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Analysis of temperature characteristics of high-speed train wheelset system under complex operating conditions

International Journal of Mechanical System Dynamics 2024年第3期4卷 331-345页

作者： Baosen Wang Yongqiang Liu Yingying Liao Yixuan Wang School of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuangChina Hebei Key Laboratory of Mechanical Power and Transmission Control Shijiazhuang Tiedao UniversityShijiazhuangChina School of Civil Engineering Shijiazhuang Tiedao UniversityShijiazhuangChina Taiyuan Vehicle Depot Daqin Railway Co.Ltd.TaiyuanChina

With the rapid advancements in high-speed train technology,the importance of ensuring the safety of train operations has become ***,being a critical component of train bogies,have garnered significant attention for their role in maintaining safety *** the temperature of bearings to evaluate their motion state is a common practice in high-speed trains,emphasizing the need for further research into temperature *** this study,a dynamic model is developed for the bearing rotor system of high-speed *** considering the contact points between raceways and rolling elements,the power loss in the bearing is obtained and a transient temperature-field model of the system is *** relationship between node temperature and factors such as ambient temperature,train running speed,and load is illustrated,with a detailed presentation of the influence of bearing fault type and size on node *** analysis results reveal that the node temperature increases with higher values corresponding to those quantifiable factors and is most affected by rolling element ***,it is observed that the temperature rises rapidly in the initial stage and gradually flattens out over *** comparative analysis of temperature under different fault conditions shows that the node temperature is most affected by the rolling element *** and actual line temperature data are used to verify the validity of the *** comparison results show that the simulation aligns well with experimental and line *** transient temperature-field model of the bearing rotor system in high-speed trains can effectively simulate and predict the temperature change process of each node of the *** simulation results hold certain theoretical guiding significance for further research and practical applications in ensuring train operation safety.

关键词： high-speed train dynamic model transient temperature field bearing fault line data

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Investigation of cracking mechanism of the first tunnel lining during double-arch tunnel construction

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Underground Space 2024年第1期14卷 1-17页

作者： Yi Sui Xiaohui Cheng Zuozhou Zhao Weibin Ma railway Engineering Research institute China Academy of Railway Sciences Corporation LimitedBeijing 100081China School of Civil Engineering Tsinghua UniversityBeijing 100084China

To solve the engineering problem of the first tunnel lining cracking caused by the second tunnel construction of double-arch highway tunnels,a research method combining distributed optical-fibre monitoring,inversion analysis and numerical simulation that can reflect lining cracking was *** fibres were laid on opposite sides of the steel arches inside the first tunnel *** optical-fibre monitoring was conducted continuously during the second tunnel *** on the fibre-optic strain profile,the lining cracking was deduced and warned in *** mechanical behaviour of the steel arch was investigated by the inversion analysis,which took into consideration the integrated impact of axial force and flexural moment.A two-dimensional(2D)load-structure method–based numerical model was established,considering the influence of different load distributions in each construction *** total strain rotating crack constitutive model was applied to reflect the cracking behaviour of concrete lining in the simulation,and the model was calibrated and verified in the *** analysis between the simulated strain distribution and the distributed optical-fibre monitoring results was carried *** deformation mode and crack distribution of the lining were *** cracking mechanism was ***,the second tunnel construction led to the loading at the top of the middle partition wall and the release of rock pressure in the first *** these load changes,the secondary lining of the first tunnel cracked on the inner side of the top of the middle partition wall owing to tension,and compression-bending failure occurred near the right arch ***,the influence of the parameters on the lining force was analysed,and a construction optimisation scheme was proposed.

关键词： Double-arch tunnel Cracking mechanism Distributed optical-fibre sensing Inversion analysis Total strain rotating crack model Loadstructure method

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Dynamic analysis of axle box bearings on the high-speed train caused by wheel-rail excitation

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Applied Mathematics and Mechanics(English Edition) 2024年第3期45卷 441-460页

作者： Qiaoying MA Shaopu YANG Yongqiang LIU Baosen WANG Zechao LIU State Key Laboratory of Mechanical behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China School of Transportation Shijiazhuang Tiedao UniversityShijiazhuang 050043China School of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050043China

To explore the impact of wheel-rail excitation on the dynamic performance of axle box bearings,a dynamic model of the high-speed train including axle box bearings is ***,the dynamic response characteristics of the axle box bearing are *** investigation focuses on the acceleration characteristics of bearing vibration under excitation of track irregularities and wheel *** addition,experiments on both normal and faulty bearings are conducted separately,and the correctness of the model and some conclusions are *** to the research,track irregularity is unfavorable for bearing fault detection based on resonance *** the same speed conditions,the acceleration peak of bearing is inversely proportional to the length of the wheel flat and directly proportional to its *** paper will contribute to a deeper understanding of the dynamic performance of axle box bearings.

关键词： high-speed train track irregularity wheel flat dynamic simulation

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The variation in basal channels and basal melt rates of Pine Island Ice Shelf

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Acta Oceanologica Sinica 2024年第1期43卷 22-34页

作者： Mingliang Liu Zemin Wang Baojun Zhang Xiangyu Song Jiachun An Chinese Antarctic Center of Surveying and Mapping Wuhan UniversityWuhan 430079China Key Laboratory of Polar Environment Monitoring and Public Governance(Wuhan University) Ministry of EducationWuhan 430079China School of Civil Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050043China Key Laboratory of Roads and railway Engineering Safety Control(shijiazhuang Tiedao University) Ministry of EducationShijiazhuang 050043China

In recent years,there has been a significant acceleration in the thinning,calving and retreat of the Pine Island Ice Shelf(PIIS).The basal channels,results of enhanced basal melting,have the potential to significantly impact the stability of the *** this study,we used a variety of remote sensing data,including Landsat,REMA DEM,ICESat-1 and ICESat-2 satellite altimetry observations,and Ice Bridge airborne measurements,to study the spatiotemporal changes in the basal channels from 2003 to 2020 and basal melt rate from 2010 to 2017 of the PIIS under the Eulerian *** found that the basal channels are highly developed in the PIIS,with a total length exceeding 450 *** of the basal channels are ocean-sourced or groundingline-sourced basal channels,caused by the rapid melting under the ice shelf or near the groundingline.A raised seabed prevented warm water intrusion into the eastern branch of the PIIS,resulting in a lower basal melt rate in that *** contrast,a deepsea trough facilitates warm seawater into the mainstream and the western branch of the PIIS,resulting in a higher basal melt rate in the main-stream,and the surface elevation changes above the basal channels of the mainstream and western branch are more *** El Ni?o event in 2015–2016 possibly slowed down the basal melting of the PIIS by modulating wind field,surface sea temperature and depth seawater *** and atmospheric changes were driven by El Ni?o,which can further explain and confirm the changes in the basal melting of the PIIS.

关键词： Pine Island Ice Shelf basal channel basal melt rate digital elevation models(DEMs) satellite altimetry

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Pilot Test of Preparing 2-Alkylanthraquinone Using Alkylation-Oxidation Technology

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China Petroleum Processing & Petrochemical Technology 2024年第1期26卷 88-97页

作者： Zheng Bo Qian Jianguo Shi Peng Pan Zhiyong Qie Siyuan Zhang Yueqin Fei Jianqi Qiao Liang Zong Baoning SINOPEC Research institute of Petroleum Processing Co. LtdBeijing 100083 shijiazhuang United Petrochemical Co. LtdShijiazhuang 050011

To expedite the development of industrial technology for producing 2-alkylanthraquinone,a novel pilot test of alkylation-oxidation technology was *** process mainly included anthracene alkylation,separation of anthracene and 2-alkylanthracene,oxidation of 2-alkylanthracene,and product *** alkylation conditions yielded a 91.1%conversion of anthracene and a 71.73%selectivity for *** address the separation problem of anthracene and 2-alkylanthracene,solvent-assisted distillation technology was developed,resulting in a 98.9%purity of 2-alkylanthracene and a 91.82%separation *** the molar ratio of H2O_(2) to 2-alkylanthracene was 7:1,a 98.96%conversion of 2-alkylanthracene and a 99.94%selectivity for 2-alkylanthraquinone were achieved.A novel composition of 2-alkylanthraquinone,including 2-tert-butylanthraquinone,2-tert-amylanthraquinone,and 2-hexylanthraquinone,was *** composition could be effectively separated and purified through a combination of crystallization and washing *** elemental composition of the product met the existing standards,and its hydrogenation performance closely matched that of commercially available 2-tert-amylanthraquinone products.

关键词： anthracene 2-alkylanthracene 2-alkylanthraquinone alkylation oxidation hydrogen peroxide

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An improved effective liquid drop model for cluster radioactivity

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Communications in Theoretical Physics 2024年第3期76卷 127-137页

作者：崔建坡邢凤竹高永浩齐立倩王艳召顾建中 Department of Mathematics and Physics Shijiazhuang Tiedao UniversityShijiazhuang 050043China institute of Applied Physics Shijiazhuang Tiedao UniversityShijiazhuang 050043China Hebei Research Center of the Basic Discipline Engineering Mechanics Shijiazhuang Tiedao UniversityShijiazhuang 050043China Hebei Key Laboratory of Physics and Energy Technology North China Electric Power UniversityBaoding 071000China China institute of Atomic Energy P.O.Box 275(10)Beijing 102413China

The effective liquid drop model(ELDM)is improved by introducing an accurate nuclear charge radius formula and an analytic expression for assaulting *** the improved effective liquid drop model(IMELDM),the experimental cluster radioactivity half-lives of the trans-lead region are *** is shown that the accuracy of the IMELDM is improved compared with that of the *** last,the cluster radioactivity half-lives that are experimentally unavailable for the trans-lead nuclei are predicted by the *** predictions may be useful for searching for new candidates for cluster radioactivity in future experiments.

关键词： cluster radioactivity nuclear charge radius assaulting frequency effective liquid drop model

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Damage Evolution of Ballastless Track Concrete Exposed to Flexural Fatigue Loads:The Application of Ultrasonic Pulse Velocity,Impact-echo and Surface Electrical Resistance Method

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Journal of Wuhan University of Technology(Materials Science) 2024年第2期39卷 353-363页

作者：杨志强李化建 WEN Jiaxing DONG Haoliang HUANG Fali WANG Zhen YI Zhonglai railway Engineering Research institute China Academy of Railway Science Corporation LimitedBeijing 100081China State Key Laboratory for Track System of High-Speed railway Beijing 100081China School of Civil Engineering Beijing Jiaotong UniversityBeijing 100044China

In order to clarify the fatigue damage evolution of concrete exposed to flexural fatigue loads,ultrasonic pulse velocity(UPV),impact-echo technology and surface electrical resistance(SR) method were *** variable based on the change of velocity of ultrasonic pulse(Du) and impact elastic wave(Di)were defined according to the classical damage *** influences of stress level,loading frequency and concrete strength on damage variable were *** experimental results show that Du and Di both present a three-stages trend for concrete exposed to fatigue *** impact elastic wave is more sensitive to the microstructure damage in stage Ⅲ,the critical damage variable,i e,the damage variable before the final fracture of concrete of Di is slightly higher than that of ***,the evolution of SR of concrete exposed to fatigue loads were analyzed and the relationship between SR and Du,SR and Di of concrete exposed to fatigue loads were *** is found that the SR of concrete was decreased with the increasing fatigue cycles,indicating that surface electrical resistance method can also be applied to describe the damage of ballastless track concrete exposed to fatigue loads.

关键词： ballastless track fatigue damage ultrasonic pulse velocity impact-echo surface electrical resistance

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Tongxinluo Activates PI3K/AKT Signaling Pathway to Inhibit Endothelial Mesenchymal Transition and Attenuate Myocardial Fibrosis after Ischemia-Reperfusion in Mice

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Chinese Journal of Integrative Medicine 2024年第7期30卷 608-615页

作者： WEI Ya-ru HOU Yun-long YIN Yu-jie LI Zhen LIU Yi HAN Ning-xin WANG Zi-xuan LIU Lu WANG Xiao-qi HAO Yuan-jie MA Kun GU Jiao-jiao JIA Zhen-hua Graduate School Hebei University of Chinese MedicineShijiazhuang050090China shijiazhuang Yiling Pharmaceutical New Drug Evaluation Center Shijiazhuang050035China Hebei institute of Integrated Traditional and Western Medicine Shijiazhuang050035China National Key Laboratory for Innovation and Transformation of Luobing Theory Shijiazhuang050035China Department of Cardiology Hebei Yiling HospitalShijiazhuang050091China Graduate School Hebei Medical UniversityShijiazhuang050017China

Objective To investigate the potential role of Tongxinluo(TXL)in attenuating myocardial fibrosis after myocardial ischemia-reperfusion injury(MIRI)in *** A MIRI mouse model was established by left anterior descending coronary artery ligation for 45 *** to a random number table,66 mice were randomly divided into 6 groups(n=11 per group):the sham group,the model group,the LY-294002 group,the TXL group,the TXL+LY-294002 group and the benazepril(BNPL)*** day after modeling,TXL and BNPL were administered by *** injection of LY-294002 was performed twice a week for 4 consecutive *** was used to measure cardiac function in *** staining was used to evaluate the degree of myocardial fibrosis in *** and quantitative analysis of endothelial mesenchymal transition(EndMT)after MIRI was performed by immunohistochemistry,immunofluorescence staining and flow cytometry,*** protein expressions of platelet endothelial cell adhesion molecule-1(CD31),α-smoth muscle actin(α-SMA),phosphatidylinositol-3-kinase(PI3K)and phospho protein kinase B(p-AKT)were assessed using Western *** TXL improved cardiac function in MIRI mice,reduced the degree of myocardial fibrosis,increased the expression of CD31 and inhibited the expression ofα-SMA,thus inhibited the occurrence of EndMT(P0.05).In addition,the use of the PI3K/AKT pathway-specific inhibitor LY-294002 to block this pathway and combination with TXL intervention,eliminated the protective effect of TXL,further supporting the protective effect of *** TXL activated the PI3K/AKT signaling pathway to inhibit EndMT and attenuated myocardial fibrosis after MIRI in mice.

关键词： myocardial fibrosis endothelial mesenchymal transition myocardial ischemia-reperfusion injury phosphatidylinositol-3-kinase/protein kinase B(PI3K/AKT)pathway

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Demand-Responsive Transportation Vehicle Routing Optimization Based on Two-Stage Method

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Computers, Materials and Continua 2024年第1期81卷 443-469页

作者： Ma J. Liu H. Chen L. School of railway Transportation Shanghai Institute of Technology Shanghai 201418 China

Demand-responsive transportation (DRT) is a flexible passenger service designed to enhance road efficiency, reduce peak-hour traffic, and boost passenger satisfaction. However, existing optimization methods for initial passenger requests fall short in addressing real-time passenger needs. Consequently, there is a need to develop real-time DRT route optimization methods that integrate both initial and real-time requests. This paper presents a two-stage, multi-objective optimization model for DRT vehicle scheduling. The first stage involves an initial scheduling model aimed at minimizing vehicle configuration, and operational, and CO2 emission costs while ensuring passenger satisfaction. The second stage develops a real-time scheduling model to minimize additional operational costs, penalties for time window violations, and costs due to rejected passengers, thereby addressing real-time demands. Additionally, an enhanced genetic algorithm based on Non-dominated Sorting Genetic Algorithm-II (NSGA-II) is designed, incorporating multiple crossover points to accelerate convergence and improve solution efficiency. The proposed scheduling model is validated using a real network in Shanghai. Results indicate that real-time scheduling can serve more passengers, and improve vehicle utilization and occupancy rates, with only a minor increase in total operational costs. Compared to the traditional NSGA-II algorithm, the improved version enhances convergence speed by 31.7% and solution speed by 4.8%. The proposed model and algorithm offer both theoretical and practical guidance for real-world DRT scheduling. © 2024 The Authors.

关键词： artificial intelligence applications Demand responsive transit genetic algorithm muti-objective optimization

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Research on the stability of virtual coupling train formation based on a PID controller under the influence of time delay

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Transportation Safety and Environment 2024年第3期6卷 133-139页

作者： Sixuan Qiu Ningzhou Li Xiaojuan Wei Gaosong Li School of railway Transportation Shanghai Institute of TechnologyShanghai 201418China

As the latest research direction of train-to-train communication,virtual coupling train formation technology has attracted the attention of many *** paper studies the influence of time delay on the formation of virtual coupled *** proposed a distributed PID controller,which means that trains can still form a stable fleet operation under the influence of communication delay and control *** modelling and analysis,the research uses Matlab to conduct simulation,involving two sets of *** including speed,acceleration,position,position error,expected distance between adjacent trains and actual distance between adjacent trains are *** results demonstrate that the distributed PID controller can effectively control the impact of time delay on the virtual coupling fleet.

关键词： virtual coupling train-to-train communication time delay PID controller

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