The a-preformation factors of medium and heavy-mass nuclei are calculated by using the cluster-formation model.The obtained preformation factors of even–even,odd-A,and odd–odd nuclei consist in both magnitude and tr...The a-preformation factors of medium and heavy-mass nuclei are calculated by using the cluster-formation model.The obtained preformation factors of even–even,odd-A,and odd–odd nuclei consist in both magnitude and trend with the general features predicted by standard calculations.The variation of a clustering affected by the evolution of nuclear structure is observed from different behaviors of preformation factors.We typically analyze the variation of preformation factors in the closed-shell N =126 and Z =82 regions,and discuss in detail the structural effects on a-cluster formation.This work shows the strong correlation between a-preformation factors and the shell structure,which would be a useful reference for microscopic cluster-model calculations of a-decay half-lives.展开更多
We investigate the properties of the η-nucleus interaction by postulating the N*(1535) dominance for ηN system. Since the mass gap of N* and N is very close to the η meson mass,there is the possibility of the level...We investigate the properties of the η-nucleus interaction by postulating the N*(1535) dominance for ηN system. Since the mass gap of N* and N is very close to the η meson mass,there is the possibility of the level crossing between the N*-h and η modes in finite density. We postulate the N*(1535) resonance for the ηN system and consider quite distinct N* properties in finite density which are predicted by two independent chiral models. We find that we can obtain clearer information on the in-medium N* properties and also on the η-nucleus interaction through the formation of the η-mesic nuclei by (π,N) reactions under the appropriate experimental conditions,which can be performed at existing and/or forthcoming facilities like J-PARC.展开更多
Both the content of 5-hydroxytryptamine (5-HT) and the activity of the tryptophan hydroxylase in the substantia nigra (SN) are high. Studies of autoradiography and electrophysiology indicate that some nerve fibres pro...Both the content of 5-hydroxytryptamine (5-HT) and the activity of the tryptophan hydroxylase in the substantia nigra (SN) are high. Studies of autoradiography and electrophysiology indicate that some nerve fibres projecting to SN are originated from the raphe nuclei. Our previous work showed that the contents of 5-HT and its metabolite 5-hydroxy-indoleacetic acid (5-HIAA) in the raphe展开更多
The integrated spectrum of discrete X-ray sources (mainly the active galactic nuclei, AGN) is inconsistent with the observed spectrum of cosmic X-ray background (CXB), and it is so called CXB spectral paradox. The med...The integrated spectrum of discrete X-ray sources (mainly the active galactic nuclei, AGN) is inconsistent with the observed spectrum of cosmic X-ray background (CXB), and it is so called CXB spectral paradox. The medium X-ray spectra of 68 AGNs are adopted, the evolution function of X-ray spectral indices is analyzed statistically, the fraction of CXB is calculated due to AGNs X-ray emission, which shows that almost 100% CXB comes from AGNs X-ray emission. Especially, the integrated spectrum in 2-10 keV is consistent with the observed spectrum of CXB. The spectral paradox of CXB can be interpreted by this result.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11535004,11375086,11120101005,11175085 and11235001)the 973 National Major State Basic Research and Development of China(No.2013CB834400)the Science and Technology Development Fund of Macao(No.068/2011/A)
文摘The a-preformation factors of medium and heavy-mass nuclei are calculated by using the cluster-formation model.The obtained preformation factors of even–even,odd-A,and odd–odd nuclei consist in both magnitude and trend with the general features predicted by standard calculations.The variation of a clustering affected by the evolution of nuclear structure is observed from different behaviors of preformation factors.We typically analyze the variation of preformation factors in the closed-shell N =126 and Z =82 regions,and discuss in detail the structural effects on a-cluster formation.This work shows the strong correlation between a-preformation factors and the shell structure,which would be a useful reference for microscopic cluster-model calculations of a-decay half-lives.
基金Grant for Scientific Research from the Japan Society for the Promotion of Science(18-8661)
文摘We investigate the properties of the η-nucleus interaction by postulating the N*(1535) dominance for ηN system. Since the mass gap of N* and N is very close to the η meson mass,there is the possibility of the level crossing between the N*-h and η modes in finite density. We postulate the N*(1535) resonance for the ηN system and consider quite distinct N* properties in finite density which are predicted by two independent chiral models. We find that we can obtain clearer information on the in-medium N* properties and also on the η-nucleus interaction through the formation of the η-mesic nuclei by (π,N) reactions under the appropriate experimental conditions,which can be performed at existing and/or forthcoming facilities like J-PARC.
文摘Both the content of 5-hydroxytryptamine (5-HT) and the activity of the tryptophan hydroxylase in the substantia nigra (SN) are high. Studies of autoradiography and electrophysiology indicate that some nerve fibres projecting to SN are originated from the raphe nuclei. Our previous work showed that the contents of 5-HT and its metabolite 5-hydroxy-indoleacetic acid (5-HIAA) in the raphe
文摘The integrated spectrum of discrete X-ray sources (mainly the active galactic nuclei, AGN) is inconsistent with the observed spectrum of cosmic X-ray background (CXB), and it is so called CXB spectral paradox. The medium X-ray spectra of 68 AGNs are adopted, the evolution function of X-ray spectral indices is analyzed statistically, the fraction of CXB is calculated due to AGNs X-ray emission, which shows that almost 100% CXB comes from AGNs X-ray emission. Especially, the integrated spectrum in 2-10 keV is consistent with the observed spectrum of CXB. The spectral paradox of CXB can be interpreted by this result.
