Hybrid graphene/h-BN model is studied via molecular dynamics simulation to observe the evolution of graphene layer upon heating. Model containing 20,064 atoms is heated up from 50 to 8000 K via Tersoff and Lennard–Jones potentials. Various thermodynamic quantities, structural characteristics, and the occurrence of liquid-like atoms are studied. The Lindemann criterion for 2D case is calculated and used to observe the appearance of liquid-like atoms. The atomic mechanism of structural evolution upon heating is analyzed on the basis of the occurrence/growth of liquid-like atoms, the formation of clusters, the coordination number, and the ring statistics. The liquid-like atoms tend to form clusters and the largest cluster increases slightly in order to form a single largest cluster of liquid-like atoms. The other models such as free-standing graphene, zigzag GNR, and armchair GNR are also presented to have an entire picture about the evolution of graphene upon heating in different models. Note that the largest clusters of free-standing graphene as well as zigzag GNR, and armchair GNR tend to decrease to form a ring-like 2D liquid carbon.

Ground source heat pumps are clean, energy-efficient and environment-friendly systems. Although the initial cost of ground source heat pump system is higher than that of air source heat pump, it is now widely accepted as an economical system since the installation cost can be returned within an short period of time due to its high efficiency. In the present study, performances of ground source compound hybrid heat pump system applied to a resort building are simulated. The system design and operation process appropriate for the surrounding circumstance guarantee the high benefit of the heat pump system applied to a resort building. If among several renewable energy sources, ground, river, sea, waste water source are chosen as available alternative energies are combined, COP of the system can be increased largely and hybrid heat pump system can reduced the fuel cost.