In low-density steel,κ-carbides primarily precipitate in the form of nanoscale particles within austenite grains.However,their precipitation within ferrite matrix grains has not been comprehensively explored,and the ...In low-density steel,κ-carbides primarily precipitate in the form of nanoscale particles within austenite grains.However,their precipitation within ferrite matrix grains has not been comprehensively explored,and the second-phase evolution mechanism during aging remains unclear.In this study,the crystallographic characteristics and morphological evolution ofκ-carbides in Fe-28Mn-10Al-0.8C(wt%)low-density steel at different aging temperatures and times and the impacts of these changes on the steels’microhardness and properties were comprehensively analyzed.Under different heat treatment conditions,intragranularκ-carbides exhibited various morpho-logical and crystallographic characteristics,such as acicular,spherical,and short rod-like shapes.At the initial stage of aging,acicularκ-carbides primarily precipitated,accompanied by a few spherical carbides.κ-Carbides grew and coarsened with aging time,the spherical carbides were considerably reduced,and rod-like carbides coarsened.Vickers hardness testing demonstrated that the material’s hardness was affected by the volume fraction,morphology,and size ofκ-carbides.Extended aging at higher temperatures led to an increase in carbide size and volume fraction,resulting in a gradual rise in hardness.During deformation,the primary mechanisms for strengthening were dislocation strengthening and second-phase strengthening.Based on these findings,potential strategies for improving material strength are proposed.展开更多
Rechargeable batteries of high energy density and overall performance are becoming a critically important technology in the rapidly changing society of the twenty-first century.While lithium-ion batteries have so far ...Rechargeable batteries of high energy density and overall performance are becoming a critically important technology in the rapidly changing society of the twenty-first century.While lithium-ion batteries have so far been the dominant choice,numerous emerging applications call for higher capacity,better safety and lower costs while maintaining sufficient cyclability.The design space for potentially better alternatives is extremely large,with numerous new chemistries and architectures being simultaneously explored.These include other insertion ions(e.g.sodium and numerous multivalent ions),conversion electrode materials(e.g.silicon,metallic anodes,halides and chalcogens)and aqueous and solid electrolytes.However,each of these potential“beyond lithium-ion”alternatives faces numerous challenges that often lead to very poor cyclability,especially at the commercial cell level,while lithium-ion batteries continue to improve in performance and decrease in cost.This review examines fundamental principles to rationalise these numerous developments,and in each case,a brief overview is given on the advantages,advances,remaining challenges preventing cell-level implementation and the state-of-the-art of the solutions to these challenges.Finally,research and development results obtained in academia are compared to emerging commercial examples,as a commentary on the current and near-future viability of these“beyond lithium-ion”alternatives.展开更多
Insect pest damage to crops is a threat to global food security(Tilman et al.,2011).Climate change,the evolution of insecticide resistance,and the phasing out of insecticides due to environmental and safety concerns e...Insect pest damage to crops is a threat to global food security(Tilman et al.,2011).Climate change,the evolution of insecticide resistance,and the phasing out of insecticides due to environmental and safety concerns exacerbate this problem.Farmers urgently need safe and effective crop protection tools to sustainably generate yields that meet ever-increasing global demand.展开更多
All solid-state batteries(ASSBs)are the holy grails of rechargeable batteries,where extensive searches are ongoing in the pursuit of ideal solid-state electrolytes.Nevertheless,there is still a long way off to the sat...All solid-state batteries(ASSBs)are the holy grails of rechargeable batteries,where extensive searches are ongoing in the pursuit of ideal solid-state electrolytes.Nevertheless,there is still a long way off to the satisfactorily high(enough)ionic conductivity,long-term stability and especially being able to form compatible interfaces with the solid electrodes.Herein,we have explored ionic transport behavior and high mobility in the sub-nano pore networks in the framework structures.Macroscopically,the frameworked electrolyte behaves as a solid,and however in the(sub)-nano scales,the very limited number of solvent molecules in confinement makes them completely different from that in liquid electrolyte.Differentiated from a liquid-electrolyte counterpart,the interactions between the mobile ions and surrounding molecules are subject to dramatic changes,leading to a high ionic conductivity at room temperature with a low activation energy.Li+ions in the sub-nano cages of the network structure are highly mobile and diffuse rather independently,where the rate-limiting step of ions crossing cages is driven by the local concentration gradient and the electrostatic interactions between Li^(+)ions.This new class of frameworked electrolytes(FEs)with both high ionic conductivity and desirable interface with solid electrodes are demonstrated to work with Li-ion batteries,where the ASSB with LiFePO_(4)shows a highly stable electrochemical performance of over 450 cycles at 2℃ at room temperature,with an almost negligible capacity fade of 0.03‰ each cycle.In addition,the FE shows outstanding flexibility and anti-flammability,which are among the key requirements of large-scale applications.展开更多
Lithium-ion batteries(LIBs)are undoubtedly the current working-horse in almost all portable electronic devices,electric vehicles,and even large-scale stationary energy storage.Given the problems faced by LIBs,a big qu...Lithium-ion batteries(LIBs)are undoubtedly the current working-horse in almost all portable electronic devices,electric vehicles,and even large-scale stationary energy storage.Given the problems faced by LIBs,a big question arises as to which battery(ies)would be the“Beyond LIBs”batteries.Among the front-runners,lithium-sulfur batteries(LSBs)have been extensively pursued owing to their intrinsically high energy density and extremely low cost.Despite the steady and sometimes exciting progress reported on sulfur chemistry and cell performance at laboratory scales over the past decade,one of the major bottlenecks is the poor cyclability.In this perspective,we examine the key challenges and opportunities faced by LSBs,as well as approaches at the materials,electrode/electrolyte and cell integration levels that can be taken to transform LSBs from a front-runner to a real leading champion in the pursuit of the“Beyond LIBs”.While the key new mechanistic insights are very important,we propose a set of the near-future research directions for both the liquid and solid state LSBs,where the currently on-going parallel pursuits of both liquid and solid LSBs will be converging.The“liquid current”will gradually be taken over by“solid future”in the expected LSBs commercialization in the coming decade.展开更多
With the scaling up of high-performance computing systems in recent years,their reliability has been descending continuously.Therefore,system resilience has been regarded as one of the critical challenges for large-sc...With the scaling up of high-performance computing systems in recent years,their reliability has been descending continuously.Therefore,system resilience has been regarded as one of the critical challenges for large-scale HPC systems.Various techniques and systems have been proposed to ensure the correct execution and completion of parallel programs.This paper provides a comprehensive survey of existing software resilience approaches.Firstly,a classification of software resilience approaches is presented;then we introduce major approaches and techniques,including checkpointing,replication,soft error resilience,algorithmbased fault tolerance,fault detection and prediction.In addition,challenges exposed by system-scale and heterogeneous architecture are also discussed.展开更多
As the most important non-cereal food crop,potatoes are a staple food for 1.3 billion people(Stokstad,2019).However,these cultivated potatoes are challenged with multiple biotic stresses(i.e.,pathogens and pests),some...As the most important non-cereal food crop,potatoes are a staple food for 1.3 billion people(Stokstad,2019).However,these cultivated potatoes are challenged with multiple biotic stresses(i.e.,pathogens and pests),some of which can evade host resistance,leading to a serious dampening of potato yield.One of these pests is the Colorado potato beetle(hereafter referred to as CPB,Leptinotarsa decemlineata Say).CPB is a member of the order Coleoptera,and originated in the southwestern United States and Mexico(Alyokhin et al.,2008).展开更多
基金supported by the National Key Research and Development Program of China(No.2023YFB3711702).
文摘In low-density steel,κ-carbides primarily precipitate in the form of nanoscale particles within austenite grains.However,their precipitation within ferrite matrix grains has not been comprehensively explored,and the second-phase evolution mechanism during aging remains unclear.In this study,the crystallographic characteristics and morphological evolution ofκ-carbides in Fe-28Mn-10Al-0.8C(wt%)low-density steel at different aging temperatures and times and the impacts of these changes on the steels’microhardness and properties were comprehensively analyzed.Under different heat treatment conditions,intragranularκ-carbides exhibited various morpho-logical and crystallographic characteristics,such as acicular,spherical,and short rod-like shapes.At the initial stage of aging,acicularκ-carbides primarily precipitated,accompanied by a few spherical carbides.κ-Carbides grew and coarsened with aging time,the spherical carbides were considerably reduced,and rod-like carbides coarsened.Vickers hardness testing demonstrated that the material’s hardness was affected by the volume fraction,morphology,and size ofκ-carbides.Extended aging at higher temperatures led to an increase in carbide size and volume fraction,resulting in a gradual rise in hardness.During deformation,the primary mechanisms for strengthening were dislocation strengthening and second-phase strengthening.Based on these findings,potential strategies for improving material strength are proposed.
基金J.Wang acknowledges the support by MOE,Singapore Ministry of Education(MOE2018-T2-2-095)for research work conducted at the National University of Singapore.Z.L.Liu acknowledges the A*STAR’s Central Research Funds(CRF)Award(Project:SC25/21-111312)+1 种基金Y.Gao acknowledges financial support by ST Engineering Advanced Material Engineering Pte.Ltd.and Singapore Economic Development BoardOpen access funding provided by Shanghai Jiao Tong University
文摘Rechargeable batteries of high energy density and overall performance are becoming a critically important technology in the rapidly changing society of the twenty-first century.While lithium-ion batteries have so far been the dominant choice,numerous emerging applications call for higher capacity,better safety and lower costs while maintaining sufficient cyclability.The design space for potentially better alternatives is extremely large,with numerous new chemistries and architectures being simultaneously explored.These include other insertion ions(e.g.sodium and numerous multivalent ions),conversion electrode materials(e.g.silicon,metallic anodes,halides and chalcogens)and aqueous and solid electrolytes.However,each of these potential“beyond lithium-ion”alternatives faces numerous challenges that often lead to very poor cyclability,especially at the commercial cell level,while lithium-ion batteries continue to improve in performance and decrease in cost.This review examines fundamental principles to rationalise these numerous developments,and in each case,a brief overview is given on the advantages,advances,remaining challenges preventing cell-level implementation and the state-of-the-art of the solutions to these challenges.Finally,research and development results obtained in academia are compared to emerging commercial examples,as a commentary on the current and near-future viability of these“beyond lithium-ion”alternatives.
基金supported by the Science and Technology Innovation Project of the Chinese Academy of Agricultural Sciences(CAAS-2060302).
文摘Insect pest damage to crops is a threat to global food security(Tilman et al.,2011).Climate change,the evolution of insecticide resistance,and the phasing out of insecticides due to environmental and safety concerns exacerbate this problem.Farmers urgently need safe and effective crop protection tools to sustainably generate yields that meet ever-increasing global demand.
基金Singapore Ministry of Education,Grant/Award Number:A-8000186-01-00National Research Foundation(NRF)Singapore,Grant/Award Numbers:CRP NRF-CRP26-2021-0003,NRFCRP24-2020-0002A*STAR SERC CRF Award。
文摘All solid-state batteries(ASSBs)are the holy grails of rechargeable batteries,where extensive searches are ongoing in the pursuit of ideal solid-state electrolytes.Nevertheless,there is still a long way off to the satisfactorily high(enough)ionic conductivity,long-term stability and especially being able to form compatible interfaces with the solid electrodes.Herein,we have explored ionic transport behavior and high mobility in the sub-nano pore networks in the framework structures.Macroscopically,the frameworked electrolyte behaves as a solid,and however in the(sub)-nano scales,the very limited number of solvent molecules in confinement makes them completely different from that in liquid electrolyte.Differentiated from a liquid-electrolyte counterpart,the interactions between the mobile ions and surrounding molecules are subject to dramatic changes,leading to a high ionic conductivity at room temperature with a low activation energy.Li+ions in the sub-nano cages of the network structure are highly mobile and diffuse rather independently,where the rate-limiting step of ions crossing cages is driven by the local concentration gradient and the electrostatic interactions between Li^(+)ions.This new class of frameworked electrolytes(FEs)with both high ionic conductivity and desirable interface with solid electrodes are demonstrated to work with Li-ion batteries,where the ASSB with LiFePO_(4)shows a highly stable electrochemical performance of over 450 cycles at 2℃ at room temperature,with an almost negligible capacity fade of 0.03‰ each cycle.In addition,the FE shows outstanding flexibility and anti-flammability,which are among the key requirements of large-scale applications.
基金Fundamental Research Funds for the Central Universities(Tongji University),MOE,Singapore Ministry of Education,Grant/Award Number:MOE2018-T2-2-095。
文摘Lithium-ion batteries(LIBs)are undoubtedly the current working-horse in almost all portable electronic devices,electric vehicles,and even large-scale stationary energy storage.Given the problems faced by LIBs,a big question arises as to which battery(ies)would be the“Beyond LIBs”batteries.Among the front-runners,lithium-sulfur batteries(LSBs)have been extensively pursued owing to their intrinsically high energy density and extremely low cost.Despite the steady and sometimes exciting progress reported on sulfur chemistry and cell performance at laboratory scales over the past decade,one of the major bottlenecks is the poor cyclability.In this perspective,we examine the key challenges and opportunities faced by LSBs,as well as approaches at the materials,electrode/electrolyte and cell integration levels that can be taken to transform LSBs from a front-runner to a real leading champion in the pursuit of the“Beyond LIBs”.While the key new mechanistic insights are very important,we propose a set of the near-future research directions for both the liquid and solid state LSBs,where the currently on-going parallel pursuits of both liquid and solid LSBs will be converging.The“liquid current”will gradually be taken over by“solid future”in the expected LSBs commercialization in the coming decade.
基金supported by the GHFund A(No.ghfund202107010337).
文摘With the scaling up of high-performance computing systems in recent years,their reliability has been descending continuously.Therefore,system resilience has been regarded as one of the critical challenges for large-scale HPC systems.Various techniques and systems have been proposed to ensure the correct execution and completion of parallel programs.This paper provides a comprehensive survey of existing software resilience approaches.Firstly,a classification of software resilience approaches is presented;then we introduce major approaches and techniques,including checkpointing,replication,soft error resilience,algorithmbased fault tolerance,fault detection and prediction.In addition,challenges exposed by system-scale and heterogeneous architecture are also discussed.
基金the National Key R&D Program of China(2022YFD1700200,2021YFD1400200)Science Technology and Innovation Commission of Shenzhen Municipality of China(ZDSYS 20200811142605017)Major Projects for Talent Development in Guangdong Province of China(2021QN02N756).
文摘As the most important non-cereal food crop,potatoes are a staple food for 1.3 billion people(Stokstad,2019).However,these cultivated potatoes are challenged with multiple biotic stresses(i.e.,pathogens and pests),some of which can evade host resistance,leading to a serious dampening of potato yield.One of these pests is the Colorado potato beetle(hereafter referred to as CPB,Leptinotarsa decemlineata Say).CPB is a member of the order Coleoptera,and originated in the southwestern United States and Mexico(Alyokhin et al.,2008).