RESUMEN
The effect of Y intercalation on the atomic, electronic, and magnetic properties of the graphene/Co(0001) interface is studied using state-of-the-art density functional theory calculations. Different structural models of the graphene/Y/Co(0001) interface are considered: (i) graphene/Y/Co(0001), (ii) graphene/1ML-YCo2/Co(0001), and (iii) graphene/bulk-like-YCo2(111). It is found that the interaction strength between graphene and the substrate is strongly affected by the presence of Y at the interface and the electronic structure of graphene (doping and the appearance of the energy gap) is defined by the Y concentration. For the Co-terminated interfaces between graphene and the metallic support in the considered systems, the electronic structure of graphene is strongly disturbed, leading to the absence of the linear dispersion for the graphene π band; in the case of the Y-terminated interfaces, a graphene layer is strongly n-doped, but the linear dispersion for this band is preserved. Our calculations show that the magnetic anisotropy for the magnetic atoms at the graphene/metal interface is strongly affected by the adsorption of a graphene layer, giving a possibility for one to engineer the magnetic properties of the graphene/ferromagnet systems.
RESUMEN
Aiming at improving the operating efficiency of air freight station, the problem of optimizing the sequence of inbound/outbound tasks meanwhile scheduling the actions of elevating transfer vehicles (ETVs) is discussed in this paper. First of all, the scheduling model in airport container storage area, which considers not only the influence of picking sequence, optimal ETVs routing without collision, but also the assignment of input and output ports, is established. Then artificial bee colony (ABC) is proposed to solve the above scheduling issue. For further balancing the abilities of exploration and exploitation, improved multi-dimensional search (IMABC) algorithm is proposed where more dimensions will be covered, and the best dimension of the current optimal solution is used to guide the evolutionary direction in the following exploitation processes. Numerical experiments show that the proposed method can generate optimal solution for the complex scheduling problem, and the proposed IMABC outperforms original ABC and other improved algorithms.