Thermodynamic estimation is still too much requested for scientific applications in spite of great advances in simulation methods for efficient determination of phase equilibrium of multi-component systems. In this wo...Thermodynamic estimation is still too much requested for scientific applications in spite of great advances in simulation methods for efficient determination of phase equilibrium of multi-component systems. In this work, thermodynamic properties of deuterium-tritium mixture in a wide range of temperatures and pressures have been predicted. Buckingham exp-6 potential has been utilized in calculations, based on statistical perturbation theory. The effects of various values of density, temperature and isotopic concentrations on pressure have been studied. Eventually, we have found out symmetrical effects of tritium concentration in deuterium-tritium mixtures.展开更多
In this work, the isotherm and energy distribution atT= 304 K of dense helium are studied by molecular dynamic (MD) simulations with exp-6 potential r* = 2.967 3 á (the position of the weil minimum) and ?/k B = 1...In this work, the isotherm and energy distribution atT= 304 K of dense helium are studied by molecular dynamic (MD) simulations with exp-6 potential r* = 2.967 3 á (the position of the weil minimum) and ?/k B = 10.8 K (? is the well-depth andk B is the Boltzmann constant) given by Peter et al., and different values of stiffness parameter α. The optimized value of α= 12.7 is deduced that can describe the atomic interactions for dense helium satisfactorily. This optimized α in exp-6 potential is used to conduct MD simulations of two isotherms of dense helium atT= 300 K andT = 298 K. The calculations are in good agreement with the experimental. We further employed this method to investigate the equation-of-state and structure of dense helium at higher temperatures and found that when the density remained 1.6 g/cm3, the second peak of the radial distribution function would disappear in the temperature range from 2 000 to 3 040 K, demonstrating that a solid-liquid transition or decrystallization had occurred.展开更多
文摘Thermodynamic estimation is still too much requested for scientific applications in spite of great advances in simulation methods for efficient determination of phase equilibrium of multi-component systems. In this work, thermodynamic properties of deuterium-tritium mixture in a wide range of temperatures and pressures have been predicted. Buckingham exp-6 potential has been utilized in calculations, based on statistical perturbation theory. The effects of various values of density, temperature and isotopic concentrations on pressure have been studied. Eventually, we have found out symmetrical effects of tritium concentration in deuterium-tritium mixtures.
文摘In this work, the isotherm and energy distribution atT= 304 K of dense helium are studied by molecular dynamic (MD) simulations with exp-6 potential r* = 2.967 3 á (the position of the weil minimum) and ?/k B = 10.8 K (? is the well-depth andk B is the Boltzmann constant) given by Peter et al., and different values of stiffness parameter α. The optimized value of α= 12.7 is deduced that can describe the atomic interactions for dense helium satisfactorily. This optimized α in exp-6 potential is used to conduct MD simulations of two isotherms of dense helium atT= 300 K andT = 298 K. The calculations are in good agreement with the experimental. We further employed this method to investigate the equation-of-state and structure of dense helium at higher temperatures and found that when the density remained 1.6 g/cm3, the second peak of the radial distribution function would disappear in the temperature range from 2 000 to 3 040 K, demonstrating that a solid-liquid transition or decrystallization had occurred.
