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Articles 1 - 6 of 6
Full-Text Articles in Physical Sciences and Mathematics
Nonlinear Effects Of Physisorption On Static Friction, G.T. Gao, Xiao Cheng Zeng, Dennis J. Diestler
Nonlinear Effects Of Physisorption On Static Friction, G.T. Gao, Xiao Cheng Zeng, Dennis J. Diestler
Xiao Cheng Zeng Publications
The effects of a physisorbed film on the force of static friction in a model contact (monatomic adsorbate confined between plane-parallel walls) were investigated by Monte Carlo simulation. At fixed coverage the friction curve (shear yield stress vs normal stress) exhibits a marked nonlinearity, which results from a competition between adsorbate–wall interactions that predominate at low loads and wall–wall interactions that set in beyond a threshold load, which increases with coverage. Previous proximal-probe and computer experiments, carried out at high coverages, see only the initial (low-load) linear portion of the friction curve.
Ice Nanotube: What Does The Unit Cell Look Like?, Kenichiro Koga, Ruben D. Parra, Hideki Tanaka, Xiao Cheng Zeng
Ice Nanotube: What Does The Unit Cell Look Like?, Kenichiro Koga, Ruben D. Parra, Hideki Tanaka, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
It is discovered that for an n-gonal ice nanotube built from stacking a single type of n-gonal rings of water, the unit cell consists of two stacked n-gonal rings. In one ring the O–H bonds of water molecules line up clockwise whereas in the other ring the O-H bonds line up counterclockwise. Among the n-gonal ice nanotubes examined, the pentagonal or hexagonal ice nanotube appears to be the most stable.
The Melting Temperature Of Proton-Disordered Hexagonal Ice: A Computer Simulation Of 4-Site Transferable Intermolecular Potential Model Of Water, G.T. Gao, Xiao Cheng Zeng, Hideki Tanaka
The Melting Temperature Of Proton-Disordered Hexagonal Ice: A Computer Simulation Of 4-Site Transferable Intermolecular Potential Model Of Water, G.T. Gao, Xiao Cheng Zeng, Hideki Tanaka
Xiao Cheng Zeng Publications
We report computer simulation results of free energies of proton-disordered hexagonal ice and liquid water at atmospheric pressure with the 4-site transferable intermolecular potential model of water. A new reference system is used to calculate the free energy of the ice phase. The melting point of proton-disordered hexagonal ice at atmospheric pressure is found to be Tm=238 (±7) K. This result is consistent with a previous estimation, 230K< TmK, from molecular dynamic simulation of the surface melting of the proton-disordered hexagonal ice [G.-J. Kroes, Surf. Sci. 275, 365 (1992)].
Freezing Transition Of A Strongly Dipolar Simple Fluid, G.T. Gao, Xiao Cheng Zeng
Freezing Transition Of A Strongly Dipolar Simple Fluid, G.T. Gao, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
The freezing transition of a strongly dipolar Lennard-Jones fluid is investigated using Monte Carlo simulation. It is found that the system undergoes a ferroelectric liquid-to-solid transition when cooled under a constant pressure. Near the triple point the stable solid phase is a body-centered orthorhombic ferroelectric crystal; a metastable ferroelectric solid phase with distorted hexagonal lattice structure is also discovered. To locate the freezing point, Gibbs free energies of the solid and liquid phase are determined using a thermodynamic integration method.
Molecular Dynamics Simulation Of Supersaturated Vapor Nucleation In Slit Pore, K. Yasuoka, G.T. Gao, Xiao Cheng Zeng
Molecular Dynamics Simulation Of Supersaturated Vapor Nucleation In Slit Pore, K. Yasuoka, G.T. Gao, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
Molecular dynamics simulations of nucleation of Lennard-Jones vapor confined in a slit pore have been performed. The walls of the slit pore are structureless walls; each wall interacts with vapor molecules via Lennard-Jones 9–3 potential. The rate of nucleation in the steady state is determined by analyzing time evolution of the cluster size distribution. At the same vapor density and temperature, the nucleation rate in the slit pore is higher than in the homogeneous vapor [K. Yasuoka and M. Matsumoto, J. Chem. Phys. 109, 8451 (1998)], irrespective of the strength of attraction between the wall and vapor molecules. However, this …
A Small-System Ensemble Monte Carlo Simulation Of Supersaturated Vapor: Evaluation Of Barrier To Nucleation, K.J. Oh, Xiao Cheng Zeng
A Small-System Ensemble Monte Carlo Simulation Of Supersaturated Vapor: Evaluation Of Barrier To Nucleation, K.J. Oh, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
A small-system grand canonical ensemble Monte Carlo method is developed to evaluate cluster size distribution and barrier to the nucleation in a supersaturated Lennard-Jones vapor. The theoretical foundation is a physical cluster theory in which the Stillinger cluster is used as a prototypical physical cluster. Using method of Mayer’s cluster expansion, the cluster–vapor interaction is effectively taken into account. From a separate canonical ensemble Monte Carlo simulation using a test particle method, the averaged volume of the cluster is obtained and is also incorporated in the small-system ensemble simulation. By this implementation our simulation is computationally more efficient compared to …