A thermal model of kinetic friction is assigned to a classical loaded particle moving on a fluctuating smooth surface.A sinusoidal wave resembles surface fluctuations with a relaxation time.The Hamiltonian is approxim...A thermal model of kinetic friction is assigned to a classical loaded particle moving on a fluctuating smooth surface.A sinusoidal wave resembles surface fluctuations with a relaxation time.The Hamiltonian is approximated to the mean energy of the wave describing a system of Harmonic oscillators.The quantization of amplitudes yields in terms of annihilation and creation operators multiplied by a quantum phase.Further,we consider acoustic dispersion relation and evaluate the friction coefficient from the force autocorrelation function.While the sliding particle remains classical describing a nano-particle or a tip with negligible quantum effects like tunneling or delocalization in the wave function,the quantized model of the surface fluctuations results in the temperature dependence of the kinetic friction coefficient.It follows an asymptotic value for higher temperatures and supper-slipperiness at low temperatures.展开更多
By making use of the modified quantum molecular dynamics(MQMD)which includes thePauli potential and the isospin dependent interaction as well as the frictional cooling method for getting aground state of nucleus,the f...By making use of the modified quantum molecular dynamics(MQMD)which includes thePauli potential and the isospin dependent interaction as well as the frictional cooling method for getting aground state of nucleus,the fermionic behavior of nucleons and the distribution of fragments in heavy ioncollisions(HIC)have been studied.The calculated results obviously show the shell effect of fragments.Aqualitative agreement is established between the experimental data and the results of antisymmetrizedmolecular dynamics(AMD)calculation.展开更多
In this paper, an irreversible quantum Otto refrigeration cycle working with harmonic systems is established. Base on Heisenberg quantum master equation, the equations of motion for the set of harmonic systems thermod...In this paper, an irreversible quantum Otto refrigeration cycle working with harmonic systems is established. Base on Heisenberg quantum master equation, the equations of motion for the set of harmonic systems thermodynamic observables are derived. The simulated diagrams of the quantum Otto refrigeration cycle are plotted. The relationship between average power of friction, cooling rate, power input, and the time of adiabatic process is analyzed by using numerical calculation. Moreover, the influence of the heat conductance and the time of iso-frequency process on the performance of the cycle is discussed.展开更多
文摘A thermal model of kinetic friction is assigned to a classical loaded particle moving on a fluctuating smooth surface.A sinusoidal wave resembles surface fluctuations with a relaxation time.The Hamiltonian is approximated to the mean energy of the wave describing a system of Harmonic oscillators.The quantization of amplitudes yields in terms of annihilation and creation operators multiplied by a quantum phase.Further,we consider acoustic dispersion relation and evaluate the friction coefficient from the force autocorrelation function.While the sliding particle remains classical describing a nano-particle or a tip with negligible quantum effects like tunneling or delocalization in the wave function,the quantized model of the surface fluctuations results in the temperature dependence of the kinetic friction coefficient.It follows an asymptotic value for higher temperatures and supper-slipperiness at low temperatures.
基金①The project supported by the National Natural Science Foundation of Chinathe Science Foundation of Chinese Academy of Sciences
文摘By making use of the modified quantum molecular dynamics(MQMD)which includes thePauli potential and the isospin dependent interaction as well as the frictional cooling method for getting aground state of nucleus,the fermionic behavior of nucleons and the distribution of fragments in heavy ioncollisions(HIC)have been studied.The calculated results obviously show the shell effect of fragments.Aqualitative agreement is established between the experimental data and the results of antisymmetrizedmolecular dynamics(AMD)calculation.
文摘In this paper, an irreversible quantum Otto refrigeration cycle working with harmonic systems is established. Base on Heisenberg quantum master equation, the equations of motion for the set of harmonic systems thermodynamic observables are derived. The simulated diagrams of the quantum Otto refrigeration cycle are plotted. The relationship between average power of friction, cooling rate, power input, and the time of adiabatic process is analyzed by using numerical calculation. Moreover, the influence of the heat conductance and the time of iso-frequency process on the performance of the cycle is discussed.
