The Zhuxi W(Cu)skarn deposit,the world’s largest tungsten deposit is newly discovered in Jingdezhen city,northeastern Jiangxi province,China.It mainly occurs near the contact zone between the Yanshanian granites and ...The Zhuxi W(Cu)skarn deposit,the world’s largest tungsten deposit is newly discovered in Jingdezhen city,northeastern Jiangxi province,China.It mainly occurs near the contact zone between the Yanshanian granites and the Late Paleozoic carbonate rocks.Three types of mineralization including skarn type,altered granite type and quartz vein veinlet type orebodies have been observed.In this study,the 40Ar 39Ar age of hydrothermal muscovite coexisting with copper mineralization in the altered granite type orebody formed near the unconformity interface is determined by step-heating technology using CO2 laser.The plateau age,isochron age,and inverse isochron age of muscovite are(147.39±0.94)Ma,(147.2±1.5)Ma,and(147.1±1.5)Ma,respectively.These ages are almost identical to the ages of ore-related granite and other mineralization types in the Zhuxi W(Cu)deposit,indicating that the Cu mineralizations occurred at the shallow depth and near the unconformity interface are contemporaneous during the Late Jurassic.This further suggested that the acompanied W and Cu mineralization in the Zhuxi W(Cu)deposit which may be controlled by the magma source is enriched in both W and Cu.展开更多
Resin matrix carbon brush composites(RMCBCs)are critical materials for high-powered electric tools.However,effectively improving their wear resistance and heat dissipation remains a challenge.RMCBCs prepared with flak...Resin matrix carbon brush composites(RMCBCs)are critical materials for high-powered electric tools.However,effectively improving their wear resistance and heat dissipation remains a challenge.RMCBCs prepared with flake graphite powders that were evenly loaded with tungsten copper composite powder(RMCBCs-W@Cu)exhibited a low wear rate of 1.63 mm^(3)/h,exhibiting 48.6%reduction in the wear rate relative to RCMBCs without additives(RMCBCs-0).In addition,RMCBCs-W@Cu achieved a low friction coefficient of 0.243 and low electric spark grade.These findings indicate that tungsten copper composite powders provide particle reinforcement and generate a gradation effect for the epoxy resin(i.e.,connecting phase)in RMCBCs,which weakens the wear of RMCBCs caused by fatigue under a cyclic current-carrying wear.展开更多
By taking tetragonal tungsten bronze(TTB)phase Nb_(18)W_(16)O_(93)as an example,an improved solid-state sintering method at lower temperature of 1000℃for 36 h was proposed via applying nanoscale raw materials.XRD,SEM...By taking tetragonal tungsten bronze(TTB)phase Nb_(18)W_(16)O_(93)as an example,an improved solid-state sintering method at lower temperature of 1000℃for 36 h was proposed via applying nanoscale raw materials.XRD,SEM and XPS confirm that the expected sample was produced.GITT results show that the lithium-ion diffusion coefficient of Nb_(18)W_(16)O_(93)(10−12 cm^(2)/s)is higher than that of the conventional titanium-based anode,ensuring a relatively superior electrochemical performance.The lithium-ion diffusion mechanism was thoroughly revealed by using density functional theory simulation.There are three diffusion paths in TTB phase,among which the interlayer diffusion with the smallest diffusion barrier(0.46 eV)has more advantages than other typical anodes(such as graphite,0.56 eV).The relatively smaller lithium-ion diffusion barrier makes TTB phase Nb_(18)W_(16)O_(93)become a potential highspecific-power anode material.展开更多
The dissimilar joining of CP-copper to 304 stainless steel was performed by gas tungsten arc welding process using different filler materials. The results indicated the formation of defect free joint by using copper f...The dissimilar joining of CP-copper to 304 stainless steel was performed by gas tungsten arc welding process using different filler materials. The results indicated the formation of defect free joint by using copper filler material. But, the presence of some defects like solidification crack and lack of fusion caused decreasing tensile strength of other joints. In the optimum conditions, the tensile strength of the joint was 96% of the weaker material. Also, this joint was bent till to 180° without any macroscopic defects like separation, tearing or fracture. It was concluded that copper is a new and good candidate for gas tungsten arc welding of copper to 304 stainless steel.展开更多
In this work, with the analysis on MO and electronic structure for a series of heteronuclear cluster with cubane type (Mo4S1 )xMn1(x=1.2. M = Cu, W, Ni, Sb, Mo, Sn, Cu2) we found that it is with the multiple center d-...In this work, with the analysis on MO and electronic structure for a series of heteronuclear cluster with cubane type (Mo4S1 )xMn1(x=1.2. M = Cu, W, Ni, Sb, Mo, Sn, Cu2) we found that it is with the multiple center d-pir orbitals that the ligand Mo3S44+ bonds to the M atom to form these class clusters. It is revealed that the charges transfer from the M atom to Mo atom of the ligand Mo3S44+ and its relationship with the MC (multiple center) d-pπ orbitals. Based on the charge transfer the electronic spectrum and the magnetic property of some cubane clusters have been discussed.展开更多
The complex [Et4N][(Ph3P)2{CuS2WS2Fe} Br2] (1 ), C44, H50NBr2CuFeP2S4W, M4= 1246. 13, has been obtained by reaction of [Et4N]2[WS4] andFeBr2 with Cu (Ph3P )3I in MeCN/CH2Cl2. Crystal data for [Et4N][(Ph3P)2{CuS2WS2Fe)...The complex [Et4N][(Ph3P)2{CuS2WS2Fe} Br2] (1 ), C44, H50NBr2CuFeP2S4W, M4= 1246. 13, has been obtained by reaction of [Et4N]2[WS4] andFeBr2 with Cu (Ph3P )3I in MeCN/CH2Cl2. Crystal data for [Et4N][(Ph3P)2{CuS2WS2Fe) Br2] (1): triclinic, P1, Z = 2, a= 13. 495 (7), b = 15. 322 (5), c =12. 361 (4), a=105. 32(3), β=93. 19(4), γ=101. 35(4) and V=2401. 2 The bond lengths of W-Fe bond and the W-Cu distance are 2. 793(2) A and 2. 823(2), respectively. Three kind metal atoms of the title structure [Et4N][(Ph3P)2{CuS2WS2Fe}Br2] (1) are nearly distributed along a line, and along which three metalatoms (W, Cu, Fe) are approximately tetrahedral coordination.展开更多
The Zhuxi ore deposit is a super-large scheelite(copper) polymetallic deposit discovered in recent years. It grew above copper/tungsten-rich Neoproterozoic argilloarenaceous basement rocks and was formed in the contac...The Zhuxi ore deposit is a super-large scheelite(copper) polymetallic deposit discovered in recent years. It grew above copper/tungsten-rich Neoproterozoic argilloarenaceous basement rocks and was formed in the contact zone between Yanshanian granites and Carboniferous-Permian limestone. Granites related to this mineralization mainly include equigranular, middle- to coarse-grained granites and granitic porphyries. There are two mineralization types: skarn scheelite(copper) and granite scheelite mineralization. The former is large scale and has a high content of scheelite, whereas the latter is small scale and has a low content of scheelite. In the Taqian-Fuchun Basin, its NW boundary is a thrust fault, and the SE boundary is an angular unconformity with Proterozoic basement. In Carboniferous-Permian rock assemblages, the tungsten and copper contents in the limestone are both very high. The contents of major elements in granitoids do not differ largely between the periphery and the inside of the Zhuxi ore deposit. In both areas, the values of the aluminum saturation index are A/CNK>1.1, and the rocks are classified as potassium-rich strongly peraluminous granites. In terms of trace elements, compared to granites on the periphery of the Zhuxi ore deposit, the granites inside the Zhuxi ore deposit have smaller d Eu values, exhibit a significantly more negative Eu anomaly, are richer in Rb, U, Ta, Pb and Hf, and are more depleted in Ba, Ce, Sr, La and Ti, which indicates that they are highly differentiated S-type granites with a high degree of evolution. Under the influence of fluids, mineralization of sulfides is evident within massive rock formations inside the Zhuxi ore deposit, and the mean SO_3 content is 0.2%. Compared to peripheral rocks, the d Eu and total rare earth element(REE) content of granites inside the Zhuxi ore deposit are both lower, indicating a certain evolutionary inheritance relationship between the granites on the periphery and the granites inside the Zhuxi ore deposit. For peripheral and ore district plutons, U-Pb zircon dating shows an age range of 152–148 Ma. In situ Lu-Hf isotope analysis of zircon in the granites reveals that the calculated e_(Hf)(t) values are all negative, and the majority range from -6 to -9. The T_(DM2) values are concentrated in the range of 1.50–1.88 Ga(peak at 1.75 Ga), suggesting that the granitic magmas are derived from partial melting of ancient crust. This paper also discusses the metallogenic conditions and ore-controlling conditions of the ore district from the perspectives of mineral contents, hydrothermal alteration, and ore-controlling structures in the strata and the ore-bearing rocks. It is proposed that the Zhuxi ore deposit went through a multistage evolution, including oblique intrusion of granitic magmas, skarn mineralization, cooling and alteration, and precipitation of metal sulfides. The mineralization pattern can be summarized as "copper in the east and tungsten in the west, copper at shallow-middle depths and tungsten at deep depths, tungsten in the early stage and copper in the late stage".展开更多
Photocatalytic CO2 reduction is thought to be a promising strategy in mitigating the energy crisis and several other environmental problems.Hence,modifying or developing suitable semiconductors with high efficiency of...Photocatalytic CO2 reduction is thought to be a promising strategy in mitigating the energy crisis and several other environmental problems.Hence,modifying or developing suitable semiconductors with high efficiency of photocatalytic CO2 reduction property has become a topic of interest to scientists.In this study,a series of Mo-modified Cs0.33WO3 tungsten bronze were prepared using a"watercontrollable releasing"solvothermal method to produce effective photocatalytic CO2 reduction performance.Interestingly,Mo atoms replaced W partially within the hexagonal crystal structure,leading to a significant increase in photocatalytic CO2 reduction activity of Cs0.33WO3.The 5%Modoped compound displayed the best performance,with the production yield rates of 7.5μmol g^-1h^-1 for CO and3.0μmol g^-1h^-1 for CH3OH under low concentration of CO2 under anaerobic conditions,which is greatly higher than those of pure Cs0.33WO3(3.2μmol g^-1h^-1 for CO and 1.2μmol g^-1h^-1 for CH3OH)and Mo-doped W18O49(1.5μmol g^-1h^-1for CO and 0μmol g^-1h^-1 for CH3OH).More importantly,the as-prepared Mo-doped Cs0.33WO3 series could also induce the photocatalytic reduction of CO2 directly from the air in the presence of oxygen,which is beneficial for practical applications.The superior photocatalytic performance of Mo-doped Cs0.33WO3 series over the popular reduced WO3 may be due to the increase in light absorption induced by the localized surface plasmon resonance(LSPR)effect of Mo5+,large improved charge separation ability,and the co-effect of Mo and Cs in crystal.This study provides a simple strategy for designing highly efficient photocatalysts in low concentration of CO2 reduction.展开更多
基金Project(41873059)supported by the National Natural Science Foundation of ChinaProject(JGMEDB [2017]78)supported by the Jiangxi Geological and Mineral Exploration and Development Bureau Foundation,China+2 种基金Project(2011BAB04B02)supported by the National Science and Technology Support Plan Project,ChinaProject(201411035)supported by the Welfare Research Program of Ministry of Land and Resources,ChinaProject(20150013)supported by Jiangxi Provincial Geological Exploration Fund Management Center,China
文摘The Zhuxi W(Cu)skarn deposit,the world’s largest tungsten deposit is newly discovered in Jingdezhen city,northeastern Jiangxi province,China.It mainly occurs near the contact zone between the Yanshanian granites and the Late Paleozoic carbonate rocks.Three types of mineralization including skarn type,altered granite type and quartz vein veinlet type orebodies have been observed.In this study,the 40Ar 39Ar age of hydrothermal muscovite coexisting with copper mineralization in the altered granite type orebody formed near the unconformity interface is determined by step-heating technology using CO2 laser.The plateau age,isochron age,and inverse isochron age of muscovite are(147.39±0.94)Ma,(147.2±1.5)Ma,and(147.1±1.5)Ma,respectively.These ages are almost identical to the ages of ore-related granite and other mineralization types in the Zhuxi W(Cu)deposit,indicating that the Cu mineralizations occurred at the shallow depth and near the unconformity interface are contemporaneous during the Late Jurassic.This further suggested that the acompanied W and Cu mineralization in the Zhuxi W(Cu)deposit which may be controlled by the magma source is enriched in both W and Cu.
基金Projects(51772081,51837009,51971091)supported by the National Natural Science Foundation of ChinaProject(HFZL2018CXY003-4)supported by the Industry-University-Research Cooperation of AECC,ChinaProject(kq1902046)supported by the Major Science and Technology Projects of Changsha City,China。
文摘Resin matrix carbon brush composites(RMCBCs)are critical materials for high-powered electric tools.However,effectively improving their wear resistance and heat dissipation remains a challenge.RMCBCs prepared with flake graphite powders that were evenly loaded with tungsten copper composite powder(RMCBCs-W@Cu)exhibited a low wear rate of 1.63 mm^(3)/h,exhibiting 48.6%reduction in the wear rate relative to RCMBCs without additives(RMCBCs-0).In addition,RMCBCs-W@Cu achieved a low friction coefficient of 0.243 and low electric spark grade.These findings indicate that tungsten copper composite powders provide particle reinforcement and generate a gradation effect for the epoxy resin(i.e.,connecting phase)in RMCBCs,which weakens the wear of RMCBCs caused by fatigue under a cyclic current-carrying wear.
基金the Key R&D Program of Shaanxi Province,China(No.2019ZDLGY04-05)the Natural Science Foundation of Shaanxi Province,China(No.2019JLZ-01)+1 种基金the Fundamental Research Funds for the Central Universities of China(Nos.19GH020302,3102019JC005,3102021ZD0401,3102021TS0406)the Science,Technology,and Innovation Commission of Shenzhen Municipality,China(No.JCYJ20180508151856806).
文摘By taking tetragonal tungsten bronze(TTB)phase Nb_(18)W_(16)O_(93)as an example,an improved solid-state sintering method at lower temperature of 1000℃for 36 h was proposed via applying nanoscale raw materials.XRD,SEM and XPS confirm that the expected sample was produced.GITT results show that the lithium-ion diffusion coefficient of Nb_(18)W_(16)O_(93)(10−12 cm^(2)/s)is higher than that of the conventional titanium-based anode,ensuring a relatively superior electrochemical performance.The lithium-ion diffusion mechanism was thoroughly revealed by using density functional theory simulation.There are three diffusion paths in TTB phase,among which the interlayer diffusion with the smallest diffusion barrier(0.46 eV)has more advantages than other typical anodes(such as graphite,0.56 eV).The relatively smaller lithium-ion diffusion barrier makes TTB phase Nb_(18)W_(16)O_(93)become a potential highspecific-power anode material.
文摘The dissimilar joining of CP-copper to 304 stainless steel was performed by gas tungsten arc welding process using different filler materials. The results indicated the formation of defect free joint by using copper filler material. But, the presence of some defects like solidification crack and lack of fusion caused decreasing tensile strength of other joints. In the optimum conditions, the tensile strength of the joint was 96% of the weaker material. Also, this joint was bent till to 180° without any macroscopic defects like separation, tearing or fracture. It was concluded that copper is a new and good candidate for gas tungsten arc welding of copper to 304 stainless steel.
文摘In this work, with the analysis on MO and electronic structure for a series of heteronuclear cluster with cubane type (Mo4S1 )xMn1(x=1.2. M = Cu, W, Ni, Sb, Mo, Sn, Cu2) we found that it is with the multiple center d-pir orbitals that the ligand Mo3S44+ bonds to the M atom to form these class clusters. It is revealed that the charges transfer from the M atom to Mo atom of the ligand Mo3S44+ and its relationship with the MC (multiple center) d-pπ orbitals. Based on the charge transfer the electronic spectrum and the magnetic property of some cubane clusters have been discussed.
文摘The complex [Et4N][(Ph3P)2{CuS2WS2Fe} Br2] (1 ), C44, H50NBr2CuFeP2S4W, M4= 1246. 13, has been obtained by reaction of [Et4N]2[WS4] andFeBr2 with Cu (Ph3P )3I in MeCN/CH2Cl2. Crystal data for [Et4N][(Ph3P)2{CuS2WS2Fe) Br2] (1): triclinic, P1, Z = 2, a= 13. 495 (7), b = 15. 322 (5), c =12. 361 (4), a=105. 32(3), β=93. 19(4), γ=101. 35(4) and V=2401. 2 The bond lengths of W-Fe bond and the W-Cu distance are 2. 793(2) A and 2. 823(2), respectively. Three kind metal atoms of the title structure [Et4N][(Ph3P)2{CuS2WS2Fe}Br2] (1) are nearly distributed along a line, and along which three metalatoms (W, Cu, Fe) are approximately tetrahedral coordination.
基金supported by the National Basic Research Program of China(Grant No.2012CB416701)National Natural Science Foundation of China(Grant Nos.41330208+3 种基金41572200)National Science and Technology Support Program(Grant No.2011BAB04B02)the Jiangxi Geological Exploration Fund(Grant No.20100112)Jiangxi Science and Technology Project(Grant No.20122BBG70068)
文摘The Zhuxi ore deposit is a super-large scheelite(copper) polymetallic deposit discovered in recent years. It grew above copper/tungsten-rich Neoproterozoic argilloarenaceous basement rocks and was formed in the contact zone between Yanshanian granites and Carboniferous-Permian limestone. Granites related to this mineralization mainly include equigranular, middle- to coarse-grained granites and granitic porphyries. There are two mineralization types: skarn scheelite(copper) and granite scheelite mineralization. The former is large scale and has a high content of scheelite, whereas the latter is small scale and has a low content of scheelite. In the Taqian-Fuchun Basin, its NW boundary is a thrust fault, and the SE boundary is an angular unconformity with Proterozoic basement. In Carboniferous-Permian rock assemblages, the tungsten and copper contents in the limestone are both very high. The contents of major elements in granitoids do not differ largely between the periphery and the inside of the Zhuxi ore deposit. In both areas, the values of the aluminum saturation index are A/CNK>1.1, and the rocks are classified as potassium-rich strongly peraluminous granites. In terms of trace elements, compared to granites on the periphery of the Zhuxi ore deposit, the granites inside the Zhuxi ore deposit have smaller d Eu values, exhibit a significantly more negative Eu anomaly, are richer in Rb, U, Ta, Pb and Hf, and are more depleted in Ba, Ce, Sr, La and Ti, which indicates that they are highly differentiated S-type granites with a high degree of evolution. Under the influence of fluids, mineralization of sulfides is evident within massive rock formations inside the Zhuxi ore deposit, and the mean SO_3 content is 0.2%. Compared to peripheral rocks, the d Eu and total rare earth element(REE) content of granites inside the Zhuxi ore deposit are both lower, indicating a certain evolutionary inheritance relationship between the granites on the periphery and the granites inside the Zhuxi ore deposit. For peripheral and ore district plutons, U-Pb zircon dating shows an age range of 152–148 Ma. In situ Lu-Hf isotope analysis of zircon in the granites reveals that the calculated e_(Hf)(t) values are all negative, and the majority range from -6 to -9. The T_(DM2) values are concentrated in the range of 1.50–1.88 Ga(peak at 1.75 Ga), suggesting that the granitic magmas are derived from partial melting of ancient crust. This paper also discusses the metallogenic conditions and ore-controlling conditions of the ore district from the perspectives of mineral contents, hydrothermal alteration, and ore-controlling structures in the strata and the ore-bearing rocks. It is proposed that the Zhuxi ore deposit went through a multistage evolution, including oblique intrusion of granitic magmas, skarn mineralization, cooling and alteration, and precipitation of metal sulfides. The mineralization pattern can be summarized as "copper in the east and tungsten in the west, copper at shallow-middle depths and tungsten at deep depths, tungsten in the early stage and copper in the late stage".
基金supported by the National Natural Science Foundation of China(21975193 and 51602237)the Fundamental Research Funds for the Central Universities(195208011)。
文摘Photocatalytic CO2 reduction is thought to be a promising strategy in mitigating the energy crisis and several other environmental problems.Hence,modifying or developing suitable semiconductors with high efficiency of photocatalytic CO2 reduction property has become a topic of interest to scientists.In this study,a series of Mo-modified Cs0.33WO3 tungsten bronze were prepared using a"watercontrollable releasing"solvothermal method to produce effective photocatalytic CO2 reduction performance.Interestingly,Mo atoms replaced W partially within the hexagonal crystal structure,leading to a significant increase in photocatalytic CO2 reduction activity of Cs0.33WO3.The 5%Modoped compound displayed the best performance,with the production yield rates of 7.5μmol g^-1h^-1 for CO and3.0μmol g^-1h^-1 for CH3OH under low concentration of CO2 under anaerobic conditions,which is greatly higher than those of pure Cs0.33WO3(3.2μmol g^-1h^-1 for CO and 1.2μmol g^-1h^-1 for CH3OH)and Mo-doped W18O49(1.5μmol g^-1h^-1for CO and 0μmol g^-1h^-1 for CH3OH).More importantly,the as-prepared Mo-doped Cs0.33WO3 series could also induce the photocatalytic reduction of CO2 directly from the air in the presence of oxygen,which is beneficial for practical applications.The superior photocatalytic performance of Mo-doped Cs0.33WO3 series over the popular reduced WO3 may be due to the increase in light absorption induced by the localized surface plasmon resonance(LSPR)effect of Mo5+,large improved charge separation ability,and the co-effect of Mo and Cs in crystal.This study provides a simple strategy for designing highly efficient photocatalysts in low concentration of CO2 reduction.
