Thirty two aquatic vascular plant communities and their water environments were surveyed in Jiangxi province.The communities were analysed using PCA(principal component analysis) ordination to determine the relationsh...Thirty two aquatic vascular plant communities and their water environments were surveyed in Jiangxi province.The communities were analysed using PCA(principal component analysis) ordination to determine the relationship between the communities and environmental factors,according to pH value,depth of water,COD, DO,NP and HM.The results showed that information in original environmental data of communities was held 71.0% in the first two components of PCA ordination,COD, DO,NP and HM were the principal factors to determine the ecological distribution of aquatic vascular plant..展开更多
On the basis of that the catalytic decomposition of the title reagent with manganese in sodium tetraborate sodium carborate anhydrous buffer solution,and hydrogen peroxide can accelerate the reaction,a new catalytic s...On the basis of that the catalytic decomposition of the title reagent with manganese in sodium tetraborate sodium carborate anhydrous buffer solution,and hydrogen peroxide can accelerate the reaction,a new catalytic spectrophotometry determination is described.The effect of various experimental factors was studied and the optimal conditions for the determination of Mn(Ⅱ) were found.A better linear relation ship was obtained over the range of 0-0.25 and 0.3-2.0μg/25ml, and the detection limit for Mn(Ⅱ) is 1ng/ml. The method has been used to determine trace Mn(Ⅱ) in waste water,hair and tea satisfactorily.The mechanism of reaction has been studied kinetically.展开更多
文摘Thirty two aquatic vascular plant communities and their water environments were surveyed in Jiangxi province.The communities were analysed using PCA(principal component analysis) ordination to determine the relationship between the communities and environmental factors,according to pH value,depth of water,COD, DO,NP and HM.The results showed that information in original environmental data of communities was held 71.0% in the first two components of PCA ordination,COD, DO,NP and HM were the principal factors to determine the ecological distribution of aquatic vascular plant..
文摘On the basis of that the catalytic decomposition of the title reagent with manganese in sodium tetraborate sodium carborate anhydrous buffer solution,and hydrogen peroxide can accelerate the reaction,a new catalytic spectrophotometry determination is described.The effect of various experimental factors was studied and the optimal conditions for the determination of Mn(Ⅱ) were found.A better linear relation ship was obtained over the range of 0-0.25 and 0.3-2.0μg/25ml, and the detection limit for Mn(Ⅱ) is 1ng/ml. The method has been used to determine trace Mn(Ⅱ) in waste water,hair and tea satisfactorily.The mechanism of reaction has been studied kinetically.