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Using first-principles calculations, we predict mechanical and thermodynamic properties of both Mg17Al12and Mg2Sn precipitates in Mg–Al–Sn alloys. The elastic properties including the polycrystalline bulk modulus, shear modulus, Young’s modulus, Lame’s coefficients and Poisson’s ratio of both Mg17Al12and Mg2Sn phases are determined with the Voigt–Reuss–Hill approximation. Our results of equilibrium lattice constants agree closely with previous experimental and other theoretical results. The ductility and brittleness of the two phases are characterized with the estimation from Cauchy pressure and the value ofB/G. Mechanical anisotropy is characterized by the anisotropic factors and direction-dependent Young’s modulus. The higher Debye temperature of Mg17Al12phase means that it has a higher thermal conductivity and strength of chemical bonding relative to Mg2Sn. The anisotropic sound velocities also indicate the elastic anisotropies of both phase structures. Additionally, density of states and Mulliken population analysis are performed to reveal the bonding nature of both phases. The calculations associated with phonon properties indicate the dynamical stability of both phase structures. The temperature dependences of thermodynamic properties of the two phases are predicted via the quasi-harmonic approximation. [ABSTRACT FROM PUBLISHER]

The goal of the research on ontology framework for content-based 3D model retrieval is to develop a rich set of 3D model semantic representation so that both humans and machines can generate and understand model descriptions and processing for fast efficient retrieval from model collections. The purpose of ontology development for content-based 3D model retrieval is intended to describe model information regardless of storage, feature extraction and creation. The ontology includes the information on media features, low level visual descriptors, non media features of 3D model and their relationships. It is implemented in protégé 3.1. [ABSTRACT FROM AUTHOR]