جستجوی مقالات مرتبط با کلیدواژه « مدول حجمی » در نشریات گروه « مواد و متالورژی »

In this paper, we investigate the structural, electronic and optical properties of tetragonal and cubic phase ofSr2NiWO6. The calculations have been performed using the FP-LAPW method in the framework of perturbation density functional theory whit GGA+U approximation by Wien2k package. In this research structural properties of  Sr2NiWO6such as lattice constants, bulk modulus and its derivative properties are investigated during structural calculations. The result of band structureshow that there isbandgap 2.80 eV for tetragonal and 2.73 eV for cubic phase. The calculated are in good agreement with theoretical and experimental results.

In this article, the stress-time or speed-time relation for a steady intense shock wave front and effective parameters on it in solid metals (except alkaline metals) were studied. First, the parameters relevant to the deformation of a pure material were identified and a relation between them was found. Then with simplifying assumptions, a stress change equation was obtained. Afterwards, the modulus of the material was considered and after some simplification, it was substituted in the equation. After non-dimensionalization, effective parameters for a loading by an intense shock wave were obtained. The results of solving the dimensionless equations simulated the profile of the shock loading, gived the approximated rise time and width of the strong shock wave front and helped to explain that the maximum strain rate occurred near the centre of the shock wave profile. It was shown that when the local shear stress is higher than the lattice strength, a small step is formed on the particle velocity-time profile.