Grand Canonical Monte Carlo (GCMC) method was employed to simulate the adsorption properties of molecular hydrogen on ion-exchanged X zeolites at 100–293 K and pressures up to 10 MPa in this paper. The effect of cation type, temperature, and pressure on hydrogen adsorption capacity, heat of adsorption, adsorption sites, and adsorption potential energy of ion-exchanged X zeolites was analyzed. The results indicate that the hydrogen adsorption capacity increases with the decrease in temperatures and the increase in pressures and decreases in the order ofKX<LiX<CaX. The isosteric heat of adsorption for all the three zeolites decreases appreciably with the increase in hydrogen adsorption capacity. The hydrogen adsorption sites in the three zeolites were determined by the simulated distribution of hydrogen adsorption energy and the factors that influence their variations were discussed. Adsorption temperature has an important effect on the distribution of hydrogen molecules in zeolite pores.

In the present study, the composites have been prepared using vacuum hot pressing process technique. The influence of 2.0 wt.% nanometric SiC particles (n-SiC_p) on the microstructure and fracture mechanism of 7075 aluminum alloy was studied by means of metallographic microscope, scanning electron microscope (SEM), energy-dispersive spectrometer (EDS), X-ray diffraction (XRD), laser scanning confocal (LSC). The results indicate that SiC_p fill at grain boundaries dispersing evenly and nail to aluminum grains which sizes have been reduced successfully, that making the organization tighter, the gaps fewer and the surface rougher. Meanwhile, phases (MgZn₂) precipitated from the 7075 aluminum alloy were been detected. The grain bonding states of matrix alloys are strengthened by the combination of fine grains strengthening and dispersion strengthening and thus affect the fracture morphology. The micro-fracture mechanism of 7075 aluminum alloy is micro-porous aggregation fracture, however, the 7075 aluminum matrix composites (AMCs) are quasi cleavage fracture.