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Spatio-temporal coupled mode theory for nonlocal metasurfaces

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Light(Science & Applications) 2024年第2期13卷 267-282页

作者： Adam Overvig Sander A.Mann Andrea Alù Photonics Initiative Advanced Science Research CenterCity University of New YorkNew YorkNY10031USA Physics Program Graduate Center of the City University of New YorkNew YorkNY10016USA

Diffractive nonlocal metasurfaces have recently opened a broad range of exciting developments in nanophotonics research and applications,leveraging spatially extended—yet locally patterned—resonant modes to control light with new degrees of *** conventional grating responses are elegantly captured by temporal coupled mode theory,current approaches are not well equipped to capture the arbitrary spatial response observed in the nascent field of nonlocal ***,we introduce spatio-temporal coupled mode theory(STCMT),capable of elegantly capturing the key features of the resonant response of wavefront-shaping nonlocal *** framework can quantitatively guide nonlocal metasurface design while maintaining compatibility with local metasurface frameworks,making it a powerful tool to rationally design and optimize a broad class of ultrathin optical *** validate this STCMT framework against full-wave simulations of various nonlocal metasurfaces,demonstrating that this tool offers a powerful semi-analytical framework to understand and model the physics and functionality of these devices,without the need for computationally intense full-wave *** also discuss how this model may shed physical insights into nonlocal phenomena in photonics and the functionality of the resulting *** a relevant example,we showcase STCMT’s flexibility by applying it to study and rapidly prototype nonlocal metasurfaces that spatially shape thermal emission.

关键词： theory resonant spatially

Microstructures and micromechanical behaviors of high -entropy alloys investigated by synchrotron X-ray and neutron diffraction techniques: A review

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International Journal of Minerals,Metallurgy and materials 2024年第6期31卷 1333-1349页

作者： Yubo Huang Ning Xu Huaile Lu Yang Ren Shilei Li Yandong Wang Beijing Advanced Innovation center of materials Genome Engineering State Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing 100083China AnSteel Beijing research Institute Co.Ltd. Beijing 102200China Spallation Neutron Source Science center Dongguan 523803China Department of Physics City University of Hong KongHong Kong 999077China Institute for materials Intelligent Technology Liaoning Academy of MaterialsShenyang 110004China

High-entropy alloys(HEAs)possess outstanding features such as corrosion resistance,irradiation resistance,and good mechan-ical properties.A few HEAs have found applications in the fields of aerospace and *** studies on the deformation mech-anisms of HEAs can guide microstructure control and toughness design,which is vital for understanding and studying state-of-the-art structural *** X-ray and neutron diffraction are necessary techniques for materials science research,especially for in situ coupling of physical/chemical fields and for resolving macro/microcrystallographic information on ***,several re-searchers have applied synchrotron X-ray and neutron diffraction methods to study the deformation mechanisms,phase transformations,stress behaviors,and in situ processes of HEAs,such as variable-temperature,high-pressure,and hydrogenation *** this review,the principles and development of synchrotron X-ray and neutron diffraction are presented,and their applications in the deformation mechanisms of HEAs are *** factors that influence the deformation mechanisms of HEAs are also *** review fo-cuses on the microstructures and micromechanical behaviors during tension/compression or creep/fatigue deformation and the application of synchrotron X-ray and neutron diffraction methods to the characterization of dislocations,stacking faults,twins,phases,and intergrain/interphase stress *** on future developments of synchrotron X-ray and neutron diffraction and on research directions on the deformation mechanisms of novel metals are discussed.

关键词： high-entropy alloys microstructures micromechanical behaviors synchrotron X-ray diffraction neutron diffraction

Effect of temperature and time on the precipitation ofκ-carbides in Fe-28Mn-10Al-0.8C low-density steels:Aging mechanism and its impact on material properties

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International Journal of Minerals,Metallurgy and materials 2024年第10期31卷 2189-2198页

作者： Yulin Gao Min Zhang Rui Wang Xinxin Zhang Zhunli Tan Xiaoyu Chong School of Mechanical Electronic and Control EngineeringMaterials Science and Engineering Research CenterBeijing Jiaotong UniversityBeijing 100044China Faculty of materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China

In low-density steel,κ-carbides primarily precipitate in the form of nanoscale particles within austenite ***,their precipitation within ferrite matrix grains has not been comprehensively explored,and the second-phase evolution mechanism during aging remains *** 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 *** different heat treatment conditions,intragranularκ-carbides exhibited various morpho-logical and crystallographic characteristics,such as acicular,spherical,and short rod-like *** 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 *** hardness testing demonstrated that the material’s hardness was affected by the volume fraction,morphology,and size ofκ-*** aging at higher temperatures led to an increase in carbide size and volume fraction,resulting in a gradual rise in *** deformation,the primary mechanisms for strengthening were dislocation strengthening and second-phase *** on these findings,potential strategies for improving material strength are proposed.

关键词： low-density steel κ-carbide solution-aging treatment hardness

Origin of the Disparity between the Stability of Transmutated Mix-Cation and Mix-Anion Compounds

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Chinese Physics Letters 2024年第5期41卷 53-60页

作者：野仕伟耿松源梁汉普张燮魏苏淮 Beijing Computational Science research center Beijing 100193China Advanced materials Thrust Function HubHong Kong University of Science and TechnologyGuangzhou 511458China School of materials Science and Engineering Northwestern Polytechnical UniversityXi’an 710072China

Transmutation is an efficient approach for material design. For example, ternary compound CuGaSe_(2) in chalcopyrite structure is a promising material for novel optoelectronic and thermoelectric device applications. It can be considered as formed from the binary host compound ZnSe in zinc-blende structure by cation transmutation(i.e., replacing two Zn atoms by one Cu and one Ga). While cation-transmutated materials are common, aniontransmutated ternary materials are rare, for example, Zn_(2)As Br(i.e., replacing two Se atoms by one As and one Br)is not reported. The physical origin for this puzzling disparity is unclear. In this work, we employ first-principles calculations to address this issue, and find that the distinct differences in stability between cation-transmutated(mix-cation) and anion-transmutated(mix-anion) compounds originate from their different trends of ionic radii as functions of their ionic state, i.e., for cations, the radius decreases with the increasing ionic state, whereas for anions, the radius increases with the increasing absolute ionic state. Therefore, for mix-cation compounds,the strain energy and Coulomb energy can be simultaneously optimized to make these materials stable. In contrast, for mix-anion systems, minimization of Coulomb energy will increase the strain energy, thus the system becomes unstable or less stable. Thus, the trend of decreasing strain energy and Coulomb energy is consistent in mix-cation compounds, while it is opposite in mix-anion compounds. Furthermore, the study suggests that the stability strategy for mix-anion compounds can be controlled by the ratio of ionic radii r3/r1, with a smaller ratio indicating greater stability. Our work, thus, elucidates the intrinsic stability trend of transmutated materials and provides guidelines for the design of novel ternary materials for various device applications.

关键词： stability stability ternary

Exciting lattice oxygen of nickel–iron bi-metal alkoxide for efficient electrochemical oxygen evolution reaction

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Journal of Energy Chemistry 2024年第1期88卷 194-201,I0005页

作者： Saihang Zhang Senchuan Huang Fengzhan Sun Yinghui Li Li Ren Hao Xu Zhao Li Yifei Liu Wei Li Lina Chong Jianxin Zou National Engineering research center of Light Alloy Net Forming&State Key Laboratory of Metal Matrix Composites Center of Hydrogen ScienceSchool of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Department of Chemistry Laboratory of Advanced MaterialsShanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsiChEM and State Key Laboratory of Molecular Engineering of PolymersCollege of Chemistry and MaterialsFudan UniversityShanghai 200433China

High efficiency,cost-effective and durable electrocatalysts are of pivotal importance in energy conversion and storage *** electro-oxidation of water to oxygen plays a crucial role in such energy conversion ***,we report a robust method for the synthesis of a bimetallic alkoxide for efficient oxygen evolution reaction(OER)for alkaline electrolysis,which yields current density of 10 mA cm^(-2)at an overpotential of 215 mV in 0.1 M KOH *** catalyst demonstrates an excellent durability for more than 540 h operation with negligible degradation in *** spectra revealed that the catalyst underwent structure reconstruction during OER,evolving into oxyhydroxide,which was the active site proceeding OER in alkaline ***-situ synchrotron X-ray absorption experiment combined with density functional theory calculation suggests a lattice oxygen involved electrocatalytic reaction mechanism for the in-situ generated nickel–iron bimetal-oxyhydroxide *** mechanism together with the synergy between nickel and iron are responsible for the enhanced catalytic activity and *** findings provide promising strategies for the rational design of nonnoble metal OER catalysts.

关键词： Oxygen evolution reaction Nickel-iron bi-metal alkoxide Lattice oxygen-mediated reaction mechanism Alkaline electrolysis Electrocatalysts

Adhesion strength of tetrahydrofuran hydrates is dictated by substrate stiffness

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Petroleum Science 2024年第1期21卷 667-673页

作者： Yan-Wen Lin Tong Li Yi Zhang Wei-Wei Yan Xiao-Ming Chen Zhi-Sen Zhang Jian-Yang Wu Department of Physics Research Institute for Biomimetics and Soft MatterJiujiang Research Institute and Fujian Provincial Key Laboratory for Soft Functional Materials ResearchXiamen UniversityXiamen361005FujianChina Key Laboratory of Marine materials and Related Technologies Zhejiang Key Laboratory of Marine Materials and Protective TechnologiesNingbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo315201ZhejiangChina Key Laboratory of Icing and Anti/De-icing China Aerodynamics Research and Development CenterMianyang621000SichuanChina Micro-and Nano-technology research center State Key Laboratory for Manufacturing Systems EngineeringXi’an Jiaotong UniversityXi’an710049ShaanxiChina Electronic materials research Lab Key Laboratory of the Ministry of EducationXi’an Jiaotong UniversityXi’an710049ShaanxiChina NTNU Nanomechanical Lab Norwegian University of Science and Technology(NTNU)Trondheim7491Norway

Understanding the hydrate adhesion is important to tackling hydrate accretion in ***,the relationship between the Tetrahydrofuran(THF)hydrate adhesion strength(AS)and surface stiffness on elastic coatings is systemically examined by experimental shear force measurements and theoretical *** mechanical factor-elastic modulus of the coatings greatly dictates the hydrate AS,which is explained by the adhesion mechanics theory,beyond the usual factors such as wettability and structural ***,the hydrate AS increases with reducing the thickness of the elastic coatings,resulted from the decrease of the apparent surface elastic *** effect of critical thickness for the elastic materials with variable elastic modulus on the hydrate AS is also *** study provides deep perspectives on the regulation of the hydrate AS by the elastic modulus of elastic materials,which is of significance to design anti-hydrate surfaces for mitigation of hydrate accretion in petro-pipelines.

关键词： Hydrate Adhesion strength Elastic modulus Coatings

An efficient CuZr-based metallic glasses electrode material for electrocatalytic degradation of azo dyes

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Journal of Environmental Sciences 2024年第2期136卷 537-546页

作者： Zhiwang Deng Bowen Zhao Songtao Li Zhengkun Li Shiming Zhang Kewei Zhang Zhengwang Zhu Taiyuan University of Science and Technology School of materials science and engineeringTaiyuan 030024China Shi-changxu Innovation center for Advanced materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Chinese Academy of Sciences Key Laboratory of Nuclear materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Qingdao Yunlu Advanced materials Technology Co. Ltd.Qingdao 266232China

Metallic glasses have received a lot of attention on wastewater treatment due to their unique atomic structure,and the use of metallic glasses as electrodes has produced unexpected electrocatalytic degradation effects for many pollutants through combining with electrochemical ***,it still is a formidable challenge to find a metallic glass electrode material with both efficient and clean for the catalytic degradation of *** this work,the Cu_(55)Zr_(45)metallic glassy ribbons are used as an electrode to degrade azo dyes and show the excellent degradation effect,which can reach 95.6%within 40 *** the degradation process,almost no additives are produced and Cu_(55)Zr_(45)metallic glassy ribbons have excellent effects under different pH ***,it exhibits good stability for degradation efficiency during the 8 cycle degradation tests of the amorphous alloy *** the copper nanoparticles are exposed on the surface of the ribbons,the oxidized copper obtained synergistically produce activated radicals is the primary degradation mechanism,where the auxiliary degradation mechanisms include electron transfer and the promotion of active *** research develops a new type of electrode material for wastewater treatment,and the economy and high efficiency of Cu55Zr45metallic glass endow it the expandable functional applications.

关键词： Metallic glasses Azo dyes Electrocatalytic Degradation Oxidized copper

Hybrid effect on mechanical properties and high-temperature performance of copper matrix composite reinforced with micro-nano dual-scale particles

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Journal of materials Science & Technology 2024年第5期172卷 94-103页

作者： Xingde Zhang Yihui Jiang Fei Cao Tian Yang Fan Gao Shuhua Liang School of materials Science and Engineering Xi’an University of TechnologyXi’an 710048China Engineering research center of Conducting materials and Composite Technology Ministry of EducationXi’an University of TechnologyXi’an 710048China Shaanxi Province Key Laboratory of Electrical materials and Infiltration Technology Xi’an University of TechnologyXi’an 710048China

A dual-scale hybrid HfB_(2)/Cu-Hf composite with HfB_(2) microparticles and Cu_(5) Hf nanoprecipitates was designed and *** contribution of the hybrid effect to the mechanical properties and high-temperature performances was studied from macro and micro perspectives,*** hybrid of dual-scale particles can make the strain distribution of the composite at the early deformation stage more uniform and delay the strain concentration caused by the HfB_(2) *** dislocation pinning of HfB_(2) particles and the coherent strengthening of Cu_(5) Hf nanoprecipitates simultaneously play a strengthening role,but the strength of the hybrid composite is not a simple superposition of two strengthening *** addition,both Cu_(5) Hf nanoprecipitates and HfB_(2) microparticles contribute to the high-temperature performance of the composite,the growth and phase transition of nanoprecipitates at high temperature will reduce their contribution to strength,while the stable HfB_(2) particles can inhibit the coarsening of matrix grains and maintain the high-density geometrically necessary dislocations(GNDs)in the matrix,which ensures more excellent high-temperature resistance of the hybrid *** a result,the hy-brid structure can simultaneously possess the advantages of multiple reinforcements and make up for the shortcomings of each ***,a copper matrix composite with high strength,high conductivity,and excellent high-temperature performance is displayed.

关键词： Copper matrix composite HfB 2 particles Hybrid effect High strength and high conductivity High-temperature performance

Ni-Catalyzed Enantioselective Difunctionalization of Alkynes to Azepine Derivatives Bearing a Quaternary center and an Unprotected Imine

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Chinese Journal of Chemistry 2024年第8期42卷 873-878页

作者： Jian Long Zhiwu Lu Xiao-Lin Li Peng Xue Wen-Bo Liu Engineering research center of Organosilicon Compounds&materials(Ministry of Education)and College of Chemistry and Molecular Sciences Wuhan UniversityWuhanHubei430072 China

Comprehensive Summary,The azepine ring is a prominent structural scaffold in biologically significant molecules. In this study, we present a Ni(II)-catalyzed asymmetric difunctionalization of alkynes, involving intermolecular regioselective arylation and intramolecular nitrile addition, enabling the synthesis of enantioenriched azepine derivatives. This reaction simultaneously installs an all-carbon quaternary stereocenter and introduces an unprotected imine functionality, showing great promise for subsequent transformations. The reaction exhibits good tolerance toward various functional groups, resulting in high yields and enantioselectivities. The synthetic utility of this methodology is further demonstrated through gram-scale synthesis and product derivatization. This research offers an efficient approach to the synthesis of seven-membered nitrogen heterocycles.

关键词： Nickel Asymmetric catalysis N-Heterocycles Alkyne functionalization Quaternary centers