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Evolution of suspension bridge structural systems,design theories,and shape-finding methods:A literature survey

Journal of Traffic and Transportation Engineering(English Edition) 2024年第2期11卷 225-244页

作者： Wenming Zhang Genmin Tian Yupeng Chen key laboratory of Concrete and Pre-stressed Concrete Structures of Ministry of Education Southeast UniversityNanjing 210096China state key laboratory of safety Durability and Healthy Operation of Long Span BridgesSoutheast UniversityNanjing 210096China

Modern suspension bridges exhibit a trend of lighter structures,more diversified structural forms,and longer spans,the latter already exceeding two *** performance under dead and live loads depends on their structural and main cable systems,while cablesupported bridges especially rely on the design analysis and construction control of the main *** literary survey systematically analyzes the research progress and state-ofthe-art status quo in the structural systems and design theories of suspension bridges,focusing on the structural systems,main cable shape analyses,live load effect analyses,and emerging lucrative research *** than 100 reliable references have been surveyed.(1)Multi-span or multi-main cable schemes appeal to increasing attention,which may become a better choice in terms of structural systems in scenarios with extremely long spans and heavy *** cable layouts,such as spatial main cables and hybrid cable-stayed suspension systems have also become feasible approaches for enhancing structural stiffness.(2)The shape-finding analysis during the construction phase is more complex and has more essential factors than that of the completed bridge *** theories combining analytical methods and finite element methods are more suitable for the shape-finding analysis of complex cable systems than any single theory of the two,especially for novel cable systems.(3)The live load effect analysis methods based on traditional deflection theory or modified/improved deflection theories still have wide applications,but the refined theory of treating hangers as discrete members is also constantly developing,which is expected to provide new ideas for more complex structural analysis under the different types of live loads and their distribution forms.

关键词： Suspension bridges Structural system Cable analysis Shape-finding analysis Construction control and calculation Live load effect

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On the Polygonal Wear Evolution of Heavy-Haul Locomotive Wheels due to Wheel/Rail Flexibility and Its Mitigation Measures

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 40-61页

作者： Yunfan Yang Feifan Chai Pengfei Liu Liang Ling Kaiyun Wang Wanming Zhai state key laboratory of Mechanical Behavior and System safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China state key laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610031China

Wheel polygonal wear can immensely worsen wheel/rail interactions and vibration performances of the train and track,and ultimately,lead to the shortening of service life of railway *** present,wheel/rail medium-or high-frequency frictional interactions are perceived as an essential reason of the high-order polygonal wear of railway wheels,which are potentially resulted by the flexible deformations of the train/track system or other external *** this work,the effect of wheel/rail flexibility on polygonal wear evolution of heavy-haul locomotive wheels is explored with aid of the long-term wheel polygonal wear evolution simulations,in which different flexible modeling of the heavy-haul wheel/rail coupled system is ***,the mitigation measures for the polygonal wear of heavy-haul locomotive wheels are *** results point out that the evolution of polygonal wear of heavy-haul locomotive wheels can be veritably simulated with consideration of the flexible effect of both wheelset and *** of mixed-line operation of heavy-haul trains and application of multicut wheel re-profiling can effectively reduce the development of wheel polygonal *** research can provide a deep-going understanding of polygonal wear evolution mechanism of heavy-haul locomotive wheels and its mitigation measures.

关键词： Heavy-haul locomotive Wheel polygonal wear Wheel/rail flexibility long-term polygonal wear evolution Mitigation measures

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3D-printed self-healing,biodegradable materials and their applications

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Frontiers of Mechanical Engineering 2024年第3期19卷 1-22页

作者： Yu LI Guangmeng MA Fawei GUO Chunyi LUO Han WU Xin LUO MingtaoZHANG Chenyun WANG Qingxin JIN Yu long School of Mechanical Engineering Guangxi UniversityNanning 530004China state key laboratory of Featured Metal Materials and Life-cycle safety for Composite Structures Guangxi UniversityNanning 530004China Institute of Laser Intelligent Manufacturing and Precision Processing School of Mechanical EngineeringGuangxi UniversityNanning 530004China College of Mechanical and Electrical Engineering Central South UniversityChangsha 410083China state key laboratory of Precision Manufacturing for Extreme service Performance Central South UniversityChangsha 410083China

3D printing is a versatile technology capable of rapidly fabricating intricate geometric structures and enhancing the performance of flexible devices in comparison to conventional fabrication ***,3D-printed devices are susceptible to failure as a result of minuscule structural impairments,thereby impacting their overall *** utilization of self-healing,biodegradable materials in 3D printing holds immense potential for increasing the longevity and safety of devices,thereby expanding the application prospects for such ***,enhancing the self-repairing capability of devices and refining the 3D printing performance of self-healing materials are still considerable challenges that need to be addressed to achieve optimal *** paper reviews recent developments in the field of advancements in 3D printing using self-healing and biodegradable ***,it investigates self-healing and biodegradable materials that are compatible with 3D printing techniques,discussing their printability,material properties,and factors that influence print ***,it explores practical applications of selfhealing and biodegradable 3D printing technology in ***,it critically offers practical perspectives on this topic.

关键词： 3D printing self-healing biodegradable soft materials covalent bonds non-covalent bonds

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Sulfate-assisted Ni/Fe-based electrodes for anion exchange membrane saline splitting

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Nano Research 2024年第7期17卷 5985-5995页

作者： Yujun Han Li Shao Yuhang Liu Guodong Li Tongzhou Wang Xuerong Zheng Jihong Li Xiaopeng Han Wenbin Hu Yida Deng School of Materials Science and Engineering Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of EducationTianjin UniversityTianjin 300072China state key laboratory of Marine Resource Utilization in South China Sea School of Materials Science and EngineeringHainan UniversityHaikou 570228China state key laboratory of Inorganic Synthesis and Preparative Chemistry College of ChemistryJilin UniversityChangchun 130012China key laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Nankai UniversityTianjin 300071China

Saline water electrolysis is an appealing strategy for hydrogen production,attracting more attention in recent ***-based electrodes exhibit promise as catalysts for saline water ***,they suffer from the inferior service life of the oxygen evolution reaction(OER).Herein,we report an oxygen-evolution electrode consisting of a sulfate-modulated nickel-iron hydroxide(NiFeOOH)affording as the catalytic active layer and Fe-Ni3S2 as the corrosion-proof *** developed electrode only requires overpotentials of 220 and 292 mV to deliver the current density of 10 and 500 mA·cm^(−2),*** importantly,it presents long-term stability exceeding 140 and 100 h in 1 M KOH at high current densities of 500 and 1000 mA·cm^(−2),respectively,as well as 120 h for saline water electrolysis at 100 mA·cm^(−2).Experimental results reveal that the generated sulfate plays an indispensable role in improving stability and corrosion *** assembled and tested an anion exchange membrane electrolyzer with Pt/C and NiFeS/NIF as the cathode and anode,respectively,under industrial *** overall water-splitting electrolyzer achieves an impressive energy conversion efficiency of 75%±0.5%.This report offers fresh insights into the design of stable NiFe-based electrodes,which may further promote its practical applications for saline water electrolysis.

关键词： saline water electrolysis oxygen evolution reaction anode material water splitting

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d-Orbital steered FeN_(4)moiety through N,S dual-site adjustation for zinc-air flow battery

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Journal of Energy Chemistry 2024年第5期92卷 8-15页

作者： Chunzhu Bao Mingwei Tong Xueli Li Zhonghua Xiang state key laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China

The implementation of pristine covalent organic polymer(CO_(2)P)with well-defined structure as air electrode may spark fresh vitality to rechargeable zinc-air flow batteries(ZAFBs),but it still remains challenges in synergistically regulating their electronic states and structural porosity for the great device ***,we conquer these issues by exploiting N and S co-doped graphene with COP rich in metal-ligand nitrogen to synergistically construct an effective catalyst for oxygen reduction reaction(ORR).Among them,the N and S co-doped sites with high electronegativity properties alter the number of electron occupations in the d orbital of the iron centre and form electron-transfer bridges,thereby boosting the selectivity of the ORR-catalysed four-electron ***,the introduction of COP materials aids the formation of pore interstices in the graphene lamellae,which both adequately expose the active sites and facilitate the transport of reactive *** from the synergistic effect,as-prepared catalyst exhibits excellent half-wave potentials(E_(1/2)=912 mV)and stability(merely 8.8%drop after a long-term durability test of 50000 s).Further,ZAFBs assembled with the N/SG@CO_(2)P catalyst demonstrate exceptional power density(163.8 mW cm^(-2))and continuous charge and discharge for approximately 140 h at 10 mA cm^(-2),outperforming the noble-metal benchmarks.

关键词： Nitrogen/sulfurdual sites Metal-coordinated nitrogen sites Covalent organic polymer Oxygen reduction reaction Zn-airflow battery

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Effect of nano-graphite on mechanical properties and oxidation resistance of ZrB_(2)-SiC-graphite electrode ceramics

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Journal of Iron and Steel Research(International) 2024年第6期31卷 1502-1513页

作者： Bo-lin Yang Chang-liu Kuang Zheng-long Liu Chao Yu Cheng-ji Deng Jun Ding The state key laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina

ZrB_(2)-based ceramic composites were prepared by spark plasma sintering using ZrB_(2) powder prepared by molten salt method as raw material and SiC and nano-graphite as *** effects of nano-graphite addition on the physical properties and oxidation resistance of ZrB_(2)-based ceramic samples were *** results show that the addition of an appropriate amount of nano-graphite can effectively improve the density of ZrB_(2)-based ceramic composites and improve the physical properties of the *** flexural strength of the ceramic sample with 8 vol.%nano-graphite reached 418.54 MPa,which was 53.14% higher than that of ZrB_(2)-SiC ceramic material(273.31 MPa),and its oxidation resistance was also significantly *** demonstrats that the addition of an appropriate amount of nano-graphite can effectively improve the physical properties and oxidation resistance of ZrB_(2)-SiC ceramic *** prolonging its service life in application and promoting the development of ZrB_(2)-based ceramic composites,it is of great significance for clean steel smelting.

关键词： ZrB_(2)-SiC-graphite electrode ceramic ZrB_(2)-based ceramic composite Nano-graphite Physical property Oxidation resistance

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Multiscale Simulation of Microstructure Evolution during Preparation and service Processes of Physical Vapor Deposited c-TiAlN Coatings

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Computers, Materials & Continua 2024年第6期79卷 3435-3453页

作者： Yehao long Jing Zhong Tongdi Zhang Li Chen Lijun Zhang state key laboratory of Powder Metallurgy Central South UniversityChangsha410083China

Physical Vapor Deposited(PVD)TiAlN coatings are extensively utilized as protective layers for cutting tools,renowned for their excellent comprehensive *** optimize quality control of TiAlN coatings for cutting tools,a multi-scale simulation approach is proposed that encompasses the microstructure evolution of coatings considering the entire preparation and service lifecycle of PVD TiAlN *** scheme employs phase-field simulation to capture the essential microstructure of the PVD-prepared TiAlN ***,cutting simulation is used to determine the service temperature experienced during cutting processes at varying ***-Hilliard modeling is finally utilized to consume the microstructure and service condition data to acquaint the microstructure evolution of TiAlN coatings throughout the cutting *** methodology effectively establishes a correlation between service temperature and its impact on the microstructure evolution of TiAlN *** is expected that the present multi-scale numerical simulation approach will provide innovative strategies for assisting property design and lifespan prediction of TiAlN coatings.

关键词： Multiscale phase-field TiAlN coatings PVD cutting

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Highly Improved Creep Resistance in Polypropylene Through Thermally Reduced Graphene Oxide and Its Creep Lifetime Prediction

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Chinese Journal of Polymer Science 2024年第2期42卷 256-266,I0010页

作者： Can-Can Zhang Jun-long Yang Ya-Jiang Huang Guang-Xian Li College of Polymer Science and Engineering State Key Laboratory of Polymer Materials Engineering of ChinaSichuan UniversityChengdu610065China

Polypropylene(PP) exhibits suboptimal creep resistance due to the presence of methyl groups on its main chain, leading to irregular chain segment distribution, diminished inter-chain interaction, and crystallinity. This structural feature causes chain slippage in PP under stress,significantly constraining its service lifetime. In this study, thermally reduced graphene oxide(TrGO) nanosheets were incorporated into the PP matrix, yielding a nanocomposite with exceptional creep resistance performance. Results demonstrated that at a stress of 25 MPa, a 2.0 wt% TrGO content could enhance the creep failure lifetime of PP by 21.5 times compared to neat PP. Rheology, transmission electron microscopy(TEM),and scanning electron microscopy(SEM) characterization techniques were employed to analyze the mechanism of TrGO's influence on PP's creep behavior. It was observed that when TrGO content exceeded 1.0 wt%, an effective particle network structure formed within the PP matrix. This homogeneously dispersed TrGO-formed particle network structure restricted the migration and rearrangement of PP molecular chains, enabling prolonged stress resistance without structural failure. By combining the time-strain superposition method with the critical failure strain as a criterion, generalized creep compliance curves for PP and its composites were established, facilitating the prediction of material creep failure lifetimes, with a strong agreement between experimental and predicted lifetime values. This research proposes a novel strategy aimed at developing polypropylene materials and products with enhanced long-term stability and durability, thus extending service life, reducing failure risk, and broadening their potential across various application domains.

关键词： Thermally reduced graphene oxide Polypropylene Creep failure and lifetime prediction

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Optimizing Optical Fiber Faults Detection:A Comparative Analysis of Advanced Machine Learning Approaches

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Computers, Materials & Continua 2024年第5期79卷 2697-2721页

作者： Kamlesh Kumar Soothar Yuanxiang Chen Arif Hussain Magsi Cong Hu Hussain Shah School of Electronics Engineering Beijing University of Posts and TelecommunicationsBeijing100876China state key laboratory of Integrated services Networks Xidian UniversityXi’an710071China state key laboratory ofNetworking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing100876China

Efficient optical network management poses significant importance in backhaul and access network communicationfor preventing service disruptions and ensuring Quality of service(QoS)*** emerging faultsin optical networks introduce challenges that can jeopardize the network with a variety of *** existingliterature witnessed various partial or inadequate *** the other hand,Machine Learning(ML)hasrevolutionized as a promising technique for fault detection and *** traditional fault managementsystems,this research has three-fold ***,this research leverages the ML and Deep Learning(DL)multi-classification system and evaluates their accuracy in detecting six distinct fault types,including fiber cut,fibereavesdropping,splicing,bad connector,bending,and PC ***,this paper assesses the classificationdelay of each classification ***,this work proposes a fiber optics fault prevention algorithm thatdetermines to mitigate the faults *** work utilized a publicly available fiber optics dataset namedOTDR_Data and applied different ML classifiers,such as Gaussian Naive Bayes(GNB),Logistic Regression(LR),Support Vector Machine(SVM),K-Nearest Neighbor(KNN),Random Forest(RF),and Decision Tree(DT).Moreover,Ensemble Learning(EL)techniques are applied to evaluate the accuracy of various *** addition,this work evaluated the performance of DL-based Convolutional Neural Network and long-Short Term Memory(CNN-LSTM)hybrid *** findings reveal that the CNN-LSTM hybrid technique achieved the highestaccuracy of 99%with a delay of 360 *** the other hand,EL techniques improved the accuracy in detecting fiberoptic ***,this research comprehensively assesses accuracy and delay metrics for various classifiers andproposes the most efficient attack detection system in fiber optics.

关键词： Fiber optics fault detection multiclassification machine learning ensemble learning

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A Semi-Mechanistic Model for Predicting the service Life of Composite Coatings on VW63Z Magnesium Alloy

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Acta Metallurgica Sinica(English Letters) 2024年第7期37卷 1161-1176页

作者： Xiaoxue Wang Jingjing Guo Zihao Zeng Peng Zhou Rongqiao Wang Xiuchun Liu Kai Gao Jingli Sun Yong Yuan Fuhui Wang School of Energy and Power Engineering Beihang UniversityBeijing100191China Beijing Institute of Space long March Vehicle Beijing100076China The School of Materials Science and Engineering Northeastern UniversityShenyang110819China The state key laboratory of Rolling and Automation Northeastern UniversityShenyang110819China Shanghai Spaceflight Precision Machinery Institute Shanghai201600China

The application of Mg alloys is always accompanied by various coating technology, but a reliable model predicting the service life of coatings on Mg alloys is lacking but urgent. In this work, a semi-mechanistic model was proposed to predict the service life of plasma electrolytic oxidation (PEO) coating/electrophoretic coatings on a VW63Z Mg alloy;the model was decomposed into three parts: a first part depicting the degradation time of organic coating (L_(1)) and the diffusion time of electrolyte in the inorganic coating (L_(2)), respectively;a second part interpreting the breakdown of coatings due to the corrosion process (L_(3));a final part establishing an algorithm converting the accelerated tests into the real service environment (α);the effect of structural stress and dissimilar metal joints on the service life of coatings was also considered. Based on the ongoing accelerated experiments, the semi-mechanistic model could be able to predict the service life of both PEO coatings and composite coatings on VW63Z Mg alloy with a satisfiable precision.

关键词： Magnesium alloy service life prediction Plasma electrolytic oxidation Electrophoretic coating Corrosion resistance

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