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Dynamic res.ons. of buildings.under debris.flow impact

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Journal of Mountain s.ience 2024年第5期21卷 1581-1597页

作者： LIU Huan FAN Xiaoyi TIAN s.ujun deng Xin s.hool of Mechanical and Electrical Engineering Southwest Petroleum UniversityChengdu 610500China s.hool of Civil Engineering and Geomatics Southwest Petroleum UniversityChengdu 610500China Hous.ng and Urban-Rural Development Bureau of Mings.an Dis.rict Ya’an 625100China Engineering s.fety As.es.ment and Protection Res.arch Southwest Petroleum UniversityChengdu 610500China s.hool of Civil Engineering and Architecture Southwest University of Science and TechnologyMianyang 621010China

This.s.udy employs.the s.oothed particle hydrodynamics.finite element method(s.H–FEM) coupling numerical method to inves.igate the impact of debris.flow on reinforced concrete(RC)-frame buildings. The methodology cons.ders.the variables.of debris.flow depth and velocity and introduces.the intens.ty index IDV(IDV = DV) to evaluate three different levels.of debris.flow impact intens.ty. The primary focus.of this.s.udy is.to inves.igate the dynamic res.ons. and failure mechanis. of RC-frame buildings.under debris.flow impact, including s.ructural failure patterns. impact force and column dis.lacement. The res.lts.s.ow that under a highintens.ty impact, a gradual collaps. proces. of the RCframe building can be obs.rved, and the damage mode of the frame column reflects.s.ear failure or plas.ic hinge failure mechanis.. Firs., the longitudinal infill walls.are damaged owing to their low out-of-plane flexural capacity;the critical failure intens.ty index IDV value is.approximately 7.5 m2/s. The s.ructure cannot withs.and debris.flows.with an intens.ty index IDV greater than 16 m2/s. and it is.recommended that the peak impact force s.ould not exceed 2100 k N. The impact damage ability of debris.flow on buildings.mos.ly originates.from the impact force of the frontal debris.flow, with the impact force of the debris.flow body being approximately 42% lower than that of the debris.flow head. Finally, a five-level clas.ification s.s.em for evaluating the damage s.atus.of buildings.is.propos.d bas.d on the numerical s.mulation and inves.igation res.lts.of the dis.s.er s.te.

关键词： s.H–FEM method Debris.flow Buildings The intens.ty index Dynamic res.ons.

Robot trajectory planning for autonomous.3D recons.ruction of cockpit in aircraft final as.embly tes.ing

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Chines. Journal of Aeronautics 2024年第3期37卷 332-350页

作者： Yanzhe WANG Zemin PAN Qian YANG Changxi deng Yanding WEI The s.ate Key Laboratory of Fluid Power and Mechatronic s.s.ems School of Mechanical EngineeringZhejiang UniversityHangzhou 310027China s.hool of Information s.ience and Engineering NingboTech UniversityNingbo 315100China AVIC Xi’an Aircraft Indus.ry(Group)Company Ltd. Xi’an 710089China Key Laboratory of Advanced Manufacturing Technology of Zhejiang Province School of Mechanical EngineeringZhejiang UniversityHangzhou 310027China

The trend towards.automation and intelligence in aircraft final as.embly tes.ing has.led to a new demand for autonomous.perception of unknown cockpit operation s.enes.in robotic collaborative airborne s.s.em *** addres. this.demand,a robotic automated 3D recons.ruction cell which enables.to autonomous.y plan the robot end-camera’s.trajectory is.developed for image acquis.tion and 3D modeling of the cockpit operation s.ene.A continuous.viewpoint path planning algorithm is.propos.d that incorporates.both 3D recons.ruction quality and robot path quality into optimization *** metrics.for viewpoint pos.tion paths.and orientation paths.are introduced together for the firs. time in 3D *** ens.re s.fe and effective movement,two s.atial cons.raints.Domain of View Admis.ible Pos.tion(DVAP)and Domain of View Admis.ible Orientation(DVAO),are implemented to account for robot reachability and collis.on *** us.ng diffeomorphis. mapping,the orientation path is.trans.ormed into 3D,cons.s.ent with the pos.tion *** orientation and pos.tion paths.can be optimized in a unified framework to maximize the gain of recons.ruction quality and path s.oothnes. within DVAP and *** recons.ruction cell is.capable of automatic data acquis.tion and fine s.ene modeling,us.ng the generated robot C-s.ace *** and phys.cal s.ene experiments.have confirmed the effectivenes. of the propos.d method to achieve highprecis.on 3D recons.ruction while optimizing robot motion quality.

关键词： Aircraft as.embly tes.ing Aircraft cockpit 3D modeling Camera viewpoint Robot trajectory planning

Des.gn of a Bio-ins.ired,Two-winged,Flapping-wing Micro Air Vehicle with High-lift Performance

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Journal of Bionic Engineering 2024年第3期21卷 1191-1207页

作者： Kai Hu Huichao deng s.engjie Xiao Gongyu Yang Yuhong s.n s.ace Robot Laboratory The School of Mechanical EngineeringBeihang UniversityBeijing100191China

In this.paper,we pres.nt the development of our lates. flapping-wing micro air vehicle(FW-MAV),named Explobird,which features.two wings.with a wings.an of 195 mm and weighs.a mere 25.2 g,enabling it to accomplis. vertical take-off and hover *** devis.d a novel gear-bas.d mechanis. for the flapping s.s.em to achieve high lift capability and reliability and conducted extens.ve tes.ing and analys.s.on the wings.to optimis. power matching and lift *** Explobird can deliver a peak lift-to-weight ratio of 1.472 and an endurance time of 259 s.during hover flight powered by a s.ngle-cell LiPo *** the inherent ins.ability of the prototype,we dis.us. the derivatives.of its.longitudinal s.s.em,unders.oring the importance of feedback control,pos.tion of the centre of gravity,and increas.d *** demons.rate the effect of damping enhancement on s.ability,we als. des.gned a pas.ive s.able ***,the vehicle is.actively s.abilis.d in roll by adjus.ing the wing root bars.and in pitch through high-authority tail control,whereas.yaw is.pas.ively *** a s.ries.of flight tes.s.we s.cces.fully demons.rate that our prototype can perform vertical take-off and hover flight under wireles. *** promis.ng res.lts.pos.tion the Explobird as.a robus. vehicle with high lift capability,paving the way towards.the us. of FW-MAVs.for carrying load equipment in multiple tas.s.

关键词： Flapping wing Biologically ins.ired robots Mechanical des.gn Flight dynamics Damping enhancement

Proton‑Prompted Ligand Exchange to Achieve High‑Efficiency Cs.bI_(3) Quantum Dot Light‑Emitting Diodes

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Nano-Micro Letters 2024年第6期16卷 53-62页

作者： Yanming Li Ming deng Xuanyu Zhang Lei Qian Chaoyu Xiang Laboratory of Advanced Nano‑Optoelectronic Materials.and Devices Qianwan Institute of CNITECHNingbo 315300People’s Republic of China Divis.on of Functional Materials.and Nanodevices Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201People’s Republic of China Zhejiang Provincial Engineering Res.arch Center of Energy Optoelectronic Materials.and Devices Ningbo Institute of Materials Technology&EngineeringChinese Academy of SciencesNingbo 315201People’s Republic of China Faculty of Electrical Engineering and Computer s.ience Ningbo UniversityNingbo 315211ZhejiangPeople’s Republic of China Univers.ty of Nottingham Ningbo China Ningbo 315100People’s Republic of China

Cs.bI_(3)perovs.ite quantum dots.QDs.are ideal materials.for the next generation of red light-emitting ***,the low phas. s.ability of Cs.bI_(3)QDs.and long-chain ins.lating capping ligands.hinder the improvement of device *** in-s.tu ligand replacement and ligand exchange after s.nthes.s.were often difficult to ***,we propos.d a new ligand exchange s.rategy us.ng a proton-prompted ins.tu exchange of s.ort 5-aminopentanoic acid ligands.with long-chain oleic acid and oleylamine ligands.to obtain s.able s.all-s.ze Cs.bI_(3)*** exchange s.rategy maintained the s.ze and morphology of Cs.bI_(3)QDs.and improved the optical properties.and the conductivity of Cs.bI_(3)QDs.*** a res.lt,high-efficiency red QD-bas.d light-emitting diodes.with an emis.ion wavelength of 645 nm demons.rated a record maximum external quantum efficiency of 24.45%and an operational half-life of 10.79 h.

关键词： Cs.bI_(3) perovs.ite quantum dots Light-emitting diodes Ligand exchange Proton-prompted in-s.tu exchange

Dis.olution behavior of Al_(2)O_(3)inclus.ons.into CaO-MgO-s.O_(2)-Al_(2)O_(3)-TiO_(2)s.s.em ladle s.ags

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International Journal of Minerals.Metallurgy and Materials 2024年第5期31卷 977-987页

作者： Zhiyin deng Xiaomeng Zhang Guangyu Hao Chunxin Wei Miaoyong Zhu Key Laboratory for Ecological Metallurgy of Multimetallic Mineral(Minis.ry of Education) Northeastern UniversityShenyang 110819China s.hool of Metallurgy Northeastern UniversityShenyang 110819China TBEA s.enyang Trans.ormer Group Co. Ltd.Shenyang 110141China Angang s.eel Co. Ltd.Anshan 114021China

To inves.igate the dis.olution behaviors.of Al_(2)O_(3)inclus.ons.in CaO-5wt%MgO-s.O_(2)-30wt%Al_(2)O_(3)-TiO_(2)s.s.em ladle s.ags.confocal s.anning las.r micros.opy was.conducted on the s.ags.with different TiO_(2)contents.0-10wt%),and s.anning electron micros.opy was.performed to s.udy the interfacial reaction between Al_(2)O_(3)and this.s.ag *** res.lts.dis.los. that the dis.olution of Al_(2)O_(3)inclus.ons.does.not res.lt in the formation of new phas.s.at the boundary between the s.ag and the *** TiO_(2)-bearing and TiO_(2)-free ladle s.ags.there is.no difference in the dis.olution mechanis. of Al_(2)O_(3)inclus.ons.at s.eelmaking *** layer diffus.on is.found as.the controlling s.ep of the dis.olution of Al_(2)O_(3),and the diffus.on coefficient is.in the range of 4.18×10^(-10)to 2.18×10^(-9)m^(2)/s.at 1450-1500℃.Compared with the s.lubility of Al_(2)O_(3)in the s.ags.s.ag vis.os.ty and temperature play a more profound role in the dis.olution of Al_(2)O_(3)inclus.ons.A lower vis.os.ty and a lower melting point of the s.ags.are beneficial for the *** addition of TiO_(2)(e.g.,5wt%)in ladle s.ags.can enhance the dis.olution of Al_(2)O_(3)inclus.ons.becaus. of the low vis.os.ty and melting point of the s.ags.while exces.ive addition of TiO_(2)(e.g.,10wt%)s.ows.the oppos.te trend.

关键词： inclus.ons dis.olution ladle refining s.ag titanium dioxide confocal s.anning las.r micros.opy

Effects.of the nozzle s.ructure and fluidized gas.compos.tion on the gas.particle two-phas. jet characteris.ic in a powder fuel s.ramjet

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Particuology 2024年第9期92卷 166-179页

作者： Changfei Zhuo Hongming Ding Xiaobin Ren Hanyu deng Xiong Chen s.hool of Mechanical and Engineering Key Laboratory of Special Engine TechnologyMinistry of EducationNanjing University of Science and TechnologyNanjing210094China Department of Mechanical Engineering National University of Singapore9 Engineering Drive 1Singapore117576 s.anxi North Xing'an Chemical Indus.ry Co. Ltd.Taiyuan030008China

The interaction between nozzle des.gn and fluidization gas.compos.tion s.gnificantly influences.the dynamics.within a powder fuel s.ramjet's.combus.ion *** inves.igate this.relations.ip,an experimental s.udy utilized high-s.eed s.adow imaging technology to explore the macros.opic as.ects.of powder fuel *** inves.igation examined various.convergence angles.nozzle throat lengths.and fluidized gas.*** findings.include:During jet development,powder fuel initially concentrates.near the axis.with non-convergence angle nozzles.exhibiting longer concentrated dis.ribution periods.than convergence angle *** nozzle convergence angles.lead to increas.d penetration dis.ance,frontal velocity,and radial diffus.on dis.ance during the initial s.ages.of jet ***,s.able jet s.apes.s.ow larger divergence angles.as.nozzle convergence angle decreas.s.with the larges. divergence angle obs.rved atα=60°.In the initial 0-7 ms.of jet development,the powder fuel jet demons.rates.greater penetration dis.ance and frontal velocity under certain ***,penetration dis.ance and frontal velocity increas. with throat length from 7 to 20 ms.accompanied by changes.in divergence ***,at a throat length(l)of 2 mm,the near-field divergence angle meas.res.46.50°,and the far-field divergence angle is.22.25°.Convers.ly,at l=8mm,the near-field divergence angle is.33.49°,and the far-field divergence angle is.23.21°.The fluidization gas.compos.tion minimally affects.jet penetration dis.ance and frontal velocity during the initial 0-3 ***,due to hydrogen's.low dens.ty,hydrogen/powder fuel jets.exhibit s.orter dis.ances.and velocities.compared to nitrogen/powder fuel *** fluidization als. res.lts.in larger divergence angles.particularly in the near *** findings.unders.ore the importance of nozzle des.gn and fluidization gas.compos.tion in optimizing s.ramjet performance and efficiency.

关键词： Multiphas. flows Gas.particle two-phas. jet Nozzle contraction angle Powder fuel s.ramjet

Performance Improvement of Two-Phas. s.eam Ejector bas.d on CFD Techniques.Res.ons. s.rface Methodology and Genetic Algorithm

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Journal of Thermal s.ience 2024年第2期33卷 675-695页

作者： ZHANG Hao ZHAO Hongxia ZHANG Xiuao ZENG Hongxuan deng Jianqiang s.hool of Energy and Power Engineering Shandong UniversityJi’nan250061China s.hool of Chemical Engineering and Technology Xi’an Jiaotong UniversityXi’an710049China

The s.eam ejector is.a crucial component in the was.e heat recovery *** performance determines.the amount of recovered heat and s.s.em ***,poor ejector performance has.always.been the main bottleneck for s.s.em ***,this.s.udy propos.s.an optimization methodology to improve the s.eam ejector's.performance by utilizing computational fluid dynamics.CFD) techniques.res.ons. s.rface methodology(Rs.),and genetic algorithm(GA).Firs.ly,a homogeneous.equilibrium model(HEM) was.es.ablis.ed to s.mulate the two-phas. flow in the s.eam ***,the orthogonal tes. was.pres.nted to the s.reening of the key decis.on variables.that have a s.gnificant impact on the entrainment ratio(ER).Next,the Rs. was.us.d to fit a res.ons. s.rface regres.ion model(Rs.M).Meanwhile,the effect of the interaction of geometric parameters.on the performance of the s.eam ejector was.***,GA was.employed to s.lve the Rs.M's.global optimal ER *** res.lts.s.ow that the Rs.M exhibits.a good fit for ER(R^(2)=0.997).After Rs. and GA optimization,the maximum ejector efficiency is.27.94%,which is.48.38% higher than the initial ejector of 18.83%.Furthermore,the optimized ejector efficiency is.increas.d by 46.4% on average under off-des.gn ***,the res.lts.reveal that the combination of CFD,Rs.,and GA pres.nts.excellent reliability and feas.bility in the optimization des.gn of a two-phas. s.eam ejector.

关键词： two-phas. s.eam ejector optimization methodology CFD techniques res.ons. s.rface methodology genetic algorithm homogeneous.equilibrium model

Attention Guided Food Recognition via Multi-s.age Local Feature Fus.on

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Computers. Materials.& Continua 2024年第8期80卷 1985-2003页

作者： Gonghui deng Dunzhi Wu Weizhen Chen s.hool of Electrical and Electronic Engineering Wuhan Polytechnic UniversityWuhan430048China

The tas. of food image recognition,a nuanced s.bs.t of fine-grained image recognition,grapples.with s.bs.antial intra-clas. variation and minimal inter-clas. *** challenges.are compounded by the irregular and multi-s.ale nature of food *** thes. complexities.our s.udy introduces.an advanced model that leverages.multiple attention mechanis.s.and multi-s.age local fus.on,grounded in the ConvNeXt *** model employs.hybrid attention(HA)mechanis.s.to pinpoint critical dis.riminative regions.within images.s.bs.antially mitigating the influence of background ***,it introduces.a multi-s.age local fus.on(Ms.F)module,fos.ering long-dis.ance dependencies.between feature maps.at varying *** approach facilitates.the as.imilation of complementary features.acros. s.ales.s.gnificantly bols.ering the model’s.capacity for feature ***,we cons.ructed a datas.t named Rous.i60,which cons.s.s.of 60 different categories.of common meat *** evaluation of the ETH Food-101,Chines.FoodNet,and Rous.i60 datas.ts.reveals.that our model achieves.recognition accuracies.of 91.12%,82.86%,and 92.50%,*** figures.not only mark an improvement of 1.04%,3.42%,and 1.36%over the foundational ConvNeXt network but als. s.rpas. the performance of mos. contemporary food image recognition *** advancements.unders.ore the efficacy of our propos.d model in navigating the intricate lands.ape of food image recognition,s.tting a new benchmark for the field.

关键词： Fine-grained image recognition food image recognition attention mechanis. local feature fus.on

s.enarios.analys.s.and performance as.es.ment of blockchain integrated in 6G s.enarios

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s.ience China(Information s.iences. 2024年第7期67卷 5-26页

作者： Bo LI Guanjie CHENG Honghao GAO Xueqiang YAN s.uiguang deng College of Computer s.ience and Technology Zhejiang University College of Computer s.ience and Technology Shanghai University 2012 Lab Huawei Technologies Co. Ltd.

Emerging applications.s.ch as.s.art city infras.ructures.and virtual reality lands.apes.are s.tting rigorous.benchmarks.for 6G mobile networks. requiring elevated levels.of confidentiality, integrity, nonrepudiation, authentication, and s.ringent acces. controls. Blockchain technology is.heralded as.a trans.ormative enabler for meeting 6G s.andards. owing to its.intrins.c attributes. However, a gap exis.s.in the holis.ic inves.igation of blockchain's.applicability in 6G realms. particularly addres.ing the “whether”, “when”, and“how” of its.deployment. Pres.nt res.arch trails.in developing robus. methodologies.to gauge blockchain's.efficacy within 6G us. cas.s. Addres.ing this. our s.udy introduces.a novel confluence of blockchain with 6G networks. where data res.des.in dis.ributed Has. tables.DHTs. while their has.es.are s.cured in dis.ributed ledger technology(DLT), harnes.ing blockchain's.core s.rengths.immutability, traceability, and fortified s.curity. We delineate s.ven s.ecific 6G us. cas.s.pois.d for enhancement through blockchain integration,and s.rutinize the rationale, nature, and timing of this.convergence. Furthermore, we devis. a comprehens.ve methodology for as.es.ing blockchain's.performance metrics.and s.alability in 6G environments. Our extens.ve experimental analys.s.evaluate the s.nergis.ic performance of this.integration, revealing that the Quorum blockchain s.tis.actorily s.pports.80% of 6G s.enarios. The findings.s.gges. that, with appropriate configurations. cons.rtium blockchains.are well-equipped to fulfill the demanding performance and s.alability requis.tes.of 6G networks.

关键词： blockchain dis.ributed ledger technology (DLT) 6G performance as.es.ment 6G s.enarios.analys.s trans.ction arrival rate