Pb1-xSrxTiO3 （0≤x≤0.9） thin films on Si （100） substrate were prepared by the sol-gel process and their characteristics were investigated as a function of strontium content（x）. With increasing of the strontium ...Pb1-xSrxTiO3 （0≤x≤0.9） thin films on Si （100） substrate were prepared by the sol-gel process and their characteristics were investigated as a function of strontium content（x）. With increasing of the strontium content, the tetragonality （c/a） was slightly decreased, the splitting peaks become less prominent and the splitting peaks tend to merge into a single peak. Furthermore, the grain size of the films was systematically reduced with the increase in strontium content.展开更多
Due to the lack of regulation and environmental education and awareness, Sepahanshahr located in vicinity of Isfahan City, central Iran, is now a rapid growing residential area suffering from the considerable conseque...Due to the lack of regulation and environmental education and awareness, Sepahanshahr located in vicinity of Isfahan City, central Iran, is now a rapid growing residential area suffering from the considerable consequences of poorly regulated mining activities operating in its vicinity. A survey was carried out on soil Pb, Zn and Cd concentrations around Sepahanshahr Town to explore the spatial structure of Pb, Zn and Cd distribution and to map their concentrations using geostatistical techniques. 100 near-surface soil samples were collected and analyzed for Pb, Zn and Cd and some related soil physical and chemical variables such as pH, organic matter content, electrical conductivity, and clay, silt and sand contents. The variography results showed a strong spatial dependency in heavy metals concentration due to the dilution effects of natural factors including atmospheric dispersion and precipitation. The almost same range values calculated for both In-transformed Pb and sand data suggested presence of spatial co-regionalization. However, In-transformed Zn data showed a shorter spatial dependency among the three tested heavy metals. Kriged maps of all three heavy metals showed a strong gradient of contamination around the three mining sites activating in the area. The results of this study provide insight into identification of the extent and spatial variability of Pb, Zn and Cd pollution in the mining sites and surrounding urban areas.展开更多
文摘Pb1-xSrxTiO3 （0≤x≤0.9） thin films on Si （100） substrate were prepared by the sol-gel process and their characteristics were investigated as a function of strontium content（x）. With increasing of the strontium content, the tetragonality （c/a） was slightly decreased, the splitting peaks become less prominent and the splitting peaks tend to merge into a single peak. Furthermore, the grain size of the films was systematically reduced with the increase in strontium content.
文摘Due to the lack of regulation and environmental education and awareness, Sepahanshahr located in vicinity of Isfahan City, central Iran, is now a rapid growing residential area suffering from the considerable consequences of poorly regulated mining activities operating in its vicinity. A survey was carried out on soil Pb, Zn and Cd concentrations around Sepahanshahr Town to explore the spatial structure of Pb, Zn and Cd distribution and to map their concentrations using geostatistical techniques. 100 near-surface soil samples were collected and analyzed for Pb, Zn and Cd and some related soil physical and chemical variables such as pH, organic matter content, electrical conductivity, and clay, silt and sand contents. The variography results showed a strong spatial dependency in heavy metals concentration due to the dilution effects of natural factors including atmospheric dispersion and precipitation. The almost same range values calculated for both In-transformed Pb and sand data suggested presence of spatial co-regionalization. However, In-transformed Zn data showed a shorter spatial dependency among the three tested heavy metals. Kriged maps of all three heavy metals showed a strong gradient of contamination around the three mining sites activating in the area. The results of this study provide insight into identification of the extent and spatial variability of Pb, Zn and Cd pollution in the mining sites and surrounding urban areas.
