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Study on the subgrade deformation under high-speed train loading and water–soil interaction

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Acta Mechanica Sinica 2016年第2期32卷 233-243页

作者： Jian Han Guo-Tang Zhao Xiao-Zhen Sheng xue-song jin State Key Laboratory of Traction Power Southwest Jiaotong University Chengdu 610031 China China Railway Corporation Beijing 100844 China

It is important to study the subgrade characteristics of high-speed railways in consideration of the water–soil coupling dynamic problem,especially when high-speed trains operate in rainy *** study develops a nonlinear water–soil interaction dynamic model of slab track coupling with subgrade under high-speed train loading based on vehicle–track coupling *** using this model,the basic dynamic characteristics,including water–soil interaction and without water induced by the high-speed train loading,are *** main factors-the permeability coefficien and the porosity-influencin the subgrade deformation are *** developed model can characterize the soil dynamic behaviour more realistically,especially when considering the influenc of water-rich soil.

关键词： Water–soil interaction High-speed train loading Finite difference method Subgrade deformation Permeability coefficien Porosity

Formation process,key influencing factors,and countermeasures of high-order polygonal wear of locomotive wheels

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2021年第1期22卷 70-84页

作者： Gong-quan TAO Xiao-long LIU Ze-feng WEN xue-song jin State Key Laboratory of Traction Power Southwest Jiaotong UniversityChengdu 610031China

Two types of high power alternating current(AC) locomotive in China are prone to serious high-order polygonal wear, which has significant negative effects on the operation of locomotives. This study investigates factors influencing polygonal wear in locomotive wheels and determines methods of minimizing operation damage. We designed experiments to analyze the process of polygonization formation of wheels to identify the key influencing factors, finding that natural vibration of wheelsets is the central inherent factor of wheel polygonization and that these vibrations can be easily stimulated by wheel or rail irregularities. We found that poor re-profiling quality is the key external factor in these irregularities. The wheelset bending resonance is activated when the remaining wheel polygonal wear has a wavelength of 200 mm in the 1/3 octave band, in turn leading to significant increases of wheel polygonal wear. In this study, we review a new wheelset design that can mitigate and/or eliminate the polygonal wheel wear due to increased stiffness in wheel bending. We evaluate the potential capacity of the newly designed wheelset and propose two proven effective measures to further improve the wheel re-profiling quality for polygonal wear.

关键词： Locomotive Polygonal wear Wheelset dynamic analysis Wheel re-profiling

Experimental analysis of the mechanism of high-order polygonal wear of wheels of a high-speed train

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2017年第8期18卷 579-592页

作者： Yue WU Xing DU He-ji ZHANG Ze-feng WEN xue-song jin State Key Laboratory of Traction Power Southwest Jiaotong University Chengdu 610031 China

This paper presents a detailed investigation, via field experiment, into the mechanism of high-order polygonal wear of wheels of a new type of high-speed train. The investigation was carried out during the performance acceptance test of the train and its initial commercial operation. The investigation covered the performance acceptance test of 150 000 km and the commercial operation of about 150 000 km. In the performance acceptance test of the first stage of about 70 000 km, at 200-250 km/h with full loading and sometimes overloading by 30%, the serious polygonal wear of 23-order took place on all the wheels of the train, and was measured and analyzed in detail. All the potygonized wheels were re-profiled because the polygonal wear had caused strong vibration and damage to the train parts. After re-profiling, the vibration of the train and track and the wear status of the wheels were measured and analyzed at different test mileages according to the polygonal wear situation of the wheels. The measured vibration of the train includes the accelerations at different positions of a motor car and a trail car. The vibration modes of the key parts of the bogies of the two cars were calculated. Meanwhile, the track resonant frequencies were investigated at the site. The purpose of the above tests and analysis is try to find the frequency of work mode matching the passing frequency of the high-order wheel polygon. The present investigation shows that one of the working models causes the formation and development of the high-order wheel polygonal wear. The growth of this wear was effectively reduced through the frequent changing of the running speed of the train operating on the way back and forth every day.

关键词： High-speed train Wheel High-order polygonal wear Field test Model analysis System resonance frequency

高速铁路运营过程中的关键问题:轮轨磨耗等(英文)

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2014年第12期15卷 936-945页

作者： xue-song jin State Key Laboratory of Traction Power Southwest Jiaotong University

随着高速铁路运营里程和列车运营速度的不断增长,出现了一些和列车轨道耦合大系统密切相关的关键科学和技术问题。这些问题不仅影响到列车的运行品质,甚至威胁到安全运行,是当前高速铁路运用和发展中急需解决的问题。本文系统描述了高... 详细信息

随着高速铁路运营里程和列车运营速度的不断增长,出现了一些和列车轨道耦合大系统密切相关的关键科学和技术问题。这些问题不仅影响到列车的运行品质,甚至威胁到安全运行,是当前高速铁路运用和发展中急需解决的问题。本文系统描述了高速铁路在运营过程中所出现的一些关键科学和技术问题,并述评了全世界有关这些问题的研究进展、现状和不足之处,提出了今后有利于认识和解决这些问题的发展方向。在长期高速运营的铁路大系统环境中,这些问题的形成的机理、发生、发展过程和预防措施的研究,需要从列车/轨道耦合大系统运营环境(速度、路况、气候和运用维修)、系统的自身参数匹配、材料选用和运营成本等全面系统考虑,并从理论、技术、工艺、监控和维修等方面解决。

关键词：高速铁路高速列车轮轨磨耗列车/轨道耦合动力学轮轨滚动接触理论减振降噪理论和技术

Clinical features of adverse reactions associated with telbivudine

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World Journal of Gastroenterology 2008年第22期14卷 3549-3553页

作者： xue-song Zhang Rui jin Shi-Bin Zhang Ming-Ling Tao Department of GI and Hepatology Beijing Youan Hospital affiliated to Capital Medical University Beijing 100069 China

AIM: To analyze the clinical features and risk factors of adverse reactions associated with telbivudine. METHODS: Clinical data were collected from cases that presented with serious adverse reactions to telbivudine. We analyzed general information and medicine status, clinical features, results of examination, and misdiagnosis. RESULTS: Out of 105 patients who were treated with telbivudine for hepatitis B in an outpatient department from January, 2007 to January, 2008, five presented with serious adverse drug reactions. Most of these five patients had used other nucleoside analogues in the past. Four were treated with a combination of telbivudine and interferon or another nucleoside analogue, while the other received an increased dose of telbivudine. The main adverse reactions were myalgia and general weakness. This was accompanied by cardiac arrhythmia in one patient, and nervous symptoms in three. Serum creatine kinase was elevated. The rate of misdiagnosis was high. CONCLUSION: The adverse reactions were related to telbivudine, but the biological mechanism of the reactions is not yet clear. Combination therapy with interferon or another nucleoside analogue and a high dose may increase the risk of adverse reactions.

关键词： Adverse drug reaction Hepatitis B Mitochondria Nucleoside analogue Telbivudine

Characteristics of interior noise of a Chinese high-speed train under a variety of conditions

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2017年第8期18卷 617-630页

作者： Jie ZHANG Xin-biao XIAO Xiao-zhen SHENG Rong FU Dan YAO xue-song jin State Key Laboratory of Traction Power Southwest Jiaotong University Chengdu 610031 China

This paper presents an investigation into the characteristics of interior noise of a Chinese high-speed train under several typical conditions. Interior noises within Vehicle TC01, which can be used as a head car or an end car, and Vehicle TP03, the third car counting from TC01, are measured for the train running at speeds from 260 km/h to 385 km/h, along two types of track including a slab track and a ballast track and either on the ground surface or in a tunnel. Data analyses are performed for sound pressure overall levels, frequency, area contributions, and possible generation mechanisms, showing how they are affected by train speed, running direction, track type, and tunnel. The results show that, whether TC01 is used as head car or end car, the interior noise characteristics in the VIP cabin are mostly related to aerodynamic noise. Differences in interior noise between tracks become smaller as the train speed increases. The effect of a tunnel on the interior noise is more important for the middle coach than that for the head coach. This study can provide a basis for noise control of high-speed trains.

关键词： High-speed train Interior noise Noise source identification Contribution analysis Various conditions Noise characterization

Time-domain model for wheel-rail noise analysis at high operation speed

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2017年第8期18卷 593-602页

作者： Jian HAN Shuo-qiao ZHONG Xin ZHOU Xin-biao XIAO Guo-tang ZHAO xue-song jin State Key Laboratory of Traction Power Southwest Jiaotong University Chengdu 610031 China China Railway Corporation Beijing 100844 China

This paper develops a numerical model for wheel-rail noise analysis in the time-domain. This model for wheel-rail noise is based on vehicle-track coupling dynamics considering the effect of flexible wheelsets and track, and a transient wheel-rail noise prediction method. This model can approximatively characterize the components of vibration and noise in the frequency range up to 3.5 kHz. The wheel-rail forces are calculated and shown in both time and frequency domains by using the vehicle- track coupling dynamic model. Then the vibration and sound of the flexible wheelset are calculated by the transient finite element- boundary element （FE-BE） prediction model at 300 kin/h, in which the effects of random irregularity and discrete supporting excitation are considered. The numerical results calculated by using the present model are discussed. The present model is also used to calculate the effect of corrugation with wavelengths of 40 mm to 300 mm on wheel-rail noise. The numerical results can be useful for academic research and engineering application to railway noise and vibration.

关键词： Vibration and sound Wheel-rail Vehicle-track coupling dynamics Rigid wheelset Flexible wheelset High-speed operation

Development and validation of a model for predicting wheel wear in high-speed trains

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2017年第8期18卷 603-616页

作者： Gong-quan TAO Xing DU He-ji ZHANG Ze-feng WEN xue-song jin Da-bin CUI State Key Laboratory of Traction Power Southwest Jiaotong University Chengdu 610031 China Department of Mechanical Engineering Emei Campus of Southwest Jiaotong University Emei 614202 China

In this paper, we present a comprehensive model for the prediction of the evolution of high-speed train wheel profiles due to wear. The model consists of four modules： a multi-body model implemented with the commercial multi-body software SIMPACK to evaluate the dynamic response of the vehicle and track; a local contact model based on Hertzian theory and a novel method, named FaStrip （Sichani et al., 2016）, to calculate the normal and tangential forces, respectively; a wear model proposed by the University of Sheffield （known as the USFD wear function） to estimate the amount of material removed and its distribution along the wheel profile; and a smoothing and updating strategy. A simulation of the wheel wear of the high-speed train CRH3 in service on the Wuhan-Guangzhou railway line was performed. A virtual railway line based on the statistics of the line was used to represent the entire real track. The model was validated using the wheel wear data of the CRH3 operating on the Wuhan- Guangzhou line, monitored by the authors＇ research group. The results of the predictions and measurements were in good agreement.

关键词： High-speed train Wheel profile Wheel/Rail contact Wheel wear prediction

Enhancing the Circularly Polarized Luminescence of Self-assembled Cyanostilbenes through Extended π-Conjugation

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Chinese Journal of Chemistry 2024年第2期42卷 135-141页

作者： Tongjin Lv song Wu Yu jin Jianfei Ma Sixun Jiang Yuncong xue Feng Wang Key Laboratory of Precision and Intelligent Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefeiAnhui 230026China Department of Thoracic Surgery Shanghai Jiao Tong University Affiliated Sixth People's HospitalShanghai 200233China

Chiral supramolecular assembly of π-conjugated luminophores provides a promising avenue for enhancing circularly polarized *** this study,we shed light on the impact of π-conjugation length on circularly polarized luminescent performance of the resulting supramolecular assemblies,by designing a tetra-cyanostilbene monomeric compound alongside two dicyanostilbene control *** cyanostilbene-based compounds possess the ability to form chiral supramolecular polymers in toluene,driven by a synergistic combination of intermolecular hydrogen bonding and π-stacking *** extended π π-aromatic skeleton brings bathochromic-shifted fluorescence and enhanced intermolecular stacking capability for the tetra-cyanostilbene ***,chiral supramolecular assemblies formed by the tetra-cyanostilbene compound demonstrate a remarkable two-fold increase in g_(lum) values relative to the assemblies formed by the dicyanostilbene ***,this study provides valuable insights into the relationship between-conjugation length and the circularly polarized luminescent performance of π-conjugatedsupramolecularassemblies.

关键词： Self-assembly Supramolecular polymer Supramolecular chirality Circularly polarized luminescence Cyanostilbene πInteractions Aggregation Nanostructures