Surface Chemistry and Catalysis of Rare Earth Oxides I．A Study of the Reactivity of Surface Hydroxyls on CeO_2 and Pr_6O_（11） by FT－IR Spectroscopy

The surface chemical properties of CeO2 and Pr6O11 have been investigated with FT-IR spectroscopy. The reactivities of surface hydroxyls were tested through the reaction of CO. Surface formate species are formed on CeO2 and Pr6O11 under CO atmosphere at 200℃ . and the reaction becomcs more prevailing at higher temperatures especially for partially reduced samples. The surface formate species are produced via the reaction of CO with surface hydroxyls which was confirmed by the reaction of CO with D2-treated CeO2 and Pr6O11. The Surface formate can be oxidized to carbonate at temperatures exceeding 300 ℃, and the surface hydroxyls could be recovered as the formate species decompose or are oxidized to carbonate species. The roles played by the surface hydroxyls and surface active sites in the CO oxidation are discussed.

镨对青虾卵子孵化的影响

研究了镨 (Pr)对青虾 (Macrobrachiumnipponense)卵子孵化出氵蚤状幼体的影响 ,结果表明 :Pr3 + 的最佳质量浓度为 0 4～ 1 6mg/L ,可提高孵化率 12 4%～ 2 0 3%。青虾卵子对Pr3 + 的饱和吸收量为 9 2 μg/粒 ,饱和吸收率为 36 8%。

Pr(Ⅲ)和Nd(Ⅲ)的氯化物与谷氨酸和天冬氨酸的配合物

由于镧系离子与钙离子的半经相近且具特殊性质,它作为生物大分子化合物中钙离子的位置探针的研究是目前稀土生物无机化学的一个研究主题,因此对于镧系离子与生物活性物质相互作用的研究对该主题的深入了解是有意义的。于是本文研究了三价镨和钕离子与氨基酸[谷氨酸(Glu)和天冬氨酸(Asp)]的作用及其配合物的性质。