The influence of lattice misfit on the occupation behavior and the ductility effect of Zr in Ni—Ni_3AI alloys were explored.It is found in energy analysis that the preferable site of Zr between Ni sublattice and Al sublattice will change under different lattice misfit,however,the Zr prefers to segregate Ni phase rather than Ni_3AI phase in all lattice misfit range,which makes it impossible for Zr to go into Ni_3AI phase to occupy Al sublattice in Ni—Ni_3AI system.Bond order(BO)analysis shows that the localized ductility effect of Zr differs in different region,and the comparison between Zr-free and Zr-doped BO analysis successfully explain the mechanism of the embrittlement of Ni—Ni_3AI alloys and the ductility effect of Zr.
溴化镁与三苯基膦氧在乙醇溶液中反应生成新的可用于MgO粒子制备前驱体的双核镁化合物[Mg2(μ-OH2)2(H2O)4-(OPPh3)4]Br4。单晶X射线衍射分析表明:该双核镁配合物结构由一个均氧配位的双核镁阳离子基团与4个溴离子所组成,两对溴离子参与形成分子间的O H Br氢键,并组成了由[Mg2(μ-O)2(O)4]核所共享的高度扭曲立方烷构型,其中每个镁原子与2个μ-OH2、2个OH2和2个OPPh3中的6个氧原子组成了八面体的空间结构,Mg O(PPh3)、Mg O(OH2)和MgμO(OH2)的平均键长分别为198.3(2),206.1(2)和226.0(2)pm。
