Wang Xiao-Lin

Study of analytic potential energy function and stability for PuOn + with density functional theory

The theoretical study of PuOn + (n=1,2,3) using a density functional method shows that PuO+ (X6Si-) and PuO2+ (X5Si-, 7Si-, 9Si-) ions are stable and the PuO3+ (4Si+, 6Si+) ion is unstable. The analytic potential energy functions of X6Si- for PuO+ and X5Si-, 7Si-, 9Si- for PuO2+ have been derived and their force constants and spectroscopic data have been calculated.

Potentional Energy Function and Stability of PuO n

用密度泛函Ｂ３ＬＹＰ方法对ＰｕＯ＾ｎ＋（ｎ＝１，２，３）分子离子进行了理论研究。结果表明，ＰｕＯ＾＋、ＰｕＯ＾２＋分子离子能稳定存在，电子状态是Ｘ＾６∑＾－（ＰｕＯ＾＋）、Ｘ＾５（ＰｕＯ＾２＋）、＾９∑＾－（ＰｕＯ＾２＋、＾７∑＾－（ＰｕＯ＾２＋），导出了相应的几何性质，力学性质和光谱数据。ＰｕＯ＾３＋分子离子不能稳定存在。

In Situ X-ray Diffraction Study of the Tensile Deformation of U-5.8Nb Alloy

Abstract The in situ X-ray diffraction (XRD) was used during uniaxial tensile loading to study the lattice response and deformation behavior of α ″ U-5.8 wt% Nb (U5.8Nb) alloy. Diffraction patterns were recorded at incremental macroscopic strains until fracture of the sample, and the XRD data were analyzed by Rietveld method and single-peak fitting. The changes regulation of lattice parameter, diffraction peak intensity and interplanar spacing with applied stress during deformation were analyzed. It is found that the elastic deformation and the twinning deformation (reorientation) coexist in the initial stage of the first yield platform. The lattice response suggests that the remarkable anisotropy of elastic limit in various directions should be the genesis of double yield curve.