废物库周围地下水中的放射性核素分布研究

中国工程物理研究院核物理与化学研究所原工作地点 (老点 )存在两个放射性废物库 5 37 1和 5 37 2。年内分别在库周围取地下水 (或土 ) 6次 ,对 5 37 1得到地下水和泥土中的铀含量大约为 1.2 7μg L和 3.0 μg L ,对5 37 2得到的地下水中的90 Sr含量约为 5 .35× 10 - 3 Bq L。上列数据与本底无明显差异。可见 ,5 37 1废物库周围地下水中铀含量与生活区河水中含量无明显差异 ,5 37 2废物库周围地下水中锶含量与生活区河水中含量也无明显差异。至今未监测到两个废物库中的放射性核素对周围地下水中的明显影响     

Elasto-plastic buckling and post-buckling analysis of sandwich plates with functionally graded metal-metal face sheets and interfacial damage简

Based on the elasto-plastic theory, considering the effect of spherical stress tensor on the elasto-plastic deformation and using the slicing treatment to deal with the plasticity of functionally graded coatings, the elasto-plastic increment constitutive equations of the sandwich plates with functionally graded metal-metal face sheets can be derived. Applying the weak bonded theory to the interfacial constitutive relation and taking into account the geometric nonlinearity, the nonlinear increment differential equilibrium equations of the sandwich plates with functionally graded metal-metal face sheets are obtained by the minimum potential energy principle. The finite difference method and the iterative method are used to obtain the post-buckling path. When the effect of geometrical nonlinearity of the plate is ignored, the elasto-plastic critical buckling load of the sandwich plates with functionally graded metal-metal face sheets can be solved by the Galerkin method and the iterative method. In the numerical examples, the effects of the interface damages, the induced load ratio, the functionally graded index, and the geometry parameters on the elasto-plastic post-buckling path and the elasto-plastic critical buckling load are investigated.