Heterogeneous catalysis at the metal surface generally involves the transport of molecules through the interfacial water layer to access the surface,which is a rate-determining step at the nanoscale.In this study,taki...Heterogeneous catalysis at the metal surface generally involves the transport of molecules through the interfacial water layer to access the surface,which is a rate-determining step at the nanoscale.In this study,taking the oxygen reduction reaction on a metal electrode in aqueous solution as an example,using accurate molecular dynamic simulations,we propose a novel long-range regulation strategy in which midinfrared stimulation(MIRS)with a frequency of approximately 1,000 cm^(-1)is applied to nonthermally induce the structural transition of interfacial water from an ordered to disordered state,facilitating the access of oxygen molecules to metal surfaces at room temperature and increasing the oxygen reduction activity 50-fold.Impressively,the theoretical prediction is confirmed by the experimental observation of a significant discharge voltage increase in zinc-air batteries under MIRS.This MIRS approach can be seamlessly integrated into existing strategies,offering a new approach for accelerating heterogeneous reactions and gas sensing within the interfacial water system.展开更多
Modern three-dimensional nanofabrication methods make it possible to generate arbitrarily shaped nanomagnets,including periodic networks of interconnected magnetic nanowires.Structurally similar to optical or acoustic...Modern three-dimensional nanofabrication methods make it possible to generate arbitrarily shaped nanomagnets,including periodic networks of interconnected magnetic nanowires.Structurally similar to optical or acoustic metamaterials,these arrays could represent magnetic variants of such artificial materials.Using micromagnetic simulations,we investigate a three-dimensional array of interconnected magnetic nanowires with intersection points corresponding to atomic positions of a diamond lattice.The high-frequency excitation spectrum of this artificial magnetic crystal(AMC)is shaped by both microstructure and magnetization configuration.The systemdisplays characteristics of three-dimensional artificial spin ice and can host Dirac-type magnetic defect structures,which are associated with characteristic magnonic frequencies.We demonstrate how magnetic configurations and structural defects affect the spectrum and show that external magnetic fields allow continuous tuning of the overall frequency response.While our study focuses on fundamental aspects,the findings suggest AMCs may serve as reconfigurable magnonic media for future magnonic or neuromorphic devices.展开更多
Identifying crystal defects is vital for unraveling the origins of many physical phenomena.Traditionally used order parameters are system-dependent and can be computationally expensive to calculate for longmolecular d...Identifying crystal defects is vital for unraveling the origins of many physical phenomena.Traditionally used order parameters are system-dependent and can be computationally expensive to calculate for longmolecular dynamics simulations.Unsupervised algorithms offer an alternative independent of the studied system and can utilize precalculated atomistic potential descriptors from molecular dynamics simulations.We compare the performance of three such algorithms(PCA,UMAP,and PaCMAP)on silicon and water systems.Initially,we evaluate the algorithms for recognizing phases,including crystal polymorphs and the melt,followed by an extension of our analysis to identify interstitials,vacancies,and interfaces.While PCA is found unsuitable for effective classification,it has been shown to be a suitable initialization for UMAP and PaCMAP.Both UMAP and PaCMAP show promising results overall,with PaCMAP proving more robust in classification,except in cases of significant class imbalance,where UMAP performs better.Notably,both algorithms successfully identify nuclei in supercooled water,demonstrating their applicability to ice nucleation in water.展开更多
文摘Heterogeneous catalysis at the metal surface generally involves the transport of molecules through the interfacial water layer to access the surface,which is a rate-determining step at the nanoscale.In this study,taking the oxygen reduction reaction on a metal electrode in aqueous solution as an example,using accurate molecular dynamic simulations,we propose a novel long-range regulation strategy in which midinfrared stimulation(MIRS)with a frequency of approximately 1,000 cm^(-1)is applied to nonthermally induce the structural transition of interfacial water from an ordered to disordered state,facilitating the access of oxygen molecules to metal surfaces at room temperature and increasing the oxygen reduction activity 50-fold.Impressively,the theoretical prediction is confirmed by the experimental observation of a significant discharge voltage increase in zinc-air batteries under MIRS.This MIRS approach can be seamlessly integrated into existing strategies,offering a new approach for accelerating heterogeneous reactions and gas sensing within the interfacial water system.
基金funded by the LabEx NIE (ANR-11-LABX-0058_NIE) in the framework of the Interdisciplinary Thematic Institute QMat (ANR-17-EURE-0024), as part of the ITI 2021-2028 program supported by the IdEx Unistra (ANR-10-IDEX-0002-002) and SFRI STRATUS (ANR-20-SFRI-0012) through the French Program d'Investissement d’Avenirfunded by the France 2030 government investment plan managed by the French National Research Agency ANR under grant reference PEPR SPIN—[SPINTHEORY] ANR-22-EXSP-0009.The authors acknowledge the High Performance Computing Center of the University of Strasbourg for supporting this work by providing access to computing resources.
文摘Modern three-dimensional nanofabrication methods make it possible to generate arbitrarily shaped nanomagnets,including periodic networks of interconnected magnetic nanowires.Structurally similar to optical or acoustic metamaterials,these arrays could represent magnetic variants of such artificial materials.Using micromagnetic simulations,we investigate a three-dimensional array of interconnected magnetic nanowires with intersection points corresponding to atomic positions of a diamond lattice.The high-frequency excitation spectrum of this artificial magnetic crystal(AMC)is shaped by both microstructure and magnetization configuration.The systemdisplays characteristics of three-dimensional artificial spin ice and can host Dirac-type magnetic defect structures,which are associated with characteristic magnonic frequencies.We demonstrate how magnetic configurations and structural defects affect the spectrum and show that external magnetic fields allow continuous tuning of the overall frequency response.While our study focuses on fundamental aspects,the findings suggest AMCs may serve as reconfigurable magnonic media for future magnonic or neuromorphic devices.
基金support by the Doctoral College Advanced Functional Materials-Hierarchical Design of Hybrid Systems DOC 85 doc.funds and SFB-TACO 10.55776/F81 funded by the Austrian Science Fund(FWF)by the Vienna Doctoral School in Physics(VDSP).The computational results presentedhave beenpartly achievedusing the Vienna Scientific Cluster(VSC).
文摘Identifying crystal defects is vital for unraveling the origins of many physical phenomena.Traditionally used order parameters are system-dependent and can be computationally expensive to calculate for longmolecular dynamics simulations.Unsupervised algorithms offer an alternative independent of the studied system and can utilize precalculated atomistic potential descriptors from molecular dynamics simulations.We compare the performance of three such algorithms(PCA,UMAP,and PaCMAP)on silicon and water systems.Initially,we evaluate the algorithms for recognizing phases,including crystal polymorphs and the melt,followed by an extension of our analysis to identify interstitials,vacancies,and interfaces.While PCA is found unsuitable for effective classification,it has been shown to be a suitable initialization for UMAP and PaCMAP.Both UMAP and PaCMAP show promising results overall,with PaCMAP proving more robust in classification,except in cases of significant class imbalance,where UMAP performs better.Notably,both algorithms successfully identify nuclei in supercooled water,demonstrating their applicability to ice nucleation in water.
