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Interfacial characteristics and mechanical properties of additive manufacturing martensite stainless steel on the Cu-Cr alloy substrate by directed energy deposition

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Journal of Materials Science & Technology 2021年第31期90卷 121-132页

作者： Wenqi Zhang Hailong Liao Zhiheng Hu Shasha Zhang baijin chen Huanqing Yang Yun Wang Haihong Zhu Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074China State Key Laboratory of Material Processing and Die&Mould Technology School of Material Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China XI’AN Space Engine Company Limited Xi’an710100China

Copper/steel is a typical bimetal functional material,combining the excellent electrical and thermal conductivity of copper alloy and the high strength and hardness of stainless *** has been recent interest in manufacturing copper/steel bimetal by directed energy deposition(DED)due to its layer-bylayer ***,cracks tend to form on the copper/steel interface because of the great difference in thermal expansion coefficient and crystal structure between copper and *** this work,interfacial characteristics and mechanical properties of the copper/steel bimetal were studied from one layer to *** laser power has a great influence on the Cu element distribution of the molten pool,affecting the crack formation dramatically on the solidification *** tend to form along columnar grain boundaries because of the Cu-rich liquid films and spherical particles in the ***-free and good metallurgical bonding copper/steel interface is formed at a scanning velocity of 800 mm/min and the laser power of 3000 *** ultimate tensile strength(UTS)and the break elongation(EL)of the vertically combined crack-free copper/steel bimetal are 238.2±4.4 MPa and 20.6±0.7%,*** fracture occurs on the copper side instead of the copper/steel interface,indicating that the bonding strength is higher than that of the Cu-Cr *** UTS of the horizontally combined crack-free copper/steel bimetal is 746.7±22.6 MPa,which is 200%higher than that of the Cu-Cr alloy *** microhardness is 398.6±5.4 HV at the steel side and is 235.3±64.1 HV at the interface,which is400%higher than that of the Cu-Cr alloy *** paper advances the understanding of the interfacial characteristics of heterogeneous materials and provides guidance and reference for the fabrication of multi-material components by DED.

关键词： Directed energy deposition Additive manufacturing Bimetal Interfacial characteristics Crack

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快速锻造液压机技术现状及发展趋势

锻压技术 2023年第11期48卷 1-6页

作者：陈柏金刘廷君华中科技大学材料科学与工程学院湖北武汉430074

简要介绍了目前快速锻造液压机的技术现状,对其主机结构、液压传动系统、控制系统等方面的技术特点进行了分析:主机结构形式多样化,以预应力结构为主,均采用可调平面导向,立柱与横梁采用平接式或插入式结构,主缸多采用双球铰法兰连接等... 详细信息

简要介绍了目前快速锻造液压机的技术现状,对其主机结构、液压传动系统、控制系统等方面的技术特点进行了分析:主机结构形式多样化,以预应力结构为主,均采用可调平面导向,立柱与横梁采用平接式或插入式结构,主缸多采用双球铰法兰连接等;液压系统传动形式模式化,形成了以高频响比例阀和伺服锻造阀组成的阀控系统,以及正弦泵组成的泵控系统3种典型液压传动形式;控制系统标准化,均采用西门子控制器及工业以太网组成的现场网络控制系统。此外,从绿色设计、能量回收利用、预测性维护、自动锻造以及应用新技术等方面对快速锻造液压机的发展趋势进行了阐述。

关键词：锻造液压机主机结构液压传动控制系统机电液一体化

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泵控锻造液压机液压系统设计与仿真

锻压技术 2022年第6期47卷 160-168页

作者：伍乘星鲁苗张朝壮陈柏金南昌大学先进制造学院江西南昌330000 华中科技大学材料成形与模具技术国家重点实验室湖北武汉430074

针对传统的22 MN泵控锻造液压机组控制系统复杂、运行过程稳定性较差、响应速度较慢等技术现状,对泵控锻造液压机组的组成结构、传动方式及其组件的运动特性进行了研究。利用AMESim软件建立了正弦泵偏心摆变量机构模型,仿真分析了偏心... 详细信息

针对传统的22 MN泵控锻造液压机组控制系统复杂、运行过程稳定性较差、响应速度较慢等技术现状,对泵控锻造液压机组的组成结构、传动方式及其组件的运动特性进行了研究。利用AMESim软件建立了正弦泵偏心摆变量机构模型,仿真分析了偏心摆变量机构的控制性能和动态响应特性;建立了锻造液压机液压伺服控制系统模型,仿真分析了液压机在空载、镦粗、常锻和快锻4种不同运行工况下的动态特性。仿真结果表明:偏心摆变量机构设计合理,控制性能较高,能够满足小位移高频快速换向和较大驱动力的实际生产需求;液压机液压伺服控制系统的控制精度高、运行平稳、响应速度快,系统的节流损失和溢流损失小,能量利用率高。

关键词：锻造液压机液压系统正弦泵偏心摆伺服控制系统

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双向增压系统应用特性研究

锻压技术 2022年第3期47卷 191-197页

作者：颜笑鹏陈柏金张连华马海军华中科技大学材料科学与工程学院湖北武汉430074 中科聚信洁能热锻装备研发股份有限公司江苏盐城224000 江苏华威机械制造有限公司江苏盐城224000

针对锻造液压机系统中部分执行机构需要很高的工作压力,而其余大部分机构所需工作压力比较低的情况,提出了一种基于双向增压器的新型液压储能系统。泵组输出的油液经过增压系统增压后,油液压力得到显著提升,然后与传统液压动力单元一起... 详细信息

针对锻造液压机系统中部分执行机构需要很高的工作压力,而其余大部分机构所需工作压力比较低的情况,提出了一种基于双向增压器的新型液压储能系统。泵组输出的油液经过增压系统增压后,油液压力得到显著提升,然后与传统液压动力单元一起为主工作缸供能。该系统克服了液压机加工过程中负载的时序性和周期性,因此,在液压系统设计过程中可以选择装机功率更低的电机-泵组单元,从而组成更为经济合理的液压系统。通过仿真结果可知,采用双向增压装置后系统的输出流量保持较高的稳定性与响应性,且与传统液压机相比,具有质量轻、体积小和结构紧凑的优点,应用前景十分广阔。

关键词：锻造液压机双向增压器增压回路节能液压储能

Meridional deflection of global eddy propagation derived from tandem altimetry: Mechanism and implication

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Science China Earth Sciences 2024年第3期67卷 811-825页

作者： Ge chen Xiaoyan chen Frontiers Science Center for Deep Ocean Multispheres and Earth System School of Marine TechnologyOcean University of ChinaQindao 266100China Laboratory for Regional Oceanography and Numerical Modeling Laoshan LaboratoryQindao 266237China

A common view on meridional deflection of eddy propagation is poleward for cyclones and equatorward for anticyclones. This widely accepted polarity-sensitive pattern has been increasingly undermined given that it is systematically violated on both zonal and regional scales as recently reported. Here, we approach the problem by exploring these violations in terms of eddy effects of spatiotemporal geostrophy, thermal fading, and flow dragging, yielding the following main conclusions.(1) The polarity-dependent deflection discrepancy is a pseudo feature resulting from a biased fit to the normalized eddy tracks which are spatially asymmetric(though azimuthally symmetric) between the two signs;Instead, the primary pattern of eddy deflection appears to be geographically correlated and polarity independent.(2) Geostrophic adjustment plays a critical role in defining the meridional movement of an eddy. Specifically, a consistent poleward(equatorward) trajectory bending of spatially(temporally) ageostrophic eddies is observed irrespective of their polarity.(3) The mechanism of eddy deflection is also determined by its zonal propagation direction. Westward propagating eddies are substantially affected by thermal fading, while opposite ones by flow dragging. A realistic and comprehensive understanding of eddy deflection mechanisms serves as a significant contribution to the prediction of eddy trajectory, and the protection of ocean environment.

关键词： Mesoscale eddies Eddy propagation Eddy meridional deflection Satellite observation Geostrophic adjustment

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双柱上传动锻造水压机多根拉杆顺序加载预紧力分析

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中国机械工程 2008年第7期19卷 868-871页

作者：黄奎莫健华陈柏金黄树槐华中科技大学塑性成形模拟及模具技术国家重点实验室武汉430074

经典的组合结构压机机架的预紧设计方法以横梁为刚体和拉杆立柱只有轴向变形为假设条件,给出的预紧设计方法与真实情况不相符合。采用ANSYS公司新近推出的协同仿真环境ANSYS Workbench软件对水压机进行了有限元计算,得到不同预紧系数下... 详细信息

经典的组合结构压机机架的预紧设计方法以横梁为刚体和拉杆立柱只有轴向变形为假设条件,给出的预紧设计方法与真实情况不相符合。采用ANSYS公司新近推出的协同仿真环境ANSYS Workbench软件对水压机进行了有限元计算,得到不同预紧系数下水压机拉杆的受力情况,从中找出拉杆预紧力依加载顺序而递减规律,对实际设备安装具有一定的指导意义。

关键词：拉杆预紧力水压机有限元法

A refined representation method of the particle size distribution curve based on grading entropy

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Particuology 2024年第5期88卷 302-311页

作者： Xing Li Qun chen Zhaozhao Liu cheng Zhou chen Wang chen chen State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China

The particle size distribution(PSD)curve is an important expression of the basic properties of the *** characteristic parameters such as median particle size D_(50),effective particle size D_(10),and some combinations of characteristic parameters can only represent some points of the PSD curve,failing to represent all information of the PSD *** this paper,a fraction characteristic parameter F that could reflect the fraction size variation of the PSD curve was introduced based on grading *** a new presentation method of the A-B-F three parameters was proposed for a refined representation of the PSD *** was found that the newly constructed model not only better represents the differences in the width of PSD curves but also has a higher sensitivity than the A-B two-parameter model proposed by Lő*** PSD curves with similar distributions,the new presentation method has a higher degree of discrimination than that of the D_(50)-C_(u)-C_(c) three-parameter or the four-parameter combination G_(c) proposed by ***,the application of this new method in describing the spatial nonuniformity distribution of depositions and predicting the soil hydraulic conductivity was *** research results can provide a reference for the refined representation of PSD curves.

关键词： Grading entropy Particle size distribution curve Refined representation

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电机-飞轮-油泵液压动力单元实验研究

中国机械工程 2018年第11期29卷 1336-1341页

作者：罗琬先陈柏金颜笑鹏华中科技大学材料成形与模具技术国家重点实验室武汉430074

针对锻造液压机装机功率大、能量损失严重的问题,设计出一种节能型液压动力单元,通过变频器控制异步电机带动飞轮驱动油泵。控制器控制飞轮能量的储存与释放,低负载阶段时,电机带动飞轮储存能量;高负载做功时,电机与飞轮同时释放能量。... 详细信息

针对锻造液压机装机功率大、能量损失严重的问题,设计出一种节能型液压动力单元,通过变频器控制异步电机带动飞轮驱动油泵。控制器控制飞轮能量的储存与释放,低负载阶段时,电机带动飞轮储存能量;高负载做功时,电机与飞轮同时释放能量。对动力单元进行了理论与实验研究,得到不同转速下,成形能量、电机功率、电机转速与时间的关系。实验结果表明:较普通液压动力系统,该动力系统装机功率至少降低30%,且对液压机的动作影响不大。

关键词：节能液压机飞轮变频调速

Track correlation algorithm based on CNN-LSTM for swarm targets

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Journal of Systems Engineering and Electronics 2024年第2期35卷 417-429页

作者： chen Jinyang WANG Xuhua chen Xian Research Institute for National Defense Engineering Academy of Military SciencesLuoyang 471023China Information Engineering University Zhengzhou 450001China School of Computer Science and Technology Xidian UniversityXi’an 710071China

The rapid development of unmanned aerial vehicle(UAV) swarm, a new type of aerial threat target, has brought great pressure to the air defense early warning system. At present, most of the track correlation algorithms only use part of the target location, speed, and other information for *** this paper, the artificial neural network method is used to establish the corresponding intelligent track correlation model and method according to the characteristics of swarm ***, a route correlation method based on convolutional neural networks (CNN) and long short-term memory (LSTM)Neural network is designed. In this model, the CNN is used to extract the formation characteristics of UAV swarm and the spatial position characteristics of single UAV track in the formation,while the LSTM is used to extract the time characteristics of UAV swarm. Experimental results show that compared with the traditional algorithms, the algorithm based on CNN-LSTM neural network can make full use of multiple feature information of the target, and has better robustness and accuracy for swarm targets.

关键词： track correlation correlation accuracy rate swarm target convolutional neural network(CNN) long short-term memory(LSTM)neural network