The distribution and competitive behaviors of phosphotungstic acid and ferric chloride in the TBP-HCl-H_(2)O system were investigated by controlling the extractant concentration and the solution environment.The result...The distribution and competitive behaviors of phosphotungstic acid and ferric chloride in the TBP-HCl-H_(2)O system were investigated by controlling the extractant concentration and the solution environment.The results revealed that phosphotungstic acid exhibited a strong affinity for TBP with decreasing TBP concentration.Higher acidity significantly improved the W extraction efficiency with TBP,and the lower Cl^(-)concentration reduced the extraction efficiency of Fe.As the organic phase approached saturation point,phosphotungstic acid competitively displaced Fe to combine with TBP.The hydrogen bond structure(P=O·HO-P-W-O)between phosphotungstic acid and TBP was characterized by FT-IR,and the salting-out effect induced by FeCl_(3) was elucidated.In summary,high acidity is beneficial for exhaustive extraction of W,and an effective W/Fe separation can be achieved by reducing the concentrations of TBP and Cl^(-).展开更多
China began absorbing FDI towards the end of the 1970s. By the end of 2002, China had approved the establishment of 424,196 foreign-invested enterprises, involving a total contractual volume of US$ 828.06 billion, 447...China began absorbing FDI towards the end of the 1970s. By the end of 2002, China had approved the establishment of 424,196 foreign-invested enterprises, involving a total contractual volume of US$ 828.06 billion, 447.966 billion of which were put into actual use.The probability of transnational corporations monopolizing the market of a host country and their important position in certain industries in China have prompted many to ask: Will transnational corporations展开更多
The microstructure,aging behavior and mechanical properties of cast Mg–3Nd–3Gd–x Zn–0.5Zr(x=0,0.5,0.8,1 wt%)alloys are investigated in this work.Zn–Zr particles with different morphologies form during solution tr...The microstructure,aging behavior and mechanical properties of cast Mg–3Nd–3Gd–x Zn–0.5Zr(x=0,0.5,0.8,1 wt%)alloys are investigated in this work.Zn–Zr particles with different morphologies form during solution treatment due to the additions of Zn.As the Zn content increases,the number density of Zn–Zr particles also increases.Microstructural comparisons of peak-aged studied alloys indicate that varying Zn additions could profoundly influence the competitive precipitation behavior.In the peak-aged Zn-free alloy,β′′phases are the key strengthening precipitates.When 0.5 wt%Zn is added,besidesβ′′precipitates,additional fineβ_(1)precipitates form.With the addition of 0.8 wt%Zn,the peak-aged 0.8Zn alloy is characterized by predominantly prismaticβ_(1)and scanty basal precipitate distributions.The enhanced precipitation ofβ_(1)should be primarily attributable to the presence of increased Zn–Zr dispersoids.When Zn content further increases to 1 wt%,the precipitation of basal precipitates is markedly enhanced.Basal precipitates andβ_(1)phases are the key strengthening precipitates in the peak-aged 1Zn alloy.Tensile tests reveal that the relatively best tensile properties are achieved in the peak-aged alloy with 0.5 wt%Zn addition,whose yield strength,ultimate tensile strength and elongation are 179 MPa,301 MPa and 5.3%,respectively.展开更多
基金supported by the National key R&D Program of China(No.2022YFC2905105)the National Natural Science Foundation of China(No.72088101)。
文摘The distribution and competitive behaviors of phosphotungstic acid and ferric chloride in the TBP-HCl-H_(2)O system were investigated by controlling the extractant concentration and the solution environment.The results revealed that phosphotungstic acid exhibited a strong affinity for TBP with decreasing TBP concentration.Higher acidity significantly improved the W extraction efficiency with TBP,and the lower Cl^(-)concentration reduced the extraction efficiency of Fe.As the organic phase approached saturation point,phosphotungstic acid competitively displaced Fe to combine with TBP.The hydrogen bond structure(P=O·HO-P-W-O)between phosphotungstic acid and TBP was characterized by FT-IR,and the salting-out effect induced by FeCl_(3) was elucidated.In summary,high acidity is beneficial for exhaustive extraction of W,and an effective W/Fe separation can be achieved by reducing the concentrations of TBP and Cl^(-).
文摘China began absorbing FDI towards the end of the 1970s. By the end of 2002, China had approved the establishment of 424,196 foreign-invested enterprises, involving a total contractual volume of US$ 828.06 billion, 447.966 billion of which were put into actual use.The probability of transnational corporations monopolizing the market of a host country and their important position in certain industries in China have prompted many to ask: Will transnational corporations
基金financially supported by the National Natural Science Foundation of China(Nos.U2037601,51775334 and 51821001)the National Key Research&Development Program of China(No.2016YFB0701205)+3 种基金the Joint Innovation Fund of CALT and College(No.CALT2020-TS07)the Open Fund of State Key Laboratory of Advanced Forming Technology and Equipment(No.SKL2020005)the Research Program of Joint Research Center of Advanced Spaceflight Technologies(No.USCAST2020-14)。
文摘The microstructure,aging behavior and mechanical properties of cast Mg–3Nd–3Gd–x Zn–0.5Zr(x=0,0.5,0.8,1 wt%)alloys are investigated in this work.Zn–Zr particles with different morphologies form during solution treatment due to the additions of Zn.As the Zn content increases,the number density of Zn–Zr particles also increases.Microstructural comparisons of peak-aged studied alloys indicate that varying Zn additions could profoundly influence the competitive precipitation behavior.In the peak-aged Zn-free alloy,β′′phases are the key strengthening precipitates.When 0.5 wt%Zn is added,besidesβ′′precipitates,additional fineβ_(1)precipitates form.With the addition of 0.8 wt%Zn,the peak-aged 0.8Zn alloy is characterized by predominantly prismaticβ_(1)and scanty basal precipitate distributions.The enhanced precipitation ofβ_(1)should be primarily attributable to the presence of increased Zn–Zr dispersoids.When Zn content further increases to 1 wt%,the precipitation of basal precipitates is markedly enhanced.Basal precipitates andβ_(1)phases are the key strengthening precipitates in the peak-aged 1Zn alloy.Tensile tests reveal that the relatively best tensile properties are achieved in the peak-aged alloy with 0.5 wt%Zn addition,whose yield strength,ultimate tensile strength and elongation are 179 MPa,301 MPa and 5.3%,respectively.
