稀土元素钐(Samarium,Sm)及其合金在永磁材料领域应用广泛,但其高昂的提取成本与繁琐的制备工艺严重制约发展,亟需开发新型制备方法。本研究旨在阐明Sm_(2)O_(3)、ZnO及Sm_(2)O_(3)-ZnO复合氧化物在CaCl_(2)-NaCl熔盐中的电化学行为,为...稀土元素钐(Samarium,Sm)及其合金在永磁材料领域应用广泛,但其高昂的提取成本与繁琐的制备工艺严重制约发展,亟需开发新型制备方法。本研究旨在阐明Sm_(2)O_(3)、ZnO及Sm_(2)O_(3)-ZnO复合氧化物在CaCl_(2)-NaCl熔盐中的电化学行为,为制备Sm-Zn合金提供理论依据。本文采用熔盐电脱氧法,在CaCl_(2)-NaCl熔盐体系中构建三电极系统,通过循环伏安法(Cyclic Voltammetry,CV)和方波伏安法(Square Wave Voltammetry,SWV)对Sm_(2)O_(3)、ZnO及Sm_(2)O_(3)-ZnO三种金属氧化物的电化学行为进行研究分析。研究结果表明:Sm_(2)O_(3)还原为金属Sm的还原电位约为-1.80 V vs.Ag/Ag^(+),直接电脱氧效率较低;ZnO转化为金属Zn的还原电位约为-0.75 V vs.Ag/Ag^(+);Sm_(2)O_(3)-ZnO混合物在-1.13 V vs.Ag/Ag^(+)左右被还原为SmZn12,在约-1.56 V vs.Ag/Ag^(+)处被还原形成Sm_(2)Zn_(17)合金。不同电解条件下的产物分析结果显示,相比-1.70 V vs.Ag/Ag^(+),在-2.30 V vs.Ag/Ag^(+)、923 K条件下对Sm_(2)O_(3)-ZnO进行20 h恒电位电解时Sm_(2)O_(3)-ZnO能完全转化为SmZn12和Sm_(2)Zn_(17)合金。本研究为稀土金属氧化物熔盐电解制备稀土金属及其合金提供了重要的电化学机制信息与工艺优化路径选择。展开更多
针对车载自组织网络(Vehicular Ad Hoc Network,VANET)中的隐私保护问题,提出一种基于SM9算法的聚合签名方案。该方案以SM9签名算法为基础,结合聚合签名技术提高认证效率,利用雾计算降低时延,实现对数据的实时处理需求,同时满足条件隐...针对车载自组织网络(Vehicular Ad Hoc Network,VANET)中的隐私保护问题,提出一种基于SM9算法的聚合签名方案。该方案以SM9签名算法为基础,结合聚合签名技术提高认证效率,利用雾计算降低时延,实现对数据的实时处理需求,同时满足条件隐私保护、匿名性和不可链接性等安全需求。最后,通过假名机制保护车辆隐私,确保当车辆发生非法行为时能够快速追踪其真实身份。在随机谕言机模型下,证明了该方案的不可伪造性。性能分析结果表明,与现有方案相比,所提方案有效降低了聚合验证阶段的计算开销,适用于资源受限的车联网环境。展开更多
The Internet of Vehicles(IoV)operates in highly dynamic and open network environments and faces serious challenges in secure and real-time authentication and consensus mechanisms.Existing methods often suffer from com...The Internet of Vehicles(IoV)operates in highly dynamic and open network environments and faces serious challenges in secure and real-time authentication and consensus mechanisms.Existing methods often suffer from complex certificate management,inefficient consensus protocols,and poor resilience in high-frequency communication,resulting in high latency,poor scalability,and unstable network performance.To address these issues,this paper proposes a secure and efficient distributed authentication scheme for IoV with reputation-driven consensus and SM9.First,this paper proposes a decentralized authentication architecture that utilizes the certificate-free feature of SM9,enabling lightweight authentication and key negotiation,thereby reducing the complexity of key management.To ensure the traceability and global consistency of authentication data,this scheme also integrates blockchain technology,applying its inherent invariance.Then,this paper introduces a reputation-driven dynamic node grouping mechanism that transparently evaluates and groups’node behavior using smart contracts to enhance network stability.Furthermore,a new RBSFT(Reputation-Based SM9 Friendly-Tolerant)consensus mechanism is proposed for the first time to enhance consensus efficiency by optimizing the PBFT algorithm.RBSFT aims to write authentication information into the blockchain ledger to achieve multi-level optimization of trust management and decision-making efficiency,thereby significantly improving the responsiveness and robustness in high-frequency IoV scenarios.Experimental results show that it excels in authentication,communication efficiency,and computational cost control,making it a feasible solution for achieving IoV security and real-time performance.展开更多
1.Data security in smart manufacturing The global manufacturing sector is undergoing a digital transformation as traditional systems-reliant on physical assets such as raw materials and labor-struggle to meet demands ...1.Data security in smart manufacturing The global manufacturing sector is undergoing a digital transformation as traditional systems-reliant on physical assets such as raw materials and labor-struggle to meet demands for greater flexibility and efficiency.The integration of advanced information technology facilitates smart manufacturing(SM),which optimizes production,management,and supply chains[1].展开更多
In this study,Mg-Gd-Y-(Sm)-Zr(GW-(Sm))alloys were subjected to compression tests at both 293 and 77 K.The effect of Sm addition on the plastic deformation mechanism of Mg-Gd-Y-Zr(GW)alloy was investigated,and a detail...In this study,Mg-Gd-Y-(Sm)-Zr(GW-(Sm))alloys were subjected to compression tests at both 293 and 77 K.The effect of Sm addition on the plastic deformation mechanism of Mg-Gd-Y-Zr(GW)alloy was investigated,and a detailed analysis was conducted on the relationships between mechanical responses and the microstructure of the alloys.The findings suggest that dislocation slip plays a predominant role in the plastic deformation of GW-(Sm)alloys.The addition of Sm reduces the stacking fault energy(SFE)of the alloy,which promotes<c+a>slip and inhibits twinning.Meanwhile,Sm plays a role in solution strengthening,causing an elevation in the flow stress of the alloy.At cryogenic temperature(CT),the critical resolved shear stress(CRSS)of dislocation slip is increased,so the dislocation motion requires greater external force.In addition,the extensive crossed twins exhibited in the microstructure,which shorten the dislocation slip path and enhance the grain boundary strengthening.This research contributes to the advancement of plastic deformation theories for magnesium-rare earth(Mg-RE)alloys.展开更多
SmFe_(12)-based alloys perform promising potential for new generation permanent magnets,attributed to their high saturation magnetization(Ms)and anisotropy field(Ha).Introduction of the low melting point element Cu ca...SmFe_(12)-based alloys perform promising potential for new generation permanent magnets,attributed to their high saturation magnetization(Ms)and anisotropy field(Ha).Introduction of the low melting point element Cu can promote the formation of non-magnetic grain boundaries in Sm-Fe-Ti system.The effect of Cu content on the grain boundary phase formation and magnetic properties in Sm(Fe_(0.8)Co_(0.2))_(11-x)TiCu_(x)(x=0-0.5)strips has been investigated.Sm(Fe_(0.8)Co_(0.2))_(10.8)TiCu_(0.2) strip exhibited a maximum Ms value of 1.07 T.Coercivity improved from 20.96 kA m^(-1) for Sm(Fe_(0.8)Co_(0.2))_(11)Ti strip to 165.92 kA m^(-1) for Sm(Fe_(0.8)Co_(0.2))_(10.5)TiCu_(0.5) strip.When Cu content increased from 0 to 0.5 at.%,Fe content of the grain boundary phase decreased from 43.8 to 12.6 at.%.Due to the good wettability of Cu,main 1:12 phase is well isolated and enveloped by(Sm,Cu)-rich grain boundary phase.Cu addition facilitates the formation of the continuous non-magnetic grain boundaries and reduces grain size of main 1:12 phase,contributing to coercivity improvement of the strips.展开更多
文摘稀土元素钐(Samarium,Sm)及其合金在永磁材料领域应用广泛,但其高昂的提取成本与繁琐的制备工艺严重制约发展,亟需开发新型制备方法。本研究旨在阐明Sm_(2)O_(3)、ZnO及Sm_(2)O_(3)-ZnO复合氧化物在CaCl_(2)-NaCl熔盐中的电化学行为,为制备Sm-Zn合金提供理论依据。本文采用熔盐电脱氧法,在CaCl_(2)-NaCl熔盐体系中构建三电极系统,通过循环伏安法(Cyclic Voltammetry,CV)和方波伏安法(Square Wave Voltammetry,SWV)对Sm_(2)O_(3)、ZnO及Sm_(2)O_(3)-ZnO三种金属氧化物的电化学行为进行研究分析。研究结果表明:Sm_(2)O_(3)还原为金属Sm的还原电位约为-1.80 V vs.Ag/Ag^(+),直接电脱氧效率较低;ZnO转化为金属Zn的还原电位约为-0.75 V vs.Ag/Ag^(+);Sm_(2)O_(3)-ZnO混合物在-1.13 V vs.Ag/Ag^(+)左右被还原为SmZn12,在约-1.56 V vs.Ag/Ag^(+)处被还原形成Sm_(2)Zn_(17)合金。不同电解条件下的产物分析结果显示,相比-1.70 V vs.Ag/Ag^(+),在-2.30 V vs.Ag/Ag^(+)、923 K条件下对Sm_(2)O_(3)-ZnO进行20 h恒电位电解时Sm_(2)O_(3)-ZnO能完全转化为SmZn12和Sm_(2)Zn_(17)合金。本研究为稀土金属氧化物熔盐电解制备稀土金属及其合金提供了重要的电化学机制信息与工艺优化路径选择。
文摘针对车载自组织网络(Vehicular Ad Hoc Network,VANET)中的隐私保护问题,提出一种基于SM9算法的聚合签名方案。该方案以SM9签名算法为基础,结合聚合签名技术提高认证效率,利用雾计算降低时延,实现对数据的实时处理需求,同时满足条件隐私保护、匿名性和不可链接性等安全需求。最后,通过假名机制保护车辆隐私,确保当车辆发生非法行为时能够快速追踪其真实身份。在随机谕言机模型下,证明了该方案的不可伪造性。性能分析结果表明,与现有方案相比,所提方案有效降低了聚合验证阶段的计算开销,适用于资源受限的车联网环境。
基金supported by the National Natural Science Foundation of China(Grant No.61762071,Grant No.61163025).
文摘The Internet of Vehicles(IoV)operates in highly dynamic and open network environments and faces serious challenges in secure and real-time authentication and consensus mechanisms.Existing methods often suffer from complex certificate management,inefficient consensus protocols,and poor resilience in high-frequency communication,resulting in high latency,poor scalability,and unstable network performance.To address these issues,this paper proposes a secure and efficient distributed authentication scheme for IoV with reputation-driven consensus and SM9.First,this paper proposes a decentralized authentication architecture that utilizes the certificate-free feature of SM9,enabling lightweight authentication and key negotiation,thereby reducing the complexity of key management.To ensure the traceability and global consistency of authentication data,this scheme also integrates blockchain technology,applying its inherent invariance.Then,this paper introduces a reputation-driven dynamic node grouping mechanism that transparently evaluates and groups’node behavior using smart contracts to enhance network stability.Furthermore,a new RBSFT(Reputation-Based SM9 Friendly-Tolerant)consensus mechanism is proposed for the first time to enhance consensus efficiency by optimizing the PBFT algorithm.RBSFT aims to write authentication information into the blockchain ledger to achieve multi-level optimization of trust management and decision-making efficiency,thereby significantly improving the responsiveness and robustness in high-frequency IoV scenarios.Experimental results show that it excels in authentication,communication efficiency,and computational cost control,making it a feasible solution for achieving IoV security and real-time performance.
基金supported in part by the National Natural Science Foundation of China(62293511 and 62402256)in part by the Shandong Provincial Natural Science Foundation of China(ZR2024MF100)+1 种基金in part by the Taishan Scholars Program(tsqn202408239)in part by the Open Research Project of the State Key Laboratory of Industrial Control Technology,Zhejiang University,China(ICT2025B13).
文摘1.Data security in smart manufacturing The global manufacturing sector is undergoing a digital transformation as traditional systems-reliant on physical assets such as raw materials and labor-struggle to meet demands for greater flexibility and efficiency.The integration of advanced information technology facilitates smart manufacturing(SM),which optimizes production,management,and supply chains[1].
基金supported by the National Natural Science Foundation of China(Nos.52275322 and 51875127).
文摘In this study,Mg-Gd-Y-(Sm)-Zr(GW-(Sm))alloys were subjected to compression tests at both 293 and 77 K.The effect of Sm addition on the plastic deformation mechanism of Mg-Gd-Y-Zr(GW)alloy was investigated,and a detailed analysis was conducted on the relationships between mechanical responses and the microstructure of the alloys.The findings suggest that dislocation slip plays a predominant role in the plastic deformation of GW-(Sm)alloys.The addition of Sm reduces the stacking fault energy(SFE)of the alloy,which promotes<c+a>slip and inhibits twinning.Meanwhile,Sm plays a role in solution strengthening,causing an elevation in the flow stress of the alloy.At cryogenic temperature(CT),the critical resolved shear stress(CRSS)of dislocation slip is increased,so the dislocation motion requires greater external force.In addition,the extensive crossed twins exhibited in the microstructure,which shorten the dislocation slip path and enhance the grain boundary strengthening.This research contributes to the advancement of plastic deformation theories for magnesium-rare earth(Mg-RE)alloys.
文摘SmFe_(12)-based alloys perform promising potential for new generation permanent magnets,attributed to their high saturation magnetization(Ms)and anisotropy field(Ha).Introduction of the low melting point element Cu can promote the formation of non-magnetic grain boundaries in Sm-Fe-Ti system.The effect of Cu content on the grain boundary phase formation and magnetic properties in Sm(Fe_(0.8)Co_(0.2))_(11-x)TiCu_(x)(x=0-0.5)strips has been investigated.Sm(Fe_(0.8)Co_(0.2))_(10.8)TiCu_(0.2) strip exhibited a maximum Ms value of 1.07 T.Coercivity improved from 20.96 kA m^(-1) for Sm(Fe_(0.8)Co_(0.2))_(11)Ti strip to 165.92 kA m^(-1) for Sm(Fe_(0.8)Co_(0.2))_(10.5)TiCu_(0.5) strip.When Cu content increased from 0 to 0.5 at.%,Fe content of the grain boundary phase decreased from 43.8 to 12.6 at.%.Due to the good wettability of Cu,main 1:12 phase is well isolated and enveloped by(Sm,Cu)-rich grain boundary phase.Cu addition facilitates the formation of the continuous non-magnetic grain boundaries and reduces grain size of main 1:12 phase,contributing to coercivity improvement of the strips.
