The neutron capture rates and temperature dependent stellar beta decay rates of Mo isotopes are investigated within the framework of the statistical code TALYS v1.96 and the proton neutron quasi particle random phase ...The neutron capture rates and temperature dependent stellar beta decay rates of Mo isotopes are investigated within the framework of the statistical code TALYS v1.96 and the proton neutron quasi particle random phase approximation(pn-QRPA)model.The Maxwellian average cross-section(MACS)and neutron capture rates for the^(95-98)Mo(n,γ)^(96-99)Mo radiative capture process are analyzed within the framework of the statistical code TALYS v1.96 based on the phenomenological nuclear level density model and gamma strength functions.The present model-based computations for the MACS are comparable to the existing measured data.The sensitivity of stellar weak interaction rates to various densities and temperatures is investigated within the framework of the pn-QRPA model.Particular attention is paid to the impact of thermally filled excited states in the decaying nuclei(^(95-98)Mo)on electron emission and positron capture rates.Furthermore,we compare the neutron capture rates and stellar beta decay rates.It is found that neutron capture rates are higher than stellar beta decay rates at both lower and higher temperatures.展开更多
Within the framework of the modified potential cluster model with forbidden states,the total cross-sections of radiative n^(9)Be capture to the ground and five low-lying excited states are calculated at energies from ...Within the framework of the modified potential cluster model with forbidden states,the total cross-sections of radiative n^(9)Be capture to the ground and five low-lying excited states are calculated at energies from 10^(-2)eV up to 5 MeV.The thermal cross-section σ_(th)=8.35mb is in good agreement with experimental data.We considered five resonances at the excitation energies E_(x)from 7.371 MeV up to 10.570 MeV corresponding to the following states with J^(π)(E_(x),MeV):3^(-)(7.371),2^(+)(7.542),3^(+)(9.4),2^(+)(9.56),and 3^(-)(10.570).The partial and total ^(9)Be(n,γ0+1+2+3+4+5)^(10)Be reaction rates are calculated at temperatures from 0.001 to 10 T_(9).Contrary to the available data,we propose that the rise in the reaction rate near factor five at T_(9)>1 is mainly due to the first 3^(-)(E_(R)=0.559 MeV)resonance.We foresee this contrast as arising from different model approaches.展开更多
We study the effects of electrolyte temperature on DNA molecule translocation experimentally without and with a temperature gradient across nanopore membranes.The same temperatures on both electrolyte chambers are fir...We study the effects of electrolyte temperature on DNA molecule translocation experimentally without and with a temperature gradient across nanopore membranes.The same temperatures on both electrolyte chambers are first considered.The DNA molecule translocation time is measured to be 2.44 ms at 2°C in both chambers,which is 1.57 times longer than at 20°C.Then the temperature difference effect is characterized in both chambers.The results show that the DNA translocation speed can be slowed down as long as one side temperature is lowered,irrespective of the temperature gradient direction.This indicates that the thermophoretic driving force generated by a temperature gradient has no obvious effect on the threading speed of DNA molecules,while the main reason for the slowed DNA translocation speed is the increased viscosity.Interestingly,the capture rate of DNA molecules is enhanced under a temperature gradient condition,and the capture rate during DNA translocation from hot side at 21°C to cold one at 2°C is 1.7 times larger than that under the condition of both chambers at 20°C.Finally,an optimized configuration is proposed to acquire higher capture rates and lower DNA translocation speeds.展开更多
The Gamow-Teller transitions for pf shell nuclei with proton number less than 40 and neutron number larger than 40 were believed to be blocked, due to the full filling of the neutron orbit. However, recent experimenta...The Gamow-Teller transitions for pf shell nuclei with proton number less than 40 and neutron number larger than 40 were believed to be blocked, due to the full filling of the neutron orbit. However, recent experimental research shows that the Gamow-Teller transitions for these kinds of nuclei are not blocked. In this paper, we systematically calculate the GT transition of pf shell nuclei 76Se in different truncations, and the results are compared with experimental results. It is shown that, due to correlations, the believed blocked GT transition occurs, and the shell model calculations reproduce the experimental GT strength. In addition, the electron capture rates in a stellar environment are calculated and discussed.展开更多
文摘The neutron capture rates and temperature dependent stellar beta decay rates of Mo isotopes are investigated within the framework of the statistical code TALYS v1.96 and the proton neutron quasi particle random phase approximation(pn-QRPA)model.The Maxwellian average cross-section(MACS)and neutron capture rates for the^(95-98)Mo(n,γ)^(96-99)Mo radiative capture process are analyzed within the framework of the statistical code TALYS v1.96 based on the phenomenological nuclear level density model and gamma strength functions.The present model-based computations for the MACS are comparable to the existing measured data.The sensitivity of stellar weak interaction rates to various densities and temperatures is investigated within the framework of the pn-QRPA model.Particular attention is paid to the impact of thermally filled excited states in the decaying nuclei(^(95-98)Mo)on electron emission and positron capture rates.Furthermore,we compare the neutron capture rates and stellar beta decay rates.It is found that neutron capture rates are higher than stellar beta decay rates at both lower and higher temperatures.
基金Supported by the Ministry of Science and Higher Education of the Republic of Kazakhstan(AP09259021)。
文摘Within the framework of the modified potential cluster model with forbidden states,the total cross-sections of radiative n^(9)Be capture to the ground and five low-lying excited states are calculated at energies from 10^(-2)eV up to 5 MeV.The thermal cross-section σ_(th)=8.35mb is in good agreement with experimental data.We considered five resonances at the excitation energies E_(x)from 7.371 MeV up to 10.570 MeV corresponding to the following states with J^(π)(E_(x),MeV):3^(-)(7.371),2^(+)(7.542),3^(+)(9.4),2^(+)(9.56),and 3^(-)(10.570).The partial and total ^(9)Be(n,γ0+1+2+3+4+5)^(10)Be reaction rates are calculated at temperatures from 0.001 to 10 T_(9).Contrary to the available data,we propose that the rise in the reaction rate near factor five at T_(9)>1 is mainly due to the first 3^(-)(E_(R)=0.559 MeV)resonance.We foresee this contrast as arising from different model approaches.
基金supported by the National Basic Research Program of China("973"Project)(Grant Nos.2011CB707601 and 2011CB707605)the National Natural Science Foundation of China(Grants Nos.50925519 and 51375092)+1 种基金supported by the Scientific Research Foundation of Graduate School of Southeast University(Grant No.YBJJ1004)supported by the Fundamental Research Funds for the Central Universities and the Innovative Project for Graduate Students of Jiangsu Province(Grant No.KYLX_0100)
文摘We study the effects of electrolyte temperature on DNA molecule translocation experimentally without and with a temperature gradient across nanopore membranes.The same temperatures on both electrolyte chambers are first considered.The DNA molecule translocation time is measured to be 2.44 ms at 2°C in both chambers,which is 1.57 times longer than at 20°C.Then the temperature difference effect is characterized in both chambers.The results show that the DNA translocation speed can be slowed down as long as one side temperature is lowered,irrespective of the temperature gradient direction.This indicates that the thermophoretic driving force generated by a temperature gradient has no obvious effect on the threading speed of DNA molecules,while the main reason for the slowed DNA translocation speed is the increased viscosity.Interestingly,the capture rate of DNA molecules is enhanced under a temperature gradient condition,and the capture rate during DNA translocation from hot side at 21°C to cold one at 2°C is 1.7 times larger than that under the condition of both chambers at 20°C.Finally,an optimized configuration is proposed to acquire higher capture rates and lower DNA translocation speeds.
基金Supported by National Natural Science Foundation of China (11165006, 10865004, 10775123)Natural Science and Technology Foundation of Guizhou Province ([2008]2254, LKS[2010]08)+1 种基金International Scientific and Technological Cooperation Projects of Guizhou Province ([2011]7026)Doctor Funding of Guizhou Normal University
文摘The Gamow-Teller transitions for pf shell nuclei with proton number less than 40 and neutron number larger than 40 were believed to be blocked, due to the full filling of the neutron orbit. However, recent experimental research shows that the Gamow-Teller transitions for these kinds of nuclei are not blocked. In this paper, we systematically calculate the GT transition of pf shell nuclei 76Se in different truncations, and the results are compared with experimental results. It is shown that, due to correlations, the believed blocked GT transition occurs, and the shell model calculations reproduce the experimental GT strength. In addition, the electron capture rates in a stellar environment are calculated and discussed.