Monodisperse nanoparticle assembly with tunable structure, composition and properties can be taken as a superstructured building block for the construction of hierarchical nanostruc tures from the bottom up, which als...Monodisperse nanoparticle assembly with tunable structure, composition and properties can be taken as a superstructured building block for the construction of hierarchical nanostruc tures from the bottom up, which also represents a great challenge in nanotechnology. Here we report on a facile and controllable method that enables a high yield fabricatioa of uniform gold nanoparticle （AuNP） coresatellites with definable number （in average） of the satellite particles and tunable coretosatellite distance. The formation of the coresatellite nanostruc tures is driven by programmable DNAbasepairing, with the resulting nanocomplexes being isolatable via gel electrophoresis. By rationally controlling the DNA coverages on the core and shell particles, high production yields are achieved for the assembly/isolation process. As well, benefiting from a minimum DNA coverage on the satellite AuNPs, a strong affinity is observed for the asprepared coresatellites to get adsorbed on proteincoated graphene ox ide, which allows for a twodimensional hierarchical assembly of the coresatellite structures. The resulting hierarchical nanoassemblies are expected to find applications in various areas, including plasmonics, biosensing, and nanocatalysis. The method should be generalizable to make even more complicated and higherorder structures by making use of the structural programmability of DNA molecules.展开更多
This study applied multilevel modeling to investigate the impact of observed predictors and different levels or groups that households belong, on parents’ choice of discipline methods using data from 8156 households ...This study applied multilevel modeling to investigate the impact of observed predictors and different levels or groups that households belong, on parents’ choice of discipline methods using data from 8156 households derived from a nationwide survey by the Ghana Statistical Service (GSS) in 2011. The aim of the study is to provide in-depth information on why parents choose particular discipline methods as corrective measures to reduce unwanted child behaviour in the present and to increase desirable ones in the future. The results of the study show that, religion and age-group of household heads have significant effect on household’s likelihood to choose physical discipline methods whereas the wealth index of a household and ethnicity of the household head, have significant effect on households’ likelihood to choose non-physical and psychological aggression methods. The results further show significant contextual effect on the differences in choices of parents at the household and regional levels. The choice of physical discipline methods by parents was consistent across households and regional levels unlike non-physical and psychological aggression methods whose application varied across the regions. Households in the Northern, Eastern and Volta regions mostly chose to apply physical discipline methods whereas in the Upper West, Western and Northern regions the most chosen discipline methods were non-physical discipline methods. Psychological aggression discipline methods were predominantly applied in the Upper East, Central and Northern regions of the country.展开更多
A novel water control technology that com- bines the features of a reticular blind drainage system and a vertical hierarchical drainage system is developed and applied in the Yanziyan Sanitary Landfill, which is locat...A novel water control technology that com- bines the features of a reticular blind drainage system and a vertical hierarchical drainage system is developed and applied in the Yanziyan Sanitary Landfill, which is located at an area （Loudi City, Hunan Province, China） with high rainfall and high groundwater level. The reticular blind drain system, which was installed on the bottom and side walls of the landfill site, can conveniently guide the flow of groundwater out of the site while preventing a disorga- nized flow of groundwater. The vertical hierarchical drainage system was installed to separate rainfall water and leachate in the landfill site, thus efficiently reducing the pressure of leachate treatment. The whole drainage system plays a key role in foundation stabilization by seepage control and separation and in the instant drainage of rainfall water. The leachate reduction efficiency of the drainage technology was calculated in terms of leachate production before （336519 m3） and after （29664 m3） technology application. Over 90% of leachate derived from rainfall water and groundwater inflow was avoided upon installation of the vertical hierarchical drainage and reticular blind drainage systems. The technology can thus be popularized and applied for water control in landfills located in areas with high rainfall and high groundwater level. The proposed technology can be used to alleviate the pressure of leachate treatment and to reduce the risk of instability.展开更多
文摘Monodisperse nanoparticle assembly with tunable structure, composition and properties can be taken as a superstructured building block for the construction of hierarchical nanostruc tures from the bottom up, which also represents a great challenge in nanotechnology. Here we report on a facile and controllable method that enables a high yield fabricatioa of uniform gold nanoparticle （AuNP） coresatellites with definable number （in average） of the satellite particles and tunable coretosatellite distance. The formation of the coresatellite nanostruc tures is driven by programmable DNAbasepairing, with the resulting nanocomplexes being isolatable via gel electrophoresis. By rationally controlling the DNA coverages on the core and shell particles, high production yields are achieved for the assembly/isolation process. As well, benefiting from a minimum DNA coverage on the satellite AuNPs, a strong affinity is observed for the asprepared coresatellites to get adsorbed on proteincoated graphene ox ide, which allows for a twodimensional hierarchical assembly of the coresatellite structures. The resulting hierarchical nanoassemblies are expected to find applications in various areas, including plasmonics, biosensing, and nanocatalysis. The method should be generalizable to make even more complicated and higherorder structures by making use of the structural programmability of DNA molecules.
文摘This study applied multilevel modeling to investigate the impact of observed predictors and different levels or groups that households belong, on parents’ choice of discipline methods using data from 8156 households derived from a nationwide survey by the Ghana Statistical Service (GSS) in 2011. The aim of the study is to provide in-depth information on why parents choose particular discipline methods as corrective measures to reduce unwanted child behaviour in the present and to increase desirable ones in the future. The results of the study show that, religion and age-group of household heads have significant effect on household’s likelihood to choose physical discipline methods whereas the wealth index of a household and ethnicity of the household head, have significant effect on households’ likelihood to choose non-physical and psychological aggression methods. The results further show significant contextual effect on the differences in choices of parents at the household and regional levels. The choice of physical discipline methods by parents was consistent across households and regional levels unlike non-physical and psychological aggression methods whose application varied across the regions. Households in the Northern, Eastern and Volta regions mostly chose to apply physical discipline methods whereas in the Upper West, Western and Northern regions the most chosen discipline methods were non-physical discipline methods. Psychological aggression discipline methods were predominantly applied in the Upper East, Central and Northern regions of the country.
基金This research project was funded by the National High Technology Research and Development Program of China （Grant No. 2007AA06Z350）, the National Natural Science Foundation of China （Grant No. 41101225）, and the Key Laboratory for Solid Waste Management and Environment Safety, Ministry of Education of China （No. SWMES 2011-11）. The authors would like to express sincere thanks to Mr. Luis Miguel for help in language correction.
文摘A novel water control technology that com- bines the features of a reticular blind drainage system and a vertical hierarchical drainage system is developed and applied in the Yanziyan Sanitary Landfill, which is located at an area （Loudi City, Hunan Province, China） with high rainfall and high groundwater level. The reticular blind drain system, which was installed on the bottom and side walls of the landfill site, can conveniently guide the flow of groundwater out of the site while preventing a disorga- nized flow of groundwater. The vertical hierarchical drainage system was installed to separate rainfall water and leachate in the landfill site, thus efficiently reducing the pressure of leachate treatment. The whole drainage system plays a key role in foundation stabilization by seepage control and separation and in the instant drainage of rainfall water. The leachate reduction efficiency of the drainage technology was calculated in terms of leachate production before （336519 m3） and after （29664 m3） technology application. Over 90% of leachate derived from rainfall water and groundwater inflow was avoided upon installation of the vertical hierarchical drainage and reticular blind drainage systems. The technology can thus be popularized and applied for water control in landfills located in areas with high rainfall and high groundwater level. The proposed technology can be used to alleviate the pressure of leachate treatment and to reduce the risk of instability.
