In this paper, the axial tensile process of single crystal titanium nano-rod is simulated based on the Finnis-Sinclair embedded atom potential by molecular dynamics. The mechanical properties of the titanium nano-rod with different cross-section dimension along three orientations ([0001]、[-12-10]、[10-10]) are analyzed. The results show as follows: 1) The tension process of titanium nano-rod along three orientations all includes four stages which are elastic deformation, uniform plastic deformation, localized necking and fault stage. 2) The larger the cross-section is, the smaller the yield stress is. 3) Along the [0001] orientation the yield stress and elastic modulus of titanium nano-rod is the largest, but fracture strain is the smallest; along the [-12-10] orientation the yield stress and elastic modulus is the smallest, but the fracture strain is the largest; along the [10-10] orientation the tension mechanical properties is in the middle of the other two orientations.

In this paper, the method for plane wave ultrasoft pseudopotentials of first-principles is adopted to calculate electronic structures of three models including VN crystal, the absence of V atoms and the replacement of V atoms by Si atoms by the VASP software package. On the basis of the optimized VN’s lattice constant, the energy band structures and density of states(DOS) curves of those three models are analyzed. The results show that the 3d electrons of V atoms determine that VN crystal is a conductor. The crystal lack of V atoms forms a peak caused by the empty position near the Fermi level. Its valence band energy level splits and the ability to form bonds reduces to be a metastable phase structure. The formation of solid solution interface due to Si atoms replacing V atoms leads to the peak value of total DOS to decrease, the distribution of electrons to be more diffuse and the ability to form bonds to strengthen.

Ba4Sm9.33Ti18O54(BST) ceramics were prepared by conventional solid-state reaction method. The effect of CuO-Bi2O3co-doping on the sintering behavior and microwave dielectric properties of BST ceramics has been investigated. The results indicated that when the total addition of CuO-Bi2O3doping agent was 1.0wt%, the sintering temperature of BST ceramics was reduced to 1240°C as a result of liquid-phase sintering effect derived from CuBi2O4. When the total addition of CuO-Bi2O3was fixed at 1.0wt%, the microwave dielelctric properties of BST were improved by adjusting the mass percentage of Bi2O3. With the increase of Bi2O3amount from 20wt% to 80wt%, the dielectric constant (εr) decreased, the quality factor (Q•f) increased and the temperature coefficient of resonant frequency (τf) shifted from negative value to positive value. The excellent microwave dielectric properties of εr=82.51, Q•f=7878GHz and τf=+6.02ppm/ were obtained for the sample with Bi2O3amount of 80wt% when sintered at 1240°C for 3h.