Based on the first principles, the physical parameters such as point defect formation enthalpy H, elastic constants C₁₁, C₁₂, C₄₄, bulk modulus B, shear modulus G, Young's modulus E and Poisson's ratio γ that characterize the strength and toughness of materials in Ag-based alloys doped with alloying elements such as Cu, Zr, W, Cr, Sn, Ni, In, Zn, Ir were calculated in this paper. The difficulty of doping different alloy atoms in Ag matrix and the effects of the valence electron difference ΔV between the alloy atom and the Ag atom on the elastic properties of the Ag-based alloy were analyzed. With the increase of the ΔV, the ability of Ag-based alloys to resist plastic deformation, shear deformation and maintain crystal structure stability during shear deformation can be enhanced. Furthermore, differential charge density of Ag-based alloy projected on the {1 0 0} plane shows the spatial distribution of charge transfer before and after bonding. It is found that the enhanced elastic properties of Ag-base alloy can be attributed to the strong bonding between the alloy atom and Ag atom.

A corrected panel method is shown and applied to static aeroealsticity.Based on CFD data at different attack angles the method approximates curved lifting lines by linear segment.The corrected panel method fills drawback of original one by considering nonlinear factor.Compared with CFD,similar accuracy limit and higher efficiency are obtained in aerodynamic force loss and attack angle compensation of M6 wing.It indicates that the method is suitable for complex structure optimization.

The electron transport properties in 2H-,4H-,and 6H-Silicon Carbide are investigated numerically with an ensemble Monte Carlo technique.The acoustic phonon deformation potential scattering,polar optical phonon scattering,intervalley phonon deformation scattering,ionized impurity scattering and neutral impurity scattering are considered.The electron mobilities of 2H-,4H-,and 6H-SiC as a function of temperature at low electric field are obtained.The influence of the neutral impurity scattering on the transport property of 4H-SiC is discussed in detail.Finally,the static and transient variation of electron drift velocity in high electric fields are studied.The peak transient velocity in an electricfield of 1.0×10⁶ V·cm^-1 is 3.3×10⁷cm·s~(-1) for 4H-Sic and 3.0×10⁷ cm·s^-1 for 6H-Sic when the electric field is applied perpendicular to the c axis.The simulated results are in good agreement with recent experiments in a wide range of temperature and electric field.