High gradient magnetic separation was conducted in order to separate insoluble zinc ferrite from zinc calcine before acid leaching of hydrometallurgical process. Chemical composition and structural characterization of...High gradient magnetic separation was conducted in order to separate insoluble zinc ferrite from zinc calcine before acid leaching of hydrometallurgical process. Chemical composition and structural characterization of zinc calcine were studied via inductively coupled plasma （ICP）, X-ray diffraction （XRD）, Mossbauer spectra, scanning electron microscopy （SEM） and laser particle analysis （LPA）. The parameters of magnetic separation which affect the distribution of zinc ferrite and undesired elements, such as calcium, sulfur and lead in magnetic concentrate were investigated. The results of high gradient magnetic separation indicate that more than 85% of zinc ferrite is distributed into magnetic concentrate from the zinc calcine under the magnetic induction of 0.70 T. In addition, about 60% of calcium and 40% of sulfur distribute in non magnetic phases of tailings during magnetic separation process. Most of lead distributes uniformly along the zinc calcine in superfine particle size.展开更多
A resolution method based on Gaussian-like distribution for overlapped linear sweep polarographic peaks was proposed to simultaneously detect the polymetallic components, such as Zn（Ⅱ） and Co（Ⅱ）, coexisting in t...A resolution method based on Gaussian-like distribution for overlapped linear sweep polarographic peaks was proposed to simultaneously detect the polymetallic components, such as Zn（Ⅱ） and Co（Ⅱ）, coexisting in the leaching solution of zinc hydrometallurgy. A Gaussian-like distribution was constructed as the sub-model of overlapped peaks by analyzing the characteristics of linear sweep polarographic curve. Then, the abscissas of each peak and trough were pinpointed through multi-resolution wavelet decomposition, the curve and its derivative curves were fitted by using nonlinear weighted least squares （NWLS）. Finally, overlapped peaks were resolved into independent sub-peaks based on fitted reconstruction parameters. The experimental results show that the relative error of half-wave potential pinpointed by multi-resolution wavelet decomposition is less than 1% and the accuracy of Ip fitted by NWLS is higher than 96%. The proposed resolution method is effective for overlapped linear sweep polarographic peaks of Zn（Ⅱ） and Co（Ⅱ）.展开更多
The distribution of various fractions of Zn, Fe, Cu and Mn in 15 types of sods in China and its rela-tionship with plant availability were studied. Wactions of various elements were found to have some similarcharacter...The distribution of various fractions of Zn, Fe, Cu and Mn in 15 types of sods in China and its rela-tionship with plant availability were studied. Wactions of various elements were found to have some similarcharacteristic distribution regularities in wirious types of soils, but various soil types derered to varyingdegrees in the distribution of each fraction. Soil physico-chemical properties, such as pH, CEC and thecontents of OM, CaCO_3, free Fe, free Mn and P_2O_5, were signdicantly correlated with the distribution ofelemental fractions, and a significazit correlation also existed between the distribution and plant amilabilityof elemental fractions. Varfous fractions of each element were divided into two groups bed on their plantavailability. The correlation between the distribution of combination fractions aiid plaxit availability indi-cated a significantly or an extremely significantly positive correlation for Group I but a significantly or anextremely significantly negative correlation for Group II. Therefore, the fractions in Group I were primarypools of available nutrients, while those in Group II could hardly provide available nutrients for plants. Descreasing the transformation of corresponding elements into fractions of Group 11 and increasing the storagecapacity of various fractions of Group I were an important direction for regulation and controiling of soilnutrients. However, some Particular soils with too high contents of Zn, Fe, Cu and Mn should be regulatedand controlled adversely展开更多
The most remarkable effect in spinel ferrites is the strong dependence of properties on the state of structural disorder and,in particular,on the cation distribution.The structural characterization of a Co-Zn ferrite ...The most remarkable effect in spinel ferrites is the strong dependence of properties on the state of structural disorder and,in particular,on the cation distribution.The structural characterization of a Co-Zn ferrite nanoparticle sample was reported which prepared by wet chemical co-precipitation method.The samples were sintered at three different temperatures viz.650℃,850℃ and 1050℃ for 12 h.The structural details like:lattice constant and distribution of cations in the tetrahedral and octahedral interstitial voids have been deduced through X-ray diffraction (XRD) data analysis.Lattice constant was found to increase with the increase in Zn2+ ions and sintering temperature.Theoretical intensity ratios of (220),(400),(440) planes were considered,as these reflections are sensitive to cations on the A and B sites.Close agreement of the theoretical intensity ratio with the intensity ratio observed from XRD pattern supports the occupancy of Zn2+ ions and Co2+ ions on the octahedral and tetrahedral sites,respectively.展开更多
Objective:To evaluate effects of epigallocatechin-3-gallate (EGCG) on the viability, membrane properties, and zinc distribution, with and without the presence of Zn2+, in human prostate carcinoma LNCaP cells. Methods:...Objective:To evaluate effects of epigallocatechin-3-gallate (EGCG) on the viability, membrane properties, and zinc distribution, with and without the presence of Zn2+, in human prostate carcinoma LNCaP cells. Methods: We examined changes in cellular morphology and membrane fluidity of LNCaP cells, distribution of cellular zinc, and the incorporated portion of EGCG after treatments with EGCG, Zn2+, and EGCG+Zn2+. Results: We observed an alteration in cellular morphology and a decrease in membrane fluidity of LNCaP cells after treatment with EGCG or Zn2+. The proportion of EGCG incorporated into liposomes treated with the mixture of EGCG and Zn2+ at the ratio of 1:1 was 90.57%, which was significantly higher than that treated with EGCG alone (30.33%). Electron spin resonance (ESR) studies and determination of fatty acids showed that the effects of EGCG on the membrane fluidity of LNCaP were decreased by Zn2+. EGCG accelerated the accumulation of zinc in the mitochondria and cytosol as observed by atomic absorption spectrometer. Conclusion: These results show that EGCG interacted with cell membrane, decreased the membrane fluidity of LNCaP cells, and accelerated zinc accumulation in the mitochondria and cytosol, which could be the mechanism by which EGCG inhibits proliferation of LNCaP cells. In addition, high concentrations of Zn2+ could attenuate the actions elicited by EGCG.展开更多
基金Project (2011AA061001) supported by the High-tech Research and Development Program of ChinaProject (50830301) supported by the National Natural Science Foundation of China+1 种基金Project (50925417) supported by National Science Fund for Distinguished Young Scientists, ChinaProject (2012BAC12102) supported by the National "Twelfth Five-year" Plan for Science and Technology Support, China
文摘High gradient magnetic separation was conducted in order to separate insoluble zinc ferrite from zinc calcine before acid leaching of hydrometallurgical process. Chemical composition and structural characterization of zinc calcine were studied via inductively coupled plasma （ICP）, X-ray diffraction （XRD）, Mossbauer spectra, scanning electron microscopy （SEM） and laser particle analysis （LPA）. The parameters of magnetic separation which affect the distribution of zinc ferrite and undesired elements, such as calcium, sulfur and lead in magnetic concentrate were investigated. The results of high gradient magnetic separation indicate that more than 85% of zinc ferrite is distributed into magnetic concentrate from the zinc calcine under the magnetic induction of 0.70 T. In addition, about 60% of calcium and 40% of sulfur distribute in non magnetic phases of tailings during magnetic separation process. Most of lead distributes uniformly along the zinc calcine in superfine particle size.
基金Project(2012BAF03B05)supported by the National Key Technology R&D Program of ChinaProject(61025015)supported by the National Natural Science Foundation for Distinguished Young Scholars of China+1 种基金Project(61273185)supported by the National Natural Science Foundation of ChinaProject(2012CK4018)supported by the Science and Technology Project of Hunan Province,China
文摘A resolution method based on Gaussian-like distribution for overlapped linear sweep polarographic peaks was proposed to simultaneously detect the polymetallic components, such as Zn（Ⅱ） and Co（Ⅱ）, coexisting in the leaching solution of zinc hydrometallurgy. A Gaussian-like distribution was constructed as the sub-model of overlapped peaks by analyzing the characteristics of linear sweep polarographic curve. Then, the abscissas of each peak and trough were pinpointed through multi-resolution wavelet decomposition, the curve and its derivative curves were fitted by using nonlinear weighted least squares （NWLS）. Finally, overlapped peaks were resolved into independent sub-peaks based on fitted reconstruction parameters. The experimental results show that the relative error of half-wave potential pinpointed by multi-resolution wavelet decomposition is less than 1% and the accuracy of Ip fitted by NWLS is higher than 96%. The proposed resolution method is effective for overlapped linear sweep polarographic peaks of Zn（Ⅱ） and Co（Ⅱ）.
文摘The distribution of various fractions of Zn, Fe, Cu and Mn in 15 types of sods in China and its rela-tionship with plant availability were studied. Wactions of various elements were found to have some similarcharacteristic distribution regularities in wirious types of soils, but various soil types derered to varyingdegrees in the distribution of each fraction. Soil physico-chemical properties, such as pH, CEC and thecontents of OM, CaCO_3, free Fe, free Mn and P_2O_5, were signdicantly correlated with the distribution ofelemental fractions, and a significazit correlation also existed between the distribution and plant amilabilityof elemental fractions. Varfous fractions of each element were divided into two groups bed on their plantavailability. The correlation between the distribution of combination fractions aiid plaxit availability indi-cated a significantly or an extremely significantly positive correlation for Group I but a significantly or anextremely significantly negative correlation for Group II. Therefore, the fractions in Group I were primarypools of available nutrients, while those in Group II could hardly provide available nutrients for plants. Descreasing the transformation of corresponding elements into fractions of Group 11 and increasing the storagecapacity of various fractions of Group I were an important direction for regulation and controiling of soilnutrients. However, some Particular soils with too high contents of Zn, Fe, Cu and Mn should be regulatedand controlled adversely
文摘The most remarkable effect in spinel ferrites is the strong dependence of properties on the state of structural disorder and,in particular,on the cation distribution.The structural characterization of a Co-Zn ferrite nanoparticle sample was reported which prepared by wet chemical co-precipitation method.The samples were sintered at three different temperatures viz.650℃,850℃ and 1050℃ for 12 h.The structural details like:lattice constant and distribution of cations in the tetrahedral and octahedral interstitial voids have been deduced through X-ray diffraction (XRD) data analysis.Lattice constant was found to increase with the increase in Zn2+ ions and sintering temperature.Theoretical intensity ratios of (220),(400),(440) planes were considered,as these reflections are sensitive to cations on the A and B sites.Close agreement of the theoretical intensity ratio with the intensity ratio observed from XRD pattern supports the occupancy of Zn2+ ions and Co2+ ions on the octahedral and tetrahedral sites,respectively.
基金Project (No. 30470198) supported by the National Natural Science Foundation of China
文摘Objective:To evaluate effects of epigallocatechin-3-gallate (EGCG) on the viability, membrane properties, and zinc distribution, with and without the presence of Zn2+, in human prostate carcinoma LNCaP cells. Methods: We examined changes in cellular morphology and membrane fluidity of LNCaP cells, distribution of cellular zinc, and the incorporated portion of EGCG after treatments with EGCG, Zn2+, and EGCG+Zn2+. Results: We observed an alteration in cellular morphology and a decrease in membrane fluidity of LNCaP cells after treatment with EGCG or Zn2+. The proportion of EGCG incorporated into liposomes treated with the mixture of EGCG and Zn2+ at the ratio of 1:1 was 90.57%, which was significantly higher than that treated with EGCG alone (30.33%). Electron spin resonance (ESR) studies and determination of fatty acids showed that the effects of EGCG on the membrane fluidity of LNCaP were decreased by Zn2+. EGCG accelerated the accumulation of zinc in the mitochondria and cytosol as observed by atomic absorption spectrometer. Conclusion: These results show that EGCG interacted with cell membrane, decreased the membrane fluidity of LNCaP cells, and accelerated zinc accumulation in the mitochondria and cytosol, which could be the mechanism by which EGCG inhibits proliferation of LNCaP cells. In addition, high concentrations of Zn2+ could attenuate the actions elicited by EGCG.
