Using earth satellite observation means, remote sensing information distilled technique and regional research production, we have roundly analyzed and made an integrated evaluation about the Lop Nur nuclear test field...Using earth satellite observation means, remote sensing information distilled technique and regional research production, we have roundly analyzed and made an integrated evaluation about the Lop Nur nuclear test field in western China. This product reveals the rarely-known nuke explosion effect and response events of geology conditions. It also offers us legible and practical first-hand materials about human extreme effects, important engineering environment and intimidating influence process. By excavating and appraising the materials gradually on the natural environment factors changing in the test field through macroscopic elimination and typical filtration, it can supply basic scientific data for security of national nuclear usage, appraising the nuclear environment synthetically and developing nuclear strategy expediently.展开更多
We used the Cornwall, Jackiw and Tomboulis （CJT） resummation scheme to study nuclear matter. In the CJT formalism the meson propagators are treated as the bare propagators and the the higher order loop corrections o...We used the Cornwall, Jackiw and Tomboulis （CJT） resummation scheme to study nuclear matter. In the CJT formalism the meson propagators are treated as the bare propagators and the the higher order loop corrections of the thermodynamic potential are evaluated at the Hartree approximation, while the vacuum fluctuations are ignored. Under these treatments in the CJT formalism we derived exact mean-field theory （MFT） results for the nuclear matter. The results are thermodynamically consistent, and our study indicates that the MFT result is the lowest order resummation result in the CJT resummation scheme. The relation between CJT formalism and MFT is clearly presented through the calculations.展开更多
After graduating from the physics department of Qinghua University in 1952, I started working in the development of nuclear detectors (including cloud chambers and scintillometers) under the instruction of Profs. Yang...After graduating from the physics department of Qinghua University in 1952, I started working in the development of nuclear detectors (including cloud chambers and scintillometers) under the instruction of Profs. Yang Chengzhong and Dai Chuanzeng at the CAS Institute of Modern Physics.From 1956 to 1958,I studied at Lebedev’s Institute of Physics under the Soviet Academy展开更多
Based on calculating the influence of RF-field with various physical parameters on the dynamics of the spin 1/2 system,it was found that the spin state could be changed up and down by choosing appropriate RF pulses, a...Based on calculating the influence of RF-field with various physical parameters on the dynamics of the spin 1/2 system,it was found that the spin state could be changed up and down by choosing appropriate RF pulses, and the coherent control of the RF pulses could substantially modify the behavior of spin dynamics:quicker change of two states could be produced even for small pulse duration.In addition,the oscillatory structures around the resonant frequency and the propagation features of the pulses depend on the relative phase of the bichromatic RF pulses.展开更多
Nuclear-spin states of gaseous-state Cs atoms in the ground state are optically manipulated using a Ti：sapphire laser in a magnetic field of 1.516 T, in which optical coupling of the nuclear-spin states is achieved t...Nuclear-spin states of gaseous-state Cs atoms in the ground state are optically manipulated using a Ti：sapphire laser in a magnetic field of 1.516 T, in which optical coupling of the nuclear-spin states is achieved through hyperfine interactions between electrons and nuclei. The steady-state population distribution in the hyperfine Zeeman sublevels of the ground state is detected by using a tunable diode laser. Furthermore, the state population transfer among the hyperfine Zeeman sublevels, which results from the collision-induced modification δa（S·I） of the hyperfine interaction of Cs in the ground state due to stochastic collisions between Cs atoms and buffer-gas molecules, is studied at different buffer-gas pressures. The experimental results show that high-field optical pumping and the small change δa（S · I） of the hyperfine interaction can strongly cause the state population transfer and spin-state interchange among the hyperfine Zeeman sublevels. The calculated results maybe explain the steady-state population in hyperfine Zeeman sublevels in terms of rates of optical-pumping, electron-spin flip, nuclear spin flip, and electron-nuclear spin flip-flop transitions among the hyperfine Zeeman sublevels of the ground state of Cs atoms. This method may be applied to the nuclear-spin-based solid-state quantum computation.展开更多
An anomalous isotope effect exists in many heavy element isotope systems （e.g., Sr, Gd, Zn, U）. This effect used to be called the ＂odd--even isotope effect＂ because the odd mass number isotopes behave differently ...An anomalous isotope effect exists in many heavy element isotope systems （e.g., Sr, Gd, Zn, U）. This effect used to be called the ＂odd--even isotope effect＂ because the odd mass number isotopes behave differently from the even mass number isotopes. This mass-indepen- dent isotope fractionation driving force, which originates from the difference in the ground-state electronic energies caused by differences in nuclear size and shape, is cur- rently denoted as the nuclear field shift effect （NFSE）. It is found that the NFSE can drive isotope fractionation of some heavy elements （e.g., Hg, T1, U） to an astonishing degree, far more than the magnitude caused by the con- ventional mass-dependent effect （MDE）. For light ele- ments, the MDE is the dominant factor in isotope fractionation, while the NFSE is neglectable. Furthermore, the MDE and the NFSE both decrease as temperatures increase, though at different rates. The MDE decreases rapidly with a factor of 1/T2, while the NFSE decreases slowly with a factor of 1/T. As a result, even at high temperatures, the NFSE is still significant for many heavy element isotope systems. In this review paper, we begin with an introduction of the basic concept of the NSFE, including its history and recent progress, and follow with the potential implications of the inclusion of the NFSE into the kinetic isotope fractionation effect （KIE） and heavy isotope geochronology.展开更多
On the basis of fracture mechanics earthquake rupture model, the relations between source parameters and (0, the value of tectonic ambient shear stress in the place where the earthquake occurs, have been derived. Thus...On the basis of fracture mechanics earthquake rupture model, the relations between source parameters and (0, the value of tectonic ambient shear stress in the place where the earthquake occurs, have been derived. Thus, we can calculate a large number of values of tectonic ambient shear stress or values of background stress in the place where the earthquake occurs. If nuclear explosions are treated as earthquakes in the calculation, we find that (0 values of nuclear explosions have about 20 MPa, which is obviously higher than average (0 values of earthquakes with the same magnitude. This result can be used to discriminate nuclear explosions from earthquakes.展开更多
Apparent softening of the symmetry energy with the inclusion of hyperon and quark degrees of freedom is demonstrated by the fact that the phase transition causes the change of the interaction and the suppression of nu...Apparent softening of the symmetry energy with the inclusion of hyperon and quark degrees of freedom is demonstrated by the fact that the phase transition causes the change of the interaction and the suppression of nucleon fractions.The demonstration is fulfilled in the relativistic mean-field model.展开更多
Based on the new screening model, this paper discusses the influence of superstrong magnetic fields on nuclear energy generation rates on the surface of magnetars. The obtained result shows that the superstrong magnet...Based on the new screening model, this paper discusses the influence of superstrong magnetic fields on nuclear energy generation rates on the surface of magnetars. The obtained result shows that the superstrong magnetic fields can increase the nuclear energy generation rates by many orders of magnitude. The enhancement may have a significant influence for further study of the magnetars, especially for the cooling, the x-ray luminosity observation and the evolution of the magnetars.展开更多
基金The State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chi-nese Academy of Sciences, the open fund item (No. SKLLQG0701) to subsidizedthe constructprogram of the key discipline in Hunan Province, China, the fund item (No. D2007001) the State Key Labo-ratories of Continental Dynamics,Northwest University, the open fund item (No. DL2006001) to combine subsi-dized.
文摘Using earth satellite observation means, remote sensing information distilled technique and regional research production, we have roundly analyzed and made an integrated evaluation about the Lop Nur nuclear test field in western China. This product reveals the rarely-known nuke explosion effect and response events of geology conditions. It also offers us legible and practical first-hand materials about human extreme effects, important engineering environment and intimidating influence process. By excavating and appraising the materials gradually on the natural environment factors changing in the test field through macroscopic elimination and typical filtration, it can supply basic scientific data for security of national nuclear usage, appraising the nuclear environment synthetically and developing nuclear strategy expediently.
基金supported by National Natural Science Foundation of China (Nos.10905018,10875050)
文摘We used the Cornwall, Jackiw and Tomboulis （CJT） resummation scheme to study nuclear matter. In the CJT formalism the meson propagators are treated as the bare propagators and the the higher order loop corrections of the thermodynamic potential are evaluated at the Hartree approximation, while the vacuum fluctuations are ignored. Under these treatments in the CJT formalism we derived exact mean-field theory （MFT） results for the nuclear matter. The results are thermodynamically consistent, and our study indicates that the MFT result is the lowest order resummation result in the CJT resummation scheme. The relation between CJT formalism and MFT is clearly presented through the calculations.
文摘After graduating from the physics department of Qinghua University in 1952, I started working in the development of nuclear detectors (including cloud chambers and scintillometers) under the instruction of Profs. Yang Chengzhong and Dai Chuanzeng at the CAS Institute of Modern Physics.From 1956 to 1958,I studied at Lebedev’s Institute of Physics under the Soviet Academy
文摘Based on calculating the influence of RF-field with various physical parameters on the dynamics of the spin 1/2 system,it was found that the spin state could be changed up and down by choosing appropriate RF pulses, and the coherent control of the RF pulses could substantially modify the behavior of spin dynamics:quicker change of two states could be produced even for small pulse duration.In addition,the oscillatory structures around the resonant frequency and the propagation features of the pulses depend on the relative phase of the bichromatic RF pulses.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10374103 and 10574143）, and the National Basic Research Program of China （Grant No 2001CB309309）.
文摘Nuclear-spin states of gaseous-state Cs atoms in the ground state are optically manipulated using a Ti：sapphire laser in a magnetic field of 1.516 T, in which optical coupling of the nuclear-spin states is achieved through hyperfine interactions between electrons and nuclei. The steady-state population distribution in the hyperfine Zeeman sublevels of the ground state is detected by using a tunable diode laser. Furthermore, the state population transfer among the hyperfine Zeeman sublevels, which results from the collision-induced modification δa（S·I） of the hyperfine interaction of Cs in the ground state due to stochastic collisions between Cs atoms and buffer-gas molecules, is studied at different buffer-gas pressures. The experimental results show that high-field optical pumping and the small change δa（S · I） of the hyperfine interaction can strongly cause the state population transfer and spin-state interchange among the hyperfine Zeeman sublevels. The calculated results maybe explain the steady-state population in hyperfine Zeeman sublevels in terms of rates of optical-pumping, electron-spin flip, nuclear spin flip, and electron-nuclear spin flip-flop transitions among the hyperfine Zeeman sublevels of the ground state of Cs atoms. This method may be applied to the nuclear-spin-based solid-state quantum computation.
基金funding support from the973 Program(2014CB440904)Chinese NSF projects(41225012,41490635,41530210)
文摘An anomalous isotope effect exists in many heavy element isotope systems （e.g., Sr, Gd, Zn, U）. This effect used to be called the ＂odd--even isotope effect＂ because the odd mass number isotopes behave differently from the even mass number isotopes. This mass-indepen- dent isotope fractionation driving force, which originates from the difference in the ground-state electronic energies caused by differences in nuclear size and shape, is cur- rently denoted as the nuclear field shift effect （NFSE）. It is found that the NFSE can drive isotope fractionation of some heavy elements （e.g., Hg, T1, U） to an astonishing degree, far more than the magnitude caused by the con- ventional mass-dependent effect （MDE）. For light ele- ments, the MDE is the dominant factor in isotope fractionation, while the NFSE is neglectable. Furthermore, the MDE and the NFSE both decrease as temperatures increase, though at different rates. The MDE decreases rapidly with a factor of 1/T2, while the NFSE decreases slowly with a factor of 1/T. As a result, even at high temperatures, the NFSE is still significant for many heavy element isotope systems. In this review paper, we begin with an introduction of the basic concept of the NSFE, including its history and recent progress, and follow with the potential implications of the inclusion of the NFSE into the kinetic isotope fractionation effect （KIE） and heavy isotope geochronology.
文摘On the basis of fracture mechanics earthquake rupture model, the relations between source parameters and (0, the value of tectonic ambient shear stress in the place where the earthquake occurs, have been derived. Thus, we can calculate a large number of values of tectonic ambient shear stress or values of background stress in the place where the earthquake occurs. If nuclear explosions are treated as earthquakes in the calculation, we find that (0 values of nuclear explosions have about 20 MPa, which is obviously higher than average (0 values of earthquakes with the same magnitude. This result can be used to discriminate nuclear explosions from earthquakes.
基金Supported by National Natural Science Foundation of China(NSFC) projects (Nos.10975033 and 11275048)
文摘Apparent softening of the symmetry energy with the inclusion of hyperon and quark degrees of freedom is demonstrated by the fact that the phase transition causes the change of the interaction and the suppression of nucleon fractions.The demonstration is fulfilled in the relativistic mean-field model.
基金Project supported by the National Natural Science Foundation of China (Grant No 10778719)by Scientific Research and Fund of Sichuan Provincial Education Department of China (Grant Nos 2006A079 and 07BZ090)
文摘Based on the new screening model, this paper discusses the influence of superstrong magnetic fields on nuclear energy generation rates on the surface of magnetars. The obtained result shows that the superstrong magnetic fields can increase the nuclear energy generation rates by many orders of magnitude. The enhancement may have a significant influence for further study of the magnetars, especially for the cooling, the x-ray luminosity observation and the evolution of the magnetars.
