According to the new proton and neutron nuclear picture described earlier, the structure of the nucleus will also be given a new interpretation. The role of the delocalized electrons detached from the outer shell of n...According to the new proton and neutron nuclear picture described earlier, the structure of the nucleus will also be given a new interpretation. The role of the delocalized electrons detached from the outer shell of neutrons is shown in the binding energy value of the nucleus. It is pointed out that the spatial arrangement of nucleons is also very important for the stability of nuclei according to the analyzation of the magic numbers from a geometric point of view.展开更多
The solutions of temperature and solute fields around a spherical crystal growing from a binary melt under the far-field flow are obtained.Based on the results,a linear stability analysis on the spherical interface gr...The solutions of temperature and solute fields around a spherical crystal growing from a binary melt under the far-field flow are obtained.Based on the results,a linear stability analysis on the spherical interface growing from the binary melt under the far-field flow is performed.It is found that the constitutional supercooling effect ahead of the spherical crystal interface under the far-field flow is enhanced compared with that without the flow.The growth rate of the perturbation amplitude at the up-wind side of the spherical crystal interface is larger than that at the down-wind side.The critical stability radius of the crystal interface decreases with the increasing far-field flow velocity.Under the far-field flow,the whole spherical interface becomes more unstable compared with that without the flow.展开更多
Background:The liver is fundamental for keeping up the entire body’s homeostasis.The liver hepatocytes have been shown to undergo genomic instability with aging.The stability of the hepatocytes depends on its nuclear...Background:The liver is fundamental for keeping up the entire body’s homeostasis.The liver hepatocytes have been shown to undergo genomic instability with aging.The stability of the hepatocytes depends on its nuclear architecture.Calorie restriction has been shown to extend life-span favorably and this may be through the reorganization of the nuclear structure.Objective:To study the effect of cyclic feeding regime on the chromatin assembly anchored to the nuclear membrane scaffold of rat models hepatocytes nuclei.Method:Rats models underwent cyclic feeding regime,after which nuclei were isolated;then,we investigated the chromatin decondensation and nuclear membrane disintegration of the hepatocytes using fluorescence imaging methods.Results:In 60 seconds,protease decondensed the chromatin and disintegrated the nuclear membrane structure of controls.After the first fasting,the time increased to 145 seconds in 3-month-old rats.The first refeeding increased the time to 156 seconds with a further rise to 340 seconds following the second fasting,then dropped to 116 seconds by the second refeeding.20 months old rats showed 186 seconds increase in the time of chromatin decondensation and nuclear membrane disintegration after the first fasting,with a decrease to 140 seconds observed after first refeeding.The second fasting increased the time to 165 seconds,which then slightly decreased to 163 seconds after the second refeeding.Conclusion:These results show that intermittent fasting may have acted on chromatin histone interactions and the structural lamin networks of the nuclear membranes in bringing about nuclear stability,which is essential for normal cellular function.展开更多
HEAVY ion physics has been rapidly developing at the limits of energy (nuclear temperature), isospin and spin. Heavy ion research facility of Lanzhou (HIRFL) is of cyclotron family delivering intermediate energy heavy...HEAVY ion physics has been rapidly developing at the limits of energy (nuclear temperature), isospin and spin. Heavy ion research facility of Lanzhou (HIRFL) is of cyclotron family delivering intermediate energy heavy ions. During the recent years, progress has been made in the studies of heavy ion physics as well as in the development of the HIRFL. This review article will展开更多
The evolution of far wake of stationary elliptic cylinders with angle of attack is investigated for the unsteady flow at Re=200 using a stabilized finite-element method.The Reynolds number,Re,is based on the major axi...The evolution of far wake of stationary elliptic cylinders with angle of attack is investigated for the unsteady flow at Re=200 using a stabilized finite-element method.The Reynolds number,Re,is based on the major axis of cylinder and free-stream speed.Cylinder aspect ratios,AR considered are 0.2,0.5 and 0.8 while the angle of attack,αvaries from 0° to 90°.With increasingα,the Karman or primary shedding frequency of each cylinder decreases monotonically while the primary wavelength and time-averaged as well as r.m.s.drag increase monotonically.The time-averaged lift and moment coefficients initially increase withαand then decrease.The power spectrum analysis of unsteady transverse velocity signal at various stations along the wake centerline is used to study the associated frequencies.The Karman or primary shedding frequency exists for eachα.For the AR=0.2 cylinder,the secondary and subsequently,low magnitude tertiary frequencies appear in the wake asαcontinues to increase from 30°.In contrast to the decaying nature of primary frequency withα,secondary frequency exhibits a nonmonotonic variation.The secondary frequency in general is not a sub-harmonic of the primary.This suggests that the secondary structures do not form due to merging of primary vortices.With increasingα,the location of formation of secondary structures advances upstream.For a given orientation,the upstream advancement is more dominant with decreasing AR.Power spectrum analysis indicates that the wake state for confined flow is characterized by the primary frequency alone,i.e.the imposition of blockage suppresses the formation of secondary structures.展开更多
Radioactivity of nuclei in a centrifugal force field of an ultracentrifuge is considered for heavy radioactive nuclei, i.e., for the same nuclei, but with a significant virtual mass thousands of times larger than the ...Radioactivity of nuclei in a centrifugal force field of an ultracentrifuge is considered for heavy radioactive nuclei, i.e., for the same nuclei, but with a significant virtual mass thousands of times larger than the actual mass and is characterized by an angular momentum. As the nucleus leaves the centrifugal force field, the virtual mass disappears, but the spin number appears and/or changes. The role of centrifugal and gravitational forces in radioactive decay of nuclei is studied. According to the terminology of western researchers, such a virtual mass state is called the dynamic gravitation which is more adequate. The oscillator and possible changes in the nucleus state are considered under conditions of dynamic gravitation and taking into account features of atomic nucleus physics. To a first approximation, the drop model of the nucleus was used, in which shape fluctuations have much in common with geophysical and astrophysical analogues. Shape fluctuations of analogues strongly depend on the gravitational force g defined by their mass (or nucleus mass). Experiments were performed by radiometric measurements of transbaikalian uranium ore (1.5 g) with known composition in a centrifuge at various rotation rates or gravitational forces g. The existence of characteristic times or the effect of rotation frequencies (i.e., g) on atomic nuclei, which, along with the nucleus type itself, controls the nucleus response to perturbation (stability increase or decay), is found statistically significant.展开更多
The effects of 5%Ni addition on the glass forming ability,thermal stability and crystallization behavior of Mg65Cu25Tb10 bulk metallic glass were investigated using X-ray diffractometry,differential scanning calorimet...The effects of 5%Ni addition on the glass forming ability,thermal stability and crystallization behavior of Mg65Cu25Tb10 bulk metallic glass were investigated using X-ray diffractometry,differential scanning calorimetry and transmission electron microscopy.The small amount of Ni addition reduces the glass forming ability and thermal stability due to a significant decrease in the crystallization activation energy.Analyses of crystallization kinetics give evidence to the existence of quenched-in nuclei in amorphous Mg65Cu20Ni5Tb10.Final crystallization products are basically same for Mg65Cu25Tb10 and Mg65Cu20Ni5Tb10.展开更多
文摘According to the new proton and neutron nuclear picture described earlier, the structure of the nucleus will also be given a new interpretation. The role of the delocalized electrons detached from the outer shell of neutrons is shown in the binding energy value of the nucleus. It is pointed out that the spatial arrangement of nucleons is also very important for the stability of nuclei according to the analyzation of the magic numbers from a geometric point of view.
基金Project supported by the National Natural Science Foundation of China(Grants Nos.50771083 and 50901061)the National Basic Research Program of China(Grant No.2011CB610402)+1 种基金the Fund of the State Key Laboratory of Solidification Processing in NWPU,China(Grants Nos.02-TZ-2008 and 36-TP-2009)the Programme of Introducing Talents of Discipline to Universities, China(Grant No.08040)
文摘The solutions of temperature and solute fields around a spherical crystal growing from a binary melt under the far-field flow are obtained.Based on the results,a linear stability analysis on the spherical interface growing from the binary melt under the far-field flow is performed.It is found that the constitutional supercooling effect ahead of the spherical crystal interface under the far-field flow is enhanced compared with that without the flow.The growth rate of the perturbation amplitude at the up-wind side of the spherical crystal interface is larger than that at the down-wind side.The critical stability radius of the crystal interface decreases with the increasing far-field flow velocity.Under the far-field flow,the whole spherical interface becomes more unstable compared with that without the flow.
基金funding agency in the public,commercial,or not-for-profit sectors.
文摘Background:The liver is fundamental for keeping up the entire body’s homeostasis.The liver hepatocytes have been shown to undergo genomic instability with aging.The stability of the hepatocytes depends on its nuclear architecture.Calorie restriction has been shown to extend life-span favorably and this may be through the reorganization of the nuclear structure.Objective:To study the effect of cyclic feeding regime on the chromatin assembly anchored to the nuclear membrane scaffold of rat models hepatocytes nuclei.Method:Rats models underwent cyclic feeding regime,after which nuclei were isolated;then,we investigated the chromatin decondensation and nuclear membrane disintegration of the hepatocytes using fluorescence imaging methods.Results:In 60 seconds,protease decondensed the chromatin and disintegrated the nuclear membrane structure of controls.After the first fasting,the time increased to 145 seconds in 3-month-old rats.The first refeeding increased the time to 156 seconds with a further rise to 340 seconds following the second fasting,then dropped to 116 seconds by the second refeeding.20 months old rats showed 186 seconds increase in the time of chromatin decondensation and nuclear membrane disintegration after the first fasting,with a decrease to 140 seconds observed after first refeeding.The second fasting increased the time to 165 seconds,which then slightly decreased to 163 seconds after the second refeeding.Conclusion:These results show that intermittent fasting may have acted on chromatin histone interactions and the structural lamin networks of the nuclear membranes in bringing about nuclear stability,which is essential for normal cellular function.
文摘HEAVY ion physics has been rapidly developing at the limits of energy (nuclear temperature), isospin and spin. Heavy ion research facility of Lanzhou (HIRFL) is of cyclotron family delivering intermediate energy heavy ions. During the recent years, progress has been made in the studies of heavy ion physics as well as in the development of the HIRFL. This review article will
文摘The evolution of far wake of stationary elliptic cylinders with angle of attack is investigated for the unsteady flow at Re=200 using a stabilized finite-element method.The Reynolds number,Re,is based on the major axis of cylinder and free-stream speed.Cylinder aspect ratios,AR considered are 0.2,0.5 and 0.8 while the angle of attack,αvaries from 0° to 90°.With increasingα,the Karman or primary shedding frequency of each cylinder decreases monotonically while the primary wavelength and time-averaged as well as r.m.s.drag increase monotonically.The time-averaged lift and moment coefficients initially increase withαand then decrease.The power spectrum analysis of unsteady transverse velocity signal at various stations along the wake centerline is used to study the associated frequencies.The Karman or primary shedding frequency exists for eachα.For the AR=0.2 cylinder,the secondary and subsequently,low magnitude tertiary frequencies appear in the wake asαcontinues to increase from 30°.In contrast to the decaying nature of primary frequency withα,secondary frequency exhibits a nonmonotonic variation.The secondary frequency in general is not a sub-harmonic of the primary.This suggests that the secondary structures do not form due to merging of primary vortices.With increasingα,the location of formation of secondary structures advances upstream.For a given orientation,the upstream advancement is more dominant with decreasing AR.Power spectrum analysis indicates that the wake state for confined flow is characterized by the primary frequency alone,i.e.the imposition of blockage suppresses the formation of secondary structures.
文摘Radioactivity of nuclei in a centrifugal force field of an ultracentrifuge is considered for heavy radioactive nuclei, i.e., for the same nuclei, but with a significant virtual mass thousands of times larger than the actual mass and is characterized by an angular momentum. As the nucleus leaves the centrifugal force field, the virtual mass disappears, but the spin number appears and/or changes. The role of centrifugal and gravitational forces in radioactive decay of nuclei is studied. According to the terminology of western researchers, such a virtual mass state is called the dynamic gravitation which is more adequate. The oscillator and possible changes in the nucleus state are considered under conditions of dynamic gravitation and taking into account features of atomic nucleus physics. To a first approximation, the drop model of the nucleus was used, in which shape fluctuations have much in common with geophysical and astrophysical analogues. Shape fluctuations of analogues strongly depend on the gravitational force g defined by their mass (or nucleus mass). Experiments were performed by radiometric measurements of transbaikalian uranium ore (1.5 g) with known composition in a centrifuge at various rotation rates or gravitational forces g. The existence of characteristic times or the effect of rotation frequencies (i.e., g) on atomic nuclei, which, along with the nucleus type itself, controls the nucleus response to perturbation (stability increase or decay), is found statistically significant.
基金Projects(50601011,50432020) supported by the National Natural Science Foundation of ChinaProject(A2720060295) supported by the Basic Research Project of National Defense of China+1 种基金Project(BK2006533) supported by the Natural Science Foundation of Jiangsu Province, ChinaProject supported by the New Century Excellent Talents in University Program
文摘The effects of 5%Ni addition on the glass forming ability,thermal stability and crystallization behavior of Mg65Cu25Tb10 bulk metallic glass were investigated using X-ray diffractometry,differential scanning calorimetry and transmission electron microscopy.The small amount of Ni addition reduces the glass forming ability and thermal stability due to a significant decrease in the crystallization activation energy.Analyses of crystallization kinetics give evidence to the existence of quenched-in nuclei in amorphous Mg65Cu20Ni5Tb10.Final crystallization products are basically same for Mg65Cu25Tb10 and Mg65Cu20Ni5Tb10.
基金The Natural Science Foundation of China(Nos.6143500961177087+7 种基金61377099)National Program on Key Basic Research Project(973 Program)(No.2012CB722703)International Science&Technology Cooperation Program of China(No.2011DFA12040)Scientific Research Fund of Zhejiang Provincial Education Department(No.R1101263)Natural Science Foundation of Ningbo(No.2013A610118)Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions of MOE,P.R.C.Ningbo Optoelectronic Materials and Devices Creative Team(No.2009B21007)Scientific Research Foundation of Graduate School of Ningbo University,K.C.Wong Magna Fund of Ningbo University and the Outstanding(No.Postgraduate)Dissertation Growth Foundation of Ningbo University(No.PY2014014)
