Fe-12Cr-2.5W-x Si-0.4Ti-0.3Y_(2)O_(3)alloys were fabricated by mechanical alloying and vacuum sintering.The effect of sintering temperature and Si content on the microstructure and properties of the alloy was investig...Fe-12Cr-2.5W-x Si-0.4Ti-0.3Y_(2)O_(3)alloys were fabricated by mechanical alloying and vacuum sintering.The effect of sintering temperature and Si content on the microstructure and properties of the alloy was investigated systematically.The experimental results show that the relative density and tensile strength of the alloy were increased with the elevating of sintering temperature and Si content within a certain range.The alloy with 1wt%Si sintered at 1350℃exhibited superior properties,and the relative density and tensile strength were 96.8%and 692.7 MPa,respectively.HAADF and EDAX analysis of nano-precipitation in the matrix indicated that Si could combine with Y,Ti,and O in the sintering process,which was uniformly distributed with the size of 10 nm.Portion of Y_(2)O_(3)had not completely dissolved in the milling process,which was retained in the matrix of the alloy.展开更多
The monitoring system design used in anti-corrosion of coating wire of steel in ocean were concerned. A corrosion monitoring system adapting to corrosion observation of coating wire of steel was introduced in details,...The monitoring system design used in anti-corrosion of coating wire of steel in ocean were concerned. A corrosion monitoring system adapting to corrosion observation of coating wire of steel was introduced in details, including design and choice of software and hardware. This system will play an important role in the collection, procession, demonstration, deposition and accident alarm of corrosion data of oceanic coating wire of steel.展开更多
A magnetic tunnel junction(MTJ)is the core component in memory technologies,such as the magnetic random-access memory,magnetic sensors and programmable logic devices.In particular,MTJs based on twodimensional van der ...A magnetic tunnel junction(MTJ)is the core component in memory technologies,such as the magnetic random-access memory,magnetic sensors and programmable logic devices.In particular,MTJs based on twodimensional van der Waals(vd W)heterostructures offer unprecedented opportunities for low power consumption and miniaturization of spintronic devices.However,their operation at room temperature remains a challenge.Here,we report a large tunnel magnetoresistance(TMR)of up to 85%at room temperature(T=300 K)in vdW MTJs based on a thin(<10 nm)semiconductor spacer WSe_(2)layer embedded between two Fe_(3)GaTe_(2e)lectrodes with intrinsic above-room-temperature ferromagnetism.The TMR in the MTJ increases with decreasing temperature up to 164%at T=10 K.The demonstration of TMR in ultra-thin MTJs at room temperature opens a realistic and promising route for next-generation spintronic applications beyond the current state of the art.展开更多
An effective electrocatalyst being highly active in all pH range for oxygen reduction reaction(ORR)is crucial for energy conversion and storage devices.However,most of the high-efficiency ORR catalysis was reported in...An effective electrocatalyst being highly active in all pH range for oxygen reduction reaction(ORR)is crucial for energy conversion and storage devices.However,most of the high-efficiency ORR catalysis was reported in alkaline conditions.Herein,we demonstrated the preparation of atomically dispersed Fe-Zn pairs anchored on porous N-doped carbon frameworks(Fe-Zn-SA/NC),which works efficiently as ORR catalyst in the whole pH range.It achieves high half-wave potentials of 0.78,0.85 and 0.72 V in 0.1 M HClO4,0.1 M KOH and 0.1 M phosphate buffer saline(PBS)solutions,respectively,as well as respectable stability.The performances are even comparable to Pt/C.Furthermore,when assembled into a Zn-air battery,the high power density of 167.2 mWcm−2 and 120 h durability reveal the feasibility of Fe-Zn-SA/NC in real energy-related devices.Theoretical calculations demonstrate that the superior catalytic activity of Fe-Zn-SA/NC can be contributed to the lower energy barriers of ORR at the Fe-Zn-N6 centers.This work demonstrates the potential of Fe-Zn pairs as alternatives to the Pt catalysts for efficient catalytic ORR and provides new insights of dual-atom catalysts for other energy conversion related catalytic reactions.展开更多
Cold spraying(CS),or cold gas dynamic spray(CGDS),is an emerging solid-state powder deposition process,allowing fast and mass production and restoration of metallic components.CS of metal matrix composites(MMCs)has at...Cold spraying(CS),or cold gas dynamic spray(CGDS),is an emerging solid-state powder deposition process,allowing fast and mass production and restoration of metallic components.CS of metal matrix composites(MMCs)has attracted increasing attention from academia and industry over the last decades,especially in the area of Al matrix composites(AMCs),which have demonstrated a high potential for applications in aerospace,automotive,and electronics industries.This article aims to summarize the recent development of CS-processed AMCs in terms of composite powder preparation,deposition processing,microstructure evolution,mechanical and corrosion properties.Furthermore,this review also reports the relevant research progress with the focus on post-treatments of the AMCs for CS additive manufacturing applications including heat treatment,hot rolling,and friction stir processing.Finally,the challenges and perspectives on the fabrication of advanced AMCs by CS are addressed.展开更多
基金Funded by the Natural Science Foundation of China(No.51801140)the Fundamental Research Funds for the Central Universities(No.WUT3120619103)。
文摘Fe-12Cr-2.5W-x Si-0.4Ti-0.3Y_(2)O_(3)alloys were fabricated by mechanical alloying and vacuum sintering.The effect of sintering temperature and Si content on the microstructure and properties of the alloy was investigated systematically.The experimental results show that the relative density and tensile strength of the alloy were increased with the elevating of sintering temperature and Si content within a certain range.The alloy with 1wt%Si sintered at 1350℃exhibited superior properties,and the relative density and tensile strength were 96.8%and 692.7 MPa,respectively.HAADF and EDAX analysis of nano-precipitation in the matrix indicated that Si could combine with Y,Ti,and O in the sintering process,which was uniformly distributed with the size of 10 nm.Portion of Y_(2)O_(3)had not completely dissolved in the milling process,which was retained in the matrix of the alloy.
文摘The monitoring system design used in anti-corrosion of coating wire of steel in ocean were concerned. A corrosion monitoring system adapting to corrosion observation of coating wire of steel was introduced in details, including design and choice of software and hardware. This system will play an important role in the collection, procession, demonstration, deposition and accident alarm of corrosion data of oceanic coating wire of steel.
基金supported by the National Key Research and Development Program of China(Grant Nos.2022YFA1405100 and 2022YFE0134600)the Beijing Natural Science Foundation Key Program(Grant No.Z190007)+2 种基金the National Natural Science Foundation of China(Grant Nos.61774144,62005265,and 52272152)the Key Research Program of Frontier Sciences(Grant No.QYZDY-SSW-JSC020)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant Nos.XDB44000000 and XDB28000000)。
文摘A magnetic tunnel junction(MTJ)is the core component in memory technologies,such as the magnetic random-access memory,magnetic sensors and programmable logic devices.In particular,MTJs based on twodimensional van der Waals(vd W)heterostructures offer unprecedented opportunities for low power consumption and miniaturization of spintronic devices.However,their operation at room temperature remains a challenge.Here,we report a large tunnel magnetoresistance(TMR)of up to 85%at room temperature(T=300 K)in vdW MTJs based on a thin(<10 nm)semiconductor spacer WSe_(2)layer embedded between two Fe_(3)GaTe_(2e)lectrodes with intrinsic above-room-temperature ferromagnetism.The TMR in the MTJ increases with decreasing temperature up to 164%at T=10 K.The demonstration of TMR in ultra-thin MTJs at room temperature opens a realistic and promising route for next-generation spintronic applications beyond the current state of the art.
基金This work was financially supported by National Key R&D Program of China(No.2017YFA0700104)the National Natural Science Foundation of China(Nos.22075211,21601136,51971157,51761165012,and 62005173)+2 种基金Project funded by China Postdoctoral Science Foundation(No.2020TQ0201)Tianjin Science Fund for Distinguished Young Scholars(No.19JCJQJC61800)The authors also acknowledge National Supercomputing Center in Shenzhen for providing the computational resources and materials studio(version 7.0,DMol3).
文摘An effective electrocatalyst being highly active in all pH range for oxygen reduction reaction(ORR)is crucial for energy conversion and storage devices.However,most of the high-efficiency ORR catalysis was reported in alkaline conditions.Herein,we demonstrated the preparation of atomically dispersed Fe-Zn pairs anchored on porous N-doped carbon frameworks(Fe-Zn-SA/NC),which works efficiently as ORR catalyst in the whole pH range.It achieves high half-wave potentials of 0.78,0.85 and 0.72 V in 0.1 M HClO4,0.1 M KOH and 0.1 M phosphate buffer saline(PBS)solutions,respectively,as well as respectable stability.The performances are even comparable to Pt/C.Furthermore,when assembled into a Zn-air battery,the high power density of 167.2 mWcm−2 and 120 h durability reveal the feasibility of Fe-Zn-SA/NC in real energy-related devices.Theoretical calculations demonstrate that the superior catalytic activity of Fe-Zn-SA/NC can be contributed to the lower energy barriers of ORR at the Fe-Zn-N6 centers.This work demonstrates the potential of Fe-Zn pairs as alternatives to the Pt catalysts for efficient catalytic ORR and provides new insights of dual-atom catalysts for other energy conversion related catalytic reactions.
基金financial support of the Chinese Scholarship Council(No.201604490100)UniversitéBourgogne-Franche-Comté,and Centre National de la Recherche Scientifique(CNRS)+2 种基金supported by the Conseil Régional du Nord-Pas de Calaisthe European Regional Development Fund(ERDF)financial support from the National Natural Science Foundation of China(No.51875471)。
文摘Cold spraying(CS),or cold gas dynamic spray(CGDS),is an emerging solid-state powder deposition process,allowing fast and mass production and restoration of metallic components.CS of metal matrix composites(MMCs)has attracted increasing attention from academia and industry over the last decades,especially in the area of Al matrix composites(AMCs),which have demonstrated a high potential for applications in aerospace,automotive,and electronics industries.This article aims to summarize the recent development of CS-processed AMCs in terms of composite powder preparation,deposition processing,microstructure evolution,mechanical and corrosion properties.Furthermore,this review also reports the relevant research progress with the focus on post-treatments of the AMCs for CS additive manufacturing applications including heat treatment,hot rolling,and friction stir processing.Finally,the challenges and perspectives on the fabrication of advanced AMCs by CS are addressed.
