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考虑风速纵、横分量的列车气动载荷变化特性

西南交通大学学报 2024年第1期59卷 39-45页

作者：于梦阁李美香刘加利戴志远青岛大学机电工程学院山东青岛266071 中车青岛四方机车车辆股份有限公司山东青岛266111 西南交通大学轨道交通运载系统全国重点实验室四川成都610031

为探索侧向环境风作用下列车气动载荷变化特性,对任意风向角下随车移动点处的风速纵、横分量进行建模,研究考虑风速纵、横分量的列车气动载荷计算方法,并分析在列车速度200~400 km/h、平均风速10~35 m/s及风向角30°~150°时的列车气动... 详细信息

为探索侧向环境风作用下列车气动载荷变化特性,对任意风向角下随车移动点处的风速纵、横分量进行建模,研究考虑风速纵、横分量的列车气动载荷计算方法,并分析在列车速度200~400 km/h、平均风速10~35 m/s及风向角30°~150°时的列车气动载荷特性.研究发现:在不同风向角下,考虑风速横向分量后,高速列车气动载荷波动变大,作用于列车上的瞬时气动载荷极值增大;风速横向分量主要影响列车气动载荷的标准差,且影响程度与风向角有关;随着风向角接近临界风向角,风速横向分量对列车气动载荷标准差的影响逐渐变小,随着风向角远离临界风向角,风速横向分量对列车气动载荷标准差的影响逐渐变大;列车气动载荷的标准差/均值主要与侧偏角有关,且在风向角为30°及150°时较大,其次是风向角60°和120°,而在风向角90°时则较小.

关键词：高速列车随机风速非定常气动载荷风向角标准差

考虑四极子声源的高速磁浮列车气动噪声数值模拟方法

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西南交通大学学报 2024年第1期59卷 54-61页

作者：刘加利于梦阁陈大伟杨志刚中车青岛四方机车车辆股份有限公司山东青岛266111 青岛大学机电工程学院山东青岛266071 中南大学交通运输工程学院轨道交通安全教育部重点室湖南长沙410075

随着列车速度的提高,四极子声源对列车气动噪声的贡献增大,高速磁浮列车的运行速度达到600 km/h时,有必要考虑四极子声源对高速磁浮列车气动噪声的影响.为此,本文建立考虑四极子声源的高速磁浮列车气动噪声数值模拟方法,对高速磁浮列车... 详细信息

随着列车速度的提高,四极子声源对列车气动噪声的贡献增大,高速磁浮列车的运行速度达到600 km/h时,有必要考虑四极子声源对高速磁浮列车气动噪声的影响.为此,本文建立考虑四极子声源的高速磁浮列车气动噪声数值模拟方法,对高速磁浮列车流线型尾部、头部区域的积分面进行局部外推,探索流线型尾部、头部区域的四极子声源对高速磁浮列车气动噪声的影响.研究发现:高速磁浮列车的尾涡会穿过下游的积分面,流线型尾部区域不能采用全封闭积分面,否则会产生非常大的伪声;流线型尾部区域的积分面需要较多地向尾涡区延伸,并去除尾涡穿过的区域;高速磁浮列车流线型头部区域四极子声源的贡献很小,流线型头部区域的积分面可以取为流线型头型表面;在600 km/h下,高速磁浮列车四极子声源引起的气动噪声能量占比达到42%.

关键词：高速磁浮列车气动噪声四极子声源尾涡

基于吉林一号光谱星的东北地区春季水体识别方法对比研究

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测绘与空间地理信息 2024年第S1期47卷 199-201,205页

作者：于梦鸽高俣晗孙阳黑龙江地理信息工程院黑龙江哈尔滨150025 黑龙江省自然资源权益调查监测院黑龙江哈尔滨150080

以吉林省敦化市为研究,基于吉林一号5 m分辨率遥感影像选取单波段阈值法、多波段谱间关系法、NDWI水体指数、SWI水体指数、监督分类法和非监督分类法共6种常见的水体识别方法对东北地区春季冰雪交融期最适宜的水体识别方法进行探究。通... 详细信息

以吉林省敦化市为研究,基于吉林一号5 m分辨率遥感影像选取单波段阈值法、多波段谱间关系法、NDWI水体指数、SWI水体指数、监督分类法和非监督分类法共6种常见的水体识别方法对东北地区春季冰雪交融期最适宜的水体识别方法进行探究。通过Kappa系数、错分误差、漏分误差、面积精度等5种指标对水体识别效果进行对比分析,结果表明:最适宜的提取方法为监督分类法,提取精度较高的方法还有NDWI指数法、多波段谱间关系法。

关键词：水体提取遥感识别水体指数

Device design principles and bioelectronic applications for flexible organic electrochemical transistors

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International Journal of Extreme Manufacturing 2024年第1期6卷 126-153页

作者： Lin Gao mengge Wu Xinge yu Junsheng yu State Key Laboratory of Electronic Thin Films and Integrated Devices School of Optoelectronic Science and EngineeringUniversity of Electronic Science and Technology of China(UESTC)Chengdu 610054People’s Republic of China Department of Biomedical Engineering City University of Hong KongHong Kong Special Administrative Region of ChinaPeople’s Republic of China

Organic electrochemical transistors(OECTs) exhibit significant potential for applications in healthcare and human-machine interfaces, due to their tunable synthesis, facile deposition, and excellent biocompatibility. Expanding OECTs to the fexible devices will significantly facilitate stable contact with the skin and enable more possible bioelectronic applications. In this work,we summarize the device physics of fexible OECTs, aiming to offer a foundational understanding and guidelines for material selection and device architecture. Particular attention is paid to the advanced manufacturing approaches, including photolithography and printing techniques, which establish a robust foundation for the commercialization and large-scale fabrication. And abundantly demonstrated examples ranging from biosensors, artificial synapses/neurons, to bioinspired nervous systems are summarized to highlight the considerable prospects of smart healthcare. In the end, the challenges and opportunities are proposed for fexible OECTs. The purpose of this review is not only to elaborate on the basic design principles of fexible OECTs, but also to act as a roadmap for further exploration of wearable OECTs in advanced bio-applications.

关键词： flexible organic electrochemical transistors wearable bioelectronics manufacturing approaches device physics neuromorphic applications

Strategies that regulate LSD1 for novel therapeutics

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Acta Pharmaceutica Sinica B 2024年第4期14卷 1494-1507页

作者： Meng Li mengge Dai Bing Cheng Shaotong Li Enhui Guo Junwei Fu Ting Ma Bin yu School of Pharmaceutical Sciences&Key Laboratory of Advanced Drug Preparation Technologies Ministry of EducationZhengzhou UniversityZhengzhou 450001China College of Chemistry Zhengzhou UniversityZhengzhou 450001China Tianjian Laboratory of Advanced Biomedical Sciences Institute of Advanced Biomedical SciencesZhengzhou UniversityZhengzhou 450000China Pingyuan Laboratory State Key Laboratory of Antiviral DrugsHenan Normal UniversityXinxiang 453007China State Key Laboratory of Pharmaceutical Biotechnology Nanjing UniversityNanjing 210023China

Histone methylation plays crucial roles in regulating chromatin structure and gene transcrip-tion in epigenetic ***-specific demethylase 1(LSD1),the first identified histone de-methylase,is universally overexpressed in various ***1 dysregulation is closely associated with cancer,viral infections,and neurodegenerative diseases,etc.,making it a promising therapeutic *** LSD1 inhibitors and two small-molecule degraders(UM171 and BEA-17)have entered the clinical ***1 can remove methyl groups from histone 3 at lysine 4 or lysine 9(H3K4 or H3K9),resulting in either transcription repression or *** the roles of LSD1 in transcrip-tional regulation are well-established,studies have revealed that LSDl can also be dynamically regulated by other *** example,the expression or activity of LSD1 can be regulated by many proteins that form transcriptional corepressor complexes with ***,some post-transcriptional modifica-tions and cellular metabolites can also regulate LSD1 expression or its demethylase ***,in this review,we will systematically summarize how proteins involved in the transcriptional corepressor complex,various post-translational modifications,and metabolites act as regulatory factors for LSD1 ac-tivity.

关键词： LSD1 regulation Transcription repression Transcription activation the Corepressor complex Post-transcriptional modifications Metabolites

Operational Safety Assessment of a High-Speed Train Exposed to the Strong Gust Wind

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Fluid Dynamics & Materials Processing 2020年第1期16卷 55-66页

作者： mengge yu Zhenkuan Pan Jiali Liu Haiqing Li Postdoctoral Research Station of System Science College of Automation and Electrical EngineeringQingdao UniversityQingdao266071China College of Mechanical and Electronic Engineering Qingdao UniversityQingdao266071China College of Computer Science&Technology Qingdao UniversityQingdao266071China CRRC Qingdao Sifang Co. Ltd.Qingdao266111China

The operational safety characteristics of trains exposed to a strong wind have caused great concern in recent *** the present paper,the effect of the strong gust wind on a high-speed train is investigated.A typical gust wind model for any wind angle,named“Chinese hat gust wind model”,was first constructed,and an algorithm for computing the aerodynamic loads was elaborated accordingly.A vehicle system dynamic model was then set up in order to investigate the vehicle system dynamic *** assessment of the operational safety has been conducted by means of characteristic wind curves(CWC).As some of the parameters of the wind-train system were difficult to measure,we also investigated the impact of the uncertain system parameters on the *** indicate that,the descending order of the operational safety index of the vehicle for each wind angle is 90°-60°-120°-30°-150°,and the worst condition for the operational safety occurs when the wind angle reaches around 90°.According to our findings,the gust factor and aerodynamic side force coefficient have great impact on the critical wind ***,these two parameters require special attention when considering the operational safety of a railway vehicle subjected to strong gust wind.

关键词： Operational safety high-speed train gust wind aerodynamic loads characteristic wind curves

A Numerical Study of the Aerodynamic Characteristics of a High-Speed Train under the Effect of Crosswind and Rain

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Fluid Dynamics & Materials Processing 2020年第1期16卷 77-90页

作者： Haiqing Li mengge yu Qian Zhang Heng Wen College of Mechanical and Electronic Engineering Qingdao UniversityQingdao266071China

The performances of high-speed trains in the presence of coupling effects with crosswind and rain have attracted great attention in recent *** objective of the present paper was to investigate the aerodynamic characteristics of a high-speed train under such conditions in the framework of an Eulerian-Lagrangian *** aerodynamic model of a high-speed train was first set up,and the side force coefficient obtained from numerical simulation was compared with that provided by wind tunnel experiments to verify the accuracy of the ***,the effects of the yaw angle,the resultant wind speed,and the rainfall rate on aerodynamic coefficients were *** results indicate that the aerodynamic coefficients grow almost linearly with the rainfall rate,and increase with a decrease in the resultant wind *** to the impact of raindrops on the train surface and the airflow,the pressure coefficients of windward and leeward side of the train become larger with the increase of the rainfall *** can accelerate the airflow and suppress the vortices ***,the flow velocity in regions surrounding the train increases with an increase in the rainfall rate.

关键词： High-speed trains Eulerian-Lagrangian crosswinds and rains aerodynamic coefficients pressure coefficients velocity distribution

A Study on the Reduction of the Aerodynamic Drag and Noise Generated By the Roof Air Conditioner of High-Speed Trains

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Fluid Dynamics & Materials Processing 2020年第1期16卷 21-30页

作者： Jiali Liu mengge yu Dawei Chen Zhigang Yang CRRC Qingdao Sifang Co. Ltd.Qingdao266111China College of Mechanical and Electronic Engineering Qingdao UniversityQingdao266071China School of Traffic&Transportation Engineering Central South UniversityChangsha410075China

In order to investigate how the aerodynamic drag and noise produced by the roof air conditioner of a high-speed train can be reduced,the related unsteady flow in the near-field was computed using the method of large eddy *** this way,the aerodynamic source for noise generation has initially been ***,the far-field aerodynamic noise has been computed in the framework of the Lighthill’s acoustics analogy *** propulsion height and flow-guide angle of the roof air conditioner were set as the design *** to the computational results,a lower propulsion height or flow-guide angle is beneficial in terms of aerodynamic drag and noise ***,compared to the design scheme with propulsion height of 0mm,the aerodynamic drag coefficient of the configuration with propulsion height of 190mm and flow-guide angle of 30°is slightly larger,while the aerodynamic noise is obviously ***,from the viewpoint of the aerodynamic drag and noise,the design scheme with propulsion height of 190 mm and flow-guide angle of 30°is the optimal configuration in the range of conditions examined in the present work.

关键词： Aerodynamic drag aerodynamic noise roof air conditioner large eddy simulation acoustics analogy theory

Simulation of unsteady aerodynamic loads on high-speed trains in fluctuating crosswinds

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Journal of Modern Transportation 2013年第2期21卷 73-78页

作者： mengge yu Jiye Zhang Weihua Zhang Traction Power State Key Laboratory Southwest Jiaotong University

To study the unsteady aerodynamic loads of high-speed trains in fluctuating crosswinds, the fluctuating winds of a moving point shifting with high-speed trains are calculated in this paper based on Cooper theory and harmonic superposition method. The computational fluid dynamics method is used to obtain the aerodynamic load coefficients at different mean yaw angles, and the aero- dynamic admittance function is introduced to calculate unsteady aerodynamic loads of high-speed trains in fluctuating winds. Using this method, the standard deviation and maximum value of the aerodynamic force （moment） are simulated. The results show that when the train speed is fixed, the varying mean wind speeds have large impact on the fluctuating value of the wind speeds and aerodynamic loads; in contrast, when the wind speed is fixed, the varying train speeds have little impact on the fluctuating value of the wind speeds or aerodynamic loads. The ratio of standard deviation to ***2, or maximum value to 0.5pKU2, can be expressed as the function of mean yaw angle. The peak factors of the side force and roll moment are the same （ - 3.28）, the peak factor of the lift force is - 3.33, and the peak factors of the yaw moment and pitch moment are also the same （- 3.77）.

关键词： Fluctuating winds - Unsteady aerodynamicloads Yaw angle Peak factor