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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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Enhanced dynamics of Al^(3+)/H^(+) ions in aqueous aluminum ion batteries:Construction of metastable structures in vanadium pentoxide upon oxygen vacancies

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Journal of Energy Chemistry 2025年第2期101卷 562-569,I0011页

作者： Zhibao Wang Hanqing Gu Tianci Wu Wenming Zhang Zhanyu Li Hebei Key Laboratory of Optic-Electronic Information and Materials National&Local Joint Engineering Laboratory of New Energy Photoelectric DevicesCollege of Physics Science and TechnologyHebei UniversityBaoding 071002HebeiChina

In recent years,aqueous aluminum ion batteries have been widely studied owing to their abundant energy storage and high theo retical *** in-depth study of vanadium oxide materials is necessary to address the precipitation of insoluble products covered cathode surface and the slow reaction ***,a method using a simple one-step hydrothermal preparation and oxalic acid to regulate oxygen vacancies has been reported.A high starting capacity(400 mAh g^(-1))can be achieved by Ov-V2O5,and it is capable of undergoing 200 cycles at 0.4 A g^(-1),with a termination discharge capacity of103 mAh g^(-1).Mechanism analysis demonstrated that metastable structures(AlxV2O5and HxV2O5)were constructed through the insertion of Al^(3+)/H^(+)during discharging,which existed in the lattice intercalation with *** incorporation of oxygen vacancies lowers the reaction energy barrier while improving the ion transport *** addition,the metastable structure allows the electrostatic interaction between Al3+and the main backbone to establish protection and optimize the transport *** parallel,this work exploits ex-situ characterization and DFT to obtain a profound insight into the instrumental effect of oxygen vacancies in the construction of metastable structures during in-situ electrochemical activation,with a view to better understanding the mechanism of the synergistic participation of Al3+and H+in the *** work not only reports a method for cathode materials to modulate oxygen vacancies,but also lays the foundation for a deeper understanding of the metastable structure of vanadium oxides.

关键词： Vanadium pentoxide Oxygen vacancies Electrochemical activation Metastable structure

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Enhancing H^(+)intercalation kinetics and stability in Cu^(2+)pre-intercalatedδ-MnO_(2)for aqueous aluminum batteries

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Journal of Energy Chemistry 2025年第3期102卷 126-133页

作者： Hanqing Gu Mingjun Chen Zhibao Wang Wenming Zhang Zhanyu Li Hebei Key Laboratory of Optic-Electronic Information and Materials National&Local Joint Engineering Laboratory of New Energy Photoelectric DevicesCollege of Physics Science and TechnologyHebei UniversityBaoding 071002HebeiChina

Aqueous aluminum ion batteries(AAIBs)have garnered extensive attention due to their environmental friendliness,high theoretical capacity,and low ***,the sluggish reaction kinetics and severe structural collapse of the cathode material,especially manganese oxide,during the cycling process have hindered its further ***,Cu^(2+)pre-interca la ted layeredδ-MnO_(2)was synthesized via a hydrothermal *** pre-intercalated Cu^(2+)ions not only improve the conductivity of MnO_(2)cathode but also stabilize the structure to enhance stability.X-ray absorption fine structure(XAFS)combined with density functional theory(DFT)calculations confirm the formation of the covalent bond between Cu and O,increasing the electronegativity of O atoms and enhancing the H^(+)adsorption ***,ex-situ measurements not only elucidate the Al^(3+)/H^(+)co-insertion energy storage mechanism but also demonstrate the high reversibility of the Cu-MnO_(2)cathode during *** work provides a promising modification approach for the application of manganese oxides in AAIBs.

关键词： Aqueous aluminum-ion batteries Energy storage mechanism MnO_(2)cathodes Cu^(2+)pre-intercalated

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Multi UAV Inspection Optimization for Offshore Wind Farms Considering Battery Exchange Process

IEEE Transactions on Intelligent Vehicles

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IEEE Transactions on Intelligent Vehicles 2024年 1-11页

作者： Fan, Tianyuan Fu, Lijun Guo, Chuangxin Zhang, Yan Sun, Lin College of Electrical Engineering Zhejiang University Hangzhou China National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering Wuhan China National Key Laboratory of Electromagnetic Energy Naval University of Engineering Wuhan China

Unmanned Aerial Vehicles (UAVs) have become a highly effective tool for inspecting Offshore Wind Farms (OWFs) due to their controllability, speed, and safety. A practical route planning program ensures timeliness of UAV OWFs inspection. The previous studies' models do not reflect real-world constraints of battery exchange operation-based UAV multistrip flights within UAV range and airport deployments. In this paper, an OWF inspection tasks allocation problem of UAVs (OWFI-TAP-of UAVs) is analyzed, which considers the UAV battery exchange process. Firstly, the UAV model to calculate the inspection time consumption is established, which considers the relation between UAV velocity and energy and the battery exchange process;then, a multi-UAV inspection task allocation model for minimizing the UAV inspection time by combining the Multiple Traveling Salesman Problem (MTSP) mathematical expressions and the battery exchange specificities is proposed. Secondly, an improved genetic algorithm (IGA) is proposed that includes a clustering initialization strategy and a task balance strategy to optimize the OWFI-TAP-of UAVs globally. Finally, taking Jiaxing OWF as the simulation case through numerical experiments validates the effectiveness of the proposed approach. IEEE

关键词： Genetic algorithms

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Orbit-Orbit Interaction in Spatiotemporal Optical Vortex

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engineering 2025年第2期45卷 44-51页

作者： Jian Chen Jie Zhao Xi Shen Dewei Mo Cheng-Wei Qiu Qiwen Zhan School of Optical-Electrical and Computer Engineering University of Shanghai for Science and TechnologyShanghai 200093China Shanghai Key Laboratory of Modern Optical System University of Shanghai for Science and TechnologyShanghai 200093China Department of Electrical and Computer Engineering National University of SingaporeSingapore 117583Singapore

While spin-orbit interaction has been extensively studied,few investigations have reported on the interaction between orbital angular momenta(OAMs).In this work,we study a new type of orbit-orbit coupling between the longitudinal OAM and the transverse OAM carried by a three-dimensional(3D)spatiotemporal optical vortex(STOV)in the process of tight *** 3D STOV possesses orthogonal OAMs in the x-y,t-x,and y-t planes,and is preconditioned to overcome the spatiotemporal astigmatism effect.x,y,and t are the axes in the spatiotemporal *** corresponding focused wavepacket is calculated by employing the Debye diffraction theory,showing that a phase singularity ring is generated by the interactions among the transverse and longitudinal vortices in the highly confined *** Fourier-transform decomposition of the Debye integral is employed to analyze the mechanism of the orbit-orbit *** is the first revelation of coupling between the longitudinal OAM and the transverse OAM,paving the way for potential applications in optical trapping,laser machining,nonlinear light-matter interactions,and more.

关键词： Spatiotemporal optical vortex Orbital angular momentum Momentum interaction Highly confined wavepacket Diffraction

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Residual diverse ensemble for long-tailed multi-label text classification

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science China(information sciences) 2024年第11期67卷 92-105页

作者： Jiangxin SHI Tong WEI Yufeng LI National Key Laboratory for Novel Software Technology Nanjing University School of Artificial Intelligence Nanjing University School of Computer Science and Engineering Southeast University Key Laboratory of Computer Network and Information Integration Southeast UniversityMinistry of Education

Long-tailed multi-label text classification aims to identify a subset of relevant labels from a large candidate label set, where the training datasets usually follow long-tailed label distributions. Many of the previous studies have treated head and tail labels equally, resulting in unsatisfactory performance for identifying tail labels. To address this issue, this paper proposes a novel learning method that combines arbitrary models with two steps. The first step is the “diverse ensemble” that encourages diverse predictions among multiple shallow classifiers, particularly on tail labels, and can improve the generalization of tail *** second is the “error correction” that takes advantage of accurate predictions on head labels by the base model and approximates its residual errors for tail labels. Thus, it enables the “diverse ensemble” to focus on optimizing the tail label performance. This overall procedure is called residual diverse ensemble(RDE). RDE is implemented via a single-hidden-layer perceptron and can be used for scaling up to hundreds of thousands of labels. We empirically show that RDE consistently improves many existing models with considerable performance gains on benchmark datasets, especially with respect to the propensity-scored evaluation ***, RDE converges in less than 30 training epochs without increasing the computational overhead.

关键词： multi-label learning extreme multi-label learning long-tailed distribution multi-label text classification ensemble learning

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Ultra-low power MoS2 optoelectronic synapse with wavelength sensitivity for color target recognition

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science China(information sciences) 2025年第4期68卷 187-196页

作者： Bo WEI Yabo CHEN Xiaotong HAN Yan KANG Bujia LIANG Cheng LI Xiaokuo YANG Liang FANG Yuanxi PENG Institute for Quantum Information & State Key Laboratory of High Performance Computing College of ComputerNational University of Defense Technology Fundamentals Department Air Force Engineering University College of Advanced Interdisciplinary Studies National University of Defense Technology Institute of Quantum Information Science and Technology College of ScienceNational University of Defense Technology College of Computer National University of Defense Technology

Optoelectronic synapses that integrate visual perception and pre-processing hold significant potential for neuromorphic vision systems（NVSs）. However, due to a lack of wavelength sensitivity, existing NVS mainly focuses on gray-scale image processing, making it challenging to recognize color images. Additionally, the high power consumption of optoelectronic synapses, compared to the 10 fJ energy consumption of biological synapses, limits their broader application. To address these challenges, an energy-efficient NVS capable of color target recognition in a noisy environment was developed,utilizing a MoS2optoelectronic synapse with wavelength sensitivity. Benefiting from the distinct photon capture capabilities of 450, 535, and 650 nm light, the optoelectronic synapse exhibits wavelength-dependent synaptic plasticity, including excitatory postsynaptic current（EPSC）, paired-pulse facilitation（PPF）, and long-term plasticity（LTP）. These properties can effectively mimic the visual memory and color discrimination functions of the human vision system. Results demonstrate that the NVS, based on MoS2optoelectronic synapses, can eliminate the color noise at the sensor level, increasing color image recognition accuracy from 50% to 90%. Importantly, the optoelectronic synapse operates at a low voltage spike of0.0005 V, consuming only 0.075 fJ per spike, surpassing the energy efficiency of both existing optoelectronic and biological synapses. This ultra-low power, color-sensitive device eliminates the need for color filters and offers great promise for future deployment in filter-free NVS.

关键词： optoelectronic synapse neuromorphic vision system color recognition 2D materials image pre-processing

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The synergistic effect of Lewis acidic etching V_(4)C_(3)(MXene)@CuSe_(2)/CoSe_(2) as an advanced cathode material for aluminum batteries

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Journal of Materials science & technology 2024年第10期177卷 205-213页

作者： Yi Wang Hanqing Gu Yong Lu Wenming Zhang Zhanyu Li Hebei Key Laboratory of Optic-Electronic Information and Materials National&Local Joint Engineering Laboratory of New Energy Photoelectric DevicesCollege of Physics Science and TechnologyHebei UniversityBaoding 071002China

Herein,we focused on the development of the V_(4)C_(3) MXene composite bimetallic selenide heterostruc-ture(V_(4)C_(3)@CuSe_(2)/CoSe_(2))as a cathode material for aluminum *** heterostructure was pre-pared through a Lewis melt salt etching and selenization *** capitalizing on the synergistic effect between the bimetallic selenide and V_(4)C_(3) MXene,V_(4)C_(3)@CuSe_(2)/CoSe_(2) exhibited rapid charge transfer and demonstrated superior discharge specific capacity compared to V_(4)C_(3) composite monometallic ***,the incorporation of V_(4)C_(3) improved the material's stability during charging/*** initial discharge specific capacity of V_(4)C_(3)@CuSe_(2)/CoSe_(2) reached an impressive 809 mAh g^(-1) at 1 Ag^(-1).Even after nearly 3000 cycles,it retained a substantial capacity of 169.1 mAh g^(-1).Ex-situ XPS analysis confirmed the reversible valence transitions of Cu,Co,and Se elements as the main energy storage reac-tions taking place in the cathode *** functional theory analysis provided further insights,revealing that the strong metallic behavior of the heterostructure stemmed from the charge rearrange-ment facilitated by the bimetallic selenide structure and the optimization of the energy level ***,the presence of the bimetallic selenide structure significantly improved the adsorption ef-ficiency of[AlCl4]^(-).Overall,this research contributes to the advancement of rechargeable aluminum ion batteries and presents a promising avenue for future developments in composite metal selenide struc-tures and MXene-based materials.

关键词： Rechargeable aluminum batteries V_(4)C_(3) MXene Bimetallic selenides Heterostructure Electrochemical performance

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Heteronuclear Magnetisms with Ultracold Spinor Bosonic Gases in Optical Lattices

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Chinese Physics Letters 2024年第2期41卷 69-82页

作者： Yongqiang Li Chengkun Xing Ming Gong Guangcan Guo Jianmin Yuan Department of Physics National University of Defense TechnologyChangsha 410073China Hunan Key Laboratory of Extreme Matter and Applications National University of Defense TechnologyChangsha 410073China Key Lab of Quantum Information(CAS) University of Science and Technology of ChinaHefei 230026China CAS Key Laboratory of Quantum Information University of Science and Technology of ChinaHefei 230026China Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China Department of Physics Graduate School of China Academy of Engineering PhysicsBeijing 100193China

Motivated by recent realizations of spin-1 NaRb mixtures in the experiments[***.114,255301(2015);***.128,223201(2022)],we investigate heteronuclear magnetism in the Mott-insulating *** from the identical mixtures where the boson statistics only admits even parity states from angular momentum composition,for heteronuclear atoms in principle all angular momentum states are allowed,which can give rise to new magnetic *** various magnetic phases can be developed over these degenerate spaces,the concrete symmetry breaking phases depend on not only the degree of degeneracy but also the competitions from many-body *** unveil these rich phases using the bosonic dynamical mean-field theory *** phases are characterized by various orders,including spontaneous magnetization order,spin magnitude order,singlet pairing order,and nematic order,which may coexist specially in the regime with odd *** we address the possible parameter regimes for observing these spin-ordered Mott phases.

关键词： parity momentum allowed

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Operando chemo-mechanical evolution in LiNi0.8Co0.1Mn0.1O2 cathodes

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national science Review 2024年第9期11卷 253-263页

作者： Yi Zhang Shuaipeng Hao Fei Pei Xiangpeng Xiao Chang Lu Xing Lin Zhe Li Haijin Ji Yue Shen Lixia Yuan Zhen Li Yunhui Huang State Key Laboratory of Material Processing and Die & Mould Technology School of Materials Science and EngineeringHuazhong University of Science and Technology School of Optical and Electronic Information National Engineering Laboratory for Next Generation Internet Access SystemWuhan National Laboratory for OptoelectronicsHuazhong University of Science and Technology Gatan Inc.& EDAX LLC. AMETEK Commercial Enterprise (Shanghai)Co. Ltd.Pilot Free Trade Zone Department of Physics The Chinese University of Hong Kong

Ni-rich LiNixCoyMnzO2（NCMxyz,x+y+z=1,x≥0.8） layered oxide materials are considered the main cathode materials for high-energy-density Li-ion ***,the endless cracking of polycrystalline NCM materials caused by stress accelerates the loss of active materials and electrolyte decomposition,limiting the cycle ***,understanding the chemo-mechanical evolution during（de）lithiation of NCM materials is crucial to performance *** this work,an optical fiber with με resolution is designed to in operando detect the stress evolution of a polycrystalline LiNi0.8Co0.1Mn0.1O2（P-NCM811） cathode during *** integrating the sensor inside the cathode,the stress variation of P-NCM811 is completely transferred to the optical *** find that the anisotropy of primary particles leads to the appearance of structural stress,inducing the formation of microcracks in polycrystalline particles,which is the main reason for capacity *** isotropy of primary particles reduces the structural stress of polycrystalline particles,eliminating the generation of ***,the P-NCM811 with an ordered arrangement structure delivered high electrochemical performance with capacity retention of 82% over 500 *** work provides a brand-new perspective with regard to understanding the operando chemo-mechanical evolution of NCM materials during battery operation,and guides the design of electrode materials for rechargeable batteries.

关键词： Ni-rich layered oxide cathode in operando stress monitoring polycrystalline chemo-mechanical evolution

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