Cyclic voltammetric behavior of electrooxidation of Mn(Ⅱ) under ultrasound and without ultrasound were compared. With the ultrasound irradiation the reduction peak potential of Pb(Ⅳ)/ Pb(Ⅱ) was found shifted negati...Cyclic voltammetric behavior of electrooxidation of Mn(Ⅱ) under ultrasound and without ultrasound were compared. With the ultrasound irradiation the reduction peak potential of Pb(Ⅳ)/ Pb(Ⅱ) was found shifted negatively about 0.14 V, initial electrolytic potential reduced 0.2 V and reduction peak current increased. At the same conditions,the conversion of Mn(Ⅱ) was increased. The optimum conditions for electrooxidation were 0.3 mol/L solution of Mn(Ⅱ), 6 mol/L H 2SO 4, electrolysis potential 2.3 V and 44 W ultrasound.展开更多
Complexes of chitosan with Mn(Ⅱ) were prepared by adding Mn(OAc)2·4H2O to Chitosan solution. IR, elemental analysis and TG analysis were used to character the complex. The results showed that there were coordina...Complexes of chitosan with Mn(Ⅱ) were prepared by adding Mn(OAc)2·4H2O to Chitosan solution. IR, elemental analysis and TG analysis were used to character the complex. The results showed that there were coordinate bands formed. H2O2 was used to degrade chitosan-Mn(Ⅱ) complex, and the molecular distribution of degraded products were investigated after eliminating Mn(Ⅱ) ions using the cation exchange resin column. The result suggested that the Chitosan could be degraded rapidly, the degradation started from higher molecular weight range, the molecular weight distribution of oligosaccharides was much more narrower than that of degradated products from common methods such as hydrolysis, acidic and oxidizing methods. The index of molecular weight distribution was changed with the average degradability. When exceeding 10 oligosaccharides, the smaller of the DP, the smaller of the index.展开更多
Three complexes of Mn（Ⅱ）with L-amino acid[L-Isoleucine（L-Ile）,L-Methionine（L-Met）,L-Tryptophan（L-Trp）]were synthesized and characterized by elemental analysis,infrared spectra and gravithem metrical analyses....Three complexes of Mn（Ⅱ）with L-amino acid[L-Isoleucine（L-Ile）,L-Methionine（L-Met）,L-Tryptophan（L-Trp）]were synthesized and characterized by elemental analysis,infrared spectra and gravithem metrical analyses.The catalytic activity of the three complexes for disproportionation of O2-was determined by NBT method.The result shows that the complexes have a high SOD-like activity,and the KQ values of complexes 1,2 and 3 are 0.78×107mol-1·L·s-1,1.28×107mol-1,and 1.50×107mol-1L·s-1,respectively.展开更多
文摘Cyclic voltammetric behavior of electrooxidation of Mn(Ⅱ) under ultrasound and without ultrasound were compared. With the ultrasound irradiation the reduction peak potential of Pb(Ⅳ)/ Pb(Ⅱ) was found shifted negatively about 0.14 V, initial electrolytic potential reduced 0.2 V and reduction peak current increased. At the same conditions,the conversion of Mn(Ⅱ) was increased. The optimum conditions for electrooxidation were 0.3 mol/L solution of Mn(Ⅱ), 6 mol/L H 2SO 4, electrolysis potential 2.3 V and 44 W ultrasound.
文摘Complexes of chitosan with Mn(Ⅱ) were prepared by adding Mn(OAc)2·4H2O to Chitosan solution. IR, elemental analysis and TG analysis were used to character the complex. The results showed that there were coordinate bands formed. H2O2 was used to degrade chitosan-Mn(Ⅱ) complex, and the molecular distribution of degraded products were investigated after eliminating Mn(Ⅱ) ions using the cation exchange resin column. The result suggested that the Chitosan could be degraded rapidly, the degradation started from higher molecular weight range, the molecular weight distribution of oligosaccharides was much more narrower than that of degradated products from common methods such as hydrolysis, acidic and oxidizing methods. The index of molecular weight distribution was changed with the average degradability. When exceeding 10 oligosaccharides, the smaller of the DP, the smaller of the index.
文摘Three complexes of Mn（Ⅱ）with L-amino acid[L-Isoleucine（L-Ile）,L-Methionine（L-Met）,L-Tryptophan（L-Trp）]were synthesized and characterized by elemental analysis,infrared spectra and gravithem metrical analyses.The catalytic activity of the three complexes for disproportionation of O2-was determined by NBT method.The result shows that the complexes have a high SOD-like activity,and the KQ values of complexes 1,2 and 3 are 0.78×107mol-1·L·s-1,1.28×107mol-1,and 1.50×107mol-1L·s-1,respectively.
