybrid method reproduced the experimental data very well. Some predictions for proton radioactivity are made for future experiments.展开更多
To explore the rotational excitation of deformed halo nuclei,the angular momentum projection(AMP)has been implemented in the deformed relativistic Hartree-Bogoliubov theory in continuum(DRHBc),in which both the mean f...To explore the rotational excitation of deformed halo nuclei,the angular momentum projection(AMP)has been implemented in the deformed relativistic Hartree-Bogoliubov theory in continuum(DRHBc),in which both the mean field and collective wave functions are expanded in terms of Dirac WoodsSaxon basis.The DRHBc+AMP approach self-consistently describes the coupling between single particle bound states and the continuum not only in the ground state but also in rotational states.The rotational modes of deformed halos in ^(42,44)Mg are investigated by studying properties of rotational states such as the excitation energy,configuration,and density distribution.Our study demonstrates that the deformed halo structure persists from the ground state in the intrinsic frame to collective states.Especially,the typical behavior of shape decoupling effects in rotating deformed halo nuclei is revealed.展开更多
基金Project supported by the National Natural Science Foundation of China （Grant No 50571112） and the National Basic Research Program of China （Grant No 2006CB601101）.
文摘The ErCo2 compound is prepared by arc-melting and its entropy changes are calculated using Maxwell relation. Its entropy change reaches 38 J/（kg·K） and its refrigerant capacity achieves 291 J/kg at 0-5 T. The mean field approximation is used to calculate the magnetic entropy of ErCo2 compound. Results estimated by using the Maxwell relation deviate from mean field approximation calculations in ferrimagnetic state; however, the data obtained by the two ways are consistent in the vicinity of phase transition or at higher temperatures. This indicates that entropy changes are mainly derived from magnetic degree of freedom, and the lattice has almost no contribution to the entropy change in the vicinity of phase transition but its influence is obvious in the ferrimagnetic state below TC.
基金Project supported by the National Natural Science Foundation of China （Grant No 50571112） and the National Basic Research Program of China （Grant No 2006CB601101）.
文摘Magnetic properties and magnetocaloric effect in TbCo2-xFex compounds are studied by DC magnetic measurement. With increasing content of Fe, the entropy changes decrease slightly, though the Curie temperature is tuned from 231 K （x = 0） to 303 K （x = 0.1）. Magnetic entropies of TbCo2 compound are calculated by using mean field approximation （MFA）. Results estimated by using Maxwell relation are consistent with that of MFA calculation. It is shown that the entropy changes are mainly derived from the magnetic entropy changes. The lattice has almost no contribution to the entropy change in the vicinity of phase transition.
基金National Natural Science Foundation of China(11175074,11475050,11265013)Knowledge Innovation Project of Chinese Academy of Sciences(KJCX2-EW-N02)
文摘The proton radioactivity half-lives are investigated theoretically within a hybrid method.The potential barriers preventing the emission of protons are determined in the quasimolecular shape path within a generalized liquid drop model(GLDM). The penetrability is calculated with the WentzelKramers-Brillouin(WKB) approximation. The spectroscopic factor has been taken into account in halflife calculation, which is obtained by employing the relativistic mean field(RMF) theory combined with the Bardeen-Cooper-Schrieffer(BCS) method. The half-lives within the present hybrid method reproduced the experimental data very well. Some predictions for proton radioactivity are made for future experiments.
基金supported by the National Key R&D Program of China(2018YFA0404402)the National Natural Science Foundation of China(11525524,12070131001,12047503,11975237,and 11961141004)+1 种基金the Key Research Program of Frontier Sciences of Chinese Academy of Sciences(QYZDB-SSWSYS013)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB34010000 and XDPB15)。
文摘To explore the rotational excitation of deformed halo nuclei,the angular momentum projection(AMP)has been implemented in the deformed relativistic Hartree-Bogoliubov theory in continuum(DRHBc),in which both the mean field and collective wave functions are expanded in terms of Dirac WoodsSaxon basis.The DRHBc+AMP approach self-consistently describes the coupling between single particle bound states and the continuum not only in the ground state but also in rotational states.The rotational modes of deformed halos in ^(42,44)Mg are investigated by studying properties of rotational states such as the excitation energy,configuration,and density distribution.Our study demonstrates that the deformed halo structure persists from the ground state in the intrinsic frame to collective states.Especially,the typical behavior of shape decoupling effects in rotating deformed halo nuclei is revealed.
