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SSRN 2023年

作者： Lu, Tian-Tian Hua, Dong-Peng An, Bai-Ling Hafeez, Muhammad Arslan Pan, Jie Lu, Jun-Yong Zhou, Qing Zhang, Cheng Liu, Lin School of Materials Science and Engineering State Key Lab for Materials Processing and Die & Mold Technology Huazhong University of Science and Technology Wuhan430074 China School of Materials Science and Engineering State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal Materials Northwestern Polytechnical University Shaanxi Xi’an710072 China National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering Wuhan430033 China

The prevention of adhesive wear between metals is challenging due to the strong adhesion forces that arise from the interaction of asperities. Here, we propose a novel approach to enhance the anti-adhesive wear performance of Cu/Al pair through interfacial energy modulation, with potential applications in electromagnetic railgun. Our findings indicate that the interfacial energy of the Cu-Al pair can be significantly reduced by magnetron sputtering a W thin film onto the Al alloy surface. A lower coefficient of friction and a substantial alleviation in adhesion and mechanical damage of the Cu alloy are thus obtained. Molecular dynamics simulations reveal that the immiscibility and low interfacial energy of the Cu/W pair result in the formation of an amorphous interfacial layer during friction, facilitating countermotion at the contacting surfaces, thus in turn enables the low friction. This study provides a guideline for designing novel wear-resistant pairs based on interfacial energy modulation. © 2023, The Authors. All rights reserved.

关键词： Adhesives

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Modeling of hybrid DC fuse based on piecewise fitting

Modeling of hybrid DC fuse based on piecewise fitting

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22nd International Symposium on High Voltage Engineering (ISH 2021)

作者： S. Liu F. Ji S. Li W. Sun National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering Wuhan 430033 People's Republic of China College of Electrical Engineering Naval University of Engineering Wuhan 430033 People's Republic of China

As a current limiting device, Hybird DC fuse can be used to limit the short-circuit current of the system, In order to precheck the current limiting capability, a simulation model of fuse needs to be established. However, the existing model is relatively complex, and there is no mature model that can be directly called in the existing simulation software. Therefore, this paper designs a piecewise fitting method based on the arcing test data of fuse to describe the whole process of arc drawing. First, considering the influence of resonance and other factors in the test data acquisition of the fuse breaking, the ripple is mixed, and a stepwise filtering algorithm is proposed; Then, according to the degree of fluctuation of the arcing curve, the piecewise points are selected using the normalized curvature criterion and the normalized residual norm criterion respectively, which solves the problem that the piecewise points rely on the designer's practical experience; Finally, according to the results of piecewise fitting, a fuse model of arcing resistance changing with time is constructed in PSCAD, and the simulation verifies the effectiveness of the method used.

关键词： arcs (electric) current limiters curve fitting data acquisition electric fuses power engineering computing short-circuit currents

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IGBT Failure mechanism and boundary analysis under large current and high temperature turn-off

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Journal of Physics: Conference Series 2021年第1期1754卷

作者： Xiao Ma Yongle Huang Yifei Luo National Key Laboratory of Science and Technology on Vessel Integrated Power System

Considering overload working conditions in electromagnetic emission, the paper presents a simulation of IGBT turn-off under large current and high temperature. Numerous simulation result is received under a specific test circuit. Boundary conditions for temperature, current and starry inductance are obtained under a set of temperature criterion. Further analysis proves that after temperature reaches the criterion, high current density path swiftly extends from local area to a vertical current path throughout the cells. This method for IGBT theoretical boundary is useful for similar projects or working conditions.

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Research on digital control design of high power middle frequency 400Hz inverter power

Research on digital control design of high power middle freq...

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International Conference on power Electronics and Motion Control (IPEMC)

作者： Chunxi Liu Weiming Ma Chi Sun Wenhua Hu Department of Electrical Engineering Liaoning Technical University Fuxin China College of Electrical Engineering University of Zhejiang Hangzhou China National Key Laboratory for Vessel Integrated Power System Technology Naval University of Engineering Wuhan China School of Electrical Engineering Huazhong University of Science and Technology Wuhan China

The device switching frequency is low and the output voltage fundamental frequency is high in high power middle frequency 400 Hz/115 V inverters, so the control bandwidth is limited and it is hard to promise a good waveform quality. The delay induced by the implementation of sampling, computing and PWM during digital control has bad impact on the system transient and steady state performances. In this paper, the cascaded topology with two H-bridge units which can get a higher equivalent switching frequency and reduce harmonic content in output voltage and P+resonant controller which can eliminate steady state error were adopted in a single-phase inverter. The delay resulting from the processes of sampling, computing and digital PWM was analyzed. The control parameters were designed in the continuous domain design by introduced an equivalent time delay. Finally, the discrete simulation on a single-phase 100 kVA, 400 Hz/115 V inverter model was presented, and the simulation verified the effectiveness of the proposed scheme.

关键词： Digital control Pulse width modulation inverters Pulse width modulation Switching frequency Voltage control Delay Sampling methods Steady-state Computational modeling Bandwidth

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Weakening s-d orbital hybridization of metallic iridium by tungsten atoms for acidic water splitting

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Applied Catalysis A: General 2023年 649卷

作者： Chang, Chaofeng Xie, Yuhua Luo, Fang Zhou, Shaowei Yang, Zehui Sustainable Energy Laboratory Faculty of Materials Science and Chemistry China University of Geosciences Wuhan 388 Lumo RD Wuhan430074 China State Key Laboratory for Hubei New Textile Materials and Advanced Processing Technology School of Materials Science and Engineering Wuhan Textile University Wuhan430200 China Power system and new energy China Ship Development and Design Center Wuhan430074 China

To economically realize proton electrolyte membrane water splitting technology, stable and high-performance oxygen evolution reaction (OER) electrocatalyst is significantly demanded. In this work, we invite tungsten atoms to metallic iridium (Ir) to weaken s-d hybridization of Ir-Ir bond due to the higher electronegativity accepting electron from Ir atoms;as a result, the adsorbed O* species become electrophilic favorable for the nucleophilic attack by H2O leading to 22 % decrement in energy barrier for the formation of OOH* species. Therefore, iridium-tungsten (IrW) electrocatalyst exhibits 3.7-fold higher turnover frequency (TOF) than metallic Ir at overpotential of 370 mV in acidic OER catalysis. Moreover, stable OER performance is recorded due to the high cohesive energy of tungsten atoms. Additionally, TOF of IrW electrocatalyst reaches 10.1 s−1 at overpotential of 100 mV in acidic hydrogen evolution reaction (HER) test, 7.6-time higher than Pt/C and metallic Ir. IrW electrocatalyst only needs 1.52 V to attain 10 mA cm−2 in acidic overall water splitting. © 2022 Elsevier B.V.

关键词： Chemical bonds

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Degradation of Anti-Rust Oil Film in a Simulated Coastal Atmosphere: Inhibition Mechanism and In-Situ Monitoring

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SSRN 2024年

作者： Ma, Xiao-Ze Jiang, Wan-Juan Cai, Guang-Yi Zhang, Xinxin Meng, Ling-Dong Dong, Zehua Hubei Key Laboratory of Material Chemistry and Service Failure School of Chemistry and Chemical Engineering Huazhong University of Science and Technology Wuhan430074 China National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering Wuhan430033 China School of Materials Army Academy of Armored Forces Beijing100086 China Central China Normal University China

This work investigates the inhibition mechanism and degradation dynamics of an anti-rust oil (ARO) containing sodium petroleum sulfonate (SPS) and white oil in a simulated coastal atmosphere. The emulsification of saline droplets in ARO was evaluated using Quartz crystal microbalance (QCM) and electrochemical mapping techniques. The results indicate that the reverse micelle effect plays a crucial role in the inhibition performance of AROs on mild steel specimens. Moreover, a capacitive sensor was invented to evaluate the degree of degradation of ARO in situ by dielectric constant measurement. © 2024, The Authors. All rights reserved.

关键词： Quartz crystal microbalances

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Supermaneuverable Flipping Control and Planning Based on Multi-Rotor Mode of Tilt-Rotor UAVs

Supermaneuverable Flipping Control and Planning Based on Mul...

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IEEE International Conference on Robotics and Biomimetics

作者： Hongpeng Wang Qinghao Zhang Yue Fei Kun Deng Jun Liang Chuanyu Sun Li Xu The Key Laboratory of Civil Aviation Smart Airport Theory and System Civil Aviation University of China College of Artificial Intelligence Nankai University Tianjin China Laboratory of Science and Technology on Integrated Logistics Support National University of Defense Technology Changsha China Institute of Intelligence Technology and Robotic Systems Shenzhen Research Institute of Nankai University Shenzhen China China Nuclear Power Technology Research Institute Co. Ltd Shenzhen China

ISBN: (数字)9798331509644

ISBN: (纸本)9798331509651

Maneuverability is a critical factor for UAV s to survive in high-intensity combat scenarios. Traditional UAV s typically operate in a stable motion state to ensure flight safety. However, in highly contested environments, special missions require high mobility while maintaining safety. Tilt-rotor UAV s, which combine the characteristics of fixed-wing and multi-rotor UAVs, can perform extreme maneuvers, such as high angles of attack and post-stall maneuvers, to rapidly change posture and complete tasks like positioning and defense. Therefore, integrating and optimizing safety and maneuverability metrics is necessary for enabling UAV s to achieve extreme maneuverability. In this paper, extreme maneuver planning and control for tilt-rotor UAV s are realized through a method based on third-order Bezier curve planning of body angular velocity. Experimental results demonstrate tilt-rotor UAVs can perform extreme super-maneuverable flips while maintaining overall process control.

关键词： Measurement Biomimetics Process control Autonomous aerial vehicles Angular velocity Planning Safety Kalman filters Robots

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A Wideband Linear-to-Circular Polarizer based on Hexagonal FSS on PDMS Substrate for CubeSats 4

A Wideband Linear-to-Circular Polarizer based on Hexagonal F...

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4th IEEE International Conference on Electronic Information and Communication technology, ICEICT 2021

作者： Mirza, Hidayath Soh, Ping Jack Sheikh, Rais Ahmad Hossain, Toufiq M. Yan, Sen Zhang, Jiahao Luo, Fengyi Dept. of Electrical Engineering College of Engineering Jazan University Jazan Saudi Arabia Centre for Wireless Communications University of Oulu P.O. Box 4500 OuluFI-90014 Finland Dept. of Electrical Engineering College of Engineering Jazan University Jazan Saudi Arabia School of Engineering and Information Technology University of New South Wales Canberra CampbellACT2600 Australia School of Information and Communications Engineering Xi’an Jiaotong University Xi’an710049 China National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering Wuhan China

ISBN: (纸本)9781665432030

A novel flexible single-layered and single-sided linear to-circular polarizer is proposed in this work. The proposed polarizer is designed for a deployable format for application in a 3U Cube Satellites. It features a near-zero 3 dB AR, with a size of 0. 22 λ0 × 0. 27λ0 × 0. 03λ0 and a 3dB AR fractional bandwidth of 34.39 %, starting from 1.95 GHz to 2.76 GHz. It performs with a conversion efficiency bandwidth covering 90% of 43.47 %, starting from 1.8 GHz to 2.8 GHz. This indicates the polarizer’s wideband CP performance, with a pure CP centered at 2.41 GHz. ©2021 IEEE

关键词： Frequency selective surfaces

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Augmented Reality-Based Digital-Physical Space Registration and Projection for Cognitive Enhancement and Assessment

Augmented Reality-Based Digital-Physical Space Registration ...

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IEEE International Conference on Robotics and Biomimetics

作者： Hongpeng Wang Yue Fei Qinghao Zhang Kun Deng Jun Liang Chuanyu Sun Li Xu The Key Laboratory of Civil Aviation Smart Airport Theory and System Civil Aviation University of China College of Artificial Intelligence. Nankai University Tianjin China Laboratory of Science and Technology on Integrated Logistics Support National University of Defense Technology Changsha China Institute of Intelligence Technology and Robotic Systems Shenzhen Research Institute of Nankai University Shenzhen China China Nuclear Power Technology Research Institute Co. Ltd. Shenzhen China

ISBN: (数字)9798331509644

ISBN: (纸本)9798331509651

Driven by information technology, mod-ern warfare is more diverse and intelligent than traditional warfare, in which intelligent unmanned system plays an increasingly important role. To defend against distant threat of unmanned military arma-ments, it's essential to deploy radars, sonars, satellites, and other long-range detection equipment to build a multidimensional national defense monitoring system. Due to the unpredictable nature of battlefield, radar-based reconnaissance missions require operators to have extensive experience and maintain a high level of focus. However, prolonged radar operations may impose a heavy psychological burden on operators and even affect their mental functions. To address these challenges, this paper proposes a cognitive en-hancement and assessment system that projects virtual 3D battlefield scenarios onto the real world based on augmented reality and evaluates operators' mental state through eye-tracking technology.

关键词： Three-dimensional displays Satellites Spaceborne radar Virtual environments Sonar Reconnaissance Robot sensing systems Radar equipment Monitoring Sonar detection

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Field-Harmonic-Oriented Design of Vernier Permanent Magnet Machine Towards High Torque Density and Low Torque Ripple

Field-Harmonic-Oriented Design of Vernier Permanent Magnet M...

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International Conference on Electrical Machines and systems (ICEMS)

作者： Li Fang Dawei Li Yuanzhi Zhang Jiewen Wu School of Electrical and Electronics Engineering Huazhong University of Science and Technology Wuhan China School of Electricla Engineering and Automation (Hubei Key Laboratory of Power Equipment and System Security for Integrated Energy) Wuhan University Wuhan China College of Design and Engineering National University of Singapore Singapore

Vernier permanent magnet machine (VPMM) has been a promising candidate for low-speed large-torque applications owing to high torque density based on multiple-magnetic field-harmonics working principle However, rich field harmonics also cause large torque ripple, meanwhile the regular reducing methods will also undermine torque density. In this paper, the field-harmonic-oriented design approach is proposed for the VPMM towards high torque density and low torque ripple. Based on the permeance unit model, the mapping relationship between torque output and field harmonics is built. Explicit design regulations are established for the airgap structure so as to modulate the optimal field harmonics composition. Via the proposed method, a surface-mounted VPMM is purposely designed and the electromagnetic performance is verified by FEA. Finally, a prototype of the proposed machine has been manufactured and tested. Both analytical and experimental results validate the feasibility of the proposed design method.

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