Single-phase SrM ultrafine powders with single-domain particle ranging from 200 to 400 nm in size were successfully synthesized by a cetyltrimethylammonium bromide（CTAB）-as sis ted co-precipitation method,and excell...Single-phase SrM ultrafine powders with single-domain particle ranging from 200 to 400 nm in size were successfully synthesized by a cetyltrimethylammonium bromide（CTAB）-as sis ted co-precipitation method,and excellent magnetic properties with saturation magnetization of 68.6 A·m^2·kg^（-1） and coercive field of 0.5250 T are obtained.As CTAB content exceeds 5.0 wt%,the impurities emerge due to the deterioration of simultaneous precipitations of the starting materials and the deviation of Sr/Fe molar ratio from stoichiometry ratio in the local microdomains by employing CTAB in co-precipitation process.Also,the use of CTAB can effectively improve the homogeneities of Fe-precursor particles with Sr-precursor particles,exert surface barriers to inhibit interdiffusion,and constrain the crystal growth in the local microdomains during sintering,resulting in smaller particle sizes and more uniform particle size distribution.展开更多
Understanding the hydrochemical characteristics and genesis mechanisms of strontium-rich groundwater is pivotal for supporting the exploitation and utilization of natural strontium-rich groundwater.In this research,27...Understanding the hydrochemical characteristics and genesis mechanisms of strontium-rich groundwater is pivotal for supporting the exploitation and utilization of natural strontium-rich groundwater.In this research,27 groundwater samples were collected.By analyzing major ion chemistry and strontium isotope data,and considering the hydrogeological context,various analytical approaches,including multivariate statistics,ion ratios,and isotopes,were used to reveal the characteristics and genesis mechanisms of strontium-rich groundwater in the study area.The findings indicate that the predominant hydrochemical type of groundwater is HCO_(3)-Ca,with Ca^(2+)and HCO_(3)^(-)as the primary cations and anions.The hydrochemistry of the strontium-rich groundwater is predominantly influenced by rock weathering processes.A combination of factors,including ion exchange,and anthropogenic activities,shapes the compositional characteristics of the groundwater in the region.The dissolution of calcite due to weathering emerges as the principal source of strontium in the groundwater.While ion exchange processes are not conducive to strontium enrichment in groundwater,their effect is relatively limited.The impact of human activities on the groundwater is minor.展开更多
The hollow strontium carbonate pompons was synthesized for the first time by a controlled reaction precipitation method with sodium dodecyl benzene sulfonate(SDBS)and polyvinyl pyrrolidone(PVP)work together as templat...The hollow strontium carbonate pompons was synthesized for the first time by a controlled reaction precipitation method with sodium dodecyl benzene sulfonate(SDBS)and polyvinyl pyrrolidone(PVP)work together as template.The sampled particles were characterized by scanning electron microscopy(SEM),transmission electron microscopy(TEM),nitrogen adsorption-desorption measurement,X-ray diffraction(XRD),Energy dispersive X-Ray spectroscopy(EDX),Fourier transform infrared spectroscopy(FTIR),Thermogravimetric analysis and differential scanning calorimetry(TGA-DSC),etc.It is shown that the assynthesized hollow strontium carbonate pompons with the size of about 2μm consist of flake-like particles under the optimal reaction conditions.The formation mechanism of hollow strontium carbonate pompons was preliminarily explored.展开更多
基金financially supported by the National Natural Science Foundation of China(No.51103125)the China Postdoctoral Science Foundation(No.2015M570483)+1 种基金the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions,the Natural Science Foundation of Yangzhou(No.YZ2014043)the Science Innovative Foundation of Yangzhou University(No.2014CXJ017)
文摘Single-phase SrM ultrafine powders with single-domain particle ranging from 200 to 400 nm in size were successfully synthesized by a cetyltrimethylammonium bromide（CTAB）-as sis ted co-precipitation method,and excellent magnetic properties with saturation magnetization of 68.6 A·m^2·kg^（-1） and coercive field of 0.5250 T are obtained.As CTAB content exceeds 5.0 wt%,the impurities emerge due to the deterioration of simultaneous precipitations of the starting materials and the deviation of Sr/Fe molar ratio from stoichiometry ratio in the local microdomains by employing CTAB in co-precipitation process.Also,the use of CTAB can effectively improve the homogeneities of Fe-precursor particles with Sr-precursor particles,exert surface barriers to inhibit interdiffusion,and constrain the crystal growth in the local microdomains during sintering,resulting in smaller particle sizes and more uniform particle size distribution.
基金supported by the Guangxi Natural Science Foundation(2020GXNSFAA297025)the Guangxi Natural Science Foundation(GuikeAB22080046)+3 种基金the Guangxi Natural Science Foundation(GuikeAB21196050)the National Natural Science Foundation of China(42177075)the Natural Resources Science and Technology Strategic Research Project(2023-ZL-23)the Survey and China Geological Survey(DD20221808 and DD20230547).
文摘Understanding the hydrochemical characteristics and genesis mechanisms of strontium-rich groundwater is pivotal for supporting the exploitation and utilization of natural strontium-rich groundwater.In this research,27 groundwater samples were collected.By analyzing major ion chemistry and strontium isotope data,and considering the hydrogeological context,various analytical approaches,including multivariate statistics,ion ratios,and isotopes,were used to reveal the characteristics and genesis mechanisms of strontium-rich groundwater in the study area.The findings indicate that the predominant hydrochemical type of groundwater is HCO_(3)-Ca,with Ca^(2+)and HCO_(3)^(-)as the primary cations and anions.The hydrochemistry of the strontium-rich groundwater is predominantly influenced by rock weathering processes.A combination of factors,including ion exchange,and anthropogenic activities,shapes the compositional characteristics of the groundwater in the region.The dissolution of calcite due to weathering emerges as the principal source of strontium in the groundwater.While ion exchange processes are not conducive to strontium enrichment in groundwater,their effect is relatively limited.The impact of human activities on the groundwater is minor.
基金Funded by the National Natural Science Foundation of China(No.22002143)the Natural Science Foundation of Shanxi Province of China(No.201901D211223)the Postgraduate Students Scientific Research Project of North University of China(No.20201766)。
文摘The hollow strontium carbonate pompons was synthesized for the first time by a controlled reaction precipitation method with sodium dodecyl benzene sulfonate(SDBS)and polyvinyl pyrrolidone(PVP)work together as template.The sampled particles were characterized by scanning electron microscopy(SEM),transmission electron microscopy(TEM),nitrogen adsorption-desorption measurement,X-ray diffraction(XRD),Energy dispersive X-Ray spectroscopy(EDX),Fourier transform infrared spectroscopy(FTIR),Thermogravimetric analysis and differential scanning calorimetry(TGA-DSC),etc.It is shown that the assynthesized hollow strontium carbonate pompons with the size of about 2μm consist of flake-like particles under the optimal reaction conditions.The formation mechanism of hollow strontium carbonate pompons was preliminarily explored.
基金the National Natural Science Foundation of China(NSFC)(61461052,11564044,and 61863035)Yunnan Provincial Department of Science and Technology Agricultural Joint Special Project(202101BD070001-064)Yunnan Province Basic Research Project(202301AT070495)。
