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Fabrication of Zn-0.5Mn-0.05 Mg Micro-Tube with Suitable Strength and Ductility for Vascular Stent Application

Acta Metallurgica Sinica(English Letters) 2025年第2期38卷 327-337页

作者： Dongfang Lou Mingda Zhang Yuping Ren Hongxiao Li Gaowu Qin Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Materials Science and EngineeringNortheastern UniversityShenyang 110819China Institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang 110004China Research Center for Metallic Wires Northeastern UniversityShenyang 110819China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China

Biodegradable Zn alloys are a hot topic in the biodegradable vascular stent materials,the study on preparing Zn alloys microtubes for vascular stent is still insufficient and none of the tubes could well meet the mechanical requirement by *** this study,we fabricate Zn-0.5Mn-0.05 Mg microtube with outer diameter of 3.5 mm and wall thickness of 0.2 mm by five passes three-roller *** mechanical properties of the microtube are 277±2.9 MPa,330±3.3 MPa and 39.8±5.25%for the yield tensile strength(YTS),ultimate tensile strength(UTS)and break elongation,respectively,which well satisfies the requirements of the vascular *** leading factors to the variations of the mechanical property are texture evolution,grain size refinement and microstructure uniformity during the rolling process,and the main deformation mechanisms are twinning and dislocation *** a result of the dynamic recrystallization,the grain size decreases obviously and the microstructure gets more uniform as the rolling pass *** texture gradually changes from a basal texture<0110>‖ED(extrusion direction)for the as-extruded tube blank to deformation texture<0001>‖RD(rolling direction)and non-basal texture<0221>‖RD for the 5-pass rolled microtube.

关键词： Zn alloys Microtube Microstructure Mechanical property Three-roller rolling

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Failure Envelopes of Single-Plate Rigid Helical Anchors for Floating Offshore Wind Turbine

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China Ocean Engineering 2023年第6期37卷 1000-1010页

作者： CHEN Hong-zhen WANG Le TIAN Ying-hui ZHANG Chun-hui SHEN Zhi-chao LIU Meng-meng State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation Tianjin UniversityTianjin 300072China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China Department of Infrastructure Engineering Faculty of Engineering and Information Technology The University of MelbourneVictoria 3010Australia School of Civil Engineering Hebei University of Science and TechnologyShijiazhuang 050018China Hebei Technological Innovation Center of Disaster Prevention and Mitigation Engineering of Geotechnical and Structural System Shijiazhuang 050018China School of Marine Science and Engineering South China University of TechnologyGuangzhou 511442China Institute of Ocean Energy and Intelligent Construction Tianjin University of TechnologyTianjin 300384China

Helical anchor is a kind of novel foundation for floating offshore wind turbines,which should be subjected to combined tensile loading caused by wind,wave and ***,the research about the capacity of helical anchor was mainly examined under uniaxial loading and scarcely explored under combined *** this study,three-dimensional finite element limit analysis is adopted to assess the bearing capacities of single-plate rigid helical anchors with different ratios of helix to shaft diameter,D_(H)/D_(S) and embedment ratios L/D_(S).Result shows that the vertical,horizontal and moment bearing capacities increase with increasing D_(H)/D_(S) and L/D_(S).The normalized V-H failure envelopes expands with increasing L/D_(S),while the normalized V-M failure envelopes tend to contract with the increase of D_(H)/D_(S).With increasing D_(H)/D_(S) or decreasing L/D_(S),the normalized H-M failure envelopes expand when the horizontal and moment loading act in the same direction and contract when they act in the opposite *** effect of D_(H)/D_(S) and L/D_(S) on the shape of H-M failure envelope become insignificant when L/D_(S)≥4.A series of failure mechanisms under different loading conditions were observed and can be used to explain the ***,a series of approximate expressions were proposed to fit the uniaxial bearing capacities and the failure envelopes.

关键词： helical anchors bearing capacity failure envelope clay

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CASKA-CRT: Chinese Remainder Theorem Empowered Certificateless Aggregate Signcryption Scheme with key Agreement in IoVs

IEEE Transactions on Intelligent Vehicles

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IEEE Transactions on intelligent Vehicles 2024年 1-16页

作者： Hou, Yingzhe Cao, Yue Xiong, Hu Sun, Zhili Mumtaz, Shahid Tian, Daxin School of Cyber Science and Engineering Wuhan University Wuhan China School of Information and Software Engineering University of Electronic Science and Technology of China Chengdu China Institute of Communication Systems University of Surrey Guildford U.K Department of Applied Informatics Silesian University of Technology Akademicka Gliwice Poland State Key Laboratory of Vehicle-Infrastructure Integrated ITS the State Key Laboratory of Intelligent Transportation System and the School of Transportation Science and Engineering Beihang University Beijing China

To enhance the privacy of messages in Internet of Vehicles (IoVs), it is critical to preserve the communication security between Road Side Unit (RSU) and numerous vehicles. The primitive of signcryption is introduced to guarantee the confidentiality, integrity and unforgeability of transmitted messages. Nevertheless, the existing signcryption schemes fail to achieve a balance between security and efficiency. In this paper, we construct a Chinese remainder theorem (CRT) empowered certificateless aggregate signcryption scheme with key agreement (CASKA-CRT). As the vehicle joins and leaves dynamically, the proposed scheme can ensure the dynamic security via one modulo division operation. Besides, the certificateless aggregate signcryption and key agreement mechanisms are embedded. The former idea can both address the certificate management and key escrow problems, while the latter technology can create authentication as a premise of secure communication. Based on this construction, the hash-to-group operation and bilinear pairing are avoided, to realize a faster verification with the increased number of messages. Moreover, the security of proposed scheme is proved under the random oracle model. Finally, the performance analysis demonstrates the advantage of CASKA-CRT in terms of security and reliability over related works. IEEE

关键词： Public key cryptography

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Facial expression recognition under occlusion conditions based on multi-feature cross-attention

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Journal of intelligent and Fuzzy systems 2024年第4期46卷 9841-9856页

作者： Guo, Sheng Tan, Mian Cai, Shan Zhang, Zaijun Liang, Yihui Feng, Hongxi Zou, Xue Wang, Lin School of Data Science and Information Engineering Guizhou Key Laboratory of Pattern Recognition and Intelligent System Guizhou Minzu University Guiyang China School of Mathematics and Statistics Qiannan Normal University for Nationalities Key Laboratory of Complex Systems and Intelligent Optimization of Guizhou Province Duyun China Zhongshan Institute University of Electronic Science and Technology of China Zhongshan China Guizhou Aerospace Tianma Electromechanical Technology Co LTD Zunyi China

Although facial expression recognition (FER) has a wide range of applications, it may be difficult to achieve under local occlusion conditions which may result in the loss of valuable expression features. This issue has motivated the present study, as a part of which an effective multi-feature cross-attention network (MFCA-Net) is proposed. The MFCA-Net consists of a two-branch network comprising a multi-feature convolution module and a local cross-attention module. Thus, it enables decomposition of facial features into multiple sub-features by the multi-feature convolution module to reduce the impact of local occlusion on facial expression feature extraction. In the next step, the local cross-attention module distinguishes between occluded and unoccluded sub-features and focuses on the latter to facilitate FER. When the MFCA-Net performance is evaluated by applying it to three public large-scale datasets (RAF-DB, FERPlus, and AffectNet), the experimental results confirm its good robustness. Further validation is performed on a real FER dataset with local occlusion of the face. © 2024 – IOS Press.

关键词： Convolution

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Design and Implementation of Quasi-Direct-Drive Legs for a Frog-Like Jumping Robot 3

Design and Implementation of Quasi-Direct-Drive Legs for a F...

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3rd International Conference on Computer, Control and Robotics, ICCCR 2023

作者： Zhihui, Dong Jizhuang, Fan Qilong, Du Jie, Zhao Harbin Institute of Technology State Key Laboratory of Robotics and System Harbin150001 China

ISBN: (纸本)9781665492126

This study aims to design and optimize a motor-driven frog-like jumping robot leg for efficient vertical jumps and multiple consecutive horizontal jumps. We have conducted bionic research on frog legs' structure and motion characteristics and further explored their motion mechanism, providing new ideas and methods for designing and manufacturing robots with high mobility and adaptability. First, our research team designed a robot leg prototype based on the frog's body structure, optimized the robot using computer-Aided design software, and selected a suitable motor-driven actuator. Secondly, the weight reduction optimization of the robot body is carried out regarding material selection and topology optimization to improve the robot's maneuverability and jump height. Finally, after manufacturing the prototype of the robot legs, the robot is experimentally verified. The results show that the robot legs can achieve efficient vertical jumps (the maximum height is 1.40 meters, about 7.8 times the length of the leg link). It can also jump multiple times consecutively, which is significant for applying robots in dangerous environments, search and rescue, and other fields. © 2023 IEEE.

关键词： Machine design

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Structural Design and Experiment of a Small Wheel-legged Mobile Robot with Variable Configuration 20

Structural Design and Experiment of a Small Wheel-legged Mob...

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20th IEEE International Conference on Mechatronics and Automation, ICMA 2023

作者： Cui, Xiulong Fan, Jizhuang Dong, Zhihui Ou, Yue Zhao, Jie Harbin Institute of Technology The State Key Laboratory of Robotics and System Harbin150001 China

ISBN: (纸本)9798350320831

In this paper, we made an improved design on the traditional quadruped robot structure and developed a new small wheel-legged mobile robot structure. It has four legged configurations, which can be selected according to different situations, improving the mobility and operability of the robot. In wheeled mode, the robot can adjust its center of gravity according to actual needs. Including the rotational degree of freedom of the wheel, each leg has four degrees of freedom. Each leg adopts a series structure and moves the knee drive motor to the fuselage position using a parallel four-link mechanism and is symmetrically arranged with the hip drive motor. A wheel is installed at the end of the shank, and a DC brushless motor is built inside it, enabling the robot to have the function of wheeled motion. This article introduces the details of the wheel-legged robot, emphasizing the innovative design of the physical structure and the diversity of deformation. The forward kinematics was analyzed. Based on the full-elbow configuration (a type of legged configuration), a cycloidal motion optimization simulation was completed for the single leg structure. Simulation experiment has proven that the optimized robot's single leg motion is smoother. Finally, we conducted a typical experiment using an embedded controller to control single leg motion. The experimental results verify that the optimized cycloidal motion of the robot meets the desired motion effect. © 2023 IEEE.

关键词： Mobile robots

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Design of a dropsonde system based on rocket apply to near space and experimental research

Design of a dropsonde system based on rocket apply to near s...

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2024 Applied Optics and Photonics China: Laser technology and Applications, AOPC 2024

作者： Zheng, Dezhi Wang, Haoyu Hu, Chun Li, Zhongxiang Wu, Zhonghuai State Key Laboratory of CNS/ATM Beijing Institute of Technology Beijing100081 China MIIT Key Laboratory of Complex-field Intelligent Exploration Beijing Institute of Technology Beijing100081 China

ISBN: (数字)9781510687745

ISBN: (纸本)9781510687738

The near space holds significant importance for environmental protection, aerospace, and national defense. To address the challenges of detecting near space at altitudes above 60 km, this paper designs a rocket-based dropsonde system, innovatively employing high-dynamic temperature sensors and wide-range ultra-low pressure sensors to build an in-situ detection system for near space. To verify the feasibility of this system, a near-space detection experiment was conducted for altitudes above 60 km. The experimental results indicate that this system can successfully detect the near-space environment above 60 km. This experiment achieved the first domestic in-situ detection of near-space within the 20-70 km range, marking a pioneering effort in the detection of the near-space environment above 60 km in China. © 2024 SPIE.

关键词： Temperature sensors

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Torque Ripple Suppression Under Open-Circuit Fault for DTPPMSM Considering Back EMF Harmonics

Torque Ripple Suppression Under Open-Circuit Fault for DTPPM...

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2023 IEEE International Conference on Applied Superconductivity and Electromagnetic Devices, ASEMD 2023

作者： Liu, Chengsi Zou, Jibin Harbin Institute of Technology Hit State Key Laboratory of Robotics and System Harbin China

ISBN: (纸本)9798350301571

This paper analyzed the impact of phase back electromotive force (back EMF) harmonics on torque of dual three phase permanent magnet synchronous motor (DTPPMSM) from the view of electromagnetic power, and proposed a torque ripple suppression fault-tolerant method for open-circuit fault of DTPPMSM. The proposed method can consider the phase back EMF harmonics, thus achieveing both minimum torque ripple and maximum average torque. The proposed method is verified by both finite element analysis (FEA) and prototype experiment. © 2023 IEEE.

关键词： Dual three phase permanent magnet synchronous motor (DTPPMSM) fault-tolerant finite element analysis (FEA) open circuit

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Comparative Analysis of Advanced Optimization Algorithms for Highway Photovoltaic system Layout 22

Comparative Analysis of Advanced Optimization Algorithms for...

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22nd IEEE International Conference on Industrial Informatics, INDIN 2024

作者： Tao, Yanmeng Liu, Zhengke Ma, Wenxin Ma, Xiaolei School of Transportation Science and Engineering Beihang University Beijing China Key Laboratory of Intelligent Transportation Technology and System Ministry of Education Beijing100191 China

ISBN: (纸本)9798331527471

In the context of the current transition in energy structures and the development of renewable energy, optimizing the layout of solar energy systems along highways has become a significant research topic. This study employs five different advanced optimization algorithms, namely NSGA-II, Particle Swarm Optimization (PSO), Simulated Annealing (SA), Differential Evolution (DE), and a combination of NSGA-II and DE (NSGA-II-DE), to minimize total supply cost and maximize energy self-sufficiency. The comparative analysis reveals that the combination of NSGA-II and DE exhibits the best optimization performance. Through detailed experiment and data analysis, the performance and advantages of each algorithm in solving the layout problem of highway solar energy system are demonstrated, and specific implementation strategies are proposed for the optimal solution. In addition, sensitivity analysis is used to understand how changes in parameters such as module efficiency, energy demand fluctuations, and electricity price changes affect the optimization results, adding depth to the findings and making them more applicable to a variety of application scenarios. © 2024 IEEE.

关键词： Optimization algorithms

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Magnetic Microrobots Fabricated by Photopolymerization and Assembly

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Cyborg and Bionic systems 2023年第1期4卷 41-46页

作者： Xiyue Liang Yue Zhao Dan Liu Yan Deng Tatsuo Arai Masaru Kojima Xiaoming Liu Key Laboratory of Biomimetic Robots and Systems Ministry of EducationState Key Laboratory of Intelligent Control and Decision of Complex SystemBeijing Advanced Innovation Center for Intelligent Robots and Systemsand School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China Center for Neuroscience and Biomedical Engineering The University of Electro-CommunicationsTokyo 182-8585Japan Department of Materials Engineering Science Osaka UniversityOsaka 560-8531Japan

Magnetic soft microrobots have great potential to access narrow spaces and conduct multiple tasks in the biomedical *** now,drug delivery,microsurgery,disease diagnosis,and dredging the blocked blood vessel have been realized by magnetic soft microrobots in vivo or in ***,as the tasks become more and more complex,more functional units have been embedded in the body of the developed magnetic *** magnetic soft microrobots with complex designed geometries,mechanisms,and magnetic orientation are now greatly challenging the fabrication of the magnetic *** this paper,we propose a new method combining photopolymerization and assembly for the fabrication of magnetic soft *** the micro-hand assembly system,magnetic modules with different shapes and materials are firstly arrayed with precise position and orientation ***,the developed photopolymerization system is employed to fix and link these modules with soft *** on the proposed fabrication method,3 kinds of soft magnetic microrobots were fabricated,and the fundamental locomotion was *** believe that the presented fabrication strategy could help accelerate the clinical application of magnetic microrobots.

关键词： Magnetic system precise

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