The crystal structure, morphology, dissolution kinetics and mechanism of gibbsitic bauxite and pure gibbsite in Na OH solution under atmospheric pressure were systematically investigated by XRD and SEM. The results sh...The crystal structure, morphology, dissolution kinetics and mechanism of gibbsitic bauxite and pure gibbsite in Na OH solution under atmospheric pressure were systematically investigated by XRD and SEM. The results show that the size of single crystal of gibbsite in gibbsitic bauxite is smaller than that in pure gibbsite, but the interplanar distance is larger than that of pure gibbsite, which result in more defects in the crystal and less energy needed to dissolve in alkaline solution for the gibbsitic bauxite. The dissolution kinetic equations of gibbsitic bauxite and pure gibbsite were established, and the corresponding activation energies were calculated to be 99.144 and 115.149 k J/mol, respectively.展开更多
Temperature-sensitive molecularly imprinted microgels(MIGs)exhibiting esterase activity were prepared by a reverse emulsion method using dialdehyde dextran-histidine conjugate(PAD-His)as the functional macromonomer an...Temperature-sensitive molecularly imprinted microgels(MIGs)exhibiting esterase activity were prepared by a reverse emulsion method using dialdehyde dextran-histidine conjugate(PAD-His)as the functional macromonomer and p-nitrophenyl phosphate(NPP)as the stable transition state analogue(TSA)as well as Co2+as the coordination center.The catalytic activity of MIGs was greatly influenced by the amount of the template,and could be modulated by temperature.The hydrolysis kinetics of p-nitrophenyl acetate(NPA)in the presence of MIGs could be described by the Michaelis-Menten equation.The MichaelisMenten constant and maximum velocity were found to be 2.2×105mol/L and 2.04×10 -8mol/h,respectively.In addition,the MIGs were found to have a high catalytic selectivity to NPA.展开更多
基金Projects(5110404151174054+2 种基金51374065)supported by the National Natural Science Foundation of ChinaProject(N130402010)supported by the Fundamental Research Funds for the Central UniversitiesChina
文摘The crystal structure, morphology, dissolution kinetics and mechanism of gibbsitic bauxite and pure gibbsite in Na OH solution under atmospheric pressure were systematically investigated by XRD and SEM. The results show that the size of single crystal of gibbsite in gibbsitic bauxite is smaller than that in pure gibbsite, but the interplanar distance is larger than that of pure gibbsite, which result in more defects in the crystal and less energy needed to dissolve in alkaline solution for the gibbsitic bauxite. The dissolution kinetic equations of gibbsitic bauxite and pure gibbsite were established, and the corresponding activation energies were calculated to be 99.144 and 115.149 k J/mol, respectively.
基金supported by the National Natural Science Foundation of China(21074152,20874116,20676155 and J0730420)the Natural Science Foundation of Guangdong Province in China(8151027501000004 and 9151027501000105)the Doctoral Research Program of Ministry of Education Ministry of China(20090171110023)
文摘Temperature-sensitive molecularly imprinted microgels(MIGs)exhibiting esterase activity were prepared by a reverse emulsion method using dialdehyde dextran-histidine conjugate(PAD-His)as the functional macromonomer and p-nitrophenyl phosphate(NPP)as the stable transition state analogue(TSA)as well as Co2+as the coordination center.The catalytic activity of MIGs was greatly influenced by the amount of the template,and could be modulated by temperature.The hydrolysis kinetics of p-nitrophenyl acetate(NPA)in the presence of MIGs could be described by the Michaelis-Menten equation.The MichaelisMenten constant and maximum velocity were found to be 2.2×105mol/L and 2.04×10 -8mol/h,respectively.In addition,the MIGs were found to have a high catalytic selectivity to NPA.
