A luminescent superparamagnetic nanocomposite with an Fe3O4 SiO2-CdS structure is synthesised. Coated with a silica shell, Fe3O4 nanoparticles and CdS quantum dots （QDs） are successfully assembled together. Analysed...A luminescent superparamagnetic nanocomposite with an Fe3O4 SiO2-CdS structure is synthesised. Coated with a silica shell, Fe3O4 nanoparticles and CdS quantum dots （QDs） are successfully assembled together. Analysed from the test results of X-ray diffraction （XRD）, transmission electron microscopy （TEM）, high resolution transimission electron microscopy （HRTEM）, hysteresis loop, and photoluminescence （PL） spectrum, these nanocomposites exhibit superparamagnetic and photoluminescent properties.展开更多
The shallow groundwater in Shendong mining area was broken because of large-scale underground mining activities. Selecting 32201 working-face as research area, analyzed the change rule of groundwater level and aquifer...The shallow groundwater in Shendong mining area was broken because of large-scale underground mining activities. Selecting 32201 working-face as research area, analyzed the change rule of groundwater level and aquifer thickness under mining impact with a large number of water level observation data. Then, the impacts of groundwater level change on vegetation were analyzed by the relationship theory of arid area groundwater and vegetation. The results show that the aquifer structure and the water condition of supply flow and drainage are changed by the water proof mining. The groundwater level recovere only a little compared with the original groundwater level in two years. But the great change of groundwater level do not have notable influences on vegetation of this mining area, and further study indicates that there are certain conditions where groundwater level change impacted on vegetation. When the influence of groundwater level change was evaluated, the plant ecological water level, warning water level and spatial distribution character of original groundwater and mining-impacted groundwater-level change should be integrated.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No.50872129)
文摘A luminescent superparamagnetic nanocomposite with an Fe3O4 SiO2-CdS structure is synthesised. Coated with a silica shell, Fe3O4 nanoparticles and CdS quantum dots （QDs） are successfully assembled together. Analysed from the test results of X-ray diffraction （XRD）, transmission electron microscopy （TEM）, high resolution transimission electron microscopy （HRTEM）, hysteresis loop, and photoluminescence （PL） spectrum, these nanocomposites exhibit superparamagnetic and photoluminescent properties.
文摘The shallow groundwater in Shendong mining area was broken because of large-scale underground mining activities. Selecting 32201 working-face as research area, analyzed the change rule of groundwater level and aquifer thickness under mining impact with a large number of water level observation data. Then, the impacts of groundwater level change on vegetation were analyzed by the relationship theory of arid area groundwater and vegetation. The results show that the aquifer structure and the water condition of supply flow and drainage are changed by the water proof mining. The groundwater level recovere only a little compared with the original groundwater level in two years. But the great change of groundwater level do not have notable influences on vegetation of this mining area, and further study indicates that there are certain conditions where groundwater level change impacted on vegetation. When the influence of groundwater level change was evaluated, the plant ecological water level, warning water level and spatial distribution character of original groundwater and mining-impacted groundwater-level change should be integrated.
