CO2加氢生成醋酸的研究

ＣＯ２加氢生成醋酸的研究范宾张成芳陆岗俞丰倪燕慧（华东理工大学化工工艺研究所，上海２００２３７）关键词二氧化碳加氢，醋酸，铑催化剂关于ＣＯ２加氢直接生成醋酸，国内外学者研究得很少，日本的Ｎｏｒｉｇｕｋｉ报道了［１］在ＣＯ２催化加氢反应中有少量醋...     

ON SELF-ABSORPTION CORRECTION IN EXCIMER FLUORESCENCE MEASUREMENTS OF POLYMER SOLUTIONS

The effect of self absorption on the ratio of excimer to monochromophore emission intensities, I_e/I_m, has beenexplored by experimentally changing the solution layer thickness of the emission light path traversed in the solution in theright-angle geometry. The result shows that data obtained by front-face geometry are better than those obtained by right-angle geometry even after correction to zero solution thickness. The correction formula based on geometric optics given byTsai and Torkelson is not adequate.     

顶空GC法测定蔬菜中硫氰酸盐的新方法

本文根据ＳＣＮ－与氯胺Ｔ反应生成氯化氰的原理，应用顶空气相色谱法测定蔬菜中的ＳＣＮ－，本法变异系数０．６５％－１．９８％，回收率为９３．７－９９．７％。     

Electronic and magnetic properties of Fe-, Co-, and Ni-decorated BC3: A first-principles study

The electronic and magnetic properties of Fe-, Co-, and Ni-decorated two dimensional (2D) BC₃ are systematically investigated by first-principles calculations. We find that the Fe, Co, and Ni atoms can be strongly adsorbed on the hollow sites of 2D BC₃. Fe and Co adatoms are more stable when adsorbed on the hollow sites of the carbon rings in the 2D BC₃, while the hollow sites of boron-carbon rings in the 2D BC₃ are the most stable sites for the adsorption of Ni adatoms. These proposed metal–BC₃ complexes exhibit interesting electronic and magnetic behaviors. In particular, the Fe–BC₃ and Co–BC₃ complexes are metals with magnetic ground states , while the Ni–BC₃ complex behaves as a nonmagnetic semiconductor with a direct bandgap. Furthermore, our magnetic analysis reveals that induced magnetism in the Fe–BC₃ and Co–BC₃ complexes arises from their local magnetic moments. Functionalization of 2D BC₃ through these metal–adatom adsorption appears to be a promising way to extend its applications.     

Nonlinear instability for nonhomogeneous incompressible viscous fluids

We investigate the nonlinear instability of a smooth steady density profile solution to the three-dimensional nonhomogeneous incompressible Navier-Stokes equations in the presence of a uniform gravitational field, including a Rayleigh-Taylor steady-state solution with heavier density with increasing height (referred to the Rayleigh-Taylor instability). We first analyze the equations obtained from linearization around the steady density profile solution. Then we construct solutions to the linearized problem that grow in time in the Sobolev space H ^k , thus leading to a global instability result for the linearized problem. With the help of the constructed unstable solutions and an existence theorem of classical solutions to the original nonlinear equations, we can then demonstrate the instability of the nonlinear problem in some sense. Our analysis shows that the third component of the velocity already induces the instability, which is different from the previous known results.     

Comparisons of soil pretreatment methods for SF-ICP-MS determination of ultra-trace level plutonium in water soluble and exchangeable fractions

Journal of Radioanalytical and Nuclear Chemistry - In this study, we developed a method to evaluate the potentially bioavailable fraction of Pu in agricultural soils by determining their water...