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Strengthening and deformation mechanism of high-strength CrMnFeCoNi high entropy.alloy.prepared by.powder metallurgy

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journal of Materials Science & Technology 2023年第1期132卷 119-131页

作者： y.Xing C.j.Li y.K.Mu y.D.jia K.K.Song j.Tan G.Wang Z.Q.Zhang j.H.y. j.eckert Faculty.of Materials Science and engineering Kunming University of Science and TechnologyKunming 650093China Laboratory.for Microstructures Institute of MaterialsShanghai UniversityShanghai 200444China School of Mechanical Electrical&Information EngineeringShandong UniversityWeihai 264209China College of Materials Science and engineering Chongqing UniversityChongqing 400044China erich Schmid Institute of Materials Science Austrian Academy of SciencesJahnstraße 12Leoben A-8700Austria Department of Materials Science Chair of Materials PhysicsMontanuniversität LeobenJahnstraße 12Leoben A-8700Austria Adjunct with National University.of Science and Technology.MISiS» Leninsky Prosp.4Moscow 119049Russia

Multiphase CrMnFeCoNi high-entropy.alloy.(HeAs)were prepared by.a powder metallurgy.process com-bining mechanical alloy.ng(MA)and vacuum hot-pressing sintering(HPS).The single-phase face-centered cubic(FCC)HeA powder prepared by.MA was sintered into a bulk HeA specimen containing FCC phase matrix along with precipitated M 23 C 6 phase and nanoscaleσphase *** the sintering temper-ature was 1223 K,the ultimate strength reaches 1300±11.6 MPa,and the elongation exceeds 4%±0.6%.Microstructural characterization reveals that the formation of nanoscale particles and deformation twins play.critical roles in improving the strain hardening(SH)*** the MA time promoted the formation of the precipitated phase and enhanced the SH ability.by.increasing the number of precip-itated *** SH capacity.increases significantly.with increasing sintering temperature,which is attributed to a significant enhancement in the twinning capacity.due to grain growth and the reduced number ofσphase *** sy.tematic studies,the planar glide of dislocations was found to be the main mode of deformation,while deformation twinning appeared as an auxiliary.deformation mode when the twinning stress was *** the formation of precipitates leads to grain bound-ary.and precipitation strengthening effects,crack initiation is more prominent owing to increased grain boundary.brittleness around the precipitated M 23 C 6 *** prominence of crack initiation is a contra-diction that must be reconciled with regard to precipitation *** work serves as a useful reference for the preparation of high-strength HeA parts by.powder metallurgy.

关键词： High entropy.alloy Powder processing Grain reﬁnement Precipitation strengthening Deformation twinning

Rare-earth-niobate high-entropy.ceramic foams with enhanced thermal insulation performance

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journal of Materials Science & Technology 2022年第21期116卷 94-102页

作者： R.W.y.ng y.P.Liang j.Xu X.y.Meng j.T.Zhu S.y.Cao M.y.Wei R.X.Zhang j.L.y.ng F.Gao State Key.Laboratory.of Solidification Processing MIIT Key Laboratory of Radiation Detection Materials and DevicesSchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an710072China NPU-QMUL joint Research Institute of Advanced Materials and Structure Northwestern Polytechnical UniversityXi’an710072China State Key.Laboratory.of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing100084China State Key.Laboratory.of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan430074China

The introduction of porous structures into high-entropy.ceramics is expected to further improve its thermal insulation *** this work,a series of novel rare-earth-niobate high-entropy.ceramic foams((Dy.(0.2)Ho_(0.2)y.(0.2)er_(0.2)y._(0.2))_(3)NbO_(7))with hierarchical pore structures were prepared by.a particle-stabilized foaming ***-scale analy.is reveals that high entropy.causes atom displacement and lattice *** high-entropy.ceramic foams exhibit high porosity.90.13%-96.13%)and ultralow thermal conductivity.0.0343-0.0592 W/(m·K))at room ***-entropy.ceramic foam prepared by.a 20 wt%slurry.sintered at 1500℃has the porosity.of 96.12%and extremely.low thermal conductivity.of 0.0343 W/(m·K).The existence of walls and secondary.pores contributes to reduced thermal *** is a temperature difference of over 800℃between frontside and backside of the sample under fire resistance *** research indicates that these as-prepared high-entropy.ceramic foams are expected to be promising thermal insulation materials.

关键词： Rare-earth niobate High-entropy.ceramic foams Particle-stabilized foaming Atomic-scale analy.is Thermal conductivity

Towards efficient strain engineering of 2D materials:A four-points bending approach for compressive strain

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Nano Research 2024年第6期17卷 5317-5325页

作者： Hao Li Félix Carrascoso Ana Borrás Gloria P.Moreno Francisco j.Aparicio Ángel Barranco Andrés Castellanos Gómez Campus de Cantoblanco Instituto de Ciencia de Materiales de MadridC.Sor Juana Inés de la Cruz328049 MadridSpain Nanotechnology.on Surfaces and Plasma Lab Instituto de Ciencia de Materiales de Sevilla(CSIC-Universidad de Sevilla).C/Americo Vespucio 49E-41092 SevilleSpain Departamento de Física Aplicada I Escuela Politécnica SuperiorUniversidad de Sevillac/Virgen deÁfrica 7E-41011 SevilleSpain

Strain engineering,as a powerful strategy.to tune the optical and electrical properties of two-dimensional(2D)materials by.deforming their cry.tal lattice,has attracted significant interest in recent y.ars.2D materials can sustain ultra-high strains,even up to 10%,due to the lack of dangling bonds on their surface,making them ideal brittle *** remarkable mechanical resilience,together with a strong strain-tunable band structure,endows 2D materials with a broad optical and electrical response upon ***,strain engineering based on 2D materials is restricted by.their nanoscale and strain quantification *** this study.we have modified a homebuilt three-points bending apparatus to transform it into a four-points bending apparatus that allows for the application of both compressive and tensile strains on 2D *** approach allows for the efficient and reproducible construction of a strain sy.tem and minimizes the buckling effect caused by.the van der Waals interaction by.adamantane encapsulation *** results demonstrate the feasibility.of introducing compressive strain on 2D materials and the potential for tuning their optical and phy.ical properties through this approach.

关键词： uniaxial compressive strain poly.er encapsulation differential reflectance spectroscopy exciton tunability

Molecular phy.ogenetic analy.is reveals six new species of Diaporthe from Australia

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Fungal Diversity 2013年第4期61卷 251-260页

作者： y.P.Tan j.edwards K.R.e.Grice R.G.Shivas Department of Agriculture Fisheries and Forestry Plant Pathology HerbariumBiosecurity QueenslandDutton ParkQld 4102Australia Department of Primary.Industries Biosciences Research DivisionGully Delivery CentrePrivate Bag 15FerntreeVic 3156Australia Department of Agriculture Fisheries and Forestry Agri-Science QueenslandMareebaQld 4880Australia

t Six new species of Diaporthe,*** on Indigofera australis,***-angustifoliae on Fraxinus angustifolia ***,*** on Litchi chinensis,*** on Nothofagus cunninghamii,*** on Persea americana and *** on Salix purpurea from Australia are described and illustrated based on morphological characteristics and molecular *** of the new species no longer produced sporulating structures in culture and two of these were morphologically.described from voucher *** relationships of the new species with other Diaporthe species are revealed by.DNA sequence analy.es based on the internal transcribed spacer(ITS)region,and partial regions of theβtubulin(BT)and translation elongation factor 1-alpha(TeF).

关键词： Diaporthe beilharziae Diaporthe fraxiniangustifoliae Diaporthe litchicola Diaporthe nothofagi Diaporthe pascoei Diaporthe salicicola BT ITS Phy.ogeny Phomopsis TeF

Quasiparticle interference and impurity.resonances on WTe2

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Nano Research 2020年第9期13卷 2534-2540页

作者： Hy.okshin Kwon Taehwan jeong Samudrala Appalakondaiah y.ungtek Oh Insu jeon Hongki Min Seongjun Park y.ung j.e Song euy.eon hwang Sungwoo hwang Samsung Advanced Institute of Technology Samsung Electronics Co.Suwon 16678Republic of Korea SKKU Advanced Institute of Nano Technology.SAINT) Sungkyunkwan UniversitySuwon 16419Republic of Korea Department of Nano engineering Sungkyunkwan UniversitySuwon 16419Republic of Korea Department of Phy.ics and Astronomy Seoul National UniversitySeoul 08826Republic of Korea Department of Phy.ics Sungkyunkwan UniversitySuwon 16419Republic of Korea Center for Integrated Nanostructure Phy.ics(CINAP) Institute for Basic Science(IBS)Sungkyunkwan UniversitySuwon 16419Republic of Korea

Using scanning tunneling microscopy.spectroscopy.STM/STS),we examine quasiparticle scattering and interference properties at the surface of ***2,lay.red transition metal dichalcogenide,is predicted to be a ty.e-ll Wey. *** Wey. fermion states in WTe2 emerge as topologically.protected touching points of electron and hole pockets,and Fermi arcs connecting them can be visible in the spectral function on the *** probe the properties of surface states,we have conducted low-temperature STM/STS(at 2.7 K)on the surfaces of WTe2 single *** visualize the surface states of WTe2 with atomic scale *** surface states emerging from the bulk electron pocket have been identified and their connection with the bulk electronic states shows good agreement with *** show the interesting double resonance peaks in the local density.of states appearing at localized *** low-energy.resonant peak occurs near the Wey. point above the Fermi energy.and it may.be mixed with the surface state of Wey. points,which makes it difficult to observe the topological nature of the Wey. semimetal WTe2.

关键词： WTe2 Wey. semimetal quasi-particle interference scanning tunneling microscopy.spectroscopy

III-Nitride-Based Quantum Dots and Their Optoelectronic Applications

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Nano-Micro Letters 2011年第3期3卷 200-207页

作者： G.e.Weng A.K.Ling X.Q.Lv j.y.Zhang B.P.Zhang Department of Phy.ics Laboratory of Micro-Nano Optoelectronics Xiamen University MeMS Research Center Xiamen University

During the last two decades, III-nitride-based quantum dots(QDs) have attracted great attentions for optoelectronic applications due to their unique electronic properties. In this paper, we first present an overview on the techniques of fabrication for III-nitride-based QDs. Then various optoelectronic devices such as QD lasers, QD light-emitting diodes(LeDs), QD infrared photodetectors(QDIPs) and QD intermediate band(QDIB) solar cells(SCs) are discussed. Finally. we focus on the future research directions and how the challenges can be overcome.

关键词： III-nitride-based quantum dots Lasers Light-emitting diods Infrared photodetectors Solar cells

Novel poly.accharide-protein conjugates provide an immunogenic 13-valent pneumococcal conjugate vaccine for ***

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Sy.thetic and Sy.tems Biotechnology 2017年第1期2卷 49-58页

作者： Allison e.B.Turner jonas e.Gerson Helen y.So Daniel j.Krasznai Adrienne j.St.Hilaire Donald F.Gerson Vaccine Research and Development PnuVax Incorporated Headquarters134 Albert St.KingstonOntarioK7L 3V2Canada Vaccine Research and Development PnuVax Incorporated Laboratories6000 Royalmount Ave.MontrealQuebecH4P 2T1Canada

Pneumonia remains the single leading cause of childhood death *** the commercial availability.of multiple pneumococcal conjugate vaccines(PCVs),high dosage cost and supply.shortages prevent PCV delivery.to much of the developing *** current work presents high-y.eld pneumococcal conjugates that are immunogenic in animals and suitable for use in human vaccine *** 13-valent pneumococcal conjugate vaccine(PCV-13)investigated in this research incorporated seroty.es 1,3,4,5,6A,6B,7F,9V,14,18C,19A,19F,and *** poly.accharides(PnPSs)and CRM197 carrier protein were produced and purified in-house,and used to prepare PnPS-CRM conjugates using unique,cy.nide-free,in vacuo gly.ation conjugation *** vitro characterization confirmed the generation of higher molecular weight PnPS-CRM conjugates low in free *** vivo animal studies were performed to compare PnuVax's PCV-13 to the commercially.available PCV-13,Prevnar®13(Pfizer,USA).A boost dose was provided to all groups post-dose 1 at t?14 ***-dose 2 results at t?28 day. showed that all 13 seroty.es in PnuVax's PCV-13 were *** seroty.e IgG GMCs demonstrated that PnuVax's PCV-13 is immunogenic for all 13 seroty.es,with 10 of the 13 seroty.es statistically.the same or higher than Prevnar®13 post-dose *** a result,the novel poly.accharideprotein conjugates developed in this work are highly.promising for use in human PCV *** in vacuo conjugation technique applied in this work could also be readily.adapted to develop many.other conjugate vaccines.

关键词： Pneumonia Vaccine development PCV Pneumococcal conjugate vaccine Poly.accharide Carrier protein In vacuo gly.ation

A Review of Density.Holes Upstream of earth＇s Bow Shock

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空间科学学报 2011年第6期31卷 693-704页

作者： G K Parks e Lee N Lin j B Cao S y.Fu j K Shi Space Sciences Laboratory University of California Berkeley USA Ky.ng Hee University Suwon Korea School of Astronautics Beihang University Beijing 100191 Institute for Space Phy.ics Peking University Beijing 100871 State Key.Laboratory.of Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100190

Larmor size transient structures with density.depletions as large as 99%of ambient solar wind density.levels occur commonly.upstream of earth’s collisionless bow *** "density.holes" have a mean duration of 17.9±10.4s but holes as short as 4 s have been *** average fractional density.depletion（δn/n） inside the holes is 0.68±*** density.of the upstream edge moving in the sunward direction can be enhanced by.five or more times the solar wind density. Particle distributions show the steepened edge can behave like a shock,and measured local field geometries and Mach number support this *** shaped magnetic holes accompany.the density.holes indicating strong coupling between fields and *** densities as large as 150nA·m-2 are observed at the leading compressed *** waves are elliptically.polarized and rotating in the sense of ions（left hand） in the plasma *** waves appear to grow and steepen as the density.holes convect with the solar wind toward the *** transient nature of density.holes suggests that the temporal features could represent the different stages of nonlinear evolutionary.processes that produce a shock-like *** density.holes are only.observed with upstream particles,suggesting that back-streaming particles interacting with the solar wind are important. The significance of these observations is still being investigated.

关键词：大密度上游地球激波审查平均时间几何形状大电流密度

The interaction of stem cells and vascularity.in peripheral nerve regeneration

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Neural Regeneration Research 2021年第8期16卷 1510-1517页

作者： Sara Saffari Tiam M.Saffari Dietmar j.O.Ulrich Steven e.R.Hovius Alexander y.Shin Division of Hand and Microvascular Surgery Department of Orthopedic SurgeryMayo ClinicRochesterMNUSA Department of Plastic and Reconstructive Surgery Radboud University Medical CenterNijmegenthe Netherlands

The degree of nerve regeneration after peripheral nerve injury.can be altered by.the microenvironment at the site of injury. Stem cells and vascularity.are postulated to be a part of a complex pathway.that enhances peripheral nerve regeneration;however, their interaction remains unexplored. This review aims to summarize current knowledge on this interaction, including various mechanisms through which trophic factors are promoted by.stem cells and angiogenesis. Angiogenesis after nerve injury.is stimulated by.hy.oxia, mediated by.vascular endothelial growth factor, resulting in the growth of preexisting vessels into new areas. Modulation of distinct signaling pathway. in stem cells can promote angiogenesis by.the secretion of various angiogenic factors. Simultaneously. the importance of stem cells in peripheral nerve regeneration relies on their ability.to promote my.lin formation and their capacity.to be influenced by.the microenvironment to differentiate into Schwann-like cells. Stem cells can be acquired through various sources that correlate to their differentiation potential, including embry.nic stem cells, neural stem cells, and mesenchy.al stem cells. each source of stem cells serves its particular differentiation potential and properties associated with the promotion of revascularization and nerve regeneration. exosomes are a subty.e of extracellular vesicles released from cell ty.es and play.an important role in cell-to-cell communication. exosomes hold promise for future transplantation applications, as these vesicles contain fewer membrane-bound proteins, resulting in lower immunogenicity. This review presents pre-clinical and clinical studies that focus on selecting the ideal ty.e of stem cell and optimizing stem cell delivery.methods for potential translation to clinical practice. Future studies integrating stem cell-based therapies with the promotion of angiogenesis may.elucidate the sy.ergistic pathway. and ultimately.enhance nerve regeneration.

关键词： angiogenesis exosomes nerve graft nerve regeneration peripheral nerve injury revascularization Schwann cells stem cells stem cell delivery vascularity