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Journal of Wuhan University of Technology(Materials Science) 2019年第2期34卷 368-372页

作者：孟正华 WANG Xu GUO Wei HU Zhili Anupam Vivek HUA Lin Glenn S DAEHN Hubei Key Laboratory of advanced Technology for Automotive Components Wuhan University of Technology State Key Laboratory of advanced Design and manufacturing for Vehicle Body Hunan University department of Materials Science and Engineering The Ohio State University

Vaporizing foil actuator welding(VFAW) was used for joining 2024-T3 and 7075-T6 aluminum alloy sheets, and the resulting joint microstructure was analyzed. 2024/7075 aluminum alloy pairs with suitable processing parameters can be prepared by using VFAW. Dynamic preform addresses the poor formability problem of target material and advantage of VFAW on dissimilar materials in some conditions. But with standoff sheet inserting in the flyer and target, 2024/7075 welded pairs gets the better weld strength, compared with flyer preformed method. The microstructure of the circular weld area of the welded joint showed a wave interface, in which a thin melt layer formed at the center and edge parts. The crystal grains near the bonding interface were remarkably elongated and refined. Therefore, the joining of the 2024/7075 pairs was facilitated through plastic forming and melting.

关键词： impact welding dissimilar materials vaporizing foil actuator joining interface

Construction of upconversion fluoride/attapulgite nanocomposite for visible-light-driven photocatalytic nitrogen fixation

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Frontiers of Materials Science 2020年第4期14卷 469-480页

作者： Xuhua YE Xiangyu YAN Xini CHU Shixiang ZUO Wenjie LIU Xiazhang LI Chao YAO advanced Catalysis and Green manufacturing Collaborative Innovation Center Jiangsu Key Laboratory of Advanced Catalytic Materials and TechnologyChangzhou UniversityChangzhou 213164China department of Materials Science and Engineering University of DelawareNewarkDE 19716USA

Developing photocatalysts with wide spectrum absorption and strong nitrogen activation is critical for nitrogen fixation under mild ***,one-dimensional natural clay attapulgite(ATP)supported YFg:Sm^3+were successfully synthesized via microwave hydrothermal method,and the composites were employed as the catalyst for photocatalytic nitrogen fixation under visible-light *** indicated that the production of ammonia reached as high as 41.2 mg·L^-1 within 3 h when the molar ratio of Sm^3+and the mass fraction of YF3:Sm^3+were *** enhanced fixation performance is mainly due to that the modified ATP fibber with abundant active sites and the doped fluoride with defective vacancy facilitate the adsorption and activation of ***,the upconversion property of YF3:Sm^3+increases the harvesting of visible-light energy,meanwhile the Z-scheme heterostructure built between YF:Sm^3+and modified ATP inhibits the recombination of charge carriers and retains high redox potentials for N2 reduction.

关键词： photocatalysis nitrogen fixation attapulgite upconversion Z-scheme

Kinematics Analysis and Singularity Avoidance of a Parallel Mechanism with Kinematic Redundancy

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Chinese Journal of Mechanical Engineering 2022年第5期35卷 244-261页

作者： Chaoyu Shen Haibo Qu Sheng Guo Xiao Li robotics Research Center School of MechanicalElectronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China China Waterborne Transport Research Institute Beijing 100088China Key Laboratory of Vehicle advanced manufacturing Measuring and Control TechnologyMinistry of EducationBeijing Jiaotong UniversityBeijing 100044China

The kinematic redundancy is considered as a way to improve the performance of the parallel *** this paper,the kinematics performance of a three degree-of-freedom parallel mechanism with kinematic redundancy(3-DOF PM-KR)and the influence of redundant parts on the PM-KR are ***,the kinematics model of the PM-KR is *** inverse solutions,the Jacobian matrix,and the workspace of the PM-KR are ***,the influence of redundancy on the PM-KR is *** there exists kinematic redundancy,the PM-KR possesses fault-tolerant *** locking one actuating joint or two actuating joints simultaneously,the fault-tolerant workspace is *** the position of the redundant part is changed,the workspace and singularity will be *** results show that kinematic redundancy can be used to avoid ***,the simulations are performed to prove the theoretical analysis.

关键词： Parallel mechanism Kinematic redundancy Singularity Simulation analysis

Elliptical vibration chiseling:a novel process for texturing ultra-high-aspect-ratio microstructures on the metallic surface

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International Journal of Extreme manufacturing 2024年第2期6卷 449-467页

作者： Zhiwei Li Jianfu Zhang Zhongpeng Zheng Pingfa Feng Dingwen Yu Jianjian Wang State Key Laboratory of Tribology in advanced Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084People’s Republic of China Beijing Key Laboratory of Precision/Ultra-precision manufacturing Equipments and Control Department of Mechanical EngineeringTsinghua UniversityBeijing 100084People’s Republic of China Division of advanced manufacturing Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055People’s Republic of China

High-aspect-ratio metallic surface microstructures are increasingly demanded in breakthrough applications,such as high-performance heat transfer enhancement and surface plasmon ***,the fast and cost-effective fabrication of high-aspect-ratio microstructures on metallic surfaces remains challenging for existing *** study proposes a novel cutting-based process,namely elliptical vibration chiseling(EV-chiseling),for the high-efficiency texturing of surface microstructures with an ultrahigh aspect *** conventional cutting,EV-chiseling superimposes a microscale EV on a backward-moving *** tool chisels into the material in each vibration cycle to generate an upright chip with a high aspect ratio through material *** to the tool’s backward movement,the chip is left on the material surface to form a microstructure rather than falling *** one microstructure is generated in one vibration cycle,the process can be highly efficient using ultrafast(>1 kHz)tool vibration.A finite element analysis model is established to explore the process mechanics of ***,a mechanistic model of the microstructured surface generation is developed to describe the microstructures’aspect ratio dependency on the process ***,surface texturing tests are performed on copper to verify the efficacy of *** micro ribs with a spacing of 1–10μm and an aspect ratio of 2–5 have been successfully textured on *** with the conventional EV-cutting that uses a forward-moving tool,EV-chiseling can improve the aspect ratio of textured microstructure by up to 40 *** experimental results also verify the accuracy of the developed surface generation model of ***,the effects of elliptical trajectory,depth of cut,tool shape,and tool edge radius on the surface generation of micro ribs have been discussed.

关键词： metallic microstructure high aspect ratio backward-moving cutting vibration cutting chiseling material deformation

Microwave hydrothermal synthesis of lanthanum oxyfluoride nanorods for photocatalytic nitrogen fixation:Effect of Pr doping

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Frontiers of Materials Science 2020年第1期14卷 43-51页

作者： Xiangyu Yan Da Dai Kun Ma Shixiang Zuo Wenjie Liu Xiazhang Li Chao Yao advanced Catalysis and Green manufacturing Collaborative Innovation Center Jiangsu Key Laboratory of Advanced Catalytic Materials and TechnologyChangzhou UniversityChangzhou213164China department of Materials Science and Engineering University of DelawareNewarkDE19716USA

Photocatalytic fixation of nitrogen has been recognized as a green and promising strategy for ammonia synthesis under ambient ***,the efficient reduction of nitrogen remains a challenge due to high activation energy of nitrogen and low utilization of solar ***,lanthanum oxyfluoride with different doping content of Pr3+(LaOF:xPr3+)upconversion nanorods were synthesized by microwave hydrothermal *** indicated that the doping of Pr3+generated considerable defects on the surface of LaOF which acted as the adsorption and activation center for ***,the Pr3+ion narrowed the band gap and broadened the light response range of LaOF because LaOF:Pr3+can upconvert visible light into ultraviolet light,which excite LaOF nanorods and improve the utilization of solar *** doping amount of Pr3+had critical effect on the photocatalytic nitrogen fixation performance which reached as high as 180μmol·L?1·ho1 when the molar ratio of Pr3+to LaOF was optimized to be 2%.

关键词： LaOF defect upconversion photocatalysis nitrogen fixation

Wing-fanning frequency as a releaser boosting male mating success— High-speed video analysis of courtship behavior in Campoplex capitator, a parasitoid of Lobesia botrana

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Insect Science 2020年第6期27卷 1298-1310页

作者： Giovanni Benelli Renato Ricciardi Donato Romano Francesca Cosci Cesare Stefanini Andrea Lucchi department of Agriculture.Food and Environment University of PisaPisaItaly The Biorobotics Institute.Sant'Anna School of advanced Studies PontederaPisaItaly department of Excellence in robotics&A.I. Sant'Anna School of Advanced StudiesPisaItaly HEIC Center BME DepartmentKhalifa UniversityAbu DhabiUAE

Campoplex capitator is an ichneumonid parasitoid with a narrow host range,comprising grapevine moth *** being considered one of the possible candidates for biocontrol of Lobesia botrana,knowledge about its biology is limited and massrearing for commercial purposes is still *** research provides a quantitative analysis of the *** courtship and mating *** mating sequence was analyzed by high-speed video *** behavioral parameters,with special reference to male wing fanning and antennal tapping,were quantified and linked with mating ***,we analyzed the occurrence of population-level behavioral asymmetries during C capitator sexual interactions and their impact on male *** showed that male wing fanning was crucial to successfully approach the *** achieving higher mating success performed wing-fanning at higher frequencies over unsuccessful *** wing fanning,most of males palpated the females body with their antennae,before attempting *** overall mating success was>70%,with a rather long copula duration(254.76±14.21 s).Male wing-fanning was lateralized on the left at population level,while antennal tapping displays were *** male displays do not differ in terms of frequency and duration of their main *** research adds basic knowledge to the *** behavioral *** rearing protocols for *** are being developed male wing fanning frequency may represent a useful benchmark for monitoring mate quality over time,tackling mating success reductions due to prolonged mass-rearing.

关键词： biological control European grapevine moth Ichneumonidae koinobiont parasitoid mass-rearing mating behavior

Effects of N and/or S Doping on Structure and Photocatalytic Properties of BiOBr Crystals

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Acta Metallurgica Sinica(English Letters) 2015年第4期28卷 460-466页

作者： Guo-Hua Jiang Xia Li Zhen Wei Teng-Teng Jiang Xiang-Xiang Du Wen-Xing Chen Key Laboratory of advanced Textile Materials and manufacturing Technology (ATMT) Ministry of EducationZhejiang Sci-Tech University department of Materials Engineering College of Materials and TextileZhejiang Sci-Tech University

The BiOBr crystals doped with N and/or S have been prepared by a facile and rapid solvothermal method using urea and/or thiourea as doped resource. The morphologies and structures of the as-prepared samples were characterized by SEM, TEM, XRD, XPS and PL spectrum. Their electronic structures have been investigated and discussed using first principles based on the density functional theory. The photocatalytic properties of the products can be adjusted by the content and species of dopants.

关键词： Hydrothermal method Photocatalysis Microstructure and properties

Design and Analysis of a Multi-Legged Robot with Pitch Adjustive Units

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Chinese Journal of Mechanical Engineering 2021年第3期34卷 226-242页

作者： Qiang Ruan Jianxu Wu Yan-an Yao Key Laboratory of Vehicle advanced manufacturing Measuring and Control TechnologyMinistry of EducationBeijing Jiaotong UniversityBeijing 100044China department of Mechanical Engineering Tsinghua UniversityBeijing 100084China

The paper proposes a novel multi-legged robot with pitch adjustive units aiming at obstacle *** only 6 degrees of freedom,the robot with 16 mechanical legs walks steadily and surmounts the obstacles on the complex *** leg unit with adjustive pitch provides a large workspace and empowers the legs to climb up obstacles in large sizes,which enhances the obstacle surmounting *** pitch adjustment in leg unit requires as few independent adjusting actuators as *** on the kinematic analysis of the mechanical leg,the biped and quadruped leg units with adjustive pitch are analyzed and *** configuration of the robot is designed to obtain a compact structure and pragmatic *** uncertainty of the obstacle size and position in the surmounting process is taken into consideration and the parameters of the adjustments and the feasible strategies for obstacle surmounting are *** the 3D virtual model and the robot prototype are built and the multi-body dynamic simulations and prototype experiments are carried *** results from the simulations and the experiments show that the robot possesses good obstacle surmounting capabilities.

关键词： Mechanical leg Multi-legged robot Obstacle surmounting Adjustive pitch Leg unit

Preparation of N-Doped Bi_2WO_6 Microspheres for Efficient Visible Light-Induced Photocatalysis

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Acta Metallurgica Sinica(English Letters) 2014年第1期27卷 124-130页

作者： Bolin Tang Guohua Jiang Zhen Wei Xia Li Xiaohong Wang Tengteng Jiang Wenxing Chen Junmin Wan department of Materials Engineering College of Materials and TextileZhejiang Sci-Tech University Key Laboratory of advanced Textile Materials and manufacturing Technology(ATMT) Ministry of EducationZhejiang Sci-Tech University

The N-doped bismuth tungstate （BizWOt） photocatalysts with high visible light activity were prepared by the hydrothermal method using urea as a nitrogen source. The as-prepared N-doped Bi2WO6 samoles were characterized by X-ray diffraction, scanning electron microscopy, specific surface area, photocurrent analysis, and UV-Vis diffuse re- flectrance spectroscopy. The photocatalytic activity was evaluated by photocatalytic degradation of rhodamine B （RhB） solution under visible light irradiation. The photocatalytic mechanisms were analyzed by active species trapping experi- ments which revealed that the holes were the main active species of N-doped BizWO6 products in aqueous solution under visible light irradiation, rather than .OH and O-. With the assistance of H202, the photocatalytic activity for degradation of RhB could be further improved because H202 reacted with conduction band electrons to generate more hydroxyl radicals. KEY WORDS：

关键词： Hydrothermal method Photocatalysis Microstructure and property

Fault-tolerant cooperative control for multiple UAVs based on sliding mode techniques

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Science China(Information Sciences) 2017年第7期60卷 54-66页

作者： Peng LI Xiang YU Xiaoyan PENG Zhiqiang ZHENG Youmin ZHANG College of Mechatronics Engineering and Automation National University of Defense Technology department of Mechanical and Industrial Engineering Concordia University State Key Laboratory of advanced Design and manufacturing for Vehicle Body Hunan University

This paper proposes a fault-tolerant cooperative control(FTCC) design approach for multiple unmanned aerial vehicles(UAVs), where the outer-loop control and the inner-loop fault accommodation are explicitly considered. The reference signals for the inner-loop of the follower UAV can be directly produced by resorting to a proportional control. In the presence of actuator faults, the estimation of the fault information can be completed within finite time. Moreover, the control of the inner-loop is reconfigured based on the fault information adaptation and sliding mode techniques, such that the deleterious effects due to failed actuators can be compensated within finite time. Simulations of UAV cooperative flight are conducted to illustrate the effectiveness of this FTCC scheme.

关键词： fault-tolerant cooperative control unmanned aerial vehicle actuator faults finite-time fault ac commodation