Thermal metamaterials represent a transformative paradigm in modern physics,synergizing thermodynamic principles with metamaterial engineering to master heat flow at will.As next-generation technologies demand multi-s...Thermal metamaterials represent a transformative paradigm in modern physics,synergizing thermodynamic principles with metamaterial engineering to master heat flow at will.As next-generation technologies demand multi-scale thermal control,this field urgently requires systematic frameworks to unify its multidisciplinary advances.Curated through a global collaboration involving over 50 specialists across 25 subdisciplines,this review primarily summarizes two decades of advancements,ranging from theoretical breakthroughs to functional implementations.The review reveals groundbreaking innovations in heat manipulation through the exploration of both classical and non-classical transport regimes,topological thermal control mechanisms,and quantum-informed phonon engineering strategies.By bridging physical insights like non-Hermitian thermal dynamics and valleytronic phonon transport with cutting-edge applications,we demonstrate paradigm-shifting capabilities:environment-adaptive thermal cloaks,AI-optimized metamaterials,and nonlinear thermal circuits enabling heat-based computation.Experimental milestones include 3D thermal null media with reconfigurable invisibility and thermal designs breaking classical conductivity limits.This collaborative effort establishes an indispensable roadmap for physicists,highlighting pathways to quantum thermal management,entropy-controlled energy systems,and topological devices.As thermal metamaterials transition from laboratory marvels to technological cornerstones,this work provides the foundational lexicon and design principles for the coming era of intelligent thermal matter.展开更多
This paper presents a model of cascading failures in cyber-physical power systems(CPPSs) based on an improved percolation theory, and then proposes failure mitigation strategies. In this model, the dynamic development...This paper presents a model of cascading failures in cyber-physical power systems(CPPSs) based on an improved percolation theory, and then proposes failure mitigation strategies. In this model, the dynamic development of cascading failures is divided into several iteration stages. The power flow in the power grid, along with the data transmission and delay in the cyber layer, is considered in the improved percolation theory. The interaction mechanism between two layers is interpreted as the observability and controllability analysis and data update analysis influencing the node state transformation and security command execution. The resilience indices of the failures reflect the influence of cascading failures on both topological integrity and operational state. The efficacy of the proposed mitigation strategies is validated, including strategies to convert some cyber layer nodes into autonomous nodes and embed unified power flow controller(UPFC) into the physical layer. The results obtained from simulations of cascading failures in a CPPS with increasing initial failure sizes are compared for various scenarios.Dynamic cascading failures can be separated into rapid and slow processes. The interdependencies and gap between the observable and controllable parts of the physical layer with the actual physical network are two fundamental reasons for first-order transition failures. Due to the complexity of the coupled topological and operational relations between the two layers, mitigation strategies should be simultaneously applied in both layers.展开更多
文摘Thermal metamaterials represent a transformative paradigm in modern physics,synergizing thermodynamic principles with metamaterial engineering to master heat flow at will.As next-generation technologies demand multi-scale thermal control,this field urgently requires systematic frameworks to unify its multidisciplinary advances.Curated through a global collaboration involving over 50 specialists across 25 subdisciplines,this review primarily summarizes two decades of advancements,ranging from theoretical breakthroughs to functional implementations.The review reveals groundbreaking innovations in heat manipulation through the exploration of both classical and non-classical transport regimes,topological thermal control mechanisms,and quantum-informed phonon engineering strategies.By bridging physical insights like non-Hermitian thermal dynamics and valleytronic phonon transport with cutting-edge applications,we demonstrate paradigm-shifting capabilities:environment-adaptive thermal cloaks,AI-optimized metamaterials,and nonlinear thermal circuits enabling heat-based computation.Experimental milestones include 3D thermal null media with reconfigurable invisibility and thermal designs breaking classical conductivity limits.This collaborative effort establishes an indispensable roadmap for physicists,highlighting pathways to quantum thermal management,entropy-controlled energy systems,and topological devices.As thermal metamaterials transition from laboratory marvels to technological cornerstones,this work provides the foundational lexicon and design principles for the coming era of intelligent thermal matter.
基金supported by the National Natural Science Foundation of China(No.51537010)the National Key Basic Research Program(973 Program)(No.2013CB228206)the project of ‘‘The up layer design for DC-AC hybrid grids system protection’’(No.XT71-16-053)
文摘This paper presents a model of cascading failures in cyber-physical power systems(CPPSs) based on an improved percolation theory, and then proposes failure mitigation strategies. In this model, the dynamic development of cascading failures is divided into several iteration stages. The power flow in the power grid, along with the data transmission and delay in the cyber layer, is considered in the improved percolation theory. The interaction mechanism between two layers is interpreted as the observability and controllability analysis and data update analysis influencing the node state transformation and security command execution. The resilience indices of the failures reflect the influence of cascading failures on both topological integrity and operational state. The efficacy of the proposed mitigation strategies is validated, including strategies to convert some cyber layer nodes into autonomous nodes and embed unified power flow controller(UPFC) into the physical layer. The results obtained from simulations of cascading failures in a CPPS with increasing initial failure sizes are compared for various scenarios.Dynamic cascading failures can be separated into rapid and slow processes. The interdependencies and gap between the observable and controllable parts of the physical layer with the actual physical network are two fundamental reasons for first-order transition failures. Due to the complexity of the coupled topological and operational relations between the two layers, mitigation strategies should be simultaneously applied in both layers.
