Zinc oxide is recently being used as a magnetic semiconductor with the introduction of mag-netic elements.In this work,we report phase pure synthesis of Mg and Ni co-substituted ZnO to explore its structure,optical,ma...Zinc oxide is recently being used as a magnetic semiconductor with the introduction of mag-netic elements.In this work,we report phase pure synthesis of Mg and Ni co-substituted ZnO to explore its structure,optical,magnetic and photo-catalytic properties.X-ray di raction analysis reveals the hexagonal wurtzite type structure having P63mc space group without any impurity phase.UV-Vis spectrophotometry demonstrates the variation in bandgap with the addition of Mg and Ni content in ZnO matrix.Magnetic measurements exhibit a clear boosted magnetization in Ni and Mg co-doped compositions with its stable value of bandgap corroborating the structural stability and magnetic tuning for its advanced applications in modern-day spintronic devices.Photo-catalytic measurements performed using methyl green degradation demonstrate an enhanced trend of activity in Mg and Ni co-doped compositions.展开更多
TiO2/bauxite-tailings （TiO2/BTs） composites were prepared via a chemical liquid deposition method and characterized by X-ray diffractometry （XRD）, scanning electronic microscopy （SEM） and N2 adsorption analysis....TiO2/bauxite-tailings （TiO2/BTs） composites were prepared via a chemical liquid deposition method and characterized by X-ray diffractometry （XRD）, scanning electronic microscopy （SEM） and N2 adsorption analysis. The photocatalytic performance of TiO2/BTs composites was evaluated with UV-Vis spectrophotometer following the changes of phenol concentration under different illumination time. Effects of the calcination temperature, the pH and the cycles on the photocatalytic activity of TiO2/BTs composites were investigated. The composites calcined at 500 and 600 ℃ exhibit the best photocatalytic performance, and the phenol degradation ratios reacting for 40 and 160 rain reach 35% and 78% respectively under the same conditions, higher than those of 29% and 76% of the Degussa P25（TiO2）. The ability of TiO2/BTs500 （BTs500 represents bauxite-tailings calcined at 500 ℃） composites to degrade phenol increases with decreasing pH.展开更多
Dynamic characteristics of UV enhanced gas–solid PVC chlorination process were revealed by a UV–Vis spectral online analysis method. Experimental results showed an instantaneous increase of the chlorination rate as ...Dynamic characteristics of UV enhanced gas–solid PVC chlorination process were revealed by a UV–Vis spectral online analysis method. Experimental results showed an instantaneous increase of the chlorination rate as soon as UV light was affiliated, which demonstrated the intensified effect of UV radiation on PVC chlorination directly.Different affiliation methods of UV light were then studied, proving that continuous UV radiation could enhance the chlorination process significantly while intermittent UV radiation was able to initiate the chlorination reaction once it was conducted. Besides, experiments were carried out to study the influences of parameters on the chlorination process such as UV wavelength, chlorination temperature, partial pressure of chlorine gas and PVC raw materials. Among all the parameters, chlorination temperature and partial pressure of chlorine gas were testified as two key factors to determine the chlorination performance. Thermal analysis of CPVC products showed that their corresponding properties such as the glass transition temperature(Tg) and the homogeneity of chlorine distribution in polymer phase were improved with the increase of chlorine content.展开更多
Dengue vector is responsible for millions of deaths every year and has caused disastrous impacts on health systems. The continuous use of chemical insecticides, such as carbamates, pyrethroids and organophosphates gen...Dengue vector is responsible for millions of deaths every year and has caused disastrous impacts on health systems. The continuous use of chemical insecticides, such as carbamates, pyrethroids and organophosphates generates resistant populations of the mosquito, therefore, new control methods must be investigated. The joint action of the population and guidelines for preventing the reproduction of the mosquito associated with the use of photoactivatable insecticides can be the alternative for the control of epidemiological outbreaks in affected regions. In this study, the photo-larvicidal activity of Photogem^（PG）, a derivative of hematoporphyrin, was investigated against 2nd-early 3rd instar of Aedes aegypti larvae （Diptera： Culicidae） under different lighting conditions （artificial lighting system and sunlight）. The dynamics of PG accumulation was characterized by CLSM （confocal laser scanning microscopy） and total time PG eliminationin solution was investigated by ultraviolet-visible spectrophotometry. The maximum photo-activity of PG was observed in 0.5 h under sunlight exposure which achieved 100% larval mortality. Fluorescence images showed a uniform distribution of PG along the digestive tract. PG remained stable in the sunlight for 48 h and in an artificial lighting system for longer periods, therefore, it can be used for the control ofAedes aegypti larvae as a new alternative to chemical insecticides. The method is considered environmentally friendly due to its rapid degradation in the presence of light. Further studies are required, so that the potential of the technique can be explored in real breeding places.展开更多
In this paper, the separation of arsenopyrite from chalcopyrite, pyrite, galena with organic depressants （guergum and sodium humic ） was discussed, and the functioning mechanism of those organic depressants was disc...In this paper, the separation of arsenopyrite from chalcopyrite, pyrite, galena with organic depressants （guergum and sodium humic ） was discussed, and the functioning mechanism of those organic depressants was discussed. The experimental results of monomineral flotation indicated that both guergum and sodium humic have depressing effect on arsenopyrite in the presence of ethyl xanthate. Guergum and sodium humic showed different depressing ability to pyrite, chalcopyrite and galena, and the higher the pH value in pulp, the stronger the depressing ability. Ultraviolet-Visible Spectrophotometric study showed that the adsorption layer of xanthate on surface of minerals had been desorhed by the two organic depressants, and the selective desorption of the collector layer was found from different minerals. The xanthate cover on minerals surface was set free when dosage of the organic depressants was high enough. For artificially-mixed minerals, the separation of arsenopyrite from other sulphides was successfully realized by controlling dosage of the organic depressants. And sodium humic had been concentrates in a commercial Lead-Zinc concentrator.展开更多
Transparent,smooth and dense zinc tin oxide (ZTO) thin films have been successfully produced by using a new precursor solution,zinc acetate and tin(II) 2-ethylhexanoate mixed with 2-ethanolamine in methoxyethanol.The ...Transparent,smooth and dense zinc tin oxide (ZTO) thin films have been successfully produced by using a new precursor solution,zinc acetate and tin(II) 2-ethylhexanoate mixed with 2-ethanolamine in methoxyethanol.The ZTO films have been prepared by spin-coating,followed by thermal treatment in oxygen atmosphere.The morphology,composition,crystallinity and band gap energy (Eg) of the ZTO thin films have been characterized by Atomic Force Microscopy (AFM),Atomic Emission Spectrometry (AES),X-ray Diffraction (XRD) and UV-vis spectrophotometry.The conductivity of ZTO is about 9.8×10-9 S/cm,as estimated from the current-voltage (I-V) curve.The effect of the thermal treatment process on the morphology of ZTO thin films is also discussed.展开更多
Gallium oxide （Ga203） films were deposited on singlecrystalline sapphire （0001） substrate by radio frequency （RF） magnetron sputtering technique in the temperature range of 300--500 ℃. The microstructure of the...Gallium oxide （Ga203） films were deposited on singlecrystalline sapphire （0001） substrate by radio frequency （RF） magnetron sputtering technique in the temperature range of 300--500 ℃. The microstructure of the fl-Ga203 films were investigated in detail using X-ray diffractometer （XRD） and scanning electron microscope （SEM）. The results show that the film prepared at 500℃ exhibits the best crystallinity with a monoclinic structure （fl-Ga203）. Structure analysis reveals a clear out-of-plane orientation offl-Ga203 （201） II A1203 （0001）. The average transmittance of these films in the visible wavelength range exceeds 90%, and the optical band gap of the films varies from 4.68 eV to 4.94 eV which were measured by an ultraviolet-visible-near infrared （UV-vis-NIR） spectrophotometer. Therefore, it is hopeful that the fl-Ga203 film can be used in the UV optoelectronic devices.展开更多
基金supported by the Deanship of Scienti c Research at King Saud University for funding under Research Group(No.RG1440-021).
文摘Zinc oxide is recently being used as a magnetic semiconductor with the introduction of mag-netic elements.In this work,we report phase pure synthesis of Mg and Ni co-substituted ZnO to explore its structure,optical,magnetic and photo-catalytic properties.X-ray di raction analysis reveals the hexagonal wurtzite type structure having P63mc space group without any impurity phase.UV-Vis spectrophotometry demonstrates the variation in bandgap with the addition of Mg and Ni content in ZnO matrix.Magnetic measurements exhibit a clear boosted magnetization in Ni and Mg co-doped compositions with its stable value of bandgap corroborating the structural stability and magnetic tuning for its advanced applications in modern-day spintronic devices.Photo-catalytic measurements performed using methyl green degradation demonstrate an enhanced trend of activity in Mg and Ni co-doped compositions.
基金Project(2005CB623701) supported by the National Key Basic Research Program of China
文摘TiO2/bauxite-tailings （TiO2/BTs） composites were prepared via a chemical liquid deposition method and characterized by X-ray diffractometry （XRD）, scanning electronic microscopy （SEM） and N2 adsorption analysis. The photocatalytic performance of TiO2/BTs composites was evaluated with UV-Vis spectrophotometer following the changes of phenol concentration under different illumination time. Effects of the calcination temperature, the pH and the cycles on the photocatalytic activity of TiO2/BTs composites were investigated. The composites calcined at 500 and 600 ℃ exhibit the best photocatalytic performance, and the phenol degradation ratios reacting for 40 and 160 rain reach 35% and 78% respectively under the same conditions, higher than those of 29% and 76% of the Degussa P25（TiO2）. The ability of TiO2/BTs500 （BTs500 represents bauxite-tailings calcined at 500 ℃） composites to degrade phenol increases with decreasing pH.
基金Supported by the National Science and Technology Key Supporting Project(2013BAF08B05)the National Natural Science Foundation of China(21176137)
文摘Dynamic characteristics of UV enhanced gas–solid PVC chlorination process were revealed by a UV–Vis spectral online analysis method. Experimental results showed an instantaneous increase of the chlorination rate as soon as UV light was affiliated, which demonstrated the intensified effect of UV radiation on PVC chlorination directly.Different affiliation methods of UV light were then studied, proving that continuous UV radiation could enhance the chlorination process significantly while intermittent UV radiation was able to initiate the chlorination reaction once it was conducted. Besides, experiments were carried out to study the influences of parameters on the chlorination process such as UV wavelength, chlorination temperature, partial pressure of chlorine gas and PVC raw materials. Among all the parameters, chlorination temperature and partial pressure of chlorine gas were testified as two key factors to determine the chlorination performance. Thermal analysis of CPVC products showed that their corresponding properties such as the glass transition temperature(Tg) and the homogeneity of chlorine distribution in polymer phase were improved with the increase of chlorine content.
文摘Dengue vector is responsible for millions of deaths every year and has caused disastrous impacts on health systems. The continuous use of chemical insecticides, such as carbamates, pyrethroids and organophosphates generates resistant populations of the mosquito, therefore, new control methods must be investigated. The joint action of the population and guidelines for preventing the reproduction of the mosquito associated with the use of photoactivatable insecticides can be the alternative for the control of epidemiological outbreaks in affected regions. In this study, the photo-larvicidal activity of Photogem^（PG）, a derivative of hematoporphyrin, was investigated against 2nd-early 3rd instar of Aedes aegypti larvae （Diptera： Culicidae） under different lighting conditions （artificial lighting system and sunlight）. The dynamics of PG accumulation was characterized by CLSM （confocal laser scanning microscopy） and total time PG eliminationin solution was investigated by ultraviolet-visible spectrophotometry. The maximum photo-activity of PG was observed in 0.5 h under sunlight exposure which achieved 100% larval mortality. Fluorescence images showed a uniform distribution of PG along the digestive tract. PG remained stable in the sunlight for 48 h and in an artificial lighting system for longer periods, therefore, it can be used for the control ofAedes aegypti larvae as a new alternative to chemical insecticides. The method is considered environmentally friendly due to its rapid degradation in the presence of light. Further studies are required, so that the potential of the technique can be explored in real breeding places.
文摘In this paper, the separation of arsenopyrite from chalcopyrite, pyrite, galena with organic depressants （guergum and sodium humic ） was discussed, and the functioning mechanism of those organic depressants was discussed. The experimental results of monomineral flotation indicated that both guergum and sodium humic have depressing effect on arsenopyrite in the presence of ethyl xanthate. Guergum and sodium humic showed different depressing ability to pyrite, chalcopyrite and galena, and the higher the pH value in pulp, the stronger the depressing ability. Ultraviolet-Visible Spectrophotometric study showed that the adsorption layer of xanthate on surface of minerals had been desorhed by the two organic depressants, and the selective desorption of the collector layer was found from different minerals. The xanthate cover on minerals surface was set free when dosage of the organic depressants was high enough. For artificially-mixed minerals, the separation of arsenopyrite from other sulphides was successfully realized by controlling dosage of the organic depressants. And sodium humic had been concentrates in a commercial Lead-Zinc concentrator.
基金supported by the National Natural Science Foundation of China (50990060)
文摘Transparent,smooth and dense zinc tin oxide (ZTO) thin films have been successfully produced by using a new precursor solution,zinc acetate and tin(II) 2-ethylhexanoate mixed with 2-ethanolamine in methoxyethanol.The ZTO films have been prepared by spin-coating,followed by thermal treatment in oxygen atmosphere.The morphology,composition,crystallinity and band gap energy (Eg) of the ZTO thin films have been characterized by Atomic Force Microscopy (AFM),Atomic Emission Spectrometry (AES),X-ray Diffraction (XRD) and UV-vis spectrophotometry.The conductivity of ZTO is about 9.8×10-9 S/cm,as estimated from the current-voltage (I-V) curve.The effect of the thermal treatment process on the morphology of ZTO thin films is also discussed.
基金supported by the National Natural Science Foundation of China(Nos.61274113,61404091,61505144,51502203 and 51502204)the Opening Fund of Key Laboratory of Silicon Device Technology in Chinese Academy of Sciencesthe Tianjin Natural Science Foundation(Nos.14JCZDJC31500 and 14JCQNJC00800)
文摘Gallium oxide （Ga203） films were deposited on singlecrystalline sapphire （0001） substrate by radio frequency （RF） magnetron sputtering technique in the temperature range of 300--500 ℃. The microstructure of the fl-Ga203 films were investigated in detail using X-ray diffractometer （XRD） and scanning electron microscope （SEM）. The results show that the film prepared at 500℃ exhibits the best crystallinity with a monoclinic structure （fl-Ga203）. Structure analysis reveals a clear out-of-plane orientation offl-Ga203 （201） II A1203 （0001）. The average transmittance of these films in the visible wavelength range exceeds 90%, and the optical band gap of the films varies from 4.68 eV to 4.94 eV which were measured by an ultraviolet-visible-near infrared （UV-vis-NIR） spectrophotometer. Therefore, it is hopeful that the fl-Ga203 film can be used in the UV optoelectronic devices.
