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Mechanical behavior and response mechanism of porous metal structures manufactured by laser powder bed fusion under compressive loading

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International Journal of Minerals,Metallurgy and Materials 2024年第4期31卷 737-749页

作者： Xuanming Cai Yang Hou Wei zhang Zhiqiang Fan Yubo Gao Junyuan Wang Heyang Sun zhujun zhang Wenshu Yang School of Aerospace Engineering North University of ChinaTaiyuan 030051China School of Materials Science and Engineering North University of ChinaTaiyuan 030051China School of Astronautics Harbin Institute of TechnologyHarbin 150080China School of Mechanical Engineering North University of ChinaTaiyuan 030051China Shijiazhuang Campus Army Engineering University of PLAShijiazhuang 050003China 65589 Unit 91 Detachment Daqing 163411China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150080China

Al Si10Mg porous protective structure often produces different damage forms under compressive loading,and these damage modes affect its protective *** order to well meet the service requirements,there is an urgent need to comprehensively understand the mechanical behavior and response mechanism of AlSi10Mg porous structures under compressive *** this paper,Al Si10Mg porous structures with three kinds of volume fractions are designed and optimized to meet the requirements of high-impact,strong-energy absorption,and lightweight *** mechanical behaviors of AlSi10Mg porous structures,including the stress-strain relationship,structural bearing state,deformation and damage modes,and energy absorption characteristics,were obtained through experimental studies at different loading *** damage pattern of the damage section indicates that AlSi10Mg porous structures have both ductile and brittle mechanical *** simulation studies show that the AlSi10Mg porous structure undergoes shear damage due to relative misalignment along the diagonal cross-section,and the damage location is almost at 45°to the load direction,which is the most direct cause of its structural damage,revealing the damage mechanism of AlSi10Mg porous structures under the compressive *** normalized energy absorption model constructed in the paper well interprets the energy absorption state of Al Si10Mg porous structures and gives the sensitive location of the structures,and the results of this paper provide important references for peers in structural design and optimization.

关键词： AlSi10Mg additive manufacture energy absorption characteristics damage by deformation mechanical behavior

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AlSi10Mg多孔结构在不同加载应变率下的损伤模式及响应机制

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金属学报 2024年第7期60卷 857-868页

作者：蔡宣明张伟范志强高玉波王俊元张柱军中北大学航空宇航学院太原030051 哈尔滨工业大学航天学院哈尔滨150080 中北大学机械工程学院太原030051 65589部队91分队大庆163411

为探明AlSi10Mg多孔结构在不同加载应变率条件下的承载能力、破坏模式及破坏机理,展开了一系列实验研究、理论分析和数值模拟。通过实验研究明确了该AlSi10Mg多孔结构的损伤破坏模式主要表现为损伤断裂和剪切破坏,且其力学行为对加载应... 详细信息

为探明AlSi10Mg多孔结构在不同加载应变率条件下的承载能力、破坏模式及破坏机理,展开了一系列实验研究、理论分析和数值模拟。通过实验研究明确了该AlSi10Mg多孔结构的损伤破坏模式主要表现为损伤断裂和剪切破坏,且其力学行为对加载应变率不敏感。结合结构损伤分析和高精度数值模拟研究,发现AlSi10Mg多孔结构在轴向压缩载荷作用下沿斜截面相对错动而发生剪切破坏,这一失效模式是导致其结构发生断裂破坏的最直接原因。结合实验研究和理论分析表明,当AlSi10Mg多孔结构应变小于10%时,其在低应变率和中应变率下的吸能特性十分接近;当结构应变大于10%时,其在中应变率下的吸能特性略高于低应变率加载时。在不同高应变率(378~1639 s^(-1))加载条件下,该AlSi10Mg多孔结构吸能特性十分接近。

关键词：多孔结构选区激光熔化力学行为能量吸收剪切失效

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基于图像处理的小麦微量沉淀值自动读取方法研究

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中国农机化学报 2024年第4期45卷 149-154页

作者：王玲张晋雄田辉张驻军赵书涵河南农业大学机电工程学院郑州市450053 郑州大学电气与信息工程学院郑州市450066

为实现十二烷基硫酸钠(Sodium Dodecyl Sulfate,SDS)沉淀值读取的自动化、智能化,在SDS沉淀值自动化测定摇床上,设计一种图像自动识别沉淀值系统。通过对3种图像处理方法的可行性分析后,选定一种基于标签比对的图像识别方法。该方法包... 详细信息

为实现十二烷基硫酸钠(Sodium Dodecyl Sulfate,SDS)沉淀值读取的自动化、智能化,在SDS沉淀值自动化测定摇床上,设计一种图像自动识别沉淀值系统。通过对3种图像处理方法的可行性分析后,选定一种基于标签比对的图像识别方法。该方法包含图像前处理和体积值转换两大模块,主要步骤包括RGB转换成HSV、多通道二值化、提取标签和沉淀值前景,找标签和沉淀值轮廓等。该方法可以同时处理多个试管,并给出每个试管的体积。试验结果表明,平均识别准确率为98.945%。因图像处理光源固定,相对于人工读取示值,不仅提高试验效率,也降低每次读取示值时,因视线不同而造成的主观人为干扰,有效提高准确性,实现沉淀值读取的自动化与智能化。

关键词：小麦十二烷基硫酸钠沉淀值图像识别体积值转换标签

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硬度耦合刚度增强型软体夹持器设计研究

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机械设计 2024年第2期41卷 22-31页

作者：王玲张驻军吴鑫田辉李慧琴张红梅河南农业大学机电工程学院河南郑州450002

软体夹持器具有良好的顺应性、无损伤和安全的人机交互性能等优点,但由于其材料的特性限制,往往存在刚度不足和夹持力小等问题。文中基于传统的快速气动网络结构,提出了一种硬度耦合结构的刚度增强型软体夹持器的结构方案。首先,结合硅... 详细信息

软体夹持器具有良好的顺应性、无损伤和安全的人机交互性能等优点,但由于其材料的特性限制,往往存在刚度不足和夹持力小等问题。文中基于传统的快速气动网络结构,提出了一种硬度耦合结构的刚度增强型软体夹持器的结构方案。首先,结合硅橡胶材料的Yeoh本构模型和静力平衡及虚功原理,建立了刚度增强型软体夹持器的运动学和力学模型,描述了夹持器手指弯曲角度和末端接触力与压强之间的关系;其次,运用ABAQUS软件对不同硬度结构的夹持器进行了有限元分析,制作了夹持器实体,搭建实验台测定了夹持器手指实际变形和末端接触力数据,并通过实际抓取对比试验验证了实际抓取效果。结果表明:相较于传统结构,硬度耦合结构在同为20 kPa的驱动气压下,弯曲角度最大可减小120°;极限压力下,末端接触力最大增加0.1 N;最优设计为05HA结构,抓取物的质量是传统型的3.42倍。

关键词：刚度增强硬度耦合弯曲变形末端接触力

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Wnt3a在相关肿瘤中的作用

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检验医学与临床 2024年第13期21卷 1977-1980,1984页

作者：粟薇梁建刘宇(综述) 张竹君(审校) 重庆市北碚区妇幼保健院检验科重庆400700 陆军军医大学第一附属医院感染控制科重庆400038

Wnt信号通路异常与肿瘤的发生、发展密切相关。Wnt3a是经典Wnt信号通路的代表性配体蛋白,在多种肿瘤细胞中异常高表达并发挥原癌基因作用。该文重点从Wnt3a在肝癌、结直肠癌、肺癌、前列腺癌中的表达水平,对肿瘤细胞周期调控,对肿瘤发... 详细信息

Wnt信号通路异常与肿瘤的发生、发展密切相关。Wnt3a是经典Wnt信号通路的代表性配体蛋白,在多种肿瘤细胞中异常高表达并发挥原癌基因作用。该文重点从Wnt3a在肝癌、结直肠癌、肺癌、前列腺癌中的表达水平,对肿瘤细胞周期调控,对肿瘤发生、发展过程中细胞增殖、分化和迁移的调控,对肿瘤血管生成和对抗肿瘤药物耐药的调控,以及与结合分子的相互作用进行综述。明确Wnt3a在肿瘤发生、发展过程中发挥的作用和方式,为探寻肿瘤发生、发展的分子机制奠定基础,特别是Wnt3a在肿瘤诊断和Wnt信号通路抑制剂在肿瘤治疗中表现出的潜在价值,可为寻找肿瘤早期诊断和精准治疗的分子靶点提供新的方向和思路。

关键词： Wnt3a 肝癌结直肠癌肺癌前列腺癌

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Robust Transceiver Optimization for Multi-Antenna Multi-Carrier Multi-Hop Communications

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China Communications 2016年第4期13卷 20-29页

作者： QU Fengzhong zhang zhujun WU Zhihui WU Yezhou Zhejiang University Hangzhou 310027 Zhejiang Province China

Multi-hop communications are becoming more and more important due to its flexibility and potential to improve communication coverage and quality. In this paper, we discuss the robust transceiver optimization for multi-hop amplify-and-forward multiple-input multiple-output(MIMO) orthogonal frequency division multiplexing(OFDM) systems. In general, we consider a three-dimensional robust beamforming design, i.e.,frequency, spatial and relay domains. With inevitable channel estimation errors, in our work both weighted mean square error(MSE) minimization and minimizing maximum MSE are adopted as the performance metrics to design robust transceivers. Following the Bayesian robust philosophy, a robust transceiver design is proposed. The design is based on convex optimization, and the involved optimization variables are optimized alternatively. The proposed transceiver optimization algorithms can be applied to the network with arbitrary hops, arbitrary antennas and arbitrary subcarriers. At the end of this paper, the performance advantages of the propose design have been assessed by the numerical results.

关键词：多跳通信凸优化多天线多载波鲁棒正交频分复用多输入多输出信道估计误差

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New Method for Computer Identification Through Electromagnetic Radiation

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Computers, Materials & Continua 2018年第10期57卷 69-80页

作者： Jun Shi zhujun zhang Yangyang Li Rui Wang Hao Shi Xile Li China Academy of Electronics and Information Technology Badachu High-Tech ParkShijingshan DistrictBeijing100041China Institute of Information Engineering Chinese Academy of Sciences89 Minzhuang RoadBeijing100093China Solace Corporation 535 Legget Drive3rd FloorOttawaOntarioK2K 3B8Canada

The electromagnetic waves emitted from devices can be a source of information leakage and can cause electromagnetic compatibility(EMC)*** radiation signals from computer displays can be a security risk if they are intercepted and *** addition,the leaks may reveal the hardware information of the computer,which is more important for some attackers,protectors and security inspection *** this paper,we propose a statistical distribution based algorithm(SD algorithm)to extracted eigenvalues from electromagnetic radiate video signals,and then classified computers by using classifier based on Bayesian and *** can identify computers automatically and accurately through electromagnetic radiation by using the algorithm in our experiment environment.

关键词： computer hardware Electromagnetic

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Emergence of Erythromycin-Resistant and Pertactin-and Filamentous Hemagglutinin-Deficient Bordetella pertussis Strains—Beijing,China,2022-2023

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China CDC weekly 2024年第20期6卷 437-441页

作者： Guilan Zhou Ying Li Hairui Wang Yuanyuan Wang Yuan Gao Juan Xu Fengshuang Wang Tao Peng Maojun zhang zhujun Shao National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases National Institute for Communicable Disease Control and PreventionChinese Center for Disease Control and PreventionBeijingChina Shunyi District Center for Disease Control and Prevention BeijingChina

Summary What is already known about this topic?Pertussis has reemerged as a significant public health threat,primarily due to variations in Bordetella pertussis strains,antimicrobial resistance,and vaccine *** is added by this report?All isolated strains were identified as ptxA1/ptxC2/ptxP3/prn150/fim2-1/fim3-1/fhaB1/tcfA2 type and exhibited resistance to erythromycin.

关键词： vaccine pertussis primarily

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The Suitability of Using Leaf Area Index to Quantify Soil Loss under Vegetation Cover

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Journal of Mountain Science 2011年第4期8卷 564-570页

作者： zhang Wentai YU Dongsheng SHI Xuezheng WANG Hongjie GU zhujun zhang Xiangyan TAN Manzhi State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of SciencesNanjing 21o0o8 China Graduate University of the Chinese Academy of Sciences Beijing 100039 China School of Bio-Chemical and Environmental Engineering Nanjing Xiaozhuang University Nanjing 211171 China

Soil erosion by water under forest cover is a serious problem in southern China.A comparative study was carried out on the use of leaf area index(LAI) and vegetation fractional coverage(VFC) in quantifying soil loss under vegetation *** types of vegetation with varied LAI and VFC under field conditions were exposed to two rainfall rates(40 mm h-1 and 54 mm h-1) using a portable rainfall *** rate,sediment concentration and soil loss rate were measured at relatively runoff stable *** negative exponential relationship(p < 0.05,R2 = 0.83) and linear relationship(p < 0.05,R2 = 0.84) were obtained between LAI and sediment concentration,while no significant relationship existed between VFC and sediment *** mechanism by which vegetation canopy prevents soil loss was by reducing rainfall kinetic energy and sediment *** could better quantify such a role than ***,neither LAI nor VFC could explain runoff rate or soil loss *** must be taken when using LAI to quantify the role of certain vegetation in soil and water conservation.

关键词：植被覆盖叶面积指数量化土壤流失量损失水土保持作用 VFC 含沙量

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A novel cryptic exon identified in intron 67 of the dystrophin gene

A novel cryptic exon identified in intron 67 of the dystroph...

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2015中国遗传学会大会

作者： zhujun zhang Chang Liu Department of Pathology Medical School of Nankai University

Duchenne muscular dystrophy(DMD)is caused by mutations in the dystrophin gene,a largest human gene contains 79 exons interrupted by extreme large size of *** the dystrophin exon is recognized and proper spliced by spliceosome is still largely *** this study,we identified a novel cryptic exon in intron 67of the dystrophin gene in a DMD patient with a duplication of exon *** cryptic exon contains 204 bp sequence that precisely inserted between exons 67 and 68 in one of the dystrophin transcripts from lymphocytes of the index *** sequence corresponding to part of the intron 67,and possess the splicing donor and acceptor sites,as well as branch *** compared cryptic exon with authentic dystrophin exons,and found that cryptic exon has weaker splicing *** results may help to understand the exon definition and splicing regulation of the dystrophin gene.

关键词： dystrophin gene cryptic exon splicing

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