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Turbulent drag reduction by sector-shaped counter-flow dielectric barrier discharge plasma actuator

Chinese Physics B 2025年第2期34卷 362-370页

作者： Borui Zheng Shaojie Qi Minghao Yu Jianbo Zhang Linwu Wang Dongliang Bian School of Automation and Information Engineering Xi’an University of TechnologyXi’an 710048China School of Mechanical and Precision Instrument Engineering Xi’an University of TechnologyXi’an 710048China Science and Technology on Plasma Dynamics Laboratory Air Force Engineering UniversityXi’an 710038China Shaanxi Key Laboratory of Complex System Control and Intelligent Information Processing Xi’an 710048China Shaanxi University Key Laboratory of Photonic Power Devices and Discharge Regulation Xi’an 710048China

The primary objective in aircraft transportation is to minimize turbulent drag, thereby conserving energy and reducing emissions. We propose a sector-shaped counter-flow dielectric barrier discharge plasma actuator, which leverages jet synthesis for drag reduction. A drag control experiment was conducted in a low-speed wind tunnel with a controlled flow velocity of 9.6 m/s(Re = 1.445 × 10^(4)). This study investigated the effects of varying pulse frequencies and actuation voltages on the turbulent boundary layer. Using a hot-wire measurement system, we analyzed the pulsating and time-averaged velocity distributions within the boundary layer to evaluate the streamwise turbulent drag reduction. The results show that the local TDR decreases as the pulse frequency increases, reaching a maximum reduction of approximately 20.97% at a pulse frequency of 50 Hz. In addition, as the actuation voltage increases, the friction coefficient decreases, increasing the drag reduction rate. The maximum drag reduction of approximately 33.34% is achieved at an actuation voltage of 10 kV.

关键词： plasma flow control turbulent boundary layer turbulent drag reduction

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An intelligent matching method for the equivalent circuit of electrochemical impedance spectroscopy based on Random Forest

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材料科学技术（英文版） 2025年第6期209卷 300-310页

作者： Wenbo Chen Bingjun Yan Aidong Xu Xin Mu Xiufang Zhou Maowei Jiang Changgang Wang Rui Li Jie Huang Junhua Dong Key Laboratory of Networked Control Systems Chinese Academy of SciencesShenyang 110169China Shenyang Institute of Automation Chinese Academy of SciencesShenyang 110169China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang 110169China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Networked Control Systems Chinese Academy of SciencesShenyang 110169China Shenyang Institute of Automation Chinese Academy of SciencesShenyang 110169China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang 110169China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China General Research Institute China Oil & Gas Pipeline Network CorporationLangfang 065000China

One of the core works of analyzing Electrochemical Impedance Spectroscopy(EIS)data is to select an appropriate equivalent circuit model to quantify the parameters of the electrochemical reaction ***,this process often relies on human experience and judgment,which will introduce subjectivity and *** this paper,an intelligent approach is proposed for matching EIS data to their equivalent circuits based on the Random Forest *** can automatically select the most suitable equivalent circuit model based on the characteristics and patterns of EIS *** the typical scenario of metal corrosion,an atmospheric corrosion EIS dataset of low-carbon steel is constructed in this paper,which includes five different corrosion *** dataset was used to validate and evaluate the pro-posed method in this *** contributions of this paper can be summarized in three aspects:(1)This paper proposes a method for selecting equivalent circuit models for EIS data based on the Random Forest algorithm.(2)Using authentic EIS data collected from metal atmospheric corrosion,the paper es-tablishes a dataset encompassing five categories of metal corrosion scenarios.(3)The superiority of the proposed method is validated through the utilization of the established authentic EIS *** ex-periment results demonstrate that,in terms of equivalent circuit matching,this method surpasses other machine learning algorithms in both precision and ***,it shows strong applicability in the analysis of EIS data.

关键词： Electrochemical impedance spectroscopy Random forest Corrosion Equivalent circuit model

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Freestanding metamaterial with constant coupling response for terahertz flexible functional devices

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Photonics Research 2025年第1期13卷 177-186页

作者： QIUMING ZENG TINGTING SHI YI HUANG SHUNCONG ZHONG FUWEI SUN CHENGLONG GUAN JIANXIONG CHEN TINGLING LIN YUJIE ZHONG YONGLIN HUANG Fujian Provincial Key Laboratory of Terahertz Functional Devices and Intelligent Sensing School of Mechanical Engineering and AutomationFuzhou UniversityFuzhou 350108China Institute of Precision Instrument and Intelligent Measurement&Control Fuzhou UniversityFuzhou 350108China School of Economics and Management Minjiang UniversityFuzhou 350108China

Metamaterials(MMs)have become increasingly prominent in terahertz flexible ***,bending deformation often alters the structure of the unit,which affects the response performance and stability of ***,a metal-aperture metamaterial(MA-MM)utilizing the strong coupling effect induced by two resonance modes is innovatively proposed to address the mentioned ***,it is found that the coupling state between multiple resonance modes remains consistent at different bending *** these circumstances,the generated Rabi splitting peak presents stable response performance even under low resonance intensity caused by excessive *** experimental results demonstrate that despite the amplitude of two resonant peaks decreasing significantly by 87.6%,the Q-factor of the Rabi splitting only reduced by 14.8%.Furthermore,armed with the response mode of the Rabi splitting being unaffected by plasma excitation range,the designed MA-MMs are able to maintain constant Q-factors and frequencies on curved surfaces of varying *** findings exhibit the characteristics of electromagnetic response for multi-mode resonance-coupled MAMMs on different curved surfaces,presenting a novel design approach for terahertz flexible functional devices.

关键词： coupling splitting constant

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An Improved DeeplabV3+ Tile Image Positioning Method

An Improved DeeplabV3+ Tile Image Positioning Method

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2024 International Conference Optoelectronic Information and Optical Engineering, OIOE 2024

作者： Li, Xiaoyang Wang, Rui Tong, Xing Niu, Lianqiang Shenyang University of Technology Shenyang China Key Laboratory of Network Control Systems Chinese Academy of Sciences China Shenyang Institute of Automation Chinese Academy of Sciences China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of Sciences Shenyang China

ISBN: (数字)9781510688209

ISBN: (纸本)9781510688193

In order to improve the detection accuracy and efficiency of surface defects on ceramic tiles, a detection model based on DeepLabV3+and combined with MobileNetv2 for feature extraction was constructed. Using ECA attention mechanism and multi branch receptive field cascade fusion structure to expand the sampling range of global and local element features for the empty space pyramid pooling module ASPP of the original model. Meanwhile, the model decoder uses depthwise separable convolutions instead of the original standard convolutions. Experimental results have shown that the improved model has an MPA value of 96.12%, a MIou value of 97.29%, an F1 value of 90.03%, and an Accuracy value of 99.89%. Compared with the previous model, the improved model's indicators have increased by 4.07%, 4.44%, 2.04%, and 1.02%, respectively. The segmentation accuracy and detection speed have been significantly improved. The experimental results fully demonstrate that the algorithm proposed in this article can effectively complete the task of detecting surface defects on ceramic tiles. © 2025 SPIE.

关键词： Image segmentation

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Magnetic driving mechanics of a bistable composite cylindrical structure

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Smart Materials and Structures 2025年第4期34卷

作者： Wang, Bing Zhang, Shunnan Guan, Chenglong Zhong, Jianfeng Zhong, Shuncong Fujian Provincial Key Laboratory of Terahertz Functional Devices and Intelligent Sensing School of Mechanical Engineering and Automation Fuzhou University Fuzhou350108 China Institute of Precision Instrument and Intelligent Measurement & Control Fuzhou University Fuzhou350108 China

A bistable composite cylindrical structure is a thin-walled shell, stable in its extended and coiled configurations, that offers large shape-morphing capabilities without structural damage. It has been successfully applied to deployable structures and launched into orbit. Smart-morphing designs provide new freedom and flexibility for space-deployable mechanics, reducing structural weight and complexity. Here, we present a novel magnetically activated bistable composite cylindrical structure, where the fundamentals of the critical magnetic driving boundaries are revealed for the first time to develop a reversed smart-morphing design principle. This is achieved by employing a magnetically responsive area within a bistable composite, where the NdFeB particles are co-cured directly with the carbon layups to ensure good bonding. Theoretical analysis of the magnetic driving principle was developed to reveal the interacting mechanics of a bistable structure subjected to magnetic actuation. The magnetic field distribution was characterized through experiments;a series of magnetic-responsive bistable composite cylindrical samples were produced and subjected to magnetic activation to determine the critical shape transition intensities. Their shape-changing processes were also evaluated through mechanical testing and compared to the magnetic driving mechanics. It is found that there is an optimal level of magnetic particle concentration to minimize the magnetically responsive time and input energy. The critical boundaries in terms of the current and air gap are established through theoretical analysis and verified through experimental observations. The magnetic driving mechanics are then discussed and concluded in detail. This provides a simple and effective alternative for smart actuation and morphing control of bistable composite structures, supporting their future applications in deep space exploration. © 2025 IOP Publishing Ltd. All rights, including for text and data mini

关键词： Magnetic bubbles

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Electromagnetic stealth technology: A review of wave-absorbing structures

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Materials and Design 2025年 253卷

作者： Guan, Chenglong Su, Sihang Wang, Bing Zhong, Jianfeng Chen, Junhao Sun, Fuwei Zhan, Lihua Fujian Provincial Key Laboratory of Terahertz Functional Devices and Intelligent Sensing School of Mechanical Engineering and Automation Fuzhou University Fuzhou350108 China Institute of Precision Instrument and Intelligent Measurement & Control Fuzhou University Fuzhou350108 China School of Mechanical and Electrical Engineering Central South University Changsha410083 China

As the core combat force for gaining air superiority, fighter aircraft directly influence the course and outcome of modern warfare. To address the integrated operational mode of reconnaissance, command, control and strike under the development of optoelectronics and information technology, and improve the battlefield survivability and combat effectiveness, electromagnetic stealth performance has become a key feature for next-generation combat aircraft. On the basis of rational aerodynamic shaping to minimize the radar cross-section, the application of electromagnetic absorbing technology plays a pivotal role in further enhancing the stealth performance. In this paper, the research progress of electromagnetic absorbing technology is summarized in light of the demand for the development of high-performance collaborative combat capabilities for military fighters. Focusing on the most revolutionary direction-the electromagnetic absorbing structure, the challenges associated with its maneuverability, stealth, and operational applicability are analyzed. Furthermore, from the perspectives of material selection, structural design, and process optimization, the paper systematically discusses ways to enhance the overall performance of electromagnetic absorbing structures and offers recommendations for forthcoming research directions. © 2025 The Author(s)

关键词： Radar cross section

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Broadband mode-selective couplers of dual-core hollow core negative curvature fiber in the 1 μm band

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Optik 2025年 327卷

作者： Yang, Boyi Zhang, Jia Li Guo, Xiaojie Dong, Hangzhou Guo, Yinghao Li, Haisu Ren, Guobin Key Laboratory of All Optical Network and Advanced Telecommunication Network Ministry of Education Beijing Jiaotong University Beijing100044 China Institute of Lightwave Technology Beijing Jiaotong University Beijing100044 China Beijing Institute of Control and Electronic Technology Beijing100045 China MIIT Key Laboratory of Complex-Field Intelligent Exploration School of Optics and Photonics Beijing Institute of Technology Beijing100081 China

We design for the first time a dual-core hollow core negative curvature fiber mode-selective coupler (HCNCF-MSC) in the 1 μm band. The designed HCNCF-MSC consists of two structures, and we have analyzed the performance of these two structures separately. The shortest device length of HCNCF-MSC-A is 3.2 cm, achieving a mode conversion efficiency higher than 75 % within the transmission wavelength range of 0.8–1.7 μm. HCNCF-MSC-B can achieve mode conversion under four different core diameters, with the shortest device lengths being 4.5 cm, 3.8 cm, 3.0 cm, and 2.4 cm, respectively, and it realizes a mode conversion efficiency greater than 80 % within the transmission wavelength range of 0.8–1.7 μm. © 2025 Elsevier GmbH

关键词： 1 μm band Device lengths Mode conversion efficiency MSC

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Communication-Efficient Personalized Distributed Learning with Data and Node Heterogeneity

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IEEE Transactions on Cognitive Communications and networking 2025年

作者： Tian, Zhuojun Zhang, Zhaoyang Li, Yiwei Bennis, Mehdi Zhejiang University College of Information Science and Electronic Engineering Hangzhou310027 China University of Oulu Center for Wireless Communications Oulu90014 Finland State Key Laboratory of Industrial Control Technology Hangzhou310027 China Zhejiang Provincial Key Laboratory of Multimodal Communication Networks and Intelligent Information Processing Hangzhou310027 China Xiamen University of Technology Fujian Key Laboratory of Communication Network and Information Processing Xiamen361024 China

To jointly tackle the challenges of data and node heterogeneity in decentralized learning, we propose a distributed strong lottery ticket hypothesis (DSLTH), based on which a communication-efficient personalized learning algorithm is developed. In the proposed method, each local model is represented as the ‌Hadamard product of global real-valued parameters and a personalized binary mask for pruning. The local model is learned by updating and fusing the personalized binary masks while the real-valued parameters are fixed among different agents. To further reduce the complexity of hardware implementation, we incorporate a group sparse regularization term in the loss function, enabling the learned local model to achieve structured sparsity. Then, a binary mask aggregation algorithm is designed by introducing an intermediate aggregation tensor and adding a personalized fine-tuning step in each iteration, which constrains model updates towards the local data distribution. The proposed method effectively leverages the relativity among agents while meeting personalized requirements in heterogeneous node conditions. We also provide a theoretical proof for the DSLTH, establishing it as the foundation of the proposed method. Numerical simulations confirm the validity of the DSLTH and demonstrate the effectiveness of the proposed algorithm. © 2015 IEEE.

关键词： Iterative methods

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Indoor and outdoor bioaerosol distributions and concentration profiles during different seasons and pollution events in Qingdao city

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Building and Environment 2025年 279卷

作者： Zhao, Ru Guo, Liang Qi, Jianhua An, Taicheng Key Laboratory of Marine Environment and Ecology Ministry of Education Ocean University of China Qingdao266100 China Laboratory for Marine Ecology and Environmental Science Qingdao Marine Science and Technology Center Qingdao266237 China Qingdao Junray Intelligent Instrument Co . Ltd. Qingdao266108 China Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control School of Environmental Science and Engineering Institute of Environmental Health and Pollution Control Guangdong University of Technology Guangzhou510006 China

Most people spend more than 10 h indoors daily, accompanied by the deposition of pathogenic microbes in the respiratory system. This health risk has not been fully studied across different seasons and pollution events. We investigated bioaerosol samples from offices, laboratories, and outdoor environments at three universities in a typical coastal city. Using fluorescence microscopy with 4′,6-diamidino-2-phenylindole (DAPI) staining and live/dead BacLight™ staining, the concentrations of viable bacteria (VBs), nonviable bacteria (NVBs), and total airborne microbes (TAMs) were in the range of (3.21–6.02) × 103 cells/m3, (7.09–19.08) × 104 cells/m3, and (1.52–5.78) × 105 cells/m3, respectively. The outdoor levels of bioaerosols were consistent across the universities. The outdoor bacterial viability (1.8–14.4 %) was slightly lower than that at offices (2.71–15.94 %) and laboratories (2.12–19.34 %). Correlation analysis and indoor/outdoor (I/O) ratio comparisons revealed that outdoor sources exerted a dominant influence on indoor microbial concentrations. Notably, pollution events significantly altered both indoor and outdoor bioaerosol levels and their size distributions. During pollution events, indoor bioaerosol concentrations were 1.24–2.12 times higher than those on clean days, influenced primarily by relative humidity (RH) and particulate matter (PM) levels. The deposition characteristics of VBs from fine particles in the human respiratory tract during haze and dust events generally indicated higher levels indoors than outdoors, and higher in females than in males. The highest health risk index value was 0.752 during dust events. Our findings strongly suggested controlling indoor RH and PM levels, especially during pollution events, to reduce the health risks associated with pathogenic microbes. © 2025 Elsevier Ltd

关键词： Health risks

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Precision Synchronous control of Multiple Motion Systems: A Tube-Based MPC Approach

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IEEE/CAA Journal of Automatica Sinica 2025年第5期12卷 974-988页

作者： Chen, Shuaiqi Song, Fazhi Dong, Yue Cui, Ning Liu, Yang Chen, Xinkai School of Aeronautics Harbin Institute of Technology Department of Control Science and Engineering Harbin 150001 China Center of Ultra-precision Optoelectronic Instrument Engineering Harbin Institute of Technology Harbin 150080 China Ministry of Industry and Information Technology Key Laboratory of Ultra-Precision Intelligent Instrumentation Harbin 150080 China Shibaura Institute of Technology Department of Electronic and Information Systems Tokyo 3378570 Japan

Lithography machines operate in scanning mode for the fabrication of large-scale integrated circuits (ICs), requiring high-precision synchronous motion between the reticle and wafer stages. Disturbances generated by each stage during high-acceleration movements are transmitted through the base frame, resulting in degradation of synchronization performance. To address this challenge, this paper proposes a tube-based model predictive control (tube-MPC) approach for synchronization in lithography machines. First, the proposed modeling method accurately characterizes the coupling disturbances and synchronization dynamics. Subsequently, a tube-MPC approach is developed to ensure that the states of the nominal system are constrained within the terminal constraint set. To reduce the complexity of online computations, an approach is employed to transform online optimization problems into offline problems by creating an online lookup table. This enables the determination of optimal control inputs via a simplified online optimization algorithm. The robustness and trajectory tracking performance of the proposed approach are verified through simulation experiments, demonstrating its effectiveness in enhancing the synchronization performance of multiple motion systems. © 2014 Chinese Association of Automation.

关键词： Coupled disturbance model predictive control multiple systems precision motion control (PMC) robust control wafer scanner

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