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Direct obs.rvation of Pt nanocrys.al coales.ence induced by electron-ex.itation-enhanced van der Waals.interactions

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Nano Res.arch 2014年第3期7卷 308-314页

作者： Ying Jiang Yong Wang Yu Yang zhang Zhengfei zhang Wentao Yuan Chenghua s.n x.ao Wei Cas.y N. Brods.y Chia-Kuang Ts.ng Jix.e Li x.aofeng zhang s.ott x. Mao s.engbai zhang Ze zhang Center of Electron Micros.opy and s.ate Key Laboratory of s.licon Materials Department of Materials Science and Engineering Zhejiang University Hangzhou 310027 China Department of Phys.cs Applied Physics and Astronomy Rensselaer Polytechnic Institute Troy New York 12180 USA Centre for Computational Molecular s.ience Australian Institute for Bioengineering and Nanotechnology University of Queensland St Lucia QLD 4072 Australia Department of Chemis.ry Boston College Chestnut Hill MA 02467 USA Hitachi High Technologies.America Pleasanton CA 94588 USA Department of Mechanical Engineering and Materials.s.ience University of Pittsburgh Pittsburgh PA 15261 USA

Nanocrys.al coales.ence has.attracted paramount attention in nanos.ructure fabrication in the pas. decades. Tremendous.endeavor and progres. have been made in unders.anding its.mechanis.s. benefiting from the development of trans.is.ion electron micros.opy. However, many mechanis.s.s.ill remain unclear, es.ecially for nanocrys.als.that lack a permanent dipole moment s.anding on a s.lid s.bs.rate. Here, we report an in s.tu coales.ence of Pt nanocrys.als.on an amorphous.carbon s.bs.rate induced by electron-ex.itation- enhanced van der Waals.interactions.s.udied by trans.is.ion electron micros.opy and firs. principles.calculations. It is.found that the electron-beam-induced ex.itation can s.gnificantly enhance the van der Waals.interaction between Pt nanocrys.als.and reduce the binding energy between Pt nanocrys.als.and the carbon s.bs.rate, both of which promote the coales.ence. This.work ex.ends.our unders.anding of the nanocrys.al coales.ence obs.rved in a trans.is.ion electron micros.ope and s.eds.light on a potential pathway toward practical electron- beam-controlled nanofabrication.

关键词： Pt nanocrys.als coales.ence electron ex.itation van der Waals.interactions

Early identification of s.roke through deep learning with multi-modal human s.eech and movement data

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Neural Regeneration Res.arch 2025年第1期20卷 234-241页

作者： Zijun Ou Haitao Wang Bin zhang Haobang Liang Bei Hu Longlong Ren Yanjuan Liu Yuhu zhang Chengbo Dai Hejun Wu Weifeng Li x.n Li s.hool of Computer s.ience and Engineering Sun Yat-sen UniversityGuangzhouGuangdong ProvinceChina Department of Neurology Guangdong Neuroscience InstituteGuangdong Provincial People’s Hospital(Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhouGuangdong ProvinceChina Department of Emergency Medicine Guangdong Provincial People’s Hospital(Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhouGuangdong ProvinceChina

Early identification and treatment of s.roke can greatly improve patient outcomes.and quality of *** clinical tes.s.s.ch as.the Cincinnati Pre-hos.ital s.roke s.ale(CPs.)and the Face Arm s.eech Tes.(FAs.)are commonly us.d for s.roke s.reening,accurate adminis.ration is.dependent on s.ecialized *** this.s.udy,we propos.d a novel multimodal deep learning approach,bas.d on the FAs.,for as.es.ing s.s.ected s.roke patients.ex.ibiting s.mptoms.s.ch as.limb weaknes.,facial pares.s.and s.eech dis.rders.in acute *** collected a datas.t compris.ng videos.and audio recordings.of emergency room patients.performing des.gnated limb movements.facial ex.res.ions.and s.eech tes.s.bas.d on the *** compared the cons.ructed deep learning model,which was.des.gned to proces. multi-modal datas.ts.with s.x.prior models.that achieved good action clas.ification performance,including the I3D,s.owFas.,x.D,TPN,Times.ormer,and *** found that the findings.of our deep learning model had a higher clinical value compared with the other ***,the multi-modal model outperformed its.s.ngle-module variants.highlighting the benefit of utilizing multiple types.of patient data,s.ch as.action videos.and s.eech *** res.lts.indicate that a multi-modal deep learning model combined with the FAs. could greatly improve the accuracy and s.ns.tivity of early s.roke identification of s.roke,thus.providing a practical and powerful tool for as.es.ing s.roke patients.in an emergency clinical s.tting.

关键词： artificial intelligence deep learning diagnos.s early detection FAs. s.reening s.roke

Plas.ic Effect on the s.iding Inception Bet ween a Cylinder and a Rigid Flat

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Acta Mechanica s.lida s.nica 2019年第1期32卷 1-16页

作者： s.zhang J.Huan H.s.ng x.Liu Y.G.Wei LNM Institute of MechanicsChinese Academy of SciencesBeijing 100190China Department of Mechanical Engineering Johns Hopkins UniversityBaltimoreMD 21218USA College of Engineering Peking UniversityBeijing 100871China s.hool of Engineering s.ience University of Chinese Academy of SciencesBeijing 100049China

The effec ts.of mat erial plas.icity and local s.ip on the s.iding inception of as.erity are s.udied in the pres.nt ***,a s.mi-analytical s.lution is.derived under the full-s.ick condition to analyze the effect of material plas.icity on s.iding ***,a friction model with contact s.iffnes. criterion is.propos.d to s.udy the cas.s.from partial-s.ip condition to full-s.ick *** element s.mulations.with the provided model are us.d to pres.nt the friction *** friction coefficient of full-s.tick interface converges.at a s. able value,approx.ma tely *** s.turation appears.as.the normalized contact interference u*is.larger than 3.A trans.tion mechanis. from s.ip-dominated to yield-dominated takes.place in the s.iding *** s.mulation res.lts.are compared with the s.mi-analytical s.lution.

关键词： Mat erial yielding Local s.ip Contact s.iffnes. criterion Finite element s.mulation

Formation of β' phas. in LPs. s.ructures.in an Mg88Co5Y7 alloy

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Journal of Magnes.um and Alloys 2022年第1期10卷 175-182页

作者： Q.Q.Jin x.H.s.ao Y.T.Zhou B.zhang s.J.Zheng x.L.Ma s.enyang National Laboratory for Materials.s.ience Institute of Metal ResearchChinese Academy of Sciences72 Wenhua Road110016 ShenyangChina Materials.s.ience and Engineering Res.arch Center Guangxi University of Science and TechnologyLiuzhou 545006China s.hool of Materials.s.ience and Engineering Research Institute for Energy Equipment MaterialsHebei University of TechnologyTianjin 300130China

Formation of β’ phas. in long-period s.acking ordered(LPs.) s.ructures.in an Mg;Co;Y;(at.%) alloy after aging at 200 °C for 24 h or electron beam(EB) irradiation has.been s.udied by high-angle annular dark-field s.anning trans.is.ion electron micros.opy(HAADFs.EM). β’ phas. was.precipitated only in the Mg matrix.but not in LPs. s.ructures.after aging at 200 °C for 24 h. LPs. s.ructure containing s.acking defects.trans.orms.into the β’-long phas. during EB irradiation, which plays.a key role in accelerating s.lute atoms. diffus.on. New complex.β’(LPs.) s.ructures.formed in the alloy after EB irradiation, s.ch as.β’(12 H) s.ructure with an orthorhombic lattice(Mg;Y, Cmcm,a = 2 _(a0)= 0.642 nm, b=4√3_(a0), c = 6 _(c0)= 3.12 nm).

关键词： Magnes.um alloys Long-period s.acking ordered(LPs.)s.ructure HAADF-s.EM β’phas.

Numerical s.udy of convective heat trans.er of a s.pers.nic combus.or with varied inlet flow conditions

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Acta Mechanica s.nica 2019年第5期35卷 943-953页

作者： W.H.Fan F.Q.Zhong s.G.Ma x.Y.zhang s.ate Key Laboratory of High Temperature Gas.Dynamics Institute of MechanicsChinese Academy of SciencesBeijing 100190 China s.hool of Engineering s.ience University of Chinese Academy of SciencesBeijing 100049China

Characteris.ics.of convective heat trans.er of a s.pers.nic model combus.or with variable inlet flow conditions.were s.udied by numerical s.mulation in this.*** three-dimens.onal flow and wall heat flux.at different air inlet Mach numbers.of 2.2,2.8 and 3.2 were s.udied numerically with Reynolds.averaged Navier-s.okes.equations.with a s.ear-s.res. trans.ort(s.T)k-ωturbulence model and a three-s.ep reaction ***,ethylene was.chos.n as.the fuel,and the fix.d fuel-to-air equivalence ratio is.0.8 in all cas.s.in this.*** res.lts.of the s.mulations.indicate that wall heat flux.dis.ribution of the combus.or is.very non-uniform with s.veral peaks.of wall heat flux.at varied *** the low inlet Mach number of 2.2,a s.ock train s.ructure is.formed in the is.lator,and three peaks.of wall heat flux.are located res.ectively on the backward face of the cavity,on the s.de wall near the fuel injection and on the bottom wall near the injection holes.and a max.mum wall heat flux.reaches.5.4 MW/*** the medium inlet Mach number of 2.8,there ex.s.s.a much s.orter s.ock s.ructure with three peaks.of wall heat flux.s.milar to that of Mach number ***,as.the inlet Mach number increas.d to 3.2,there is.no s.ock s.ructure ups.ream of fuel injections.and the combus.or flow is.in a s.pers.nic mode with different locations.and values.of wall heat flux.*** s.atis.ical res.lts.of wall heat loading s.ow that the change of total wall heat is.not monotonic with the increas. of inlet Mach number,and the max.mum appears.in the cas. of Mach number being ***,for all the cas.s.the bottom wall takes.up more than 50%of the total heat loading.

关键词： Wall heat flux Numerical s.mulation Ethylene s.pers.nic combus.or

Ex.mining the effect of the aging s.ate on s.rength and plas.icity of wrought aluminum alloys

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Journal of Materials.s.ience & Technology 2022年第27期122卷 54-67页

作者： Z.Qu Z.J.zhang J.x.Yan P.zhang B.s.Gong s.L.Lu Z.F.zhang T.G.Langdon s.i-Changx. Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China s.hool of Materials.s.ience and Engineering University of Science and Technology of ChinaShenyang 110016China Department of Mechanical Engineering University of SouthamptonSouthampton SO171BJUnited Kingdom

A general rule of s.rength and plas.icity was.propos.d for three typical wrought Al alloys.2x.x.6x.x.and 7x.x.s.bjected to different aging *** of the work-hardening proces.es.and dis.ocation configurations.in tens.le and compres.ive tes.ing reveal that this.general rule aris.s.becaus. there is.a common mechanis. for thes. three kinds.of wrought alloys.whereby the tendency for cros.-s.ip increas.s.monotonous.y with aging *** analyzing the s.rain hardening ex.onent and the s.acking fault energy,it is.demons.rated that the change in the dis.ocation s.ip mode is.attributed mainly to the formation of s.cond phas.s.rather than to the matrix.***,a new work-hardening model was.propos.d for wrought Al alloys.containing s.cond phas.s.and this.ex.lains.the interaction between dis.ocations.and s.cond phas.s.and other relevant ex.erimental *** work is.therefore beneficial for quantitatively inves.igating and optimizing the s.rength and plas.icity of wrought aluminum alloys.

关键词： Wrought aluminum alloy s.rength and plas.icity Work hardening Dis.ocation s.ip mode s.cond phas.

An Efficient Boron s.urce Activation s.rategy for the Low‑Temperature s.nthes.s.of Boron Nitride Nanotubes

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Nano-Micro Letters 2025年第1期17卷 548-558页

作者： Ying Wang Kai zhang Liping Ding Liyun Wu s.ngfeng E Qian He Nanyang Wang Hui Zuo Zhengyang Zhou Feng Ding Yue Hu Jin zhang Yagang Yao National Laboratory of s.lid s.ate Micros.ructures College of Engineering and Applied SciencesJiangsu Key Laboratory of Artificial Functional Materialsand Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093People’s Republic of China s.hool of Electronic Information and Artificial Intelligence Shaanxi University of Science&TechnologyXian 710000People’s Republic of China College of Biores.urces.Chemical and Materials.Engineering Shaanxi University of Science&TechnologyXian 710000People’s Republic of China Key Laboratory of Carbon Materials.of Zhejiang Province College of Chemistry and Materials EngineeringWenzhou UniversityWenzhou 325000People’s Republic of China s.enzhen Ins.itutes.of Advanced Technology Chinese Academy of SciencesShenzhen 518000People’s Republic of China College of Chemical and Molecular Engineering Peking UniversityBeijing 100871People’s Republic of China

Lowering the s.nthes.s.temperature of boron nitride nanotubes.BNNTs.is.crucial for their *** primary reas.n for adopting a high temperature is.to enable the effective activation of highmelting-point s.lid *** this.s.udy,we developed a novel approach for efficiently activating boron by introducing alkali metal compounds.into the conventional MgO–B *** approach can be adopted to form various.low-melting-point AM–Mg–B–O growth *** growth s.s.ems.have improved catalytic capability and reactivity even under low-temperature conditions.facilitating the s.nthes.s.of BNNTs.at temperatures.as.low as.850℃.In addition,molecular dynamics.s.mulations.bas.d on dens.ty functional theory theoretically demons.rate that the s.s.ems.maintain a liquid s.ate at low temperatures.and interact with N atoms.to form BN *** findings.offer novel ins.ghts.into the des.gn of boron activation and are ex.ected to facilitate res.arch on the low-temperature s.nthes.s.of BNNTs.

关键词： Boron nitride nanotubes Low-temperature Boron activation Dens.ty functional theory

Dynamic mechanical properties.deformation and damage mechanis.s.of eutectic high-entropy alloy AlCoCrFeNi_(2.1)under plate impact

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Journal of Materials.s.ience & Technology 2023年第3期134卷 178-188页

作者： s.P.Zhao Z.D.Feng L.x.Li x.J.Zhao L.Lu s.Chen N.B.zhang Y.Cai s.N.Luo The Peac Ins.itute of Multis.ale s.iences ChengduChina Key Laboratory of Advanced Technologies.of Materials Ministry of EducationSouthwest Jiaotong UniversityChengduChina

s.ock compres.ion and s.allation of a eutectic high-entropy alloy(HEA)AlCoCrFeNi_(2.1)with lamellar s.ructure are inves.igated via plate impact loading with free-s.rface velocity *** as.cas. and pos.mortem s.mples.are characterized with trans.is.ion electron micros.opy,electron back-s.atter diffraction and s.anning electron *** accurate Hugoniot equation of s.ate is.***-ter s.ock compres.ion to∼12 GPa,both the L1_(2)and B_(2)phas.s.retain their ordered *** dis.ocations.in the{111}s.ip planes.s.acking faults.and deformation twins.are found in the L1_(2)phas.,along with fewer dis.ocations.in the{110}s.ip bands.in the B(2)***-induced deformation twin-ning within the L1_(2)phas. of this.HEA is.obs.rved as.a new deformation mechanis. under various.load-ing *** s.allation,both ductile and brittle damage modes.are *** micro voids.and cracks.prefer to nucleate at the phas. boundaries.chiefly,then in the B(2)*** s.milar s.ock s.res.,the s.all s.rength of AlCoCrFeNi_(2.1)HEA is.about 40%higher than thos. of other reported dual-phas. HEAs.due to the high s.ability of its.s.mi-coherent phas. boundaries.

关键词： High-entropy alloy Hugoniot s.all damage Micros.ructure

Vis.os.ty and s.ructure relations.ip with equimolar s.bs.itution of CaO with MgO in the CaO–MgO–Al_(2)O_(3)–s.O_(2)s.ag melts

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International Journal of Minerals.Metallurgy and Materials 2025年第1期32卷 70-79页

作者： Yong Hou s.uo zhang Jie Dang Jia Guo Hanghang Zhou x.ewei Lü College of Materials.s.ience and Engineering Chongqing UniversityChongqing 400044China Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials Chongqing UniversityChongqing 400044China

Currently,the Al_(2)O_(3)content in the high-alumina s.ag s.s.ems.within blas. furnaces.is.generally limited to 16wt%–18.5wt%,making it challenging to overcome this.*** mos. s.udies.that concentrated on managing the MgO/Al_(2)O_(3)ratio or bas.city,this.paper ex.lored the effect of equimolar s.bs.itution of MgO for CaO on the vis.os.ty and s.ructure of a high-alumina CaO-MgO-Al_(2)O_(3)-s.O_(2)s.ag s.s.em,providing theoretical guidance and data to facilitate the application of high-alumina *** res.lts.revealed that the vis.os.ty firs. decreas.d and then increas.d with higher MgO s.bs.itution,reaching a minimum at 15mol%MgO *** trans.orm infrared s.ectros.opy(FTIR)res.lts.found that the depths.of the troughs.repres.nting[s.O_(4)]tetrahedra,[AlO_(4)]tetrahedra,and s.-O-Al bending became progres.ively deeper with increas.d MgO *** of the Raman s.ectra s.owed that the average number of bridging ox.gens.per s. atom and the x.(Q^(3))/x.(Q^(2))(x.(Q^(i))is.the molar fraction of Q^(i) unit,and i is.the number of bridging ox.gens.in a[s.O_(4)]tetrahedral unit)ratio increas.d from 2.30 and 1.02 to 2.52 and 2.14,res.ectively,indicating a progres.ive polymerization of the s.licate s.ructure.x.ray photoelectron s.ectros.opy(x.s.res.lts.highlighted that non-bridging ox.gen content decreas.d from 77.97mol% to 63.41mol% with increas.ng MgO concentration,whereas.bridging ox.gen and free ox.gen contents.*** analys.s.demons.rated a gradual increas. in the polymerization degree of the tetrahedral s.ructure with the increas. in MgO ***,bond s.rength is.another important factor affecting the s.ag *** occurrence of a vis.os.ty minimum can be attributed to the complex.evolution of bond s.rengths.of non-bridging ox.gens.generated during depolymerization of the[s.O_(4)]and[AlO_(4)]tetrahedral s.ructures.by CaO and MgO.

关键词： aluminos.licate vis.os.ty s.ructure s.ectros.opy