A well designed continuous annular chromatograph （CAC） column was set to stndy the enrichment of Boron isotopes. The column is 820 mm high and consists of a rotational annulus with an outer diameter of 246 mm and a ...A well designed continuous annular chromatograph （CAC） column was set to stndy the enrichment of Boron isotopes. The column is 820 mm high and consists of a rotational annulus with an outer diameter of 246 mm and a width of 15 mm. The weak basic resin （Diaion WA21J）, the boric acid and water were used as the absorbent, the feed and the eluent respectively. The effects of CAC rotating speed, concentration of boric acid and flow ratio of eluent to feed on the enrichment of 10B were investigated. The concentration of boron isotope was determined by a Thermal Elemental X7 ICP-MS （Thermo Electron Co., USA）. It is shown from the experimental results that 10B and 11B can be separated effectively by this CAC column. By fitting the experimental elution profiles based on reliable mathematic models and software the mass transfer coefficient k and adsorp- tion equilibrium constant K values of 10B and 11B in CAC column were estimated. It is clear from this study that the CAC has practical continuous operational capabilities in comparison with fixed batch chromatography and is an effective technology for seoarating boron isotones.展开更多
Naturally occurring secolignans have drawn the considerable attention because of their novel structures and diverse biological activities.In recent years,various natural secolignans with extensive bioactivities have b...Naturally occurring secolignans have drawn the considerable attention because of their novel structures and diverse biological activities.In recent years,various natural secolignans with extensive bioactivities have been reported in the literatures.In the present review,we summarized all the available information regarding the biosynthesis,distributions,separation methods,chemical structures,spectral characteristics,and biological activities of natural secolignans,and provided some valuable new insights for the further study.展开更多
基金supported by the Scientific and Technological Innovation Capacity Promotion Plan Project of Qinghai Province of China(2010-J-749)
文摘A well designed continuous annular chromatograph （CAC） column was set to stndy the enrichment of Boron isotopes. The column is 820 mm high and consists of a rotational annulus with an outer diameter of 246 mm and a width of 15 mm. The weak basic resin （Diaion WA21J）, the boric acid and water were used as the absorbent, the feed and the eluent respectively. The effects of CAC rotating speed, concentration of boric acid and flow ratio of eluent to feed on the enrichment of 10B were investigated. The concentration of boron isotope was determined by a Thermal Elemental X7 ICP-MS （Thermo Electron Co., USA）. It is shown from the experimental results that 10B and 11B can be separated effectively by this CAC column. By fitting the experimental elution profiles based on reliable mathematic models and software the mass transfer coefficient k and adsorp- tion equilibrium constant K values of 10B and 11B in CAC column were estimated. It is clear from this study that the CAC has practical continuous operational capabilities in comparison with fixed batch chromatography and is an effective technology for seoarating boron isotones.
基金National Natural Science Foundation of China(Grant No.81374067)Shanghai Municipal Health Commission(Grant No.2018ZY002)
文摘Naturally occurring secolignans have drawn the considerable attention because of their novel structures and diverse biological activities.In recent years,various natural secolignans with extensive bioactivities have been reported in the literatures.In the present review,we summarized all the available information regarding the biosynthesis,distributions,separation methods,chemical structures,spectral characteristics,and biological activities of natural secolignans,and provided some valuable new insights for the further study.
