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Journal of Bionic Engineering 2024年第1期21卷 192-208页

作者： ang chen Bifeng Song ZhiheWang Kang Liu Dong Xue Xiaojun Yang School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China Harbin Institute of Technology Shenzhen 518055China

This paper is based on a previously developed bio-inspired Flapping Wing Aerial Vehicle(FWAV),RoboFalcon,which can fly with a morphing-coupled flapping *** this paper,a simple flapping stroke control system based on Hall effect sensors is designed and applied,which is capable of assigning different up-and down-stroke speeds for the RoboFalcon platform to achieve an adjustable downstroke *** aerodynamic and power characteristics of the morphing-coupled flapping pattern and the conventional flapping pattern with varying downstroke ratios are measured through a wind tunnel experiment,and the corresponding aerodynamic models are developed and analyzed by the nonlinear least squares *** relatively low power consumption of the slow-downstroke mode of this vehicle is verified through outdoor flight *** results of wind tunnel experiments and flight tests indicate that increased downstroke duration can improve aerodynamic and power performance for the RoboFalcon platform.

关键词： Flapping wing aerial vehicle(FWAV) Downstroke ratio Bio-inspired design Morphing-coupled flapping

Effects of dynamical spanwise retraction and stretch on flapping-wing forward flights

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Chinese Journal of Aeronautics 2024年第4期37卷 181-202页

作者： Kang LIU Bifeng SONg ang chen Zhihe Wang Dong XUE Wenqing Yang School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Intelligent Aircraft Research Center Chengdu Technological UniversityChengdu 610031China Research&Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen 518057China Harbin Institute of Technology Shenzhen 518055China

Birds and bats retract and stretch their wings dynamically during each flap in level flights, implying intriguing mechanisms for the aerodynamic performance improvement of flapping wings. A numerical investigation into the aerodynamic effects of such bio-inspired concept in forward flights has been performed based on a three-dimensional wing in plunging motion and a twosection wing in flapping motion. The currently considered Reynolds number and Strouhal number are Re=1.5×10^(5) and St=0.3, respectively. During the research, the mean angle of attack is varied in relatively wide ranges to achieve lift-thrust interconversion for the wings. The conclusive results show that dynamical spanwise retraction and stretch has induced three absolutely desirable scenarios for the oscillating wings in forward flights, namely producing more lift and consuming less power for a given thrust generation, producing more thrust and consuming less power for a given lift generation, and producing more lift and more thrust while consuming less power. Furthermore,the morphing wings have alleviated periodical aerodynamic load fluctuations compared with the non-morphing baseline. The mechanism of the aerodynamic effects of the bionic morphing mode is analyzed with the aid of field visualization. The current article is the first to reveal the absolute advantages of the bionic spanwise morphing. Hopefully, it may help comprehend the behaviors of natural fliers and provide inspirations for performance enhancement of micro artificial flappingwing vehicles.

关键词： Flapping wing Morphing wing Bionic Aerodynamics Vortex Flight

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Adaptive Control of Lower-Limb Exoskeletons for Walking Assistance Based on Inter-Joint Coordination

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Journal of Bionic Engineering 2024年第4期21卷 1775-1787页

作者： Chaoyang Li Lincong Luo Zhi Liu Tianchi chen Songxiang Liu Ye He Xiaoan chen Lei Li Wei Tech ang School of Mechanical Engineering Chongqing UniversityChongqing400044China Rehabilitation Research Institute of Singapore Singapore308232Singapore Department of Orthopedics Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China School of Mechanical and Aerospace Engineering Nanyang Technological UniversitySingapore639798Singapore

Unilateral motor impairment can disrupt the coordination between the joints,impeding the patient’s normal *** assist such patients to walk normally and naturally,an adaptive control algorithm based on inter-joint coordination was proposed in this work for lower-limb *** control strategy can generate the reference trajectory of the affected leg in real time based on a motion coordination model between the joints,and adopt an adaptive controller with virtual windows to track the reference *** Short-Term Memory(LSTM)network was also adopted to establish the coordination model between the joints of both lower limbs,which was optimized by preprocessing angle information and adding gait phase *** the adaptive controller,the virtual windows were symmetrically distributed around the reference trajectory,and its width was adjusted according to the gait phase of the auxiliary *** addition,the impedance parameters of the controller were updated online to match the motion capacity of the affected leg based on the spatiotemporal symmetry factors between the bilateral *** LSTM coordination model demonstrated good accuracy and generality in the gait database of seven individuals,with an average root mean square error of 3.5 and 4.1 for the hip and knee joint angle estimation,*** further evaluate the control algorithm,four healthy subjects walked wearing the exoskeleton while additional weights were added around the ankle joint to simulate an asymmetric *** the experimental results,it was shown that the algorithm improved the gait symmetry of the subjects to a normal level while exhibiting great adaptability to different subjects.

关键词： Lower-limb exoskeleton Adaptive control gait symmetry Inter-joint coordination Motion estimation

Recent progress in single crystal perovskite X-ray detectors

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Science China(Information Sciences) 2024年第3期67卷 5-19页

作者： Xiao LIU Jun REN Yu-ang chen Xiangshun gENg Dan XIE Tian-Ling REN School of Integrated Circuits Tsinghua University Beijing National Research Center for Information Science and Technology (BNRist)

Perovskites have attracted extensive attention as radiation detection material due to their long carrier diffusion length and lifetime, high absorption coefficient, and flexible manufacturing process. Compared with polycrystalline structures, single crystal perovskites improve the performance of optoelectronic devices due to their low defect state density, better photoelectric characteristics, and chemical ***, we review the recent progress of single crystal perovskite X-ray detectors. First, we briefly introduced the basic concepts, detection mechanisms, figure of merits of perovskite X-ray detectors, and the preparation methods of single crystal perovskites. Then, we summarized the significant advancements in single crystal perovskite X-ray detectors in recent times. Finally, we discussed the critical challenges and some practicable solutions for developing high-performance X-ray detectors.

关键词： single crystal perovskites carrier transport radiation detection X-ray detectors X-ray imaging

QBIoT:A Quantum Blockchain Framework for IoT with an Improved Proof-of-Authority Consensus Algorithm and a Public-Key Quantum Signature

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Computers, Materials & Continua 2024年第7期80卷 1727-1751页

作者： ang Liu Qing Zhang Shengwei Xu Huamin Feng Xiu-bo chen Wen Liu Network and Information Management Division Beijing Electronic Science and Technology InstituteBeijing100070China Department of Cyberspace Security Beijing Electronic Science and Technology InstituteBeijing100070China Information Security Institute Beijing Electronic Science and Technology InstituteBeijing100070China general Office Beijing Electronic Science and Technology InstituteBeijing100070China Information Security Center State Key Laboratory of Networking and Switching TechnologyBeijing University of Posts and TelecommunicationsBeijing100876China

The Internet of Things(IoT)is a network system that connects physical devices through the Internet,allowing them to ***,IoT has become an integral part of our lives,offering convenience and smart ***,the growing number of IoT devices has brought about a corresponding increase in cybersecurity threats,such as device vulnerabilities,data privacy concerns,and network *** blockchain technology with IoT has proven to be a promising approach to enhance IoT ***,the emergence of quantum computing poses a significant challenge to the security of traditional classical cryptography used in blockchain,potentially exposing it to quantum *** support the growth of the IoT industry,mitigate quantum threats,and safeguard IoT data,this study proposes a robust blockchain solution for IoT that incorporates both classical and post-quantum security ***,we present the Quantum-Enhanced Blockchain Architecture for IoT(QBIoT)to ensure secure data sharing and integrity ***,we propose an improved Proof of Authority consensus algorithm called“Proof of Authority with Random Election”(PoARE),implemented within QBIoT for leader selection and new block ***,we develop a publickey quantum signature protocol for transaction verification in the ***,a comprehensive security analysis of QBIoT demonstrates its resilience against cyber threats from both classical and quantum *** summary,this research introduces an innovative quantum-enhanced blockchain solution to address quantum security concernswithin the realmof *** proposedQBIoT framework contributes to the ongoing development of quantum blockchain technology and offers valuable insights for future research on IoT security.

关键词： IoT quantum blockchain public-key quantum signature quantum hash function

Interface catalytic reduction of alumina by nickle for the aluminum nanowire growth: Dynamics observed by in situ TEM

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Nano Research 2024年第3期17卷 1225-1231页

作者： Zichun Wang Dan Wang ang Li Lizhuo Wang Xiaodong Han Yijiao Jiang Jianfeng chen Jun Huang Beijing Advanced Innovation Center for Soft Matter Science and Engineering State Key Laboratory of Organic–Inorganic CompositesBeijing University of Chemical TechnologyBeijing 100029China Laboratory for Catalysis Engineering School of Chemical and Biomolecular EngineeringThe University of SydneyNew South Wales 2006Australia Beijing Key Laboratory of Microstructure and Property of Advanced Materials Beijing University of TechnologyBeijing 100024China Department of Engineering Macquarie UniversitySydneyNew South Wales 2109Australia

Metal nanowires show promise in a broad range of applications and can be fabricated via a number of methods,such as vapor–liquid–solid process and template-based ***,the synthesis of Al nanowires(NWs)is still challenging from the stable alumina *** this work,the Ni-catalyzed fabrication of Al NWs has been realized using various Al_(2)O_(3) *** growth dynamics of Al NWs on Ni/Al_(2)O_(3) was studied using in situ transmission electron microscopy(TEM).The effect of alumina structures,compositions,and growth temperature were *** growth of Al NWs correlates with the Na addition to the alumina *** no eutectic mixture of nickel aluminide was formed,a mechanism of Ni-catalyzed reduction of Al_(2)O_(3) for Al NWs growth has been proposed instead of the vapor–liquid–solid *** key insights reported here are not restricted to Ni-catalyzed Al NWs growth but can be extended to understanding the dynamic change and catalytic performance of Ni/Al_(2)O_(3) under working conditions.

关键词： in situ transmission electron microscopy(TEM) Al nanowires alumina reduction nanowire growth

Proposal for valleytronic materials:Ferrovalley metal and valley gapless semiconductor

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Frontiers of physics 2024年第2期19卷 131-139页

作者： San-Dong guo Yu-Ling Tao guangzhao Wang Shaobo chen Dong Huang Yee Sin ang School of Electronic Engineering Xi’an University of Posts and TelecommunicationsXi’an 710121China Key Laboratory of Extraordinary Bond Engineering and Advanced Materials Technology of Chongqing School of Electronic Information EngineeringYangtze Normal UniversityChongqing 408100China College of Electronic and Information Engineering Anshun UniversityAnshun 561000China Science Mathematics and Technology(SMT)Singapore University of Technology and Design(SUTD)8 Somapah RoadSingapore 487372Singapore

Valleytronic materials can provide new degrees of freedom to future electronic *** this work,the concepts of the ferrovalley metal(FVM)and valley gapless semiconductor(VgS)are proposed,which can be achieved in valleytronic bilayer systems by electric field *** valleytronic bilayer systems,the interaction between out-of-plane ferroelectricity and A-type antiferromagnetism can induce layer-polarized anomalous valley Hall(LP-AVH)*** K and−K valleys of FVM are both metallic,and electron and hole carriers simultaneously *** the extreme case,the FVM can become VgS by analogizing spin gapless semiconductor(SgS).Moreover,it is proposed that the valley splitting enhancement and valley polarization reversal can be achieved by electric field engineering in valleytronic bilayer *** the bilayer RuBr_(2)as an example,our proposal is confirmed by the first-principle *** FVM and VgS can be achieved in bilayer RuBr_(2)by applying electric *** appropriate electric field range,increasing electric field can enhance valley splitting,and the valley polarization can be reversed by flipping electric field *** effectively tune valley properties by electric field in bilayer systems,the parent monolayer should possess out-of-plane magnetization,and have large valley *** results shed light on the possible role of electric field in tuning valleytronic bilayer systems,and provide a way to design the ferrovalley-related material by electric field.

关键词： valleytronics electric field bilayer

Role of inflammatory lipid and fatty acid metabolic abnormalities induced by plastic additives exposure in childhood asthma

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Journal of Environmental Sciences 2024年第3期137卷 172-180页

作者： Zhiyu chen Fang Li Lei Fu Yu Xia Ying Luo ang guo Xiaona Zhu Huifang Zhong Qian Luo Institute of Biomedical and Health Engineering Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China University of Chinese Academy of Sciences Beijing 100049China Rheumatology&Immunology Department of Shenzhen Children’s Hospital Shenzhen 518038China Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances Institute of Environment and HealthJianghan UniversityWuhan 430056China

Lipid metabolism play an essential role in occurrence and development of asthma,and it can be disturbed by phthalate esters(PAEs)and organophosphate fame retardants(OPFRs).As a chronic infammatory respiratory disease,the occurrence risk of childhood asthma is increased by PAEs and OPFRs exposure,but it remains not entirely clear how PAEs and OPFRs contribute the onset and progress of the *** have profiled the serum levels of PAEs and OPFRs congeners by liquid chromatography coupled with mass spectrometry,and its relationships with the dysregulation of lipid metabolism in asthmatic,bronchitic(acute infammation)and healthy(non-infammation)*** PAEs and nine OPFRs congeners were found in the serum of children(1–5 years old)from Shenzhen,and their total median levels were 615.16 ng/m L and 17.06 ng/m L,***,the serum levels of mono-methyl phthalate(MMP),tri-propyl phosphate(TPP)and tri-n-butyl phosphate(TNBP)were significant higher in asthmatic children than in healthy and bronchitic children as ***-one characteristic lipids and fatty acids of asthma were screened by machine-learning random forest model based on serum lipidome data,and the alterations of infammatory characteristic lipids and fatty acids including palmitic acids,12,13-Di HODE,14,21-Di HDHA,prostaglandin D2 and Lyso PA(18:2)showed significant correlated with high serum levels of MMP,TPP and *** results imply PAEs and OPFRs promote the occurrence of childhood asthma via disrupting infammatory lipid and fatty acid metabolism,and provide a novel sight for better understanding the effects of plastic additives on childhood asthma.

关键词： Phthalate esters Organophosphate fame retardants Childhood asthma Lipid and fatty acid metabolism Machine-learning random forest model Chronic airway infammation

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microRNA-2184 orchestrates Mauthner-cell axon regeneration in zebrafish via syt3 modulation

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Journal of genetics and genomics 2024年第9期51卷 911-921页

作者： Xinghan chen Yueru Shen Zheng Song Xinliang Wang Huaitong Yao Yuan Cai Zi-ang Zhao Bing Hu Hefei National Research Center for Physical Sciences at the Microscale University of Science and Technology of ChinaHefeiAnhui 230026China The First Affiliated Hospital of USTC Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui 230026China Center for Advanced Interdisciplinary Science and Biomedicine of IHM Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui 230026China

MicroRNAs(miRNAs)play a significant role in axon regeneration following spinal cord ***,the functions of numerous miRNAs in axon regeneration within the central nervous system(CNS)remain largely ***,we elucidate the positive role of microRNA-2184(miR-2184)in axon regeneration within zebrafish Mauthner cells(M-cells).The upregulation of miR-2184 in a single M-cell can facilitate axon regeneration,while the specific sponge-induced silencing of miR-2184 leads to impeded *** show that syt3,a downstream target of miR-2184,negatively regulates axon regeneration,and the regeneration suppression modulated by syt3 depends on its binding to Ca2+.Furthermore,pharmacological stimulation of the cAMP/PKA pathway suggests that changes in the readily releasable pool may affect axon *** data indicate that miR-2184 promotes axon regeneration of M-cells within the CNS by modulating the downstream target syt3,providing valuable insights into potential therapeutic strategies.

关键词： Axon regeneration Axon ablation miR-2184 syt3 Readily releasable pool

A CNN-SVR model for NO_(2)profile prediction based on MAX-DOAS observations:The influence of Chinese New Year overlapping the 2020 COVID-19 lockdown on vertical distributions of tropospheric NO_(2)in Nanjing,China

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Journal of Environmental Sciences 2024年第7期141卷 151-165页

作者： Xin Tian Zijie Wang Pinhua Xie Jin Xu ang Li Yifeng Pan Feng Hu Zhaokun Hu Mingsheng chen Jiangyi Zheng Information Materials and Intelligent Sensing Laboratory of Anhui Province Institutes of Physical Science and Information TechnologyAnhui UniversityHefei 230601China Key laboratory of Environmental Optical and Technology Anhui Institute of optics and Fine MechanicsHefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China School of Environmental Science and Optoelectronic Technology University of Science and Technology of ChinaHefei 230026China

In this study,a hybrid model,the convolutional neural network-support vector regression model,was adopted to achieve prediction of the NO_(2)profile in Nanjing from January 2019to March *** the sudden decline in NO_(2)in February 2020,the contribution of the Coronavirus Disease-19(COVID-19)lockdown,Chinese New Year(CNY),and meteorologi cal conditions to the reduction of NO_(2)was ***_(2)vertical column densities(VCDs) from January to March 2020 decreased by 59.05%and 32.81%,relative to the same period in 2019 and 2021,*** the period of 2020 COVID-19,the average NO_(2)VCDs were 50.50%and 29.96%lower than those during the pre-lockdown and post-lockdown pe riods,*** NO_(2)volume mixing ratios(VMRs)during the 2020 COVID-19 lock down significantly decreased below 400 *** NO_(2)VMRs under the different wind fields were significantly lower during the lockdown period than during the pre-lockdown period This phenomenon could be attributed to the 2020 COVID-19 *** NO_(2)VMRs be fore and after the CNY were significantly lower in 2020 than in 2019 and 2021 in the same period,which further proves that the decrease in NO_(2)in February 2020 was attributed to the COVID-19 *** source analysis of an NO_(2)pollution episode during the lockdown period showed that the polluted air mass in the Beijing-Tianjin-Hebei was trans ported southwards under the action of the north wind,and the subsequent unfavorable meteorological conditions(local wind speed of<2.0 m/sec)resulted in the accumulation o pollutants.

关键词： MAX-DOAS CNN-SVR Nitrogen dioxide COVID-19 Chinese New Year Regional transport

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