The interactions between metal ions such as Zn2+, Pb2+, Mn2+, Hg2+, Cd2+, Ni2+ and chitosan have been investigated using the model cluster model method and density functional method. Full optimization and frequency an...The interactions between metal ions such as Zn2+, Pb2+, Mn2+, Hg2+, Cd2+, Ni2+ and chitosan have been investigated using the model cluster model method and density functional method. Full optimization and frequency analysis of all cluster models have been performed employing B3LYP hybrid method at 3-21G basis set level except metal ions which were invoked to use effective core potential (ECP) method. The energy changes, and the main structural parameters have been obtained during the theoretical study of the adsorption of metal ions on the chitosan. The calculations showed that the coordination modes of metal ions with chitosan models were different, the geometries of Mn2+, Zn2+, Cd2+, Hg2+, Pb2+ ions coordinated with two nitrogen atoms and two oxygen atoms were distorted tetrahedral, while the square planar structure of Ni2+ coordinated two nitrogen atoms and two oxygen atoms was observed. The heat of reaction between six metal ions and chitosan models showed the order: Mn2+ >Ni2+ >Zn2+ >Pb2+ >Hg2+ >Cd2+, this suggested that the coordination strength of Mn2+ >Ni2+ >Zn2+ >Pb2+ >Hg2+ >Cd2+.展开更多
With the continuous development of economy and society and the continuous improvement of peoples’living environment requirements,the concept of sponge city construction has been recognized and understood by more and ...With the continuous development of economy and society and the continuous improvement of peoples’living environment requirements,the concept of sponge city construction has been recognized and understood by more and more people.The country has also recognized the significance of planning and construction of sponge cities.In the process of planning and constructing a sponge city,it is necessary to combine the reality of urban development with the construction of urban water supply and drainage systems and underground pipe corridors to promote the process of urban modernization.Based on this,this paper analyzes the water supply and drainage construction of the integrated pipe corridor in the sponge city.展开更多
基金The Ph. D. Foundation (Y030426) and Post-doctoral Foundation of China University of Petroleum (East China).
文摘The interactions between metal ions such as Zn2+, Pb2+, Mn2+, Hg2+, Cd2+, Ni2+ and chitosan have been investigated using the model cluster model method and density functional method. Full optimization and frequency analysis of all cluster models have been performed employing B3LYP hybrid method at 3-21G basis set level except metal ions which were invoked to use effective core potential (ECP) method. The energy changes, and the main structural parameters have been obtained during the theoretical study of the adsorption of metal ions on the chitosan. The calculations showed that the coordination modes of metal ions with chitosan models were different, the geometries of Mn2+, Zn2+, Cd2+, Hg2+, Pb2+ ions coordinated with two nitrogen atoms and two oxygen atoms were distorted tetrahedral, while the square planar structure of Ni2+ coordinated two nitrogen atoms and two oxygen atoms was observed. The heat of reaction between six metal ions and chitosan models showed the order: Mn2+ >Ni2+ >Zn2+ >Pb2+ >Hg2+ >Cd2+, this suggested that the coordination strength of Mn2+ >Ni2+ >Zn2+ >Pb2+ >Hg2+ >Cd2+.
文摘With the continuous development of economy and society and the continuous improvement of peoples’living environment requirements,the concept of sponge city construction has been recognized and understood by more and more people.The country has also recognized the significance of planning and construction of sponge cities.In the process of planning and constructing a sponge city,it is necessary to combine the reality of urban development with the construction of urban water supply and drainage systems and underground pipe corridors to promote the process of urban modernization.Based on this,this paper analyzes the water supply and drainage construction of the integrated pipe corridor in the sponge city.
