The atomic scale computer simulation for initial precipitation mechanism of Ni75Al6V19 alloy was carried out for the first time by employing the microscopic diffusion equation. The initial precipitation process was in...The atomic scale computer simulation for initial precipitation mechanism of Ni75Al6V19 alloy was carried out for the first time by employing the microscopic diffusion equation. The initial precipitation process was invest igated throughsimulating the atomic pictures and calculating the order parameters of the two kinds of ordered phases. Simulationresults show that the γ′ordered phase precipitated earlier than θ ordered phase by congruent ordering+spinodal decomposition mechanism and thus produced a nonstoicheometric γ′ single ordered phase. Then, the nonstoichiometricθ phase precipitated by a non-classical nucleation and growth mechanism at the APBS of γ′ phase.展开更多
A new isopolyoxovanadate [Ni(1,10′-phen) 3] 2 [V Ⅳ 2V Ⅴ 8O 26] was hydrothermally synthesized and structurally characterized by the single crystal X-ray diffraction. The compound crystallizes in orthorhombic system...A new isopolyoxovanadate [Ni(1,10′-phen) 3] 2 [V Ⅳ 2V Ⅴ 8O 26] was hydrothermally synthesized and structurally characterized by the single crystal X-ray diffraction. The compound crystallizes in orthorhombic system, space group Pbcn with a=1.362 9(3) nm, b=2.215 6(4) nm, c= 2.571 2(4) nm, V=7.764(2) nm 3, Z=4, R=0.040 3, wR 2=0.044 6. The compound exhibits an unusual empty ellipsoidal cage, which is constructed by eight {V ⅤO 4} tetrahedra and two {V ⅣO 5} square pyramids via corner-sharing modes. The chiral [Ni(1,10′-phen) 3] 2+ complexes act as the counter cations.展开更多
基金National Natural Science Foundation of China (50671084 and 50875217)Natural Science Foundation of Shaanxi Province (2003E106, SJ08-ZT05)China Postdoctoral Science Foundation (20070420218)
基金This work was supported by the National Natural Science Foundation of China (Grant No.50071046)
文摘The atomic scale computer simulation for initial precipitation mechanism of Ni75Al6V19 alloy was carried out for the first time by employing the microscopic diffusion equation. The initial precipitation process was invest igated throughsimulating the atomic pictures and calculating the order parameters of the two kinds of ordered phases. Simulationresults show that the γ′ordered phase precipitated earlier than θ ordered phase by congruent ordering+spinodal decomposition mechanism and thus produced a nonstoicheometric γ′ single ordered phase. Then, the nonstoichiometricθ phase precipitated by a non-classical nucleation and growth mechanism at the APBS of γ′ phase.
文摘A new isopolyoxovanadate [Ni(1,10′-phen) 3] 2 [V Ⅳ 2V Ⅴ 8O 26] was hydrothermally synthesized and structurally characterized by the single crystal X-ray diffraction. The compound crystallizes in orthorhombic system, space group Pbcn with a=1.362 9(3) nm, b=2.215 6(4) nm, c= 2.571 2(4) nm, V=7.764(2) nm 3, Z=4, R=0.040 3, wR 2=0.044 6. The compound exhibits an unusual empty ellipsoidal cage, which is constructed by eight {V ⅤO 4} tetrahedra and two {V ⅣO 5} square pyramids via corner-sharing modes. The chiral [Ni(1,10′-phen) 3] 2+ complexes act as the counter cations.
