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Wind-Vortex-Induced Vibrations of a Deepwater Jacket Pipe and Vibration Suppression Using a Nonlinear Energy Sink

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Journal of Ocean University of China 2024年第3期23卷 633-642页

作者： LIU Liqin YU Yongjun CHEN yiqun State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China China Classification Society Haikou 570102China

The purpose of this study is to investigate the suppression effect of a nonlinear energy sink(NES)on the wind-vortex-induced pipe vibration and explore the influence of damping,stiffness,and NES installation position on the suppression *** this work,the wind-vortex-induced vibration of an elastic pipe of a deepwater jacket was studied,and vibrations were suppressed by using an NES.A van der Pol wake oscillator was used to simulate vortex-induced force,and the dynamic equation of the pipe considering the NES was *** Galerkin method was applied to discretize the motion equation,and the vortex-induced vibration(VIV)of the pipe at reduced wind speeds was numerically *** novelty of this research is that particle swarm optimization was used to optimize the parameters of the NES to improve vibration *** influence of the installation position,nonlinear stiffness,and damping parameters of the NES on vibration suppression was *** showed that the optimized parameter combinations of the NES can effectively reduce wind-vortex-induced pipe *** installation position of the NES had a significant effect on vibration suppression,and the midpoint of the pipe was the optimal NES installation *** increase in stiffness or a 10% decrease in damping may cause vibration suppression *** results of this study provide some guidance for VIV suppression in deepwater jacket pipes.

关键词： deepwater jacket wind-vortex-induced vibration NES PSO vibration suppression effect analysis

DepthGAN: GAN-based depth generation from semantic layouts

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Computational Visual Media 2024年第3期10卷 505-522页

作者： Yidi Li Jun Xiao yiqun Wang Zhengda Lu School of Artiﬁcial Intelligence University of Chinese Academy of SciencesBeijingChina College of Computer Science Chongqing UniversityChongqingChina

Existing GAN-based generative methodsare typically used for semantic image synthesis. Wepose the question of whether GAN-based architecturescan generate plausible depth maps and ﬁnd thatexisting methods have difficulty in generating depthmaps which reasonably represent 3D scene structuredue to the lack of global geometric ***, we propose DepthGAN, a novel method ofgenerating a depth map using a semantic layout asinput to aid construction, and manipulation of wellstructured 3D scene point clouds. Speciﬁcally, weﬁrst build a feature generation model with a cascadeof semantically-aware transformer blocks to obtaindepth features with global structural *** our semantically aware transformer block, wepropose a mixed attention module and a semanticallyaware layer normalization module to better exploitsemantic consistency for depth features ***, we present a novel semantically weighteddepth synthesis module, which generates adaptivedepth intervals for the current scene. We generate theﬁnal depth map by using a weighted combination ofsemantically aware depth weights for different depthranges. In this manner, we obtain a more accuratedepth map. Extensive experiments on indoor andoutdoor datasets demonstrate that DepthGAN achievessuperior results both quantitatively and visually for thedepth generation task.

关键词： depth map generation generative model transformer scene generation

Planning method of droplet fusion scheduling based on mixedinteger programming

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Science China(Technological Sciences) 2024年第1期67卷 157-171页

作者： XIONG JiaCong CHEN JianKui WANG YiXin YIN ZhouPing LI yiqun State Key Laboratory of Intelligent Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

The emergence of new display devices,such as organic light-emitting diodes,has brought about numerous advantages,including high material utilization,low cost,and high *** devices are manufactured using inkjet printing and possess the potential to become a key technology for display ***,a challenge in achieving this is the display effect that reveals uneven brightness and darkness,which can be avoided by controlling the volume of ink solution in a pixel to within 5%.Currently,the volume difference among the nozzles of commercial printheads does not meet the requirements for volume uniformity,thus challenging the printing ***,designing a suitable printing method that allows for the fusion of different volumes of ink droplets,ultimately reducing the error of the post fusion process,is *** this study,we propose a print display droplet fusion scheduling method comprising two main ***,we use a dichotomous trust domain algorithm to obtain a feasible range of printhead docking point spacings for different nozzle and pixel panel ***,we model the printing process as a droplet fusion scheduling model based on mixed integer programming,with the optimization objective of achieving intra pixel volume uniformity via ensuring the volume uniformity of ink droplets within all *** verified this method through numerical simulations and printing experiments using 394 pixels per inch(ppi)pixel panels and successfully reduced the volume uniformity error among pixels to within 5%.

关键词： printing display droplet fusion mixed-integer programming dichotomous trust domain

Investigation of FRP and SFRC Technologies for Efficient Tunnel Reinforcement Using the Cohesive Zone Model

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Structural durability & Health Monitoring 2024年第2期18卷 161-179页

作者： Gang Niu Zhaoyang Jin Wei Zhang yiqun Huang China Communications Construction Investment Development Co. Ltd.Fuzhou350000China Rail Transit Branch of China Communications Construction Co. Ltd.Beijing101317China School of Civil Engineering Fujian University of TechnologyFuzhou350118China

Amid urbanization and the continuous expansion of transportation networks,the necessity for tunnel construction and maintenance has become *** this need requires the investigation of efficient,economical,and robust tunnel reinforcement *** paper explores fiber reinforced polymer(FRP)and steel fiber reinforced concrete(SFRC)technologies,which have emerged as viable solutions for enhancing tunnel *** is celebrated for its lightweight and high-strength attributes,effectively augmenting load-bearing capacity and seismic resistance,while SFRC’s notable crack resistance and longevity potentially enhance the performance of tunnel ***,current research predominantly focuses on experimental analysis,lacking comprehensive theoretical *** bridge this gap,the cohesive zone model(CZM),which utilizes cohesive elements to characterize the potential fracture surfaces of concrete/SFRC,the rebar-concrete interface,and the FRP-concrete interface,was employed.A modeling approach was subsequently proposed to construct a tunnel segment model reinforced with either SFRC or ***,the corresponding mixed-mode constitutive models,considering interfacial friction,were integrated into the proposed *** validation and numerical simulations corroborated the accuracy of the proposed ***,this study examined the reinforcement design of tunnel *** a numerical evaluation,the effectiveness of innovative reinforcement schemes,such as substituting concrete with SFRC and externally bonding FRP sheets,was assessed utilizing a case study from the Fuzhou Metro Shield Tunnel Construction Project.

关键词： Tunnel segment FRP SFRC cohesive zone model constitutive model fracture process

Absorption properties and mechanism of lightweight and broadband electromagnetic wave-absorbing porous carbon by the swelling treatment

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International Journal of Minerals,Metallurgy and Materials 2024年第7期31卷 1701-1712页

作者： Jianghao Wen Di Lan yiqun Wang Lianggui Ren Ailing Feng Zirui Jia Guanglei Wu College of Materials and Chemistry&Chemical Engineering Chengdu University of TechnologyChengdu 610059China School of Materials Science and Engineering Hubei University of Automotive TechnologyShiyan 442002China Institute of Materials for Energy and Environment State Key Laboratory of Bio-fibers and Eco-textilesCollege of Materials Science and EngineeringQingdao UniversityQingdao 266071China Institute of Physics&Optoelectronics Technology Baoji University of Arts and SciencesBaoji 721016China

Bioderived carbon materials have garnered considerable interest in the fields of microwave absorption and shielding due to their reproducibility and environmental *** this study,KOH was evenly distributed on biomass Tremella using the swelling induction method,leading to the preparation of a three-dimensional network-structured hierarchical porous carbon(HPC)through *** achieved microwave absorption intensity is robust at-47.34 dB with a thin thickness of 2.1 ***,the widest effective absorption bandwidth,reaching 7.0 GHz(11–18 GHz),is attained at a matching thickness of 2.2 *** exceptional broadband and reflection loss performance are attributed to the 3D porous networks,interface effects,carbon network defects,and dipole *** has outstanding absorption characteristics due to its excellent impedance matching and high attenuation *** uniform pore structures considerably optimize the impedance-matching performance of the material,while the abundance of interfaces and defects enhances the dielectric loss,thereby improving the attenuation ***,the impact of carbonization temperature and swelling rate on microwave absorption performance was systematically *** research presents a strategy for preparing absorbing materials using biomass-derived HPC,showcasing considerable potential in the field of electromagnetic wave absorption.

关键词： biomass hierarchical porous carbon dielectric loss electromagnetic wave absorption

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基于结构轻量化的城市客车车身生命周期评价

汽车工程 2022年第5期44卷 778-788页

作者：王童杜轶群陈轶嵩韩日美长安大学汽车学院西安710064 长安大学国际教育学院西安710064 西安轨道交通集团西安710021

为某12 m全承载混合动力城市客车建立车身有限元模型,通过强度、刚度、模态分析、结构轻量化和生命周期评价,分析车身结构优化对整车节能减排效果的影响。结果表明,与原车身骨架相比,结构优化后车身骨架质量减轻了52.5 kg,弯曲与极限扭... 详细信息

为某12 m全承载混合动力城市客车建立车身有限元模型,通过强度、刚度、模态分析、结构轻量化和生命周期评价,分析车身结构优化对整车节能减排效果的影响。结果表明,与原车身骨架相比,结构优化后车身骨架质量减轻了52.5 kg,弯曲与极限扭转两种工况下均满足强度、刚度要求,且具有良好的固有振动特性。就全生命周期而言,轻量化后矿产资源消耗减少了0.4E04 kg Sb-eq.,化石能源消耗减少0.7E04 MJ,综合环境影响值减少0.42E11,减低率分别为3.81%、4.46%和4.56%。

关键词：客车有限元分析模态分析轻量化分析生命周期评价

Decoding the Cellular Trafficking of Prion-like Proteins in Neurodegenerative Diseases

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Neuroscience Bulletin 2024年第2期40卷 241-254页

作者： Chenjun Hu yiqun Yan Yanhong Jin Jun Yang Yongmei Xi Zhen Zhong Department of Neurology of the Second Afliated Hospital and Department of Human Anatomy Histology and EmbryologyZhejiang University School of MedicineHangzhou 310058China Department of Physiology and Department of Cardiology of the Second Afliated Hospital Zhejiang University School of MedicineHangzhou 310058China Division of Human Reproduction and Developmental Genetics Women’s Hospital and Institute of GeneticsZhejiang University School of MedicineHangzhou 310006China

The accumulation and spread of prion-like proteins is a key feature of neurodegenerative diseases(NDs)such as Alzheimer’s disease,Parkinson's disease,or Amyotrophic Lateral *** a process known as‘seeding’,prion-like proteins such as amyloid beta,microtubule-associated protein tau,α-synuclein,silence superoxide dismutase 1,or transactive response DNA-binding protein 43 kDa,propagate their misfolded conformations by transforming their respective soluble monomers into *** and molecular evidence of prion-like propagation in NDs,the clinical relevance of their‘seeding’capacities,and their levels of contribution towards disease progression have been intensively studied over recent *** review unpacks the cyclic prion-like propagation in cells including factors of aggregate internalization,endo-lysosomal leaking,aggregate degradation,and *** on the importance of the role of prion-like protein aggregates in NDs,whether causal or consequent,are also *** lead to a greater understanding of ND pathogenesis and increased potential for therapeutic strategies.

关键词： Neurodegenerative diseases Prion-like propagation Seeding Endocytosis Endolyosomal leaking Degradation

On-chip spiking neural networks based on add-drop ring microresonators and electrically reconfigurable phase-change material photonic switches

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Photonics Research 2024年第4期12卷 755-766页

作者： QIANG ZHANG NING JIANG yiqun ZHANG ANRAN LI HUANHUAN XIONG GANG HU YONGSHENG CAO KUN QIU School of Information and Communication Engineering University of Electronic Science and Technology of ChinaChengdu 611731China

We propose and numerically demonstrate a photonic computing primitive designed for integrated spiking neural networks (SNNs) based on add-drop ring microresonators (ADRMRs) and electrically reconfigurable phasechange material (PCM) photonic switches. In this neuromorphic system, the passive silicon-based ADRMR,equipped with a power-tunable auxiliary light, effectively demonstrates nonlinearity-induced dual neural dynamics encompassing spiking response and synaptic plasticity that can generate single-wavelength optical neural spikes with synaptic weight. By cascading these ADRMRs with different resonant wavelengths, weighted multiple-wavelength spikes can be feasibly output from the ADRMR-based hardware arrays when external wavelengthaddressable optical pulses are injected;subsequently, the cumulative power of these weighted output spikes is utilized to ascertain the activation status of the reconfigurable PCM photonic switches. Moreover, the reconfigurable mechanism driving the interconversion of the PCMs between the resonant-bonded crystalline states and the covalent-bonded amorphous states is achieved through precise thermal modulation. Drawing from the thermal properties, an innovative thermodynamic leaky integrate-and-firing (TLIF) neuron system is proposed. With the TLIF neuron system as the fundamental unit, a fully connected SNN is constructed to complete a classic deep learning task:the recognition of handwritten digit patterns. The simulation results reveal that the exemplary SNN can effectively recognize 10 numbers directly in the optical domain by employing the surrogate gradient algorithm. The theoretical verification of our architecture paves a whole new path for integrated photonic SNNs, with the potential to advance the field of neuromorphic photonic systems and enable more efficient spiking information processing.

关键词： neural networks precise

On the Innovation,Design,Construction,and Experiments of OMEGA-Based SSPS Prototype:The Sun-Chasing Project

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Engineering 2024年第5期36卷 90-101页

作者： Baoyan duan yiqun Zhang Guangda Chen Ze Zhao Jianwei Mi Xun Li Lin Yang Xi Li Research Institute on Mechatronics Xidian UniversityXi’an 710071China Research Institute of Antenna Xidian UniversityXi’an 710071China

This study systematically introduces the development of the world’s first full-link and full-system ground demonstration and verification system for the OMEGA space solar power satellite(SSPS).First,the OMEGA 2.0 innovation design was ***,field-coupling theoretical models of sunlight concentration,photoelectric conversion,and transmitting antennas were established,and a systematic optimization design method was ***,a beam waveform optimization methodology considering both a high beam collection efficiency and a circular stepped beam shape was ***,a control strategy was developed to control the condenser pointing toward the sun while maintaining the transmitting antenna toward the ***,a high-efficiency heat radiator design method based on bionics and topology optimization was ***,a method for improving the rectenna array’s reception,rectification,and direct current(DC)power synthesis efficiencies is ***,high-precision measurement technology for high-accuracy beam-pointing control was ***,a smart mechanical structure was designed and ***,the developed SSPS ground demonstration and verification system has the capacity for sun tracking,a high concentration ratio,photoelectric conversion,microwave conversion and emission,microwave reception,and rectification,and thus satisfactory results were obtained.

关键词： OMEGA-SSPS Full-link and full-system Beam collection efficiency Circular stepped beam shape Smart structure Field coupling theoretical model `Beam pointing control