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An Aerial–Wall Robotic Insect That Can Land, Climb, and Take Off from Vertical Surfaces

Research 2024年第1期2023卷 149-163页

作者： Qian Li Haoze Li Huan Shen Yangguang Yu Haoran He Xincheng Feng Yi Sun Zhiyuan Mao Guangming Chen zongjun tian Lida Shen Xiangming Zheng Aihong Ji College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjingChina College of Aerospace Engineering Nanjing University of Aeronautics and AstronauticsNanjingChina State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing University of Aeronautics and AstronauticsNanjingChina

Insects that can perform flapping-wing flight,climb on a wall,and switch smoothly between the 2 locomotion regimes provide us with excellent biomimetic ***,very few biomimetic robots can perform complex locomotion tasks that combine the 2 abilities of climbing and ***,we describe an aerial–wall amphibious robot that is self-contained for flying and climbing,and that can seamlessly move between the air and *** adopts a flapping/rotor hybrid power layout,which realizes not only efficient and controllable flight in the air but also attachment to,and climbing on,the vertical wall through a synergistic combination of the aerodynamic negative pressure adsorption of the rotor power and a climbing mechanism with bionic adhesion *** the basis of the attachment mechanism of insect foot pads,the prepared biomimetic adhesive materials of the robot can be applied to various types of wall surfaces to achieve stable *** longitudinal axis layout design of the rotor dynamics and control strategy realize a unique cross-domain movement during the flying–climbing transition,which has important implications in understanding the takeoff and landing of ***,it enables the robot to cross the air–wall boundary in 0.4 s(landing),and cross the wall–air boundary in 0.7 s(taking off).The aerial–wall amphibious robot expands the working space of traditional flying and climbing robots,which can pave the way for future robots that can perform autonomous visual monitoring,human search and rescue,and tracking tasks in complex air–wall environments.

关键词： robot smoothly Vertical

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热处理对激光选区熔化高强铝合金组织及性能影响

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热加工工艺 2024年第6期53卷 35-40,47页

作者：李达吕非周凯刘瑞康田宗军南京航空航天大学机电学院江苏南京210016 南京先进激光技术研究院激光装备及工艺技术研发中心江苏南京210038 中国科学院上海光学精密机械研究所上海市全固态激光器与应用技术重点实验室上海201800

为了充分发挥高强铝合金材料的性能潜力,从热处理强化角度出发,选择了4种不同的热处理制度,并从物相、组织、性能对热处理后的铝合金SLM成形样件展开研究,最终筛选出最适合的热处理制度。结果表明,300℃/6 h/炉冷的强化时效(EA)热处理... 详细信息

为了充分发挥高强铝合金材料的性能潜力,从热处理强化角度出发,选择了4种不同的热处理制度,并从物相、组织、性能对热处理后的铝合金SLM成形样件展开研究,最终筛选出最适合的热处理制度。结果表明,300℃/6 h/炉冷的强化时效(EA)热处理后的样件具有最高的抗拉强度575 MPa,较未经热处理的原SLM成形件的抗拉强度提高25%,伸长率有一定程度的下降但仍满足正常需求。强化机制主要为:过饱和Mn元素固溶体带来的固溶强化、细密且具有一定热稳定性微观组织形貌带来的细晶强化以及热处理后生成的纳米级Al3Sc相沉淀粒子带来的第二相强化。

关键词：激光选区熔化高强铝合金热处理显微组织拉伸性能

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SLM铝合金表面喷射电沉积Ni-MoS_(2)自润滑复合涂层

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热加工工艺 2024年第8期53卷 63-68页

作者：柏华文成海霞陈亚娄桂宾沈理达田宗军南京航空航天大学机电学院江苏南京210016

采用喷射电沉积在SLM铝合金表面制备Ni-MoS_(2)自润滑复合涂层。用摩擦磨损试验机评价镀液中MoS_(2)浓度对Ni-MoS_(2)自润滑复合涂层摩擦磨损性能的影响。结果表明:共沉积MoS_(2)微粒能有效降低Ni-MoS_(2)自润滑复合涂层的摩擦系数和磨... 详细信息

采用喷射电沉积在SLM铝合金表面制备Ni-MoS_(2)自润滑复合涂层。用摩擦磨损试验机评价镀液中MoS_(2)浓度对Ni-MoS_(2)自润滑复合涂层摩擦磨损性能的影响。结果表明:共沉积MoS_(2)微粒能有效降低Ni-MoS_(2)自润滑复合涂层的摩擦系数和磨损率。与纯Ni涂层相比,Ni-MoS_(2)自润滑复合涂层与316L钢球对磨的摩擦系数和磨损率显著降低,摩擦系数从0.51降至0.12,磨损率从0.41 mg/m降至0.11 mg/m,为SLM铝合金表面改善摩擦学性能提供了参考。

关键词： Ni-MoS_(2)自润滑复合涂层喷射电沉积增材制造摩擦磨损

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Microstructure development and biodegradation behavior of additively manufactured Mg-Zn-Gd alloy with LPSO structure

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Journal of Materials Science & Technology 2023年第13期144卷 1-14页

作者： Youwen Yang Chenrong Ling Yageng Li Shuping Peng Deqiao Xie Lida Shen zongjun tian Cijun Shuai Institute of Additive Manufacturing Jiangxi University of Science and TechnologyNanchang 330013China Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing 100083China The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education Xiangya HospitalCentral South UniversityChangsha 410078China NHC Key Laboratory of Carcinogenesis of Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine Cancer Research InstituteSchool of Basic Medical ScienceCentral South UniversityChangsha 410013China College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China State Key Laboratory of High Performance Complex Manufacturing Central South UniversityChangsha 410083China

Biodegradable magnesium(Mg)alloy has been considered as a new generation of orthopedic implant ***,local corrosion usually occurs since the severe micro-galvanic behavior amongα-Mg and precipitates,and results in too rapid *** this study,porous Mg-Zn-Gd part was fabricated using laser additive manufacturing combined with solution heat *** heat treatment,the precipitatedβ-(Mg,Zn)_(3) Gd phase dissolved inα-Mg,and reduced the energy threshold of stacking faults on basal planes,which finally triggered the formation of long period stacking ordered(LPSO)*** LPSO phases owned minor potential difference withα-Mg,thus causing less micro-galvanic corrosion ten-dency as compared toβ-(Mg,Zn)_(3) Gd *** importantly,they were uniformly distributed within theα-Mg grains and showed different orientations between adjacent *** a result,the LPSO-reinforced Mg-Zn-Gd tended to expand laterally during corrosion evolution,and achieved uniform degradation with a considerably reduced degradation rate of 0.34 mm/***,in-vitro cell tests further proved its favorable *** work highlighted the additively manufactured Mg-Zn-Gd with LPSO structure showed great potential for orthopedic application.

关键词： Additive manufacturing Mg alloy LPSO structure Biodegradation behavior Biocompatibility

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Flow field design and process stability in electrochemical machining of diamond holes

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Chinese Journal of Aeronautics 2016年第6期29卷 1830-1839页

作者： Zhao Jianshe Wang Feng Liu Zhuang Zhang Xiangli Gan Weimin tian zongjun College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics Digital ECM Building Laboratory of Jiangsu Province Changzhou Institute of Technology

The metal grille, commonly composed of an amount of diamond holes, has been growingly used as a key structure on stealth aircraft. Electrochemical machining(ECM) promises to be increasingly applied in aircraft manufacturing on the condition that process stability is *** this work, a flow field model was designed to improve the process stability. This model is endowed with a variety of flow channel features, together with vibrating feeding modes. The flow field distribution on the bottom surface of the diamond hole was discussed and evaluated as *** numerical results show that a short arc flow channel could significantly enhance the uniformity of electrolyte velocity distribution and a vibrating feeding of the cathode enables to reduce both fluctuations of the electrolyte velocity and pressure on the bottom surface of the diamond ***, the flow field mutations were eliminated. It is verified from the experimental results that a short arc flow channel, when combined with vibrating feeding, is capable of improving machining localization and process stability markedly. What is more, the side gap on the bottom surface of the diamond hole could also be reduced by the abovementioned approach.

关键词： Diamond hole Electrochemical machining Flow fields Stability Vibrating

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Simulation and Analysis of Electromagnetic Force in Laser Melting Deposition by Electromagnetic Impact

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第4期35卷 702-709页

作者： Xie Na Zhao Jianfeng Xie Deqiao Sun Jie tian zongjun Shen Lida College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics

Magnetic field was introduced in laser melting deposition to reduce the pores in *** 3-D model of the coil-deposition layer-substrate was *** results show that the electromagnetic force in deposition layer mainly concentrates in the projection area of the *** electromagnetic force shows repulsion in one *** experimental results indicate that the magnetic field is beneficial for grain refinement,microhardness increasement and decline of quantities and average sizes of pores.

关键词： laser melting deposition(LMD) finite element method electromagnetic force coil microstructure

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Trabecular-like Ti-6Al-4V scaffolds for orthopedic: fabrication by selective laser melting and in vitro biocompatibility

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Journal of Materials Science & Technology 2019年第7期35卷 1284-1297页

作者： Huixin Liang Youwen Yang Deqiao Xie Lan Li Ning Mao Changjiang Wang zongjun tian Qing jiang Lida Shen College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China State Key Laboratory of High Performance Complex Manufacturing Central South UniversityChangsha 410083China Jiangxi University of Science and Technology Ganzhou 341000China Department of Sports Medicine and Adult Reconstructive Surgery Nanjing University Medical School Affiliated Drum Tower HospitalNanjing 210008China Department of Engineering and Design University of SussexSussex HouseBrighton BN19RHUnited Kingdom Suzhou fCangli Orthopedics Instrument Co. Ltd. Suzhou 215624China

Porous metal scaffolds play an important role in the orthopedic field, due to their wide applications in prostheses implantation. Some previous studies showed that the scaffolds with trabecular bone structure reconstructed via computed tomography had satisfactory biocompatibility. However, the reverse modeling scaffolds were inflexible for customized design. Therefore, a top-down designing biomimetic bone scaffold with favorable mechanical performances and cytocompatibility is urgently demanded for orthopedic implants. An emerging additive manufacturing technique, selective laser melting, was employed to fabricate the trabecular-like porous Ti-6Al-4 V scaffolds with varying irregularities(0.05-0.5) and porosities(48.83%–74.28%) designed through a novel Voronoi-Tessellation based method. Micro-computed tomography and scanning electron microscopy were used to characterize the scaffolds’ ***-static compression tests were performed to evaluate the scaffolds’ mechanical properties. The MG63 cells culture in vitro experiments, including adhesion, proliferation, and differentiation, were conducted to study the cytocompatibility of scaffolds. Compressive tests of scaffolds revealed an apparent elastic modulus range of 1.93–5.24 GPa and an ultimate strength ranging within 44.9–237.5 MPa, which were influenced by irregularity and porosity, and improved by heat treatment. Furthermore, the in vitro assay suggested that the original surface of the SLM-fabricated scaffolds was favorable for osteoblasts adhesion and migration because of micro scale pores and ravines. The trabecular-like porous scaffolds with full irregularity and higher porosity exhibited enhanced cells proliferation and osteoblast differentiation at earlier time, due to their preferable combination of small and large pores with various shapes. This study suggested that selective laser melting-derived Ti-6Al-4 V scaffold with the trabecular-like porous structure designed through Voronoi-Tessellation m

关键词： Irregular porous structure Selective laser melting Voronoi-Tessellation Mechanical performance In vitro study

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From intrinsic dielectric loss to geometry patterns: Dual-principles strategy for ultrabroad band microwave absorption

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Nano Research 2021年第5期14卷 1495-1501页

作者： Bin Quan Weihua Gu Jiaqi Sheng Xinfeng Lv Yuyi Mao Lie Liu Xiaogu Huang zongjun tian Guangbin Ji College of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing210016China School of Chemistry and Materials Science Nanjing University of Information Science&TechnologyNanjing210044China National Center of Supervision and Inspection on Additive Manufacturing Products Quality Wuxi214000China Shenzhen General Test Systems Inc Taohuayuan Hi-Tech ParkShenzhen518102China College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing210016China

As electromagnetic absorbers with wide absorption bandwidth are highly pursued in the cutting-edge electronic and telecommunication industries, the traditional dielectric or magnetic bulky absorbers remain concerns of extending the effective absorption bandwidth. In this work, a dual-principle strategy has been proposed to make a better understanding of the impact of utilizing conductive absorption fillers coupled with implementing artificial structures design on the absorption performance. In the comparison based on the microscopic studies, the carbon nanotubes (CNTs)-based absorbers are confined to narrow operating bandwidth and relatively fixed response frequency range, which can not fulfill the ever-growing demands in the application. With subsequent macroscopic structure design based on the CNTs-based dielectric fillers, the artificial patterns show much more broadened absorption bandwidth, covering the majority of C-band, the whole X-band, and Ku-band, due to the tailored electromagnetic parameters and more reflections and scatterings. The results suggest that the combination of developing microscopic powder/bulky absorbers and macroscopic configuration design will fundamentally extend the effective operating bandwidth of microwave.

关键词： geometry patterns numerical simulation three-dimensional(3D)printing broadband microwave absorption

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Preparation and characterization of nanostructured Al_2O_3-13wt.%TiO_2 ceramic coatings by plasma spraying

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Rare Metals 2009年第5期28卷 465-470页

作者： WANG Dongsheng tian zongjun SHEN Lida LIU Zhidong HUANG Yinhui Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology Nanjing University of Aeronautics and Astronautics Nanjing 210016 China College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

Nanostructured and conventional Al2O3-13wt.%TiO2 ceramic coatings were prepared by plasma spraying with nanostructured agglomerated and conventional powders, respectively. The microstructure and microhardness of the coatings were investigated using scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS）, and microhardness measurement. Meanwhile, the friction and wear behaviors were analyzed and compared using a ball-on-disk tribometer. The results show that the conventional coating has lamellar stacking characteristic and has some pores. However, the nanostructured coating shows a bimodal microstructure, which is composed of both fully melted regions and partially melted regions. According to the microstructural difference, the partially melted regions can be divided into liquid-phase sintered regions （a three-dimensional net or skeleton-like structure： Al2O3-rich submicron particles embedded in the TiO2-rich matrix） and solid-phase sintered regions （remained nanoparticles）. The microstructural characteristics of the liquid-phase sintered region are formed due to the selective melting of TiO2 nanoparticles during plasma spraying. On the other hand, the TiO2 and Al2O3 nanoparticles of the solid-phase sintered regions are all unmelted during plasma spraying. Due to the existence of nanostructured microstructures, the nanostructured coating has a higher microhardness, a lower friction coefficient, and a better wear resistance than the conventional coating.

关键词： surface coating nanostructured coating plasma spraying microstructure microhardness wear resistance

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A Blockchain-Based Access Control Scheme for Reputation Value Attributes of the Internet of Things

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Computers, Materials & Continua 2024年第1期78卷 1297-1310页

作者： Hongliang tian Junyuan tian College of Electrical Engineering Northeast Electric Power UniversityJilin132012China

The Internet of Things(IoT)access controlmechanism may encounter security issues such as single point of failure and data *** address these issues,a blockchain-based IoT reputation value attribute access control scheme is ***,writing the reputation value as an attribute into the access control policy,and then deploying the access control policy in the smart contract of the blockchain system can enable the system to provide more fine-grained access control;Secondly,storing a large amount of resources fromthe Internet of Things in Inter Planetary File System(IPFS)to improve system throughput;Finally,map resource access operations to qualification tokens to improve the performance of the access control *** simulation experiments based on the Hyperledger Fabric *** simulation experimental results,it can be seen that the access control system can achieve more fine-grained and dynamic access control while maintaining high throughput and low time delay,providing sufficient reliability and security for access control of IoT devices.

关键词： Blockchain IoT access control Hyperledger Fabric

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