在BNU400注入机上搭建的离子激发发光(ion beam induced luminescence,IBIL)测量装置上,开展了相同能量(100 keV)条件下的3种离子(H^+、He^+以及O^+)辐照氟化锂材料时的IBIL光谱的原位测量工作,对比研究离子种类对氟化锂材料辐照缺陷的...在BNU400注入机上搭建的离子激发发光(ion beam induced luminescence,IBIL)测量装置上,开展了相同能量(100 keV)条件下的3种离子(H^+、He^+以及O^+)辐照氟化锂材料时的IBIL光谱的原位测量工作,对比研究离子种类对氟化锂材料辐照缺陷的生成及其演变行为的影响.结合SRIM(Stopping and Range of Ions in Matter)模拟的结果,可以发现He^+辐照时的IBIL光谱强度最高,这是由于He^+激发产生的电子空穴对密度高于H^+,而O^+辐照时由于激发出的电子空穴对密度过高引起的非辐射复合比例增加,从而导致发光效率过低;质量数越大的离子辐照时,核阻止本领越大,会加快缺陷的生成和湮灭速率,降低达到平衡状态时的发光强度.近红外波段的F^-3/F^+2色心发光峰强度及其演变行为表明其耐辐照性能好于可见光波段的F2色心.展开更多
A new method, the dynamic reduction method(DRM) combined with the strain-softening method, was applied to evaluate the possible slip surface of a highly heterogeneous rock slope of the Dagangshan hydropower station in...A new method, the dynamic reduction method(DRM) combined with the strain-softening method, was applied to evaluate the possible slip surface of a highly heterogeneous rock slope of the Dagangshan hydropower station in Southwest China.In DRM, only the strength of the failure elements is reduced and the softening reduction factor K is adopted to calculate the strength parameters. The simulation results calculated by DRM show that the further slip surface on the right slope of the Dagangshan hydropower station is limited in the middle part of the slope, while both SRM(strength reduction method) and LEM(limit equilibrium method) predict a failure surface which extends upper and longer. The observations and analysis from the three recorded sliding events indicate that the failure mode predicted by DRM is more likely the scenario.The results in this study illustrate that for highly heterogeneous slopes with geological discontinuities in different length scales, the proposed DRM can provide a reliable prediction of the location of the slip surface.展开更多
We study the angle-dependent irradiation of linear C_(4) in the strong femtoeecond laser pulses with the help of time-dependent local density approximation applied to valence electrons,coupled non-adiabatically to mol...We study the angle-dependent irradiation of linear C_(4) in the strong femtoeecond laser pulses with the help of time-dependent local density approximation applied to valence electrons,coupled non-adiabatically to molecular dynamics of ions.It is found that the excitation of C_(4) including the electrons and ions has a strong relation to the angle between the laser polarization and the internuclear axis of C4.The ionization yield decreases when theangle ranges from 0 to π/2.A clear suppression in the ionization yield is found when the laser polarization is perpendicular to the internuclear axis of C_(4).We track the dynamic motion of ionized C_(4) even in the relaxation time.It shows that the ionized C_(4) keeps on oscillating without fragmenting after the irradiation in different cases,while it is more excited when the laser polarization is along the internuclear axis.Furthermore,it is found that the change of the ELF takes place mainly in the xy plane and xz plane and the electron ejection mainly comes from the middle two atoms for the θ =0 case.展开更多
Molecular dynamics simulations are performed using an empirical potential to simulate the collision process of an energetic carbon atom hitting a graphene sheet.According to the different impact locations within the g...Molecular dynamics simulations are performed using an empirical potential to simulate the collision process of an energetic carbon atom hitting a graphene sheet.According to the different impact locations within the graphene sheet,the incident threshold energies of different defects caused by the collision are determined to be 22eV for a single vacancy,36eV for a divacancy,60eV for a Stone-Wales defect,and 65eV for a hexavacancy.Study of the evolution and stability of the defects formed by thee collisions suggests that the single vacancy reconstructs into a pentagon pair and the divacancy transforms into a pentagon-octagon-pentagon configuration.The displacement threshold energy in graphene is investigated by using the dyuanical method,and a reasonable value 22.42eV is clarified by eliminating the heating effect induced by the collision.展开更多
The proton fraction inβ-stable neutron stars is investigated within the framework of the Skyrme-Hartree-Fock theory using the extended Skyrme effective interaction for the first time.The calculated results show that ...The proton fraction inβ-stable neutron stars is investigated within the framework of the Skyrme-Hartree-Fock theory using the extended Skyrme effective interaction for the first time.The calculated results show that the proton fraction disappears at high density,which implies that the pure neutron matter may exist in the interior of neutron stars.The incompressibility of the nuclear equation-of-state is shown to be more important to determine the proton fraction.Meanwhile,it is indicated that the addition of muons in neutron stars will change the proton fraction.It is also found that the higher-order terms of the nuclear symmetry energy have obvious effects on the proton fraction and the parabolic law of the nuclear symmetry energy is not enough to determine the proton fraction.展开更多
With the frame of the time-dependent local density approximation, an efficient description of the optical response of clusters has been used to study the photo-absorption cross section of Na2 and Na4 clusters. It is s...With the frame of the time-dependent local density approximation, an efficient description of the optical response of clusters has been used to study the photo-absorption cross section of Na2 and Na4 clusters. It is shown that our calculated results are in good agreement with the experiment. In addition, our calculated spectrum for the Na4 cluster is in better agreement with experiment than the GW absorption spectrum.展开更多
文摘在BNU400注入机上搭建的离子激发发光(ion beam induced luminescence,IBIL)测量装置上,开展了相同能量(100 keV)条件下的3种离子(H^+、He^+以及O^+)辐照氟化锂材料时的IBIL光谱的原位测量工作,对比研究离子种类对氟化锂材料辐照缺陷的生成及其演变行为的影响.结合SRIM(Stopping and Range of Ions in Matter)模拟的结果,可以发现He^+辐照时的IBIL光谱强度最高,这是由于He^+激发产生的电子空穴对密度高于H^+,而O^+辐照时由于激发出的电子空穴对密度过高引起的非辐射复合比例增加,从而导致发光效率过低;质量数越大的离子辐照时,核阻止本领越大,会加快缺陷的生成和湮灭速率,降低达到平衡状态时的发光强度.近红外波段的F^-3/F^+2色心发光峰强度及其演变行为表明其耐辐照性能好于可见光波段的F2色心.
基金supported by the National Key R&D Program of China (2017YFC1501301)the National Natural Science Foundation of China (Grant Nos. 41521002, 41572283 and 41130745)+2 种基金the Funding of Science and Technology Office of Sichuan Province (Grant Nos. 2015JQ0020 and 2017TD0018)the 1000 Young Talent Program of Chinathe research fund of the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Grant No. SKLGP2017Z012)
文摘A new method, the dynamic reduction method(DRM) combined with the strain-softening method, was applied to evaluate the possible slip surface of a highly heterogeneous rock slope of the Dagangshan hydropower station in Southwest China.In DRM, only the strength of the failure elements is reduced and the softening reduction factor K is adopted to calculate the strength parameters. The simulation results calculated by DRM show that the further slip surface on the right slope of the Dagangshan hydropower station is limited in the middle part of the slope, while both SRM(strength reduction method) and LEM(limit equilibrium method) predict a failure surface which extends upper and longer. The observations and analysis from the three recorded sliding events indicate that the failure mode predicted by DRM is more likely the scenario.The results in this study illustrate that for highly heterogeneous slopes with geological discontinuities in different length scales, the proposed DRM can provide a reliable prediction of the location of the slip surface.
基金Supported by the Fundamental Research Funds for the Central Universities under Grant Nos JUSRP111A21 and JUSRP31005the“Eleven-Five”Planning Issues for Education and Science of Jiangsu Province under the Higher Education System 34 of 2008+1 种基金the“Eleven-Five”Planning Issues for Higher Education of Jiangsu Province under Grant No JS053the National Basic Research Program of China under Grant No 2010CB832903.
文摘We study the angle-dependent irradiation of linear C_(4) in the strong femtoeecond laser pulses with the help of time-dependent local density approximation applied to valence electrons,coupled non-adiabatically to molecular dynamics of ions.It is found that the excitation of C_(4) including the electrons and ions has a strong relation to the angle between the laser polarization and the internuclear axis of C4.The ionization yield decreases when theangle ranges from 0 to π/2.A clear suppression in the ionization yield is found when the laser polarization is perpendicular to the internuclear axis of C_(4).We track the dynamic motion of ionized C_(4) even in the relaxation time.It shows that the ionized C_(4) keeps on oscillating without fragmenting after the irradiation in different cases,while it is more excited when the laser polarization is along the internuclear axis.Furthermore,it is found that the change of the ELF takes place mainly in the xy plane and xz plane and the electron ejection mainly comes from the middle two atoms for the θ =0 case.
基金Supported by the National Natural Science Foundation of China under Grand Nos 11025524 and 11161130520the National Basic Research Program of China under Grant No 2010CB832903。
文摘Molecular dynamics simulations are performed using an empirical potential to simulate the collision process of an energetic carbon atom hitting a graphene sheet.According to the different impact locations within the graphene sheet,the incident threshold energies of different defects caused by the collision are determined to be 22eV for a single vacancy,36eV for a divacancy,60eV for a Stone-Wales defect,and 65eV for a hexavacancy.Study of the evolution and stability of the defects formed by thee collisions suggests that the single vacancy reconstructs into a pentagon pair and the divacancy transforms into a pentagon-octagon-pentagon configuration.The displacement threshold energy in graphene is investigated by using the dyuanical method,and a reasonable value 22.42eV is clarified by eliminating the heating effect induced by the collision.
基金Supported by the National Natural Science Foundation of China under Grant Nos.19875068 and 19847002the Major State Basic Research Development Program under Contract No.G2000077407the Foundation of the Chinese Academy of Sciences.
文摘The proton fraction inβ-stable neutron stars is investigated within the framework of the Skyrme-Hartree-Fock theory using the extended Skyrme effective interaction for the first time.The calculated results show that the proton fraction disappears at high density,which implies that the pure neutron matter may exist in the interior of neutron stars.The incompressibility of the nuclear equation-of-state is shown to be more important to determine the proton fraction.Meanwhile,it is indicated that the addition of muons in neutron stars will change the proton fraction.It is also found that the higher-order terms of the nuclear symmetry energy have obvious effects on the proton fraction and the parabolic law of the nuclear symmetry energy is not enough to determine the proton fraction.
基金The project supported by National Natural Science Foundation of China under Grant Nos. 10405025, 10575012, 10435020, and 10535010
文摘With the frame of the time-dependent local density approximation, an efficient description of the optical response of clusters has been used to study the photo-absorption cross section of Na2 and Na4 clusters. It is shown that our calculated results are in good agreement with the experiment. In addition, our calculated spectrum for the Na4 cluster is in better agreement with experiment than the GW absorption spectrum.
