The refining effect of Al3Ti1B1RE master alloy on Al sheets used for pressure can manufacture and the behavior of mixed rare earths in master alloy were investigated with XRD, OM, SEM and EDAX. It is found that the r...The refining effect of Al3Ti1B1RE master alloy on Al sheets used for pressure can manufacture and the behavior of mixed rare earths in master alloy were investigated with XRD, OM, SEM and EDAX. It is found that the refining effect of the refiner on the material has superiority over foreign or domestic Al5Ti1B refiner, and the refiner still retains its refining ability for 6 h after adding it to molten Al, thus improving the strength and plasticity of the material remarkably. The excellent refining effect and stability of AlTiBRE refiner result from that RE can lower the surface energy of molten Al and improve the wetting characteristics of molten Al on refinement nuclei such as TiAl 3, TiB 2, etc., thus giving full play to the effect of heterogeneous nucleation and impeding the congregating tendency of TiB 2 phase in molten Al. At the same time, RE gathering in front of solid/liquid interface are also easy to cause composition supercooling in molten Al, thus impeding the growth of α Al grains and promoting α Al nucleation on refinement nuclei. In addition, RE also play certain role in purification and grain refinement, or modification, especially their effect of purification can improve the metallurgical quality of AlTiBRE master alloy.展开更多
Despite being a leading candidate to meet stringent energy targets,lithium(Li) metal batteries(LMBs)face severe challenges at low temperatures such as dramatic increase in impedance,capacity loss and dendrite growth.U...Despite being a leading candidate to meet stringent energy targets,lithium(Li) metal batteries(LMBs)face severe challenges at low temperatures such as dramatic increase in impedance,capacity loss and dendrite growth.Unambiguously fingerprinting rate-limited factors of low-temperature LMBs would encourage targeted approaches to promote performances.Herein,the charge transfer impedance across solid electrolyte interphase(SEI) is identified to restrict battery operation under low temperature,and we propose a facile approach on the basis of ambiently fostering SEI(af-SEI) to facilitate charge transfer.The concept of af-SEI stems from kinetic benefits and structural merits to construct SEI at ambient temperature over low temperature developed SEI that is temporally consuming to achieve steady state and that is structurally defective to incur dendrite growth.The af-SEI allows ionically conductive and morphologically uniform layer on the anode surface,which exhibits a lower resistance and induces an even deposition of Li in the subsequent low temperature battery operation.Armed with af-SEI,the LMBs deliver the improved rate performance and prolonged cycle life when subjected to low temperature cycling.This work unveils the underlying causes that limit low temperature LMB performances,and enlightens the facile test protocols to build up favorable SEI,beyond scope of material and morphology design.展开更多
软件即服务SaaS(Software as a Service)具有技术先进和成本低廉的优势,是提高组织IT性能和竞争力的良好解决方案.但是很多企业考虑到可能存在的种种风险而不愿意采纳SaaS,因此风险因素的分析对SaaS采纳决策具有重要影响作用.使用DEMATE...软件即服务SaaS(Software as a Service)具有技术先进和成本低廉的优势,是提高组织IT性能和竞争力的良好解决方案.但是很多企业考虑到可能存在的种种风险而不愿意采纳SaaS,因此风险因素的分析对SaaS采纳决策具有重要影响作用.使用DEMATEL方法,从安全风险(SR)和IT治理风险(GR)两个维度,分别获取各自的原因—结果因素组,构成可视化SR-GR矩阵,对风险因素进行定量分析.研究结果显示,认证和授权及IT管控权等原因因素是企业Saas采纳的关键影响因素.通过计算各因素的综合影响指数,辨识因素间的因果关系和相对重要程度,从而找出影响SaaS采纳的关键因素,为企业SaaS采纳决策提供相关依据.展开更多
文摘The refining effect of Al3Ti1B1RE master alloy on Al sheets used for pressure can manufacture and the behavior of mixed rare earths in master alloy were investigated with XRD, OM, SEM and EDAX. It is found that the refining effect of the refiner on the material has superiority over foreign or domestic Al5Ti1B refiner, and the refiner still retains its refining ability for 6 h after adding it to molten Al, thus improving the strength and plasticity of the material remarkably. The excellent refining effect and stability of AlTiBRE refiner result from that RE can lower the surface energy of molten Al and improve the wetting characteristics of molten Al on refinement nuclei such as TiAl 3, TiB 2, etc., thus giving full play to the effect of heterogeneous nucleation and impeding the congregating tendency of TiB 2 phase in molten Al. At the same time, RE gathering in front of solid/liquid interface are also easy to cause composition supercooling in molten Al, thus impeding the growth of α Al grains and promoting α Al nucleation on refinement nuclei. In addition, RE also play certain role in purification and grain refinement, or modification, especially their effect of purification can improve the metallurgical quality of AlTiBRE master alloy.
基金supported by the National Natural Science Foundation of China (22379121)Shenzhen Foundation Research Fund granted by the Shenzhen Science and Technology Innovation Committee (JCYJ20220530112812028)+1 种基金Fundamental Research Funds for the Central Universities (G2022KY0606)Zhejiang Province Key Laboratory of Flexible Electronics Open Fund (No. 2023FE005)。
文摘Despite being a leading candidate to meet stringent energy targets,lithium(Li) metal batteries(LMBs)face severe challenges at low temperatures such as dramatic increase in impedance,capacity loss and dendrite growth.Unambiguously fingerprinting rate-limited factors of low-temperature LMBs would encourage targeted approaches to promote performances.Herein,the charge transfer impedance across solid electrolyte interphase(SEI) is identified to restrict battery operation under low temperature,and we propose a facile approach on the basis of ambiently fostering SEI(af-SEI) to facilitate charge transfer.The concept of af-SEI stems from kinetic benefits and structural merits to construct SEI at ambient temperature over low temperature developed SEI that is temporally consuming to achieve steady state and that is structurally defective to incur dendrite growth.The af-SEI allows ionically conductive and morphologically uniform layer on the anode surface,which exhibits a lower resistance and induces an even deposition of Li in the subsequent low temperature battery operation.Armed with af-SEI,the LMBs deliver the improved rate performance and prolonged cycle life when subjected to low temperature cycling.This work unveils the underlying causes that limit low temperature LMB performances,and enlightens the facile test protocols to build up favorable SEI,beyond scope of material and morphology design.
文摘软件即服务SaaS(Software as a Service)具有技术先进和成本低廉的优势,是提高组织IT性能和竞争力的良好解决方案.但是很多企业考虑到可能存在的种种风险而不愿意采纳SaaS,因此风险因素的分析对SaaS采纳决策具有重要影响作用.使用DEMATEL方法,从安全风险(SR)和IT治理风险(GR)两个维度,分别获取各自的原因—结果因素组,构成可视化SR-GR矩阵,对风险因素进行定量分析.研究结果显示,认证和授权及IT管控权等原因因素是企业Saas采纳的关键影响因素.通过计算各因素的综合影响指数,辨识因素间的因果关系和相对重要程度,从而找出影响SaaS采纳的关键因素,为企业SaaS采纳决策提供相关依据.
