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Comprehensive modeling strategy for thermomechanical tribological behavior analysis of railway vehicle disc brake system

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Friction 2024年第1期12卷 74-94页

作者： Jiabao yin Chun LU Jiliang MO School of Mechanical Engineering Southwest Jiaotong UniversityChengdu 610031China Technology and Equipment of Rail Transit Operation and Maintenance Key Laboratory of Sichuan Province Chengdu 610031China

A comprehensive modeling strategy for studying the thermomechanical tribological behaviors is proposed in this *** wear degradation considering the influence of temperature(T)is predicted by Archard wear model with the help of the UMESHMOTION subroutine and arbitrary Lagrangian–Eulerian(ALE)remeshing *** the proposed method,the thermomechanical tribological behaviors of railway vehicle disc brake system composed of forged steel brake disc and Cu-based powder metallurgy(PM)friction block are studied *** effectiveness of the proposed methodology is validated by experimental test on a self-designed scaled brake test bench from the perspectives of interface temperature,wear degradation,friction noise and vibration,and contact status *** work can provide an effective way for the investigation of thermomechanical tribological behaviors in the engineering field.

关键词： tribological behaviors thermomechanical field wear prediction finite element simulation disc brake system railway vehicle

A sub-grid scale model for Burgers turbulence based on the artificial neural network method

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Theoretical & Applied Mechanics Letters 2024年第3期14卷 162-165页

作者： Xin Zhao Kaiyi yin Department of Mechanics Beijing Institute of TechnologyBeijing 100081China

The present study proposes a sub-grid scale model for the one-dimensional Burgers turbulence based on the neuralnetwork and deep learning *** filtered data of the direct numerical simulation is used to establish thetraining data set,the validation data set,and the test data *** artificial neural network(ANN)methodand Back Propagation method are employed to train parameters in the *** developed ANN is applied toconstruct the sub-grid scale model for the large eddy simulation of the Burgers turbulence in the *** proposed model well predicts the time correlation and the space correlation of the Burgers turbulence.

关键词： Artificial neural network Back propagation method Burgers turbulence Large eddy simulation Sub-grid scale model

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Greedy Lattice Paths with General Weights

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Acta Mathematica Sinica,English Series 2024年第9期40卷 2213-2222页

作者： yin Shan CHANG An Qi ZHENG College of Mathematics Sichuan UniversityChengdu 610065P.R.China

Let{X_(v):v∈Z^(d)}be *** *** S(π)=Σ_(v∈π)X_(v)be the weight of a self-avoiding lattice pathπ.Let M_(n)=max{S(π):πhas length n and starts from the origin}.We are interested in the asymptotics of Mn as n→∞.This model is closely related to the first passage percolation when the weights{X_(v):v∈Z^(d)}are non-positive and it is closely related to the last passage percolation when the weights{X_(v):v∈Z^(d)}are *** general weights,this model could be viewed as an interpolation between first passage models and last passage ***,this model is also closely related to a variant of the position of right-most particles of branching random *** the two assumptions that∃α>0,E(X_(0)^(+))^(d)(log^(+)X_(0)^(+))^(d+α)0,E(X_(0)^(+))^(d)(log^(+)X_(0)^(+))^(d+α)<+∞and that E[(X_(0)^(−))^(4)]<+∞,we prove that M_(n)/n converges to the same constant M almost surely as n tends to infinity.

关键词： Last passage percolation first passage percolation greedy lattice path

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Track Defects Recognition Based on Axle-Box Vibration Acceleration and Deep- Learning Techniques

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Structural Durability & Health Monitoring 2024年第5期18卷 623-640页

作者： Xianxian yin Shimin yin Yiming Bu Xiukun Wei School of Transportation Engineering Shandong Jianzhu UniversityJinan250101China China Construction Eighth Bureau(Shandong)Design Consulting Co. Ltd.Jinan250100China State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing100044China

As an important component of load transfer,various fatigue damages occur in the track as the rail service life and train trafﬁc increase gradually,such as rail corrugation,rail joint damage,uneven thermite welds,rail squats fas-tener defects,***-time recognition of track defects plays a vital role in ensuring the safe and stable operation of rail *** this paper,an intelligent and innovative method is proposed to detect the track defects by using axle-box vibration acceleration and deep learning network,and the coexistence of the above-mentioned typical track defects in the track system is ***,the dynamic relationship between the track defects(using the example of the fastening defects)and the axle-box vibration acceleration(ABVA)is investigated using the dynamic vehicle-track ***,a simulation model for the coupled dynamics of the vehicle and track with different track defects is established,and the wavelet power spectrum(WPS)analysis is performed for the vibra-tion acceleration signals of the axle box to extract the characteristic ***,using wavelet spectrum photos as input,an automatic detection technique based on the deep convolution neural network(DCNN)is sug-gested to realize the real-time intelligent detection and identiﬁcation of various track ***ﬁndings demonstrate that the suggested approach achieves a 96.72.classiﬁcation accuracy.

关键词： Track defects intelligent detection deep convolution neural network acceleration of axle-box vibration

An approach to estimate tree height using PolInSAR data constructed by the Sentinel-1 dual-pol SAR data and RVoG model

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Journal of Electronic Science and Technology 2024年第3期22卷 69-79页

作者： yin Zhang Ding-Feng Duan School of Resources and Environment University of Electronic Science and Technology of ChinaChengdu611731China

We estimate tree heights using polarimetric interferometric synthetic aperture radar(PolInSAR)data constructed by the dual-polarization(dual-pol)SAR data and random volume over the ground(RVoG)*** the Sentinel-1 SAR dual-pol(SVV,vertically transmitted and vertically received and SVH,vertically transmitted and horizontally received)configuration,one notes that S_(HH),the horizontally transmitted and horizontally received scattering element,is *** S_(HH)data were constructed using the SVH data,and polarimetric SAR(PolSAR)data were *** proposed approach was first verified in simulation with satisfactory *** was next applied to construct PolInSAR data by a pair of dual-pol Sentinel-1A data at Duke Forest,North Carolina,*** to local observations and forest descriptions,the range of estimated tree heights was overall *** the heights with the ICESat-2.tree heights at 2. sampling locations,relative errors of 5 points were within±30%.Errors of 8 points ranged from 30%to 40%,but errors of the remaining 10 points were>40%.The results should be encouraged as error reduction is *** instance,the construction of PolSAR data should not be limited to using SVH,and a combination of SVH and SVV should be ***,an ensemble of tree heights derived from multiple PolInSAR data can be considered since tree heights do not vary much with time frame in months or one season.

关键词： Constructed polarimetric SAR data Dual polarization Sentinel-1 SAR data Polarimetric interferometric SAR Random volume over the ground model Tree height estimation

Effect of Inter-Stage Pressure on Performances of Two-Stage Transcritical CO2.Refrigeration Cycle with Dedicated Absorption Dual-Subcooling and Mechanical Recooling

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Journal of Thermal Science 2024年第06期33卷 2179-2189页

作者： LI Zeyu HUANG Caoxuheng yin Jianhui School of Electric Power South China University of Technology Guangdong Province Key Laboratory of High Efficient and Clean Energy Utilization South China University of Technology Guangdong Province Engineering Research Center of High Efficient and Low Pollution Energy Conversion Ningbo Jetron Technology Co.Ltd.

The two-stage transcritical CO2.efrigeration cycle with dedicated dual-subcooling and mechanical recooling is *** inter-stage pressure is critical for such cycle performances;however,it has not been studied ***,the research aim is to disclose the effect of inter-stage pressure on performances of the proposed *** main work consists of four ***,the comparative study is performed to display advantages of the proposed ***,the key temperatures,heat and power consumptions as well as performance indicators for different inter-stage pressures are analyzed in detail,based on the parametric ***,the optimal inter-stage pressure for different conditions is obtained by the nonlinear direct search ***,the economic performance is *** is found that the compressor power of the proposed cycle drops by 12.,and the working temperature lower limit is reduced by 11℃.Furthermore,it is considered that the optimal inter-stage pressure is insensitive to the heat source *** novelty lies in illustrating the effect of inter-stage pressure,obtaining trends of the optimal value,and pointing out the system *** paper is favorable for design and operation optimization of the proposed system.

关键词： CO2.refrigeration dedicated absorption subcooling recooling thermodynamics two-stage cycle

A Bubble Column Dehumidifier using Ionic Liquid Desiccant for Low-Humidity Industries:Insights into Transfer Processes Integrating Experiment and CFD Modelling

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Journal of Thermal Science 2024年第06期33卷 2348-2371页

作者： CAO Bowen yin Yonggao SAITO Kiyoshi School of Energy and Environment Southeast University School of Fundamental Science and Engineering Waseda University Department of Applied Mechanics and Aerospace Engineering Waseda University

Liquid desiccant deep dehumidification（LDDD） is an excellent energy-saving technology for low-humidity *** liquids（ILs） are favored as optimal working fluids for LDDD,owing to their low vapor pressure,non-crystallization,and *** combined application of IL desiccant with the bubble column has been proven to effectively improve deep *** present work focuses specifically on the insights into air-liquid transfer processes in bubble column dehumidifier using ionic liquid *** effect of operating parameters on volumetric transfer coefficient is examined based on the experimental ***,the bubble swarms meso-scale flow structure is predicted using computational fluid dynamics coupled with a population balance model（CFD-PBM）.Besides,the structure-activity relationship between meso-scale flow structure and transfer performance is *** results indicated a notable phenomenon of bubble aggregation/breakage in the moist air-IL desiccant bubbly deep dehumidification（MA-ILD BDD）system,with a specific interfacial area is basically less than 40 ***,a decrease in solution temperature,correlated with a significant increase in viscosity,leads to larger turbulent eddies and a slower breakage ***,a high transfer potential difference enhances heat and mass transfer coefficients at lower solution temperatures,with the mass transfer coefficient at 4℃ being approximately three times that at 10℃.As the superficial velocity changes,the specific interfacial area and heat and mass transfer coefficients have a positive synergistic effect on volumetric transfer ***,this synergistic effect is reversed with variations in solution *** study aims to clarify the air-liquid transfer mechanism in bubble column dehumidifier using IL desiccant.

关键词： bubble column deep dehumidification heat and mass transfer ionic liquid liquid desiccant low-humidity industries

Review of chiplet-based design: system architecture and interconnection

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Science China(Information Sciences) 2024年第10期67卷 5-24页

作者： Yafei LIU Xiangyu LI Shouyi yin School of Integrated Circuits Tsinghua University Laboratory of Integrated Circuits and Intelligence Systems Research Institute of Tsinghua University in Shenzhen

Chiplet-based design, which breaks a system into multiple smaller dice(or “chiplets”) and reassembles them into a new system chip through advanced packaging, has received extensive attention in the post Moore's law era due to its advantages in terms of cost, performance, and agility. However, significant challenges arise in this implementation approach, including the mapping of functional components onto chiplets, co-optimization of package and architecture, handling the increased latency of communication across functions in different dies, the uncertainty problems of fragment communication subsystems, such as maintaining deadlock-free when independently designed chiplets are combined. Despite various design approaches that attempt to address these challenges, surveying these approaches one-after-another is not the most helpful way to offer a comparative viewpoint. Accordingly, in this paper, we present a more comprehensive and systematic strategy to survey the various approaches. First, we divide them into chiplet-based system architecture design and interconnection design, and further classify them based on different architectures and building blocks of interconnection. Then, we analyze and cross-compare each classification separately, and in addition, we present a topical discussion on the evolution of memory architectures, design automation, and other relevant topics in chiplet-based designs. Finally, some discussions on important topics are presented,emphasizing future needs and challenges in this rapidly evolving field.

关键词： chiplet-based design package architecture interconnection silicon interposer

Boundary-lubricated biomaterials with drug delivery for osteoarthritis treatment

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Friction 2024年第10期12卷 2167-2187页

作者： Junyu WU Kaixuan REN Jingbo yin Department of Polymer Materials School of Materials Science and EngineeringShanghai UniversityShanghai 200444China

The good lubrication ability of articular cartilage holds significant importance in our daily ***(OA),the most prevalent degenerative joint disease,causes cartilage damage,increased friction,and ***,the current clinical treatments for OA exhibit some ***,the sustained drug release systems with lubricating function have attracted considerable attention for treating *** review introduces the lubrication mechanism of cartilage,focusing particularly on the boundary lubrication *** research progress of boundary-lubricated biomaterials with drug delivery,including microcarriers,hydrogels,and nanoparticles in the treatment of OA by improving inter-articular lubrication and relieving inflammation is discussed and *** efficacy and challenges of boundary-lubricated biomaterials with drug delivery in the treatment of OA are summarized,and the prospects are also discussed.

关键词： osteoarthritis joint friction boundary lubrication hydration lubrication drug delivery