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Quantitative analysis on the separated double schottky barrier for ZnO-based ceramic nanowire

Ceramics International 2025年第10期51卷 13537-13544页

作者： Yang, Xiao Zhang, Han Qi, Bo Yu, Zexuan Li, Chuanyang Hu, Jun He, Jinliang State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Beijing102206 China State Key Laboratory of Power Systems Department of Electrical Engineering Tsinghua University Beijing100084 China

ZnO based ceramic nanowires or whiskers have been reported to possess good nonlinear conducting property similar with ZnO ceramic varistor. The energy band structure and nonlinear conduction process of the ceramic nanowire are different from the traditional back-to-back double schottky barrier structure while a model description has been absent. This paper has taken ceramic nanowire based on ZnO coated with Bi, Co oxide as an instance and proposed a separated double schottky model to quantitatively characterizes the process of interface charges at the reverse and forward bias side which are separately modulated by the corresponding voltage bias and barrier height. Computation result based on the model agree well with the measured nonlinear conducting behavior of a single ZnO ceramic nanowire and its nonlinear mechanism has been analyzed. On this basis, quantitative correlation between the property of a single ZnO ceramic nanowire and the overall nonlinear conducting behavior of its composite has been established. © 2025

关键词： II-VI semiconductors

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Mechanical Properties Inside Origami-Inspired Structures: An Overview

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Applied Mechanics Reviews 2025年第1期77卷 011001页

作者： Yan, Peng Huang, Hailin Meloni, Marco Li, Bing Cai, Jianguo Department of Mechanical Engineering and Automation Harbin Institute of Technology Shenzhen518052 China Harbin Institute of Technology Shenzhen518052 China Key Laboratory of C & PC Structures of Ministry of Education National Prestress Engineering Research Center Southeast University Nanjing211189 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China Guangdong Provincial Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robotics Harbin Institute of Technology Shenzhen518052 China Key University Laboratory of Mechanism Machine Theory and Intelligent Unmanned Systems of Guangdong Habin Institute of Technology Shenzhen518052 China

In recent decades, origami has transitioned from a traditional art form into a systematic field of scientific inquiry, characterized by attributes such as high foldability, lightweight frameworks, diverse deformation modes, and limited degrees-of-freedom. Despite the abundant literature on smart materials, actuation methods, design principles, and manufacturing techniques, comprehensive reviews focusing on the mechanical properties of origami-inspired structures are relatively rare and unsystematic. This review aims to fill this void by analyzing and summarizing the significant studies conducted on the mechanical properties of origami-inspired structures from 2013 to 2023. We begin with an overview that includes essential definitions of origami, classical origami patterns, and their associated tessellated or stacked structures. Following this, we delve into the principal dynamic modeling method for origami and conduct an in-depth analysis of the key mechanical properties of origami-inspired structures. These properties include tunable stiffness, bistability and multistability, metamechanical properties demonstrated by origami-based metamaterials, and bio-inspired mechanical properties. Finally, we conclude with a comprehensive summary that discusses the current challenges and future directions in the field of origami-inspired structures. Our review provides a thorough synthesis of both the mechanical properties and practical applications of origami-inspired structures, aiming to serve as a reference and stimulate further research. © 2025 American Society of Mechanical Engineers (ASME). All rights reserved.

关键词： Degrees of freedom (mechanics)

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Interactions between Initial and Lateral Boundary Perturbations in Convection-Permitting Ensemble Prediction

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Journal of Meteorological Research 2025年第1期39卷 116-131页

作者： Jingzhuo WANG Jing CHEN Fajing CHEN Yanan Ma CMA Earth System Modeling and Prediction Centre China Meteorological Administration(CMA)Beijing100081China State Key Laboratory of Severe Weather China Meteorological AdministrationBeijing100081China Key Laboratory of Earth System Modeling and Prediction China Meteorological AdministrationBeijing100081China Chinese Academy of Meteorological Sciences China Meteorological AdministrationBeijing100081China

How to construct appropriate perturbations for convection-permitting ensemble prediction systems(CPEPSs)is a critical issue awaiting urgent *** two common perturbations,initial perturbations(IPs)and lateral boundary perturbations(BPs)interact with each other,affecting the model error growth,especially in mesoscale *** the china Meteorological Administration(CMA)-CPEPS,this study tries to elucidate how BPs interact with matched and mismatched IPs under varied large-scale weather conditions/*** groups of experiments were conducted for strong-forcing and weak-forcing weather regimes over southern china:three with single IPs,one with single BPs,and three with combined *** is found that the perturbation magnitudes were dominated by meso-α-scale components,and IPs under weak forcing exhibited more pronounced effects than under strong forcing;whereas BPs exerted more pronounced effects under strong forcing than weak forcing ***,it lasts longer for high-level variables when the perturbation energy from BPs is higher than that from IPs,compared to low-level ***,for precipitation and dynamic variables,IPs and BPs can mutually *** source of these perturbations,and their specific vertical levels,do not alter the extent of their ***,the weather regime and the scales of the perturbations influence the strength of their mutual *** particular,the weak-forcing regimes exhibit a more pronounced reinforcing effect,and meso-α-scale perturbations are more conducive to fostering interactions compared to meso-β-scale ***,it is the perturbation magnitude inherent in the initial perturbation itself that determines the interactions between IPs and BPs.

关键词： interactions initial perturbations lateral boundary perturbations convection-permitting ensemble prediction

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Effects of Corona Discharge from the Grounding Tip on Charge Evolution of Wall Bushing

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IEEE Transactions on Power Delivery 2025年第3期40卷 1682-1693页

作者： Bai, Zheng Zhou, Yuanxiang Zhang, Yunxiao Huang, Xin Xie, Xiongjie Liu, Taiwei Tsinghua University State Key Laboratory of Power System Operation and Control Department of Electrical Engineering Beijing100084 China Electric Power Research Institute State Key Laboratory of Power Grid Environmental Protection Wuhan430204 China

Manufacturers consider that the grounding tip near the wall bushing flange is a potentially important factor in several sheath perforation accidents. Taking a ±100 kV true type SF6 gas-insulated bushing as a typical wall bushing, this paper tests the impact of the nearby grounding tip on the charge accumulation. Based on the experiment results, we propose the three-dimensional nonlinear conduction model to unravel the charge accumulation process and the three-dimensional corona ion migration model to clarify the corona process. It is concluded that the consumption of gas ions leads to the nonlinear charge relaxation process. When the corona of grounding tip incepts, numerous ions are generated, forming an "overcharge" phenomenon. The electric field at the insulator-sheds interface and the SF6-insulator interface increases compared to the normal condition, with non-uniform distribution along the circumferential direction. Material inhomogeneity amplifies electric field distortion and creates insulation weaknesses, making insulation aging more likely and potentially leading to a slowly developing electrical tree breakdown process. The length of the needle tip affects the duration of the corona effect;an excessively long needle tip can cause a sustained corona discharge. This research provides a foundation for bushing accidents analysis and operation reliability improvement. © 1986-2012 IEEE.

关键词： Bushings

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UAGE: A Supervised Contrastive Method for Unconstrained Adaptive Gaze Estimation 17th

UAGE: A Supervised Contrastive Method for Unconstrained Ada...

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17th Asian Conference on Computer Vision, ACCV 2024

作者： Lan, Enfan Hu, Zhengxi Liu, Jingtai Institute of Robotics and Automatic Information System Nankai University Tianjin China Tianjin Key Laboratory of Intelligent Robotics Tianjin China TBI Center Nankai University Tianjin China

ISBN: (纸本)9789819609628

Gaze estimation, which involves perceiving human gaze directions, is the foundation of gaze analysis. It provides crucial clues for understanding human attention and intention. However, most existing methods are designed for constrained environments, which leads to a significant performance drop in unconstrained practical applications. In this work, we propose a supervised contrastive method for Unconstrained Adaptive Gaze Estimation (UAGE), which consists of an unconstrained gaze estimation method and a Gaze-guided Contrastive Domain Adaptation (GCDA) framework. Our method leverages the entire human body states and the uncertainty of gaze behaviors to robustly estimate gazes in unconstrained environments, rather than solely relying on head states. Additionally, we employ the GCDA framework to adapt the model to new domains, thereby improving its generalization ability. Experiment results show that our UAGE method has achieved state-of-the-art within-domain performance on the unconstrained GAFA dataset and has reduced the angular error by 14% compared to the baseline in cross-domain gaze estimation, with GAFA as the source domain and Gaze360 as the target domain. The code is available at https://***/youthhfor/***. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.

关键词： Domain adaptation Gaze estimation Unconstrained environment

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Toward Aerial Collaborative Stereo: Real-Time Cross-Camera Feature Association and Relative Pose Estimation for UAVs

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IEEE Sensors Journal 2025年第6期25卷 9861-9875页

作者： Wang, Zhaoying Dong, Wei Shanghai Jiao Tong University State Key Laboratory of Mechanical System and Vibration School of Mechanical Engineering Shanghai200240 China

The collaborative unmanned aerial vehicles (UAVs) can construct a wide and variable baseline stereo camera, providing potential benefits in flexible and large-scale depth perception. Compared to the fixed-baseline stereo camera, the collaborative stereo system in dynamic flight face the additional challenge of continuously varying baselines, which necessitates real-time cross-camera stereo feature association and real-time relative pose estimation on resource-constrained onboard computers. To tackle these challenges, we propose a real-time dual-channel feature association with a guidance-prediction framework. This framework utilizes a graph neural network (GNN) to periodically guide cross-camera feature associations between two UAVs, while the guided features are continuously predicted to enable real-time feature association. Additionally, we propose a real-time relative multistate-constrained Kalman filter (Rel-MSCKF) algorithm, which efficiently integrates covisual overlapping features with the UAVs' visual-inertial odometry (VIO), enabling accurate and fast relative pose estimation. Extensive real-world experiments are performed using the widely adopted but resource-constrained NVIDIA NX onboard computer. The results demonstrate that the dual-channel algorithm achieves cross-camera feature association for 30 Hz image streams, with an average runtime of 14 ms, significantly outperforming the conventional cross-camera feature matching algorithms, which typically require over 70 ms. For the relative pose estimation of two cameras, the proposed Rel-MSCKF algorithm achieves pose estimation within 16 ms, outperforming the current pose-graph optimization (PGO) manner with 330 ms. Additionally, we examine the convergence behavior of Rel-MSCKF under various spatial configurations. The system's robustness is further evaluated under the challenges of asynchronous image acquisition, communication interruptions, and field-of-view (FOV) occlusions. Online video: https://youtu.

关键词： Graph neural networks

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Biosyncretic robotic systems:Comprehensive construction,application,and future challenges

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Science china(Technological Sciences) 2025年第4期68卷 1-23页

作者： Qi ZHANG Chuang ZHANG Lianchao YANG Hengshen QIN Yiwei ZHANG Ying ZHAO Lianqing LIU State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110016China University of Chinese Academy of Sciences Beijing 100049China Department of General Surgery Shengjing Hospital of China Medical UniversityShenyang 117004China

Owing to the deep integration of biological and electromechanical systems,biosyncretic robotic systems have emerged as a significant research interest in *** study presents the latest related research featuring various biological *** the classification of biosyncretic robotic systems,the key technologies for construction are elucidated and summarized,including comprehensive structural design,fabrication,and behavior control ***,emphasis has been placed on their applications,particularly within the biomedical ***,the challenges are summarized,and their future developments are envisioned.

关键词： biosyncretic robots biohybrid robots bioactuators cell actuation living machines

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Fault-induced gear meshing modulation sideband extraction and evaluation for fault diagnosis of planetary gearboxes

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Science china(Technological Sciences) 2025年第1期68卷 335-351页

作者： Peng ZHOU Xiaoluo YU Yang YANG Qingbo HE Zhike PENG State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China School of Mechanical Engineering Ningxia UniversityYinchuan 750021China Science and Technology on Vehicle Transmission Laboratory China North Vehicle InstituteBeijing 100072China

Gearboxes,known for their compact size and stable transmission capability,are widely used as power transmission structures in various types of mechanical equipment,such as wind turbines,helicopters,and special ***,due to harsh and non-stationary working conditions,gear surfaces often deteriorate,leading to faults such as wear,pitting,and ***,it is vital to monitor the working status of gearboxes and diagnose gear faults as early as *** faults can induce characteristic modulation effects near the gear meshing frequency(GMF),resulting in the appearance of faultinduced sidebands in a vibration *** of these sidebands allows for the diagnosis of gear faults in a ***,when faced with a planetary gearbox having a complex configuration,strong background noise and additional faultunrelated sidebands can interfere with fault-induced sidebands,making accurate diagnosis *** address these challenging issues,this paper proposes a novel fault-induced gear meshing modulation sideband extraction *** the process,the sidebands directly related to the gear fault near the GMF are first identified and then extracted by a variational harmonic mode decomposition(VHMD)***,a fault-related gear meshing modulation component(GMMC)can be accurately reconstructed by summing up the extracted fault-induced *** the GMMC,the gear fault severity can be assessed by evaluating its amplitude modulation(AM)*** superior performance of the proposed method is finally demonstrated by experimental data.

关键词： planetary gearbox gear meshing frequency modulation sideband signal decomposition fault diagnosis

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High-precision magnetic field measurement system based on a coherent population trapping magnetometer onboard the SATech-01 satellite

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Science china(Technological Sciences) 2025年第2期68卷 227-242页

作者： Hongbo XUE Wei SONG Haoran ZHAO Yiteng ZHANG Shanzhi YE Jindong WANG Ran TAO Peng SANG Keli CHEN Xingzi BI Bingjun CHENG Bin ZHOU Yongliang XUE Yingying TANG Liu LIU Jinsong LI Xiaocheng ZHU Baoquan LI Jinguo LIU Wen CHEN Xiaofeng ZHANG Yonghe ZHANG Lei LI State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China Key Laboratory of Solar Activity and Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China Key Laboratory of Electronics and Information Technology for Space Systems National Space Science CenterChinese Academy of SciencesBeijing 100190China State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110016China Innovation Academy for Microsatellites Chinese Academy of SciencesShanghai 201304China

On July 27,2022,a high-precision system for measuring the magnetic field based on a coherent population trapping magnetometer(referred to as the CPT system)was launched onboard the Space Advanced Technology demonstration satellite(SATech-01)by a ZK-1A *** payload comprises a scalar coherent population trapping magnetometer(CPTM),triaxial anisotropic magnetoresistance magnetometer(AMRM),and nano star tracker mounted on a non-magnetic telescopic tubular *** configuration enables synchronized measurement of scalar and vector geomagnetic fields,as well as the attitude,making the payload with its compact sensors suitable for applications on miniature satellite *** November 7,2022,the novel telescopic tubular mast was deployed in orbit,extending to a length of 5.28 *** CPTM,an absolute scalar magnetometer with an omnidirectional sensor,is the first china-developed quantum/atomic magnetometer successfully operating in *** orbit,the CPTM has sensitivity of~10 pT/Hz^(1/2) and can automatically operate under complex magnetic field *** difference between the scalar fields obtained using the CPTM and CHAOS model has a mean deviation of -3.73 nT and a standard deviation of 26.11 nT(1σ),without on-orbit calibration or *** miniaturized AMRM has a sensitivity of~0.3 nT/Hz^(1/2) and maintains stable and reliable operation in *** low-power and miniaturized nano star tracker has a measurement uncertainty of 14.23″(1σ)in *** mission has realized the on-orbit technical verification of the integrated and synchronized detection of the vector magnetic field and attitude and fully validated the system’s performance,automation level,and reliability.

关键词： magnetic field measurement system coherent population trapping magnetometer anisotropic magnetoresistance magnetometer nano star tracker non-magnetic telescopic tubular mast satellite

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Robust Scheduling of Fast-charging EVs with Exogenous and Endogenous Uncertainties for Urban Power Congestion Relief

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IEEE Transactions on Industry Applications 2025年第3期61卷 4530-4540页

作者： Wang, Zhe Hu, Huanyu Pan, Xi'an Zhang, Zhi Huang, Liyan Yan, Tingyu North China Electric Power University Department of State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources Beijing102206 China

As fast-charging electric vehicles (FCEVs) become one of the primary modes of urban transportation, the randomness and uncertainty of users' charging behaviors pose significant congestion risks to the grid's scheduling. In this paper, the urban power system guides FCEVs to orderly charge through appropriate pricing strategies. To do this, a novel demand response (DR) model is established to simulate the spatial flexibility of FCEVs under different charging prices. In order to realistically reflect the power deviations when FCEVs participate in DR, a hybrid exogenous and endogenous uncertainty set is proposed to capture the effects of environmental and user psychological factors. Furthermore, a two-stage robust model is developed to relieve congestion. Specifically, a bi-level model is employed to optimize locational marginal electricity prices, aiming to achieve collaboration between transmission and distribution networks in the first stage. The two-stage robust model is then transformed into a tractable form and solved using the modified parametric column-and-constraint generation (CCG) algorithm proposed in this paper. Numerical simulations verify the proposed model and algorithm's effectiveness and practicability using both modified IEEE standard test cases and real-world cases from Puyang's urban power system in china. © 1972-2012 IEEE.

关键词： Power distribution networks

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