No abstract

This study employed the molecular dynamics (MD) and grand canonical Monte-Carlo (GCMC) methods to investigate the adsorption and diffusion performances of methane and carbon dioxide in illite, montmorillonite, and calcite and to explore their molecular dynamic properties under different buried depths. The results suggested that, in the adsorption simulation, with the increase in buried depths, the adsorption capacities and adsorption heats of illite and montmorillonite for methane and carbon dioxide at the buried depths of 0−6 km first showed an increase and then a decrease, while those of calcite showed a continuous decreasing trend. The adsorption capacity for methane conformed to the following order: montmorillonite > illite > calcite, while that for carbon dioxide followed the order of montmorillonite > calcite > illite. The adsorption capacities of these three minerals for carbon dioxide were superior to those for methane. In the diffusion simulation, at the buried depths of 0−6 km, the self-diffusion coefficients of methane and carbon dioxide first showed a decrease and then an increase. In the mixed adsorption, methane was more susceptible to competitive adsorption, and the competitive adsorption between methane and carbon dioxide was more obvious in montmorillonite.

No abstract

This paper investigates the effects of interparticle distance and heating rate on the aggregation characteristics of Cu/Au nanoparticles using molecular dynamics (MD) simulations, and focuses on discussing the effects of the two above-mentioned factors on the entire system. Our results suggested that the reduction in heating rate and increasing the initial distance of the particles would both contribute to raising the initial sintering temperature. However, when the particles’ initial distance was greater than the cut-off radius of the system, the initial sintering temperature was not increased any longer, but fluctuated within a certain range. Furthermore, the sintering force of the nanoparticles at the initial sintering temperature was investigated, and it was found that the heating rate made no obvious difference to it. Nonetheless, the sintering force varied under different initial distance of the particles (at the same heating rate) due to system energy changes.

No abstract