Aim To study chemical constituents from Ampelopsis grossedentata. Methods Separation and purification were performed by using silica gel, polyamide, reverse-phase silica gel, Sephadex LH-20 column chromatographic tech...Aim To study chemical constituents from Ampelopsis grossedentata. Methods Separation and purification were performed by using silica gel, polyamide, reverse-phase silica gel, Sephadex LH-20 column chromatographic techniques and silica gel PTLC. Structures were determined by means of physicochemical properties and spectral analysis. Results Four flavonoids were separated and identified from Ampelopsis grossedentata including dihydromyricetin (1), myricetin (2), myricitrin (3), and myricetin-3-O-β-D-galactopy...展开更多
Anodic coatings were prepared by micro-arc oxidation on AZ91HP magnesium alloys in a base solution containing 10 g/L NaOH and 12 g/L phytic acid with addition of 0-8 g/L sodium tungstate.The effects of sodium tungstat...Anodic coatings were prepared by micro-arc oxidation on AZ91HP magnesium alloys in a base solution containing 10 g/L NaOH and 12 g/L phytic acid with addition of 0-8 g/L sodium tungstate.The effects of sodium tungstate on the coating thickness, mass gain,surface morphology and corrosion resistance were studied by eddy current instrument,electronic scales,scanning electron microscope and immersion tester.With the addition of sodium tungstate,the electrolytic conductivity increases and the final voltage decreases.The sodium tungstate has a minor effect on the coating thickness,but lightens the coating color.With increasing sodium tungstate concentration,the size of micropores on the coatings is enlarged and the corrosion resistance of the anodized samples decreases.展开更多
文摘Aim To study chemical constituents from Ampelopsis grossedentata. Methods Separation and purification were performed by using silica gel, polyamide, reverse-phase silica gel, Sephadex LH-20 column chromatographic techniques and silica gel PTLC. Structures were determined by means of physicochemical properties and spectral analysis. Results Four flavonoids were separated and identified from Ampelopsis grossedentata including dihydromyricetin (1), myricetin (2), myricitrin (3), and myricetin-3-O-β-D-galactopy...
基金Projects(GJJ08363,GJJ09573)supported by the Scientific Research Fund of Jiangxi Provincial Education Department,China
文摘Anodic coatings were prepared by micro-arc oxidation on AZ91HP magnesium alloys in a base solution containing 10 g/L NaOH and 12 g/L phytic acid with addition of 0-8 g/L sodium tungstate.The effects of sodium tungstate on the coating thickness, mass gain,surface morphology and corrosion resistance were studied by eddy current instrument,electronic scales,scanning electron microscope and immersion tester.With the addition of sodium tungstate,the electrolytic conductivity increases and the final voltage decreases.The sodium tungstate has a minor effect on the coating thickness,but lightens the coating color.With increasing sodium tungstate concentration,the size of micropores on the coatings is enlarged and the corrosion resistance of the anodized samples decreases.
