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Research Methodology and Analysis of Innovative Pedagogical Models in Mechanical Engineering Courses for International Students at the School of Mechanical Engineering and Automation, Beihang University
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作者 Zhao Rui 《Contemporary Social Sciences》 2023年第5期141-155,共15页
Taking the engineering courses“Introduction to Mechanical Engineering”and“Machining Process”taught by the author at Beihang University’s International School as examples,this article systematically analyzed the c... Taking the engineering courses“Introduction to Mechanical Engineering”and“Machining Process”taught by the author at Beihang University’s International School as examples,this article systematically analyzed the current status and background of international student education,focused on research strategies for interdisciplinary education and industry-education integration innovation models from the perspectives of technical demands,student needs,and societal requirements.This article aims to cultivate highly qualified international students who come to China for their studies,help them better adapt to China’s social employment environment,and enhance their capabilities for career development in China.This article proposes a comprehensive set of innovative teaching models for mechanical engineering courses for international students at Beihang University,which encompasses eight key aspects,including talent development programs,curriculum outline reforms,optimization of classroom teaching content,respect for individual student characteristics,the establishment of practical teaching components,the use of open-ended assignments to stimulate enthusiasm for learning,the cultivation of international students’interest in China,their belief in developing friendships with China,and their goals of staying in China,and the incorporation of external experts to facilitate industry-education integration. 展开更多
关键词 international students mechanical courses teaching models strategies and practices
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Human lunar base:“Lunar Palace 1”team of Beihang University unveils China’s“Lunar Palace”plan
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作者 Hui Liu Zhikai Yao Hong Liu 《The Innovation》 EI 2024年第2期3-4,共2页
Recently,the“Lunar Palace 1”team of Beihang University,China,in response to the long-term habitation and healthcare of humans on the Moon,released the“Lunar Palace”plan through the official account“Beihang Univer... Recently,the“Lunar Palace 1”team of Beihang University,China,in response to the long-term habitation and healthcare of humans on the Moon,released the“Lunar Palace”plan through the official account“Beihang University”on WeChat’s video platform.With the development of crewed deep-space exploration,human permanent residence on the Moon is no longer an unattainable dream but an anticipated future.Humans on the Moon will live in a Lunar Palace equipped with a bioregenerative life support system(BLSS),creating an Earth-like environment,much like the Lunar Palace 1 facility on Earth. 展开更多
关键词 EARTH HUMAN equipped
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Passive activity enhances residual control ability in patients with complete spinal cord injury 被引量:2
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作者 Yanqing Xiao Mingming Gao +6 位作者 Zejia He Jia Zheng Hongming Bai Jia-Sheng Rao Guiyun Song Wei Song Xiaoguang Li 《Neural Regeneration Research》 SCIE CAS 2025年第8期2337-2347,共11页
Patients with complete spinal cord injury retain the potential for volitional muscle activity in muscles located below the spinal injury level.However,because of prolonged inactivity,initial attempts to activate these... Patients with complete spinal cord injury retain the potential for volitional muscle activity in muscles located below the spinal injury level.However,because of prolonged inactivity,initial attempts to activate these muscles may not effectively engage any of the remaining neurons in the descending pathway.A previous study unexpectedly found that a brief clinical round of passive activity significantly increased volitional muscle activation,as measured by surface electromyography.In this study,we further explored the effect of passive activity on surface electromyographic signals during volitional control tasks among individuals with complete spinal cord injury.Eleven patients with chronic complete thoracic spinal cord injury were recruited.Surface electromyography data from eight major leg muscles were acquired and compared before and after the passive activity protocol.The results indicated that the passive activity led to an increased number of activated volitional muscles and an increased frequency of activation.Although the cumulative root mean square of surface electromyography amplitude for volitional control of movement showed a slight increase after passive activity,the difference was not statistically significant.These findings suggest that brief passive activity may enhance the ability to initiate volitional muscle activity during surface electromyography tasks and underscore the potential of passive activity for improving residual motor control among patients with motor complete spinal cord injury. 展开更多
关键词 complete spinal cord injury cycle training epidural electrical stimulation motor training passive activity physiological state spinal cord circuit surface electromyography volitional control task
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Assessing the corrosion protection property of coatings loaded with corrosion inhibitors using the real-time atmospheric corrosion monitoring technique 被引量:1
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作者 Xiaoxue Wang Lulu Jin +8 位作者 Jinke Wang Rongqiao Wang Xiuchun Liu Kai Gao Jingli Sun Yong Yuan Lingwei Ma Hongchang Qian Dawei Zhang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2025年第1期119-126,共8页
The atmospheric corrosion monitoring(ACM)technique has been widely employed to track the real-time corrosion behavior of metal materials.However,limited studies have applied ACM to the corrosion protection properties ... The atmospheric corrosion monitoring(ACM)technique has been widely employed to track the real-time corrosion behavior of metal materials.However,limited studies have applied ACM to the corrosion protection properties of organic coatings.This study compared a bare epoxy coating with one containing zinc phosphate corrosion inhibitors,both applied on ACM sensors,to observe their corrosion protection properties over time.Coatings with artificial damage via scratches were exposed to immersion and alternating dry and wet environments,which allowed for monitoring galvanic corrosion currents in real-time.Throughout the corrosion tests,the ACM currents of the zinc phosphate/epoxy coating were considerably lower than those of the blank epoxy coating.The trend in ACM current variations closely matched the results obtained from regular electrochemical tests and surface analysis.This alignment highlights the potential of the ACM technique in evaluating the corrosion protection capabilities of organic coatings.Compared with the blank epoxy coating,the zinc phosphate/epoxy coating showed much-decreased ACM current values that confirmed the effective inhibition of zinc phosphate against steel corrosion beneath the damaged coating. 展开更多
关键词 atmospheric corrosion monitoring technology corrosion inhibitor COATING carbon steel corrosion protection
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Artificial Intelligence-Enhanced Digital Twin Systems Engineering Towards the Industrial Metaverse in the Era of Industry 5.0 被引量:3
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作者 He Zhang Yilin Li +2 位作者 Shuai Zhang Lukai Song Fei Tao 《Chinese Journal of Mechanical Engineering》 2025年第2期98-119,共22页
With the continuous advancement and maturation of technologies such as big data,artificial intelligence,virtual reality,robotics,human-machine collaboration,and augmented reality,many enterprises are finding new avenu... With the continuous advancement and maturation of technologies such as big data,artificial intelligence,virtual reality,robotics,human-machine collaboration,and augmented reality,many enterprises are finding new avenues for digital transformation and intelligent upgrading.Industry 5.0,a further extension and development of Industry 4.0,has become an important development trend in industry with more emphasis on human-centered sustainability and flexibility.Accordingly,both the industrial metaverse and digital twins have attracted much attention in this new era.However,the relationship between them is not clear enough.In this paper,a comparison between digital twins and the metaverse in industry is made firstly.Then,we propose the concept and framework of Digital Twin Systems Engineering(DTSE)to demonstrate how digital twins support the industrial metaverse in the era of Industry 5.0 by integrating systems engineering principles.Furthermore,we discuss the key technologies and challenges of DTSE,in particular how artificial intelligence enhances the application of DTSE.Finally,a specific application scenario in the aviation field is presented to illustrate the application prospects of DTSE. 展开更多
关键词 Digital twins Systems engineering Industrial metaverse Artificial intelligence Industry 5.0 Smart manufacturing
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Structural Topology Design for Electromagnetic Performance Enhancement of Permanent-Magnet Machines 被引量:2
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作者 Pengjie Xiang Liang Yan +3 位作者 Xiaoshuai Liu Xinghua He Nannan Du Han Wang 《Chinese Journal of Mechanical Engineering》 2025年第1期411-432,共22页
Permanent-magnet(PM)machines are the important driving components of various mechanical equipment and industrial applications,such as robot joints,aerospace equipment,electric vehicles,actuators,wind generators and el... Permanent-magnet(PM)machines are the important driving components of various mechanical equipment and industrial applications,such as robot joints,aerospace equipment,electric vehicles,actuators,wind generators and electric traction systems.The PM machines are usually expected to have high torque/power density,low torque ripple,reduced rotor mass,a large constant power speed range or strong anti-magnetization capability to match different requirements of industrial applications.The structural topology of the electric machines,including stator/rotor arrangements and magnet patterns of rotor,is one major concern to improve their electromagnetic performance.However,systematic reviews of structural topology are seldom found in literature.Therefore,the objective of this paper is to summarize the stator/rotor arrangements and magnet patterns of the permanent-magnet brushless machines,in depth.Specifically,the stator/rotor arrangements of the PM machines including radial-flux,axialflux and emerging hybrid axial-radial flux configurations are presented,and pros and cons of these topologies are discussed regarding their electromagnetic performance.The magnet patterns including various surface-mounted and interior magnet patterns,such as parallel magnetization pole pattern,Halbach arrays,spoke-type designs and their variants are summarized,and the characteristics of those magnet patterns in terms of flux-focusing effect,magnetic self-shielding effect,torque ripple,reluctance torque,magnet utilization ratio,and anti-demagnetization capability are compared.This paper can provide guidance and suggestion for the structure selection and design of PM brushless machines for high-performance industrial applications. 展开更多
关键词 Actuators Robot joint Electric-vehicle motor Permanent-magnet machines Axial-flux PM machine Dualrotor machine Magnet patterns Torque density Torque ripple Power density
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Dynamic effect web generation for heterogeneous UAV cluster using DQN-based NSGA-Ⅱ:Methods and applications 被引量:1
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作者 Pei CHI Chen LIU +2 位作者 Jiang ZHAO Kun WU Yingxun WANG 《Chinese Journal of Aeronautics》 2025年第7期374-388,共15页
Effect web will be an important combat means to achieve accurate,efficient,agile and reliable destruction of enemy targets.The use of Unmanned Aerial Vehicles(UAV)cluster in warfare has become a key element in the bat... Effect web will be an important combat means to achieve accurate,efficient,agile and reliable destruction of enemy targets.The use of Unmanned Aerial Vehicles(UAV)cluster in warfare has become a key element in the battle for military superiority between nations.The construction of UAV cluster effect web is a kind of combinatorial optimization in essence.By selecting the optimal combination in the limited equipment concentration,the whole network can be optimized.Firstly,in order to improve the combinatorial optimization efficiency of UAV cluster effect web,NSGA-Ⅱbased on deep Q-network(DQN-based NSGA-Ⅱ)is proposed.This algorithm is used to solve the Multi-Objective Combinatorial Optimization(MOCO)problem in the construction of effect web.Secondly,a dynamic generation method is devised to solve the problem caused by the possible destruction of enemy and our node under the fierce confrontation between the two sides.Finally,the simulation results show that the DQN-based NSGA-Ⅱis better than the genetic algorithm with single operator.The comparison experiment shows that the weight of evaluation indexes will have a corresponding influence on the optimization results. 展开更多
关键词 Optimization Effect web Unmanned Aerial Vehicles(UAV) Deep learning Genetic algorithm
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SCS-Net:A DNN-based electromagnetic shielding effectiveness analysis method for slotted composite structures 被引量:1
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作者 Wanli DU Guangzhi CHEN +4 位作者 Ziang ZHANG Xinsong WANG Shunchuan YANG Xingye CHEN Donglin SU 《Chinese Journal of Aeronautics》 2025年第3期505-520,共16页
As the proportion of composite materials used in aircraft continues to increase, the electromagnetic Shielding Effectiveness (SE) of these materials becomes a critical factor in the electromagnetic safety design of ai... As the proportion of composite materials used in aircraft continues to increase, the electromagnetic Shielding Effectiveness (SE) of these materials becomes a critical factor in the electromagnetic safety design of aircraft structures. The assessment of electromagnetic SE for Slotted Composite Structures(SCSs) is particularly challenging due to their complex geometries and there remains a lack of suitable models for accurately predicting the SE performance of these intricate configurations. To address this issue, this paper introduces SCS-Net, a Deep Neural Network (DNN) method designed to accurately predict the SE of SCS. This method considers the impacts of various structural parameters, material properties and incident wave parameters on the SE of SCSs. In order to better model the SCS, an improved Nicolson-Ross-Weir (NRW) method is introduced in this paper to provide an equivalent flat structure for the SCS and to calculate the electromagnetic parameters of the equivalent structure. Additionally, the prediction of SE via DNNs is limited by insufficient test data, which hinders support for large-sample training. To address the issue of limited measured data, this paper develops a Measurement-Computation Fusion (MCF) dataset construction method. The predictions based on the simulation results show that the proposed method maintains an error of less than 0.07 dB within the 8–10 GHz frequency range. Furthermore, a new loss function based on the weighted L1-norm is established to improve the prediction accuracy for these parameters. Compared with traditional loss functions, the new loss function reduces the maximum prediction error for equivalent electromagnetic parameters by 47%. This method significantly improves the prediction accuracy of SCS-Net for measured data, with a maximum improvement of 23.88%. These findings demonstrate that the proposed method enables precise SE prediction and design for composite structures while reducing the number of test samples needed. 展开更多
关键词 Deep neural networkcs Measurement-computation fusion Electromagnetic shielding effectiveness Slotted composite structures Structural paranmeters
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Clustering optimization strategy for cooperative positioning system aided by UAV 被引量:1
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作者 Hongbo ZHAO Zeqi YIN Shan HU 《Chinese Journal of Aeronautics》 2025年第9期421-435,共15页
For multi-vehicle networks,Cooperative Positioning(CP)technique has become a promising way to enhance vehicle positioning accuracy.Especially,the CP performance could be further improved by introducing Sensor-Rich Veh... For multi-vehicle networks,Cooperative Positioning(CP)technique has become a promising way to enhance vehicle positioning accuracy.Especially,the CP performance could be further improved by introducing Sensor-Rich Vehicles(SRVs)into CP networks,which is called SRV-aided CP.However,the CP system may split into several sub-clusters that cannot be connected with each other in dense urban environments,in which the sub-clusters with few SRVs will suffer from degradation of CP performance.Since Unmanned Aerial Vehicles(UAVs)have been widely used to aid vehicular communications,we intend to utilize UAVs to assist sub-clusters in CP.In this paper,a UAV-aided CP network is constructed to fully utilize information from SRVs.First,the inter-node connection structure among the UAV and vehicles is designed to share available information from SRVs.After that,the clustering optimization strategy is proposed,in which the UAV cooperates with the high-precision sub-cluster to obtain available information from SRVs,and then broadcasts this positioning-related information to other low-precision sub-clusters.Finally,the Locally-Centralized Factor Graph Optimization(LC-FGO)algorithm is designed to fuse positioning information from cooperators.Simulation results indicate that the positioning accuracy of the CP system could be improved by fully utilizing positioning-related information from SRVs. 展开更多
关键词 Clustering optimization Cooperative positioning Locally-centralized FGO Networking wireless sensors Unmanned aerial vehicles Urban degradation environments
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Cumulative thermal coupling modeling and analysisof oil-immersed motor-pump assembly forelectro–hydrostatic actuator 被引量:1
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作者 Siming FAN Shaoping WANG +3 位作者 Qiyang WANG Xingjian WANG Di LIU Xiao WU 《Chinese Journal of Aeronautics》 2025年第5期394-410,共17页
The Electro–Hydrostatic Actuator(EHA)is applied to drive the control surface in flightcontrol system of more electric aircraft.In EHA,the Oil-Immersed Motor Pump(OMP)serves asthe core as a power assembly.However,the ... The Electro–Hydrostatic Actuator(EHA)is applied to drive the control surface in flightcontrol system of more electric aircraft.In EHA,the Oil-Immersed Motor Pump(OMP)serves asthe core as a power assembly.However,the compact integration of the OMP presents challenges inefficiently dissipating internal heat,leading to a performance degradation of the EHA due to ele-vated temperatures.Therefore,accurately modeling and predicting the internal thermal dynamicsof the OMP hold considerable significance for monitoring the operational condition of the EHA.In view of this,a modeling method considering cumulative thermal coupling was hereby proposed.Based on the proposed method,the thermal models of the motor and the pump were established,taking into account heat accumulation and transfer.Taking the leakage oil as the heat couplingpoint between the motor and the pump,the dynamic thermal coupling model of the OMP wasdeveloped,with the thermal characteristics of the oil considered.Additionally,the comparativeexperiments were conducted to illustrate the efficiency of the proposed model.The experimentalresults demonstrate that the proposed dynamic thermal coupling model accurately captured thethermal behavior of OMP,outperforming the static thermal parameter model.Overall,thisadvancement is crucial for effectively monitoring the health of EHA and ensuring flight safety. 展开更多
关键词 Electro-hydrostatic actuator Oil-immersed motor-pump Dynamic thermal coupling model Heat transfer Heat accumulation
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A LODBO algorithm for multi-UAV search and rescue path planning in disaster areas 被引量:1
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作者 Liman Yang Xiangyu Zhang +2 位作者 Zhiping Li Lei Li Yan Shi 《Chinese Journal of Aeronautics》 2025年第2期200-213,共14页
In disaster relief operations,multiple UAVs can be used to search for trapped people.In recent years,many researchers have proposed machine le arning-based algorithms,sampling-based algorithms,and heuristic algorithms... In disaster relief operations,multiple UAVs can be used to search for trapped people.In recent years,many researchers have proposed machine le arning-based algorithms,sampling-based algorithms,and heuristic algorithms to solve the problem of multi-UAV path planning.The Dung Beetle Optimization(DBO)algorithm has been widely applied due to its diverse search patterns in the above algorithms.However,the update strategies for the rolling and thieving dung beetles of the DBO algorithm are overly simplistic,potentially leading to an inability to fully explore the search space and a tendency to converge to local optima,thereby not guaranteeing the discovery of the optimal path.To address these issues,we propose an improved DBO algorithm guided by the Landmark Operator(LODBO).Specifically,we first use tent mapping to update the population strategy,which enables the algorithm to generate initial solutions with enhanced diversity within the search space.Second,we expand the search range of the rolling ball dung beetle by using the landmark factor.Finally,by using the adaptive factor that changes with the number of iterations.,we improve the global search ability of the stealing dung beetle,making it more likely to escape from local optima.To verify the effectiveness of the proposed method,extensive simulation experiments are conducted,and the result shows that the LODBO algorithm can obtain the optimal path using the shortest time compared with the Genetic Algorithm(GA),the Gray Wolf Optimizer(GWO),the Whale Optimization Algorithm(WOA)and the original DBO algorithm in the disaster search and rescue task set. 展开更多
关键词 Unmanned aerial vehicle Path planning Meta heuristic algorithm DBO algorithm NP-hard problems
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Fast-zoom and high-resolution sparse compound-eye camera based on dual-end collaborative optimization 被引量:1
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作者 Yi Zheng Hao-Ran Zhang +5 位作者 Xiao-Wei Li You-Ran Zhao Zhao-Song Li Ye-Hao Hou Chao Liu Qiong-Hua Wang 《Opto-Electronic Advances》 2025年第6期4-15,共12页
Due to the limitations of spatial bandwidth product and data transmission bandwidth,the field of view,resolution,and imaging speed constrain each other in an optical imaging system.Here,a fast-zoom and high-resolution... Due to the limitations of spatial bandwidth product and data transmission bandwidth,the field of view,resolution,and imaging speed constrain each other in an optical imaging system.Here,a fast-zoom and high-resolution sparse compound-eye camera(CEC)based on dual-end collaborative optimization is proposed,which provides a cost-effective way to break through the trade-off among the field of view,resolution,and imaging speed.In the optical end,a sparse CEC based on liquid lenses is designed,which can realize large-field-of-view imaging in real time,and fast zooming within 5 ms.In the computational end,a disturbed degradation model driven super-resolution network(DDMDSR-Net)is proposed to deal with complex image degradation issues in actual imaging situations,achieving high-robustness and high-fidelity resolution enhancement.Based on the proposed dual-end collaborative optimization framework,the angular resolution of the CEC can be enhanced from 71.6"to 26.0",which provides a solution to realize high-resolution imaging for array camera dispensing with high optical hardware complexity and data transmission bandwidth.Experiments verify the advantages of the CEC based on dual-end collaborative optimization in high-fidelity reconstruction of real scene images,kilometer-level long-distance detection,and dynamic imaging and precise recognition of targets of interest. 展开更多
关键词 compound-eye camera ZOOM high resolution collaborative optimization
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Fluid-based moderate collision avoidance for UAV formation in 3-D low-altitude environments 被引量:1
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作者 Menghua ZHANG Honglun WANG +5 位作者 Zhiyu LI Yanxiang WANG Xianglun ZHANG Qiang TANG Shichao MA Jianfa WU 《Chinese Journal of Aeronautics》 2025年第6期533-551,共19页
Aiming to address the Unmanned Aerial Vehicle(UAV) formation collision avoidance problem in Three-Dimensional(3-D) low-altitude environments where dense various obstacles exist, a fluid-based path planning framework n... Aiming to address the Unmanned Aerial Vehicle(UAV) formation collision avoidance problem in Three-Dimensional(3-D) low-altitude environments where dense various obstacles exist, a fluid-based path planning framework named the Formation Interfered Fluid Dynamical System(FIFDS) with Moderate Evasive Maneuver Strategy(MEMS) is proposed in this study.First, the UAV formation collision avoidance problem including quantifiable performance indexes is formulated. Second, inspired by the phenomenon of fluids continuously flowing while bypassing objects, the FIFDS for multiple UAVs is presented, which contains a Parallel Streamline Tracking(PST) method for formation keeping and the traditional IFDS for collision avoidance. Third, to rationally balance flight safety and collision avoidance cost, MEMS is proposed to generate moderate evasive maneuvers that match up with collision risks. Comprehensively containing the time and distance safety information, the 3-D dynamic collision regions are modeled for collision prediction. Then, the moderate evasive maneuver principle is refined, which provides criterions of the maneuver amplitude and direction. On this basis, an analytical parameter mapping mechanism is designed to online optimize IFDS parameters. Finally, the performance of the proposed method is validated by comparative simulation results and real flight experiments using fixed-wing UAVs. 展开更多
关键词 Unmanned aerial vehicle Formation collision avoidance:3-D low-altitude environments Interfered fluid dynamical system 3-D dynamic collision region
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The Collaborative Development of Sensors and Artificial Intelligence 被引量:1
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作者 Shangchun Fan Feiyang Zhang Yufu Qu 《Instrumentation》 2025年第1期1-10,共10页
Sensors are the source of information technology and the first unit of intelligent systems,providing real-world"data"for artificial intelligence.They play a crucial role in various aspects of the national ec... Sensors are the source of information technology and the first unit of intelligent systems,providing real-world"data"for artificial intelligence.They play a crucial role in various aspects of the national economy and the people's livelihood,such as national defense security and the development of new quality productive forces.This paper provides a comprehensive survey of how sensors should adapt to the current upsurge of artificial intelligence,analyzing their technical connotations,application characteristics,and inherent limitations.Furthermore,with a sensor-oriented mindset,it is proposed that sensors will dominate information technology,upgrade connotations,advance ubiquitous bionic intelligence and engage in a"symbiotic dance"with artificial intelligence.This overview provides a promising direction for the higher-level development of sensors and artificial intelligence. 展开更多
关键词 SENSOR artificial intelligence information technology new quality productive forces collaborative development
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Synthesis and high frequency structure simulator electromagnetic simulation of hollow NC@CeO_(2)nanospheres for broad absorption bandwidth 被引量:1
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作者 Shuhao Yang Peiyan Zhao +5 位作者 Xianyong Lu Xiaoyuan Hao Yufan Wu Huiya Wang Tao Zhou Guangsheng Wang 《International Journal of Minerals,Metallurgy and Materials》 2025年第3期678-688,共11页
Recent progress in microwave absorption materials stimulates the extensive exploration of rare earth oxide materials.Herein,we report the synthesis of a hollow sphere-based carbon material compounded with rare earth o... Recent progress in microwave absorption materials stimulates the extensive exploration of rare earth oxide materials.Herein,we report the synthesis of a hollow sphere-based carbon material compounded with rare earth oxides.Hollow N-doped carbon nano-spheres loaded ceria composites(H-NC@CeO_(2))were designed and prepared by the template method,combined with in-situ coating,pyrolysis and chemical etching.By controlling the loading content of H-NC@CeO_(2)and adjusting the impedance matching of the material,the H-NC@CeO_(2)/PS(polystyrene)composite exhibited a minimum reflection loss(RL)of-50.8 dB and an effective absorption band-width(EAB)of 4.64 GHz at a filler ratio of 20wt%and a thickness of 2 mm.In accordance with measured electromagnetic parameters,simulations using the high frequency structure simulator(HFSS)software were conducted to investigate the impact of the honeycomb structure on the electromagnetic wave performance of H-NC@CeO_(2)/PS.By calculating the surface electric field and the material’s bulk loss density,the mechanism of electromagnetic loss for the honeycomb structure was elaborated.A method for structural design and man-ufacturing of broadband absorbing devices was proposed and a broadband absorber with an EAB of 11.9 GHz was prepared.This study presents an innovative approach to designing advanced electromagnetic(EM)wave absorbing materials with broad absorption band-widths. 展开更多
关键词 rare earth oxides carbon matrix composites hollow structure electromagnetic simulation
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Resource Allocation for RSMA-Aided Multibeam Satellite Communications 被引量:1
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作者 Cui Huanxi Xiao Zhenyu Zhu Lipeng 《China Communications》 2025年第2期241-255,共15页
This paper investigates the resource allocation for rate-splitting multiple access(RSMA)enabled multibeam satellite communication systems.Specifically,we minimize the total unmet user rate,which denotes the difference... This paper investigates the resource allocation for rate-splitting multiple access(RSMA)enabled multibeam satellite communication systems.Specifically,we minimize the total unmet user rate,which denotes the difference between the users’rate requirement and the practical achievable rate,as well as the total transmit power of the satellite by optimizing the precoding,power allocation,and rate allocation,under the per-feed power and rate constraints.To solve the non-convex optimization problem,a twostage scheme is proposed.In particular,in the first stage,we present a precoding scheme by maximizing the signal-to-leakage-plus-noise ratio of each beam to eliminate the inter-beam interference.In the second stage,we introduce auxiliary variables to obtain an upper bound on the objective function under the given precoding matrix and transform the rate constraints of the original problem into second-order cones(SOC)and linear matrix inequations(LMI).Then,the successive convex approximation(SCA)technique is used to obtain suboptimal power and rate allocation solutions.Moreover,the initial feasible solution for power allocation is provided by using the standard interior point method.Finally,numerical results verify the superiority of our proposed solution compared to the benchmark methods in terms of objective function values. 展开更多
关键词 multibeam satellite power allocation PRECODING rate allocation rate-splitting multiple access(RSMA)
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Insight Into the Separation-of-Variable Methods for the Closed-Form Solutions of Free Vibration of Rectangular Thin Plates
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作者 Yufeng Xing Ye Yuan Gen Li 《Computer Modeling in Engineering & Sciences》 SCIE EI 2025年第1期329-355,共27页
The separation-of-variable(SOV)methods,such as the improved SOV method,the variational SOV method,and the extended SOV method,have been proposed by the present authors and coworkers to obtain the closed-form analytica... The separation-of-variable(SOV)methods,such as the improved SOV method,the variational SOV method,and the extended SOV method,have been proposed by the present authors and coworkers to obtain the closed-form analytical solutions for free vibration and eigenbuckling of rectangular plates and circular cylindrical shells.By taking the free vibration of rectangular thin plates as an example,this work presents the theoretical framework of the SOV methods in an instructive way,and the bisection–based solution procedures for a group of nonlinear eigenvalue equations.Besides,the explicit equations of nodal lines of the SOV methods are presented,and the relations of nodal line patterns and frequency orders are investigated.It is concluded that the highly accurate SOV methods have the same accuracy for all frequencies,the mode shapes about repeated frequencies can also be precisely captured,and the SOV methods do not have the problem of missing roots as well. 展开更多
关键词 Separation-of-variable method Rayleigh quotient nodal line eigenvalue equation bisection method
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Improving DOA estimation of GNSS interference through sparse non-uniform array reconfiguration 被引量:1
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作者 Rongling LANG Hao XU +3 位作者 Fei GAO Zewen TANG Zhipeng WANG Amir HUSSAIN 《Chinese Journal of Aeronautics》 2025年第8期104-118,共15页
Interference significantly impacts the performance of the Global Navigation Satellite Systems(GNSS),highlighting the need for advanced interference localization technology to bolster anti-interference and defense capa... Interference significantly impacts the performance of the Global Navigation Satellite Systems(GNSS),highlighting the need for advanced interference localization technology to bolster anti-interference and defense capabilities.The Uniform Circular Array(UCA)enables concurrent estimation of the Direction of Arrival(DOA)in both azimuth and elevation.Given the paramount importance of stability and real-time performance in interference localization,this work proposes an innovative approach to reduce the complexity and increase the robustness of the DOA estimation.The proposed method reduces computational complexity by selecting a reduced number of array elements to reconstruct a non-uniform sparse array from a UCA.To ensure DOA estimation accuracy,minimizing the Cramér-Rao Bound(CRB)is the objective,and the Spatial Correlation Coefficient(SCC)is incorporated as a constraint to mitigate side-lobe.The optimization model is a quadratic fractional model,which is solved by Semi-Definite Relaxation(SDR).When the array has perturbations,the mathematical expressions for CRB and SCC are re-derived to enhance the robustness of the reconstructed array.Simulation and hardware experiments validate the effectiveness of the proposed method in estimating interference DOA,showing high robustness and reductions in hardware and computational costs associated with DOA estimation. 展开更多
关键词 GNSS interference location Direction of arrival estimation Adaptive reconfigurable array Cramér-Raobound Quadratic fractional programming
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Few-shot anomaly detection with adaptive feature transformation and descriptor construction 被引量:1
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作者 Zhengnan HU Xiangrui ZENG +4 位作者 Yiqun LI Zhouping YIN Erli MENG Leyan ZHU Xianghao KONG 《Chinese Journal of Aeronautics》 2025年第3期491-504,共14页
Anomaly Detection (AD) has been extensively adopted in industrial settings to facilitate quality control of products. It is critical to industrial production, especially to areas such as aircraft manufacturing, which ... Anomaly Detection (AD) has been extensively adopted in industrial settings to facilitate quality control of products. It is critical to industrial production, especially to areas such as aircraft manufacturing, which require strict part qualification rates. Although being more efficient and practical, few-shot AD has not been well explored. The existing AD methods only extract features in a single frequency while defects exist in multiple frequency domains. Moreover, current methods have not fully leveraged the few-shot support samples to extract input-related normal patterns. To address these issues, we propose an industrial few-shot AD method, Feature Extender for Anomaly Detection (FEAD), which extracts normal patterns in multiple frequency domains from few-shot samples under the guidance of the input sample. Firstly, to achieve better coverage of normal patterns in the input sample, we introduce a Sample-Conditioned Transformation Module (SCTM), which transforms support features under the guidance of the input sample to obtain extra normal patterns. Secondly, to effectively distinguish and localize anomaly patterns in multiple frequency domains, we devise an Adaptive Descriptor Construction Module (ADCM) to build and select pattern descriptors in a series of frequencies adaptively. Finally, an auxiliary task for SCTM is designed to ensure the diversity of transformations and include more normal patterns into support features. Extensive experiments on two widely used industrial AD datasets (MVTec-AD and VisA) demonstrate the effectiveness of the proposed FEAD. 展开更多
关键词 Industrial applications Anomaly detection Learning algorithms Feature extraction Feature selection
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Wearable Biodevices Based on Two-Dimensional Materials:From Flexible Sensors to Smart Integrated Systems 被引量:1
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作者 Yingzhi Sun Weiyi He +3 位作者 Can Jiang Jing Li Jianli Liu Mingjie Liu 《Nano-Micro Letters》 2025年第5期207-255,共49页
The proliferation of wearable biodevices has boosted the development of soft,innovative,and multifunctional materials for human health monitoring.The integration of wearable sensors with intelligent systems is an over... The proliferation of wearable biodevices has boosted the development of soft,innovative,and multifunctional materials for human health monitoring.The integration of wearable sensors with intelligent systems is an overwhelming tendency,providing powerful tools for remote health monitoring and personal health management.Among many candidates,two-dimensional(2D)materials stand out due to several exotic mechanical,electrical,optical,and chemical properties that can be efficiently integrated into atomic-thin films.While previous reviews on 2D materials for biodevices primarily focus on conventional configurations and materials like graphene,the rapid development of new 2D materials with exotic properties has opened up novel applications,particularly in smart interaction and integrated functionalities.This review aims to consolidate recent progress,highlight the unique advantages of 2D materials,and guide future research by discussing existing challenges and opportunities in applying 2D materials for smart wearable biodevices.We begin with an in-depth analysis of the advantages,sensing mechanisms,and potential applications of 2D materials in wearable biodevice fabrication.Following this,we systematically discuss state-of-the-art biodevices based on 2D materials for monitoring various physiological signals within the human body.Special attention is given to showcasing the integration of multi-functionality in 2D smart devices,mainly including self-power supply,integrated diagnosis/treatment,and human–machine interaction.Finally,the review concludes with a concise summary of existing challenges and prospective solutions concerning the utilization of2D materials for advanced biodevices. 展开更多
关键词 Two-dimensional material Wearable biodevice Flexible sensor Smart integrated system Healthcare
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