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Influence of Anteroposterior Symmetrical Aero-Wings on the Aerodynamic Performance of High-Speed Train

Computer Modeling in Engineering & Sciences 2024年第4期139卷 937-953页

作者： peiheng he Jiye Zhang Lan Zhang Jiaqi Wang Yuzhe Ma State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu610031China

The running stability of high-speed train is largely constrained by the wheel-rail coupling relationship,and the continuous wear between the wheel and rail surfaces will profoundly affect the dynamic performance of the *** recent years,under the background of increasing train speed,some scientific researchers have proposed a new idea of using the lift force generated by the aerodynamic wings(aero-wing)installed on the roof to reduce the sprung load of the carriage in order to alleviate the wear and tear of the wheel and *** on the bidirectional running characteristics of high-speed train,this paper proposes a scheme to apply aero-wings with anteroposterior symmetrical cross-sections on the roof of the *** the verification of the wind tunnel experimental data,the relatively better airfoil section and extension formof anteroposterior symmetrical aero-wing is selected respectively in this paper,and the aero-wings are fixedly connected to the roof of the train through the mounting column to conduct aerodynamic simulation *** research shows that:compared with the circular-arc and oval crosssections,this paper believes that the crescent cross-section can form greater aerodynamic lift force in a limited *** factors such as aerodynamic parameters,ground effect,and manufacturing process,this paper proposes to adopt aero-wings with arc type extension form and connect them to the roof of the train through mounting columns with shuttle *** the roof of the train is covered with aero-wings and runs at high speed,the sprung load of the carriages can be effectively ***,there are certain hidden dangers in the tail carriage due to the large amount of lift force,so,the intervention of the aero-wing lifting mechanism is *** the same time,it is necessary to optimize the overall aerodynamic drag force reduction in the followup work.

关键词： Anteroposterior symmetrical aero-wing wheel-rail wear aerodynamic lift force ground effect numerical simulation

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轨道不平顺激励对高温超导磁浮列车电机悬挂的影响

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机车电传动 2024年第1期 101-108页

作者：郑杰何沛恒李强邓斌邓自刚西南交通大学先进驱动节能技术教育部工程研究中心四川成都610031 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

高温超导磁浮列车在运行过程中受到轨道随机不平顺激励的影响,车体和磁浮架的振动会传递至直线电机动子而导致气隙变化,变化后的电磁力反作用于电机悬挂系统,进而影响磁浮架和车体振动。二者的耦合振动一定程度上会影响高温超导磁浮列... 详细信息

高温超导磁浮列车在运行过程中受到轨道随机不平顺激励的影响,车体和磁浮架的振动会传递至直线电机动子而导致气隙变化,变化后的电磁力反作用于电机悬挂系统,进而影响磁浮架和车体振动。二者的耦合振动一定程度上会影响高温超导磁浮列车的安全运行。为了减少轨道随机不平顺激励对电机悬挂系统的影响,文章建立了多刚体动力学理论模型,并在周期性激励的作用下,对理论模型进行了动力学响应的仿真验证,证明了动力学理论模型的正确性。进一步地,在UM软件中以电机法向力和轨道随机不平顺作为外部激励,对高温超导磁浮列车动力学模型进行仿真,研究了电机悬挂系统的垂向刚度对直线电机气隙、车体和悬浮架振动、列车运行平稳性等参数的影响并对该刚度值进行了合理优化。结果表明:增大直线电机悬挂系统的垂向刚度能一定程度提高车体平稳性;同时增大垂向刚度能一定程度上减小气隙的变化和电机的振动,从而降低和悬浮架的耦合作用。研究结果是在特定的结构参数、负载条件下的仿真分析结果,可为高温超导磁浮列车动力学分析提供一定参考作用。

关键词：轨道随机不平顺法向力高温超导磁浮列车直线电机悬挂 UM

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高温超导磁浮车水平曲线通过适应性研究

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机车电传动 2024年第3期 90-98页

作者：李强何沛恒郑杰邓斌邓自刚西南交通大学先进驱动节能技术教育部工程研究中心四川成都610031 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

针对高温超导磁浮车刚性悬浮架曲线通过性差,文章提出了一种具有一定点头和摇头自由度的半解耦悬浮架结构,将高温超导的悬浮力和导向力简化为线性特性,建立了高温超导磁悬浮车辆的动力学理论模型,通过UM软件,在周期性激励的作用下,对理... 详细信息

针对高温超导磁浮车刚性悬浮架曲线通过性差,文章提出了一种具有一定点头和摇头自由度的半解耦悬浮架结构,将高温超导的悬浮力和导向力简化为线性特性,建立了高温超导磁悬浮车辆的动力学理论模型,通过UM软件,在周期性激励的作用下,对理论模型进行了动力力学响应的仿真验证,证明了动力学理论模型的合理性。文章进一步利用UM软件分析了高温超导磁浮车的水平曲线通过性能,对比了悬浮架不同垂向扭转刚度、横向扭转刚度、空气弹簧垂向刚度对杜瓦的横向位移、垂向位移的影响。仿真结果表明,释放一定点头自由度和摇头自由度的半解耦悬浮架,能够更好地适应曲线轨道的线路弯曲和线路扭曲,减少了构架对悬浮系统的不利影响,充分发挥了高温超导钉扎效应的特性,提高了车辆的曲线通过性能,同时合理的空气弹簧刚度能够很好地抑制杜瓦的振动,使车辆运行平稳。最后提出了满足车辆安全运行的悬浮架方案,高温超导磁悬浮车辆曲线通过性能有明显的提升。

关键词：高温超导磁悬浮悬浮架水平曲线 UM仿真

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国人髌骨嵴高点位置与截骨面形态关系的数字化研究

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中国修复重建外科杂志 2022年第7期36卷 853-859页

作者：李昌钊何沛恒刘勇徐栋梁中山大学附属第一医院关节外科广州510080

目的测量膝关节髌骨嵴高点位置和截骨面形态,分析两者关系、分布情况以及性别差异。方法选择2020年9月—2021年9月127例因外伤需行前交叉韧带重建或半月板修复患者作为研究对象。其中男71例,女56例;年龄19~43岁,平均30.5岁。男女患者... 详细信息

目的测量膝关节髌骨嵴高点位置和截骨面形态,分析两者关系、分布情况以及性别差异。方法选择2020年9月—2021年9月127例因外伤需行前交叉韧带重建或半月板修复患者作为研究对象。其中男71例,女56例;年龄19~43岁,平均30.5岁。男女患者身高及体质量差异有统计学意义(P0.05)。基于膝关节CT图像在Mimics软件中重建髌骨三维模型,然后导入Geomagic Studio软件中进行虚拟髌骨截骨,截骨面水平轴和垂直轴分别代表截骨面总宽度(W)和总高度(H),并以两轴将截骨面划分为内近、内远、外近和外远4个象限,进一步测量内侧宽度(W1)、近端高度(H1)、外侧宽度(W2)和远端高度(H2)。选择髌骨嵴中点作为其高点,其投射到截骨面上的点定义为髌骨假体最佳放置点(optimal point for patellar prosthesis positioning,OPPP)。测量OPPP在水平轴(L1)、垂直轴(L2)上相对于截骨面中心距离,并计算L1/W1、L2/H1;记录OPPP象限分布情况。将患者根据性别分组,对截骨面形态学参数(W、W1、W2、H、H1、H2)以及OPPP位置相关参数(L1、L2、L1/W1、L2/H1)进行组间比较。结果男性髌骨各截骨面宽度、高度均大于女性(P<0.05)。OPPP相对于截骨面中心位置情况:男女患者L1均在1~7 mm范围内,两组分布差异无统计学意义(χ^(2)=8.068,P=0.149);L1/W1均主要在1/10~3/10范围内。男性患者L2在0~5 mm范围内,女性患者在-1~4 mm范围内;两组分布差异有统计学意义(χ^(2)=15.500,P=0.006);男女患者L2/H1均主要在0~1/5范围内。男性患者OPPP主要分布于内近(98.59%)和外近(1.41%)象限,女性患者分布于内近(91.07%)、内远(7.14%)和外近(1.79%)象限;两组OPPP象限分布比较,差异有统计学意义(χ^(2)=5.186,P=0.036)。结论 OPPP分布广泛,但集中分布于截骨面偏内1/5和偏近1/10;女性OPPP分布总体比男性更偏向于远端,且存在一小部分女性分布于远端,而男性均分布于近端。

关键词：髌骨关节置换解剖学形态测量

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Honeycomb-like biochar framework coupled with Fe_(3)O_(4)/FeS nanoparticles as efficient heterogeneous Fenton catalyst for phenol degradation

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Journal of Environmental Sciences 2024年第2期136卷 390-399页

作者： Aihua Cheng Yi he Xiaohe Liu Chi he Department of Environmental Engineering College of Geology and EnvironmentXi’an University of Science and TechnologyXi’an 710054China State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an 710049China National Engineering Laboratory for VOCs Pollution Control Material and Technology University of Chinese Academy of SciencesBeijing 101408China

Achieving an efficient and stable heterogeneous Fenton reaction over a wide pH range is of great significance for wastewater ***,a pollen-derived biochar catalyst with a unique honeycomb-like structure,coupled with the dispersion of magnetic Fe_(3)O_(4)/FeS(Fe/S)nanoparticles,was synthesized by simple impregnation precursor,followed by *** prepared Fe/S-biochar catalyst demonstrated outstanding phenol degradation efficiency across a wide pH range,with 98%of which eliminated even under neutral conditions(pH 7.0).The high catalytic activity was due to the multilevel porous structure of pollenderived biochar provided enough active sites and allowed for better electron transfer,then increases oxidation ability to promote the ***,the acid microenvironment formed by SO_(4)^(2-)group from Fe/S composite extended the pH range for Fenton reaction,and S^(2-)facilitated the conversion of≡Fe^(3+)to≡Fe^(2+),resulting in remarkable degradation ***,biochar can effectively promote cycling stability by limiting Fe *** work may provide a general strategy for designing 3D framework biochar-based Fe/S catalysts with excellent performance for heterogeneous Fenton reactions.

关键词： Biomass Biochar Fenton reaction Fe_(3)O_(4)/FeS(Fe/S) Phenol degradation

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Emergent ultra-high temperature ferromagnetism in La_(2)CoO_(4±x) thin films

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Nano Research 2024年第8期17卷 7250-7255页

作者： Ziang Meng Han Yan Peixin Qin Zhuo Yin peiheng Jiang Xiaorong Zhou Xiaoning Wang Hongyu Chen Li Liu Zhiyuan Duan Guojian Zhao Weisheng Zhao Fengxia Hu Qinghua Zhang Zhicheng Zhong Zhiqi Liu School of Materials Science and Engineering Beihang UniversityBeijing 100191China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China CAS Key Laboratory of Magnetic Materials and Devices and Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China Fert Beijing Institute School of Integrated Circuit Science and EngineeringBeihang UniversityBeijing 100191China

Searching for novel ferromagnetic oxides with high Curie temperature(TC)has been one of the main goals for oxide *** well-known perovskite cobaltate LaCoO_(3)is a classical ferromagnet in its thin-film form;however,it suffers from a low TC(~85 K).here we report a new type of ferromagnetic La-Co-O films with an ultrahigh TC of~820 *** are fabricated by pulsed laser deposition from a LaCoO_(3)target at low oxygen partial *** structural analysis indicates that they crystallize in terms of the Ruddlesden–Popper phase of La_(2)CoO_(4±x).In sharp contrast to the antiferromagnetism of bulk La_(2)CoO_(4),the strong ferromagnetism in the La_(2)CoO_(4±x) thin films is firmly demonstrated by magnetometry measurements,X-ray magnetic circular dichroism characterization,and magnetotransport *** importantly,density functional theory calculations indicate that the nonstoichiometric oxygen induces an antiferromagnetic-to-ferromagnetic phase transition,accompanied by the orbital reconstruction of Co 3d ***,our study provides an attractive strategy for designing or synthesizing exotic magnetic oxides with high ordering temperatures.

关键词： ferromagnetic oxides ultra-high Curie temperature La_(2)CoO_(4) spin current transport oxygen engineering

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Distributed Optimal Variational GNE Seeking in Merely Monotone Games

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IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1621-1630页

作者： Wangli he Yanzhen Wang IEEE the Key Laboratory of Smart Manufacturing in Energy Chemical Process Ministry of EducationEast China University of Science and TechnologyShanghai 200237China

In this paper, the optimal variational generalized Nash equilibrium(v-GNE) seeking problem in merely monotone games with linearly coupled cost functions is investigated, in which the feasible strategy domain of each agent is coupled through an affine constraint. A distributed algorithm based on the hybrid steepest descent method is first proposed to seek the optimal v-GNE. Then, an accelerated algorithm with relaxation is proposed and analyzed, which has the potential to further improve the convergence speed to the optimal v-GNE. Some sufficient conditions in both algorithms are obtained to ensure the global convergence towards the optimal v-GNE. To illustrate the performance of the algorithms, numerical simulation is conducted based on a networked Nash-Cournot game with bounded market capacities.

关键词： Distributed algorithms equilibria selection generalized Nash equilibrium(GNE) merely monotone games

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Distributed Nash Equilibrium Seeking on Compact Action Sets over Jointly Strongly Connected Switching Networks

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Journal of Systems Science & Complexity 2024年第1期37卷 63-81页

作者： he Xiongnan HUANG Jie Department of Mechanical and Automation Engineering The Chinese University of Hong KongHong Kong 999077China.

This paper studies the distributed Nash equilibrium seeking(DNES)problem for games whose action sets are compact and whose network graph is switching satisfying the jointly strongly connected *** keep the actions of all players in their action sets all the time,one has to resort to the projected gradient-based *** the assumption that the unique Nash equilibrium is the unique equilibrium of the pseudogradient system,an algorithm is proposed that is able to exponentially find the Nash ***,the authors also consider the distributed Nash equilibrium seeking problem for games whose actions are governed by high-order integrator dynamics and belong to some compact *** examples are used to illustrate the proposed approach.

关键词： Compact action sets jointly strongly connected switching graphs Nash equilibrium seeking projected gradient-based algorithm.

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High-Order Two-Scale Asymptotic Paradigm for the Elastodynamic Homogenization of Periodic Composites

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Acta Mechanica Solida Sinica 2024年第1期37卷 124-138页

作者： Wei-Zhi Luo Mu he Liang Xia Qi-Chang he State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China Laboratoire Modélisation et Simulation Multi-Echelle MSME UMR 8208 CNRSUniversite Gustave Eiffel77454 Marne-la-ValléeFrance

The classical two-scale asymptotic paradigm provides macroscopic and microscopic analyses for the elastodynamic homogenization of periodic composites based on the spatial or/and temporal variable,which offers an approximate framework for the asymptotic homogenization analysis of the motion ***,in this framework,the growing complexity of the homogenization formulation gradually becomes an obstacle as the asymptotic order *** such a context,a compact,fast,and accurate asymptotic paradigm is *** work reviews the high-order spatial two-scale asymptotic paradigm with the effective displacement field representation and optimizes the implementation by symmetrizing the tensor to be ***,the modified implementation gets rid of the excessive memory consumption required for computing the high-order tensor,which is demonstrated by representative one-and two-dimensional *** numerical results show that(1)the contrast of the material parameters between media in composites directly affects the convergence rate of the asymptotic results for the homogenization of periodic composites,(2)the convergence error of the asymptotic results mainly comes from the truncation error of the modified asymptotic homogenized motion equation,and(3)the excessive norm of the normalized wavenumber vector in the two-dimensional inclusion case may lead to a non-convergence of the asymptotic results.

关键词： Composites Homogenization Asymptotic analysis Dynamics Dispersion

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Coupled Numerical Simulation of Electromagnetic and Flow Fields in a Magnetohydrodynamic Induction Pump

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Fluid Dynamics & Materials Processing 2024年第4期20卷 889-899页

作者： he Wang Ying he College of Transportation Ludong UniversityYantai264025China College of Intelligent Manufacturing City College of HuizhouHuizhou516025China

Magnetohydrodynamic(MHD)induction pumps are contactless pumps able to withstand harsh *** rate of fluid flow through the pump directly affects the efficiency and stability of the *** explore the influence of induction pump settings on the related delivery speed,in this study,a numerical model for coupled electromagnetic and flow field effects is introduced and used to simulate liquid metal lithium flow in the induction *** effects of current intensity,frequency,coil turns and coil winding size on the velocity of the working fluid are *** is shown that the first three parameters have a significant impact,while changes in the coil turns have a negligible *** maximum increase in working fluid velocity within the pump for the parameter combination investigated in this paper is approximately 618%.As the frequency is increased from 20 to 60 Hz,the maximum increase in the mean flow rate of the working fluid is approximately 241%.These research findings are intended to support the design and optimization of these devices.

关键词： Magnetic fluid multi-physical field coupling induction pump numerical simulation liquid metal conveying

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