In order to clarify the apparent discrepancy in determinations of melting temperature Tm of Mo between diamondanvil cell （DA C） measurements from 0 to about 100 GPa and shock wave （SW） measurement at only one pres...In order to clarify the apparent discrepancy in determinations of melting temperature Tm of Mo between diamondanvil cell （DA C） measurements from 0 to about 100 GPa and shock wave （SW） measurement at only one pressure of about 390 GPa by comparison with visual extrapolation, we perform SW experiments to replenish more Tm data on purpose to make this comparison more directly and rationally as well. The techniques adopted consist of Hvgoniot sound velocity measurement for porous Mo and shock-induced release Tm measurements for both solid and porous Mo. Totally five SW Tm data, which extends the measured pressure range from previous about 390 GPa down to about 136 GPa that is close to the highest pressure （about 100 GPa） attained by previous DAC experiments, are therefore obtained. These measured Tm data, other than the extrapolated as mentioned above, exhibit a manner of continuous variation with pressure and can be fitted well with Lindemann melting description. More significantly, the measured Tm data at lowest pressure are still much higher than that of the DACs and the overall trend of these Tm data is against to the two-segment melting curve model, with a sudden change in dTm/dp at about 210 GPa, previously proposed by Errandonea [Physica B 357 （2005） 356]. Though the problem of large discrepancy in Tm data measured between DAC and SW has not been completely explained, our knowledge on this matter achieves indubitable progress since it is of value to programme the next clarification. Some suggestions for further clarifying the issue of large discrepancy between DAC and SW measurements are also proposed.展开更多
The double complex symmetric gravitational theory is extended to the parametric symmetric gravitational theory by introducing a parameter β. Hence parametric Friedmann-Robertson-Walker equations are obtained and some...The double complex symmetric gravitational theory is extended to the parametric symmetric gravitational theory by introducing a parameter β. Hence parametric Friedmann-Robertson-Walker equations are obtained and some characters of dark energy in corresponding spaces are discussed by taking different values of β. In our method some previous results can be included as the special case of our results. It is worth noting that some characters of dark energy can be more intuitively described in our model. By analysis, we can predict that the fate of universe would be a Big Rip in the future, and also find that the state parameters for the two different constraint conditions wФ are consistent with the present cosmological observations.展开更多
We study the expansion behaviors of a Fermionic superfluid in a cigar-shaped optical dipole trap for the whole BEC-BCS crossover and various temperatures.At low temperature(0:06(1)T_F),the atom cloud undergoes an anis...We study the expansion behaviors of a Fermionic superfluid in a cigar-shaped optical dipole trap for the whole BEC-BCS crossover and various temperatures.At low temperature(0:06(1)T_F),the atom cloud undergoes an anisotropic hydrodynamic expansion over 30 ms,which behaves like oscillation in the horizontal plane.By analyzing the expansion dynamics according to the superfluid hydrodynamic equation,the effective polytropic index y of Equation-of-State(EoS)of Fermionic superfluid is extracted.The y values show a non-monotonic behavior over the BEC-BCS crossover,and have a good agreement with the theoretical results in the unitarity and BEC side.The normalized quasi-frequencies of the oscillatory expansion are measured,which drop significantly from the BEC side to the BCS side and reach a minimum value of 1.73 around 1/k_Fa=-0:25.Our work improves the understanding of the dynamic properties of strongly interacting Fermi gas.展开更多
Shock wave data for Jilin ordinary chondrite and Nandan iron meteorite are measured by electric-pin techniques on the dynamic high-pressure device equipped with a two-stage light gas gun, and then equation-of-states s...Shock wave data for Jilin ordinary chondrite and Nandan iron meteorite are measured by electric-pin techniques on the dynamic high-pressure device equipped with a two-stage light gas gun, and then equation-of-states supposedly fit for describing their P-V-E relations are chosen to evaluate the values of their parameters. Demonstrated from the comparison between P-V curves of equation-of-states and experimental data points, P-V relation of Jilin ordinary chondrite can be described by the universal equation-of-state, of which bulk modulus value of zero-pressure K0s = 48.10 GPa, its pressure derivative K'os = 4.13. That of Nandan iron meteorite can be described by the three-term form of equation-of-state, of which the values of two matter parameters Q = 41.23531 GPa, 5 = 12.271 79. The Hugoniot data and equation-of-states for Jilin ordinary chondrite and Nandan iron meteorite are first reported in this paper. The equation-of-state defined by Hugoniot data measurement provides strong empirical support for describing the compression of meteorites to high pressure.展开更多
A simplified version of generalized Chaplygin gas （GCG） as a dark energy model is studied. By using the latest 162 ESSENCE type Ia supernovae （She Ia） data, 30 high redshift She Ia data, the baryonic acoustic osci...A simplified version of generalized Chaplygin gas （GCG） as a dark energy model is studied. By using the latest 162 ESSENCE type Ia supernovae （She Ia） data, 30 high redshift She Ia data, the baryonic acoustic oscillation peak from SDSS and the CMB data from WMAP3, a strong constraint on this simplified GCG model is obtained. At the 95.4% confidence level we obtain 0.21 ≤ Ωm ≤ 0.31 and 0.994 〈 α 〈 1.0 with the best fit Ωm = 0.25 and a = 1. This best fit scenario corresponds to an accelerating universe with qo ≈-0.65 and z ≈ 0.81 （a redshiR of cosmic phase transition from deceleration to acceleration）.展开更多
In this paper,we investigate the quantum dynamics of a non-relativistic particle confined by the Aharonov-Bohm quantum flux field with pseudoharmonic-type potential in the background of topological defect produced by ...In this paper,we investigate the quantum dynamics of a non-relativistic particle confined by the Aharonov-Bohm quantum flux field with pseudoharmonic-type potential in the background of topological defect produced by a point-like global monopole.We solve the radial Schrödinger equation analytically and determine the exact eigenvalue solution of the quantum system.Afterwards,we consider a Mie-type potential in the quantum system and solve the radial equation analytically and obtain the eigenvalue solution.We analyze the effects of the topological defect and the quantum flux with these potentials on the energy eigenvalue and wave function of the nonrelativistic particles.In fact,it is shown that the energy levels and wave functions are influenced by the topological defect shifted the result compared to the flat space results.In addition,the quantum flux field also shifted the eigenvalue solutions and an analogue of the Aharonov-Bohm effect for bound-states is observed.Finally,we utilize these eigenvalue solutions to some known diatomic molecular potential models and presented the energy eigenvalue and wave function.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No I0776029/A06, the National Key Laboratory Fund for Shock Wave and Detonation Physics Research under Grant No 9140C6702030802, and the Science Foundation of China Academy of Engineering Physics under Grant No 2007B09002
文摘In order to clarify the apparent discrepancy in determinations of melting temperature Tm of Mo between diamondanvil cell （DA C） measurements from 0 to about 100 GPa and shock wave （SW） measurement at only one pressure of about 390 GPa by comparison with visual extrapolation, we perform SW experiments to replenish more Tm data on purpose to make this comparison more directly and rationally as well. The techniques adopted consist of Hvgoniot sound velocity measurement for porous Mo and shock-induced release Tm measurements for both solid and porous Mo. Totally five SW Tm data, which extends the measured pressure range from previous about 390 GPa down to about 136 GPa that is close to the highest pressure （about 100 GPa） attained by previous DAC experiments, are therefore obtained. These measured Tm data, other than the extrapolated as mentioned above, exhibit a manner of continuous variation with pressure and can be fitted well with Lindemann melting description. More significantly, the measured Tm data at lowest pressure are still much higher than that of the DACs and the overall trend of these Tm data is against to the two-segment melting curve model, with a sudden change in dTm/dp at about 210 GPa, previously proposed by Errandonea [Physica B 357 （2005） 356]. Though the problem of large discrepancy in Tm data measured between DAC and SW has not been completely explained, our knowledge on this matter achieves indubitable progress since it is of value to programme the next clarification. Some suggestions for further clarifying the issue of large discrepancy between DAC and SW measurements are also proposed.
基金Supported by the National Natural Science Foundation of China under Grant No 10475036, the Natural Science Foundation of Liaoning Province under Grant No 20032102, and the Scientific Research Foundation of the Higher Education Institute of Liaoning Province under Grant No 05L215.
文摘The double complex symmetric gravitational theory is extended to the parametric symmetric gravitational theory by introducing a parameter β. Hence parametric Friedmann-Robertson-Walker equations are obtained and some characters of dark energy in corresponding spaces are discussed by taking different values of β. In our method some previous results can be included as the special case of our results. It is worth noting that some characters of dark energy can be more intuitively described in our model. By analysis, we can predict that the fate of universe would be a Big Rip in the future, and also find that the state parameters for the two different constraint conditions wФ are consistent with the present cosmological observations.
基金supported by the National Natural Science Foundation of China (11874340)the National Key R&D Program of China (2018YFA0306501)+2 种基金the CASthe Anhui Initiative in Quantum Information Technologiesthe Fundamental Research Funds for the Central Universities (WK2340000081)
文摘We study the expansion behaviors of a Fermionic superfluid in a cigar-shaped optical dipole trap for the whole BEC-BCS crossover and various temperatures.At low temperature(0:06(1)T_F),the atom cloud undergoes an anisotropic hydrodynamic expansion over 30 ms,which behaves like oscillation in the horizontal plane.By analyzing the expansion dynamics according to the superfluid hydrodynamic equation,the effective polytropic index y of Equation-of-State(EoS)of Fermionic superfluid is extracted.The y values show a non-monotonic behavior over the BEC-BCS crossover,and have a good agreement with the theoretical results in the unitarity and BEC side.The normalized quasi-frequencies of the oscillatory expansion are measured,which drop significantly from the BEC side to the BCS side and reach a minimum value of 1.73 around 1/k_Fa=-0:25.Our work improves the understanding of the dynamic properties of strongly interacting Fermi gas.
基金Project supported by the National Natural Science Foundation of China
文摘Shock wave data for Jilin ordinary chondrite and Nandan iron meteorite are measured by electric-pin techniques on the dynamic high-pressure device equipped with a two-stage light gas gun, and then equation-of-states supposedly fit for describing their P-V-E relations are chosen to evaluate the values of their parameters. Demonstrated from the comparison between P-V curves of equation-of-states and experimental data points, P-V relation of Jilin ordinary chondrite can be described by the universal equation-of-state, of which bulk modulus value of zero-pressure K0s = 48.10 GPa, its pressure derivative K'os = 4.13. That of Nandan iron meteorite can be described by the three-term form of equation-of-state, of which the values of two matter parameters Q = 41.23531 GPa, 5 = 12.271 79. The Hugoniot data and equation-of-states for Jilin ordinary chondrite and Nandan iron meteorite are first reported in this paper. The equation-of-state defined by Hugoniot data measurement provides strong empirical support for describing the compression of meteorites to high pressure.
文摘A simplified version of generalized Chaplygin gas （GCG） as a dark energy model is studied. By using the latest 162 ESSENCE type Ia supernovae （She Ia） data, 30 high redshift She Ia data, the baryonic acoustic oscillation peak from SDSS and the CMB data from WMAP3, a strong constraint on this simplified GCG model is obtained. At the 95.4% confidence level we obtain 0.21 ≤ Ωm ≤ 0.31 and 0.994 〈 α 〈 1.0 with the best fit Ωm = 0.25 and a = 1. This best fit scenario corresponds to an accelerating universe with qo ≈-0.65 and z ≈ 0.81 （a redshiR of cosmic phase transition from deceleration to acceleration）.
基金Program of Sichuan Province of China under Grant(06ZQ026-010)Program of Education Minis-tration of China under Grant(NCET-05-0799)Program of UESTC under Grant(23601008)
文摘In this paper,we investigate the quantum dynamics of a non-relativistic particle confined by the Aharonov-Bohm quantum flux field with pseudoharmonic-type potential in the background of topological defect produced by a point-like global monopole.We solve the radial Schrödinger equation analytically and determine the exact eigenvalue solution of the quantum system.Afterwards,we consider a Mie-type potential in the quantum system and solve the radial equation analytically and obtain the eigenvalue solution.We analyze the effects of the topological defect and the quantum flux with these potentials on the energy eigenvalue and wave function of the nonrelativistic particles.In fact,it is shown that the energy levels and wave functions are influenced by the topological defect shifted the result compared to the flat space results.In addition,the quantum flux field also shifted the eigenvalue solutions and an analogue of the Aharonov-Bohm effect for bound-states is observed.Finally,we utilize these eigenvalue solutions to some known diatomic molecular potential models and presented the energy eigenvalue and wave function.
