The adsorption capacity of a shale gas reservoir is mainly determined by the isothermal adsorption experiment. In this study, the building conditions and performances of seven single-component and five multi-component adsorption models were compared and analyzed. The results show that most shale gas reservoir adsorption characteristics obey those of type I on the macroscopic scale. The adsorption isotherms of single components can be described by the Langmuir-Freundlich, Langmuir, and Toth models. The revised Langmuir, extended Langmuir, and the loading ratio correlation (LRC) models can be applied to binarycomponent mixtures; and the extended Langmuir and LRC models perform best for shale gas. The obtained results might have an important promoting effect for modeling the shortage of shale gas.

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Abrasive flow polishing plays an important part in modern ultra-precision machining. Ultrafine particles suspended in the medium of abrasive flow removes the material in nanoscale. In this paper, three-dimensional molecular dynamics (MD) simulations are performed to investigate the effect of impacting direction on abrasive cutting process during abrasive flow polishing. The molecular dynamics simulation software Lammps was used to simulate the cutting of single crystal copper with SiC abrasive grains at different cutting angles (0o–45o). At a constant friction coefficient, we found a direct relation between cutting angle and cutting force, which ultimately increases the number of dislocation during abrasive flow machining. Our theoretical study reveal that a small cutting angle is beneficial for improving surface quality and reducing internal defects in the workpiece. However, there is no obvious relationship between cutting angle and friction coefficient.