Double-emulsion templated macroporous cellulose microspheres as a high-performance chromatographic media for protein separation

Cellulose - Cellulose microspheres are commonly chromatographic media yet seriously limited in biomacromolecules separation and purification due to the slow mass transfer kinetics resulting from...     

Flow Injection Kinetic Spectrophotometric Determination of Cerium Based on the Decolorization Reaction Between Arsenazo III and Cerium (IV)

ABSTRACT

Trace amounts of cerium were analyzed by flow injection kinetic spectrophotometry, based on the decolorization reaction between arsenazo III and Ce(IV) in sulfuric acid medium at room temperature. The absorbance difference (ΔA) of decolorization was linear with the concentration of Ce(IV). The flow injection technique was used to precisely control the timing. Under the optimum conditions, the determination of Ce(IV) in the range 0.0–8.0 µg mL^?1 with a correlation coefficient (r) of 0.9982, the regression equation was ΔA = 0.0014 + 0.0406c (µg mL^?1). The detection limit (3σ) of 0.2 µg mL^?1 was achieved at a sampling frequency of 60 h^?1. The proposed method was applied to the analyses of Ce in soil successfully.     

手性2-取代哌嗪类药物中间体的合成进展

手性2-取代哌嗪是一类重要的医药中间体,在药物合成领域有着广阔的应用前景。本文概述了当前手性2-取代哌嗪的合成方法。     

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前手翻屈体前空翻2周是男子跳马最高难度动作之一. 迄今,我国只有胡俊捷曾完成 该动作. 本文通过三维运动学分析技术揭示了胡俊捷完成前手翻屈体前空翻2周动作的运动 学规律与技术特点,获得了身体重心和主要关节的位移,水平速度和垂直速度及关节角度等 运动学指标的变化. 这些结果可为我国运动员发展和改进此类动作提供理论依据和技术参 考.