Monometallic and bimetallic model catalysts on either refractory metal singlecrystals as planar surfaces or oxide supports as nano-size clusters have been systematically studied using X-ray photoemission spectroscopy (XPS), low energy ion scattering spectroscopy (LEIS), low energy electron diffraction (LEED), infrared reflection absorption spectroscopy (IRAS), and temperature programmed desorption (TPD) under ultra-high vacuum (UHV) conditions. Of particular interest in this investigation is the characterization of the surface composition, morphology, and electronic/geometric structure of the following catalysts: Au/TiOx, Au-Pd/Mo(110), Au- Pd/SiO2, Cu-Pd/Mo(110), and Sn/Pd(100). Structure-reactivity correlations during surface-alloy formation and adsorption-desorption processes were explained in terms of ensemble and ligand effects. Prospects of translating the accumulated atomic-level information into more efficient 'real world' catalysts were discussed.

Many empirical and theoretical studies show that workers obtain jobs through their social contacts. This paper attempts to investigate how the difference of individuals’ intrinsic abilities in obtaining their jobs affects the social network structure that emerges. When the probability of players who get job information by themselves is large enough, low-ability players will maintain more contacts than high-ability players do. We analyze the equilibrium network structures in homogeneous society and heterogeneous society respectively. For analyzing more complex cases that people are heterogeneous in their ability of obtaining jobs, we suggest a new equilibrium concept: Forward Induction Network Equilibrium (FINE), a refinement of pairwise stability equilibrium. According to FINE, the possible equilibrium network structures can be reduced drastically and the outcomes are either symmetric or close-to-symmetric equilibrium networks. We show that the difference of social contacts among overall individuals is no greater than one contact in the close-to-symmetric equilibrium networks.