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Aerial refueling scheduling of multi-receiver and multi-tanker under spatial-temporal constraints for forest firefighting

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Chinese Journal of Aeronautics 2024年第5期37卷 71-91,I0001页

作者： Jing HUANG Jiaqi XING Jinrui ren quan quan Youmin ZHANG Department of Information and Control Engineering Xi’an University of TechnologyXi’an 710048China Jiujiang Measuring Test Technology Research Institute Jiujiang 332000China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China School of Automation Xi’an University of Posts&TelecommunicationsShaanxiXi’an 710121China Department of Mechanical Industrial and Aerospace EngineeringConcordia UniversityMontreal H3G 1M8Canada

Forest fires pose a significant threat to human life and property,so the utilization of unmanned aircraft systems provides new ways for forest *** the constrained load capacities of these aircraft,aerial refueling becomes crucial to extend their operational time and *** order to address the complexities of firefighting missions involving multi-receiver and multi-tanker deployed from various airports,first,a fuel consumption calculation model for aerial refueling scheduling is established based on the receiver ***,two distinct methods,including an integrated one and a decomposed one,are designed to address the challenges of establishing refueling airspace and allocating tasks for *** methods aim to optimize total fuel consumption of the receivers and tankers within the aerial refueling scheduling *** optimization problem is established as nonlinear optimization models along with *** integrated method seamlessly combines refueling rendezvous point scheduling and tanker task allocation into unified *** has a complete solution space and excels in optimizing total fuel *** decomposed method,through the separation of rendezvous point scheduling and task allocation,achieves a reduced computational ***,this comes at the cost of sacrificing optimality by excluding specific feasible ***,numerical simulations are carried out to verify the feasibility and effectiveness of the proposed *** simulations yield insights crucial for the practical engineering application of both the integrated and decomposed methods in real-world *** comprehensive approach aims to enhance the efficiency of forest firefighting operations,mitigating the risks posed by forest fires to human life and property.

关键词： Aerial refueling Scheduling Planning Spatial-temporal constraint Firefighting

Resilient control of flexible hypersonic vehicles against unmatched distributed faults

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Chinese Journal of Aeronautics 2024年第5期37卷 60-70页

作者： Dong zhao Wenjing ren School of Artificial Intelligence Anhui UniversityHefei 230601China Key Laboratory of System Control and Information Processing Ministry of EducationShanghai Jiao Tong UniversityShanghai 200240China School of Electrical Engineering and Automation Hefei University of TechnologyHefei 230009China

This paper studies a robust fault compensation and vibration suppression problem of flexible hypersonic *** controlled plant is represented by a cascade system composed of a nonlinear Ordinary Differential Equation(ODE)and an Euler-Bernoulli Beam Equation(EBBE),in which the vibration dynamics is coupled with the rigid dynamics and suffers from distributed faults.A state differential transformation is introduced to transfer distributed faults to an EBBE boundary and a longitudinal dynamics is refined by utilizing T-S fuzzy IF-THEN rules.A novel T-S fuzzy based fault-tolerant control algorithm is developed and related stability conditions are *** robust exponential stability and well-posedness are proved by using the modified l_(0)-semigroup based Lyapunov direct approach.A simulation study on the longitudinal dynamics of flexible hypersonic vehicles effectively verifies the validity of the developed theoretical results.

关键词： Flexible hypersonic vehicles ODE-EBBE cascade Robust exponential stability Unmatched distributed fault compensation Vibration suppression

A Cyclic Constitutive Model Based on Crystal Plasticity for Body-Centered Cubic Cyclic Softening Metals

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Acta Mechanica Solida Sinica 2024年第1期37卷 33-42页

作者： Xuehong ren Wenjie zhao Shaopu Yang Guilin Wen State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan UniversityChangsha 410082China School of Mechanical Engineering Tianjin Sino-German University of Applied SciencesTianjin 300350China State Key Laboratory of Mechanical Behavior in Traffic Engineering Structure and System Safety Shijiazhuang Tiedao UniversityShijiazhuang 050043China

Under the framework of the small deformation crystal plasticity theory,a crystal plastic cyclic constitutive model for body-centered cubic(BCC)cyclic softening polycrystalline metals is *** constitutive model introduces the isotropic softening rule that includes two different mechanisms:namely softening under monotonic deformation and softening under cyclic deformation on each slip ***,a modified Armstrong-Frederick nonlinear kinematic hardening rule is *** appropriate explicit scale transition rule is selected to extend the single crystal constitutive model to the polycrystalline constitutive *** the model is used to predict the uniaxial and multiaxial ratcheting deformation of BCC axle steel EA4T to verify the rationality of the proposed *** simulation results indicate that the newly established crystal plasticity model can not only describe the cyclic softening characteristics of BCC axle steel EA4T well,but also reasonably describe the evolution laws of uniaxial ratcheting and nonproportional multiaxial ratcheting ***,the established crystal plastic cyclic constitutive model can reasonably predict the ratcheting behavior of BCC single crystal as well.

关键词： Crystal plasticity Constitutive model Softening Ratcheting

Graphene enables equiatomic FeNiCrCoCu high-entropy alloy with improved TWIP and TRIP effects under shock compression

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Journal of Materials Science & Technology 2024年第3期170卷 186-199页

作者： Hongcai Xie Zhichao Ma Wei Zhang Hongwei zhao Luquan ren School of Mechanical and Aerospace Engineering Jilin UniversityChangchun 130025China Key Laboratory of CNC Equipment Reliability Ministry of Education Jilin UniversityChangchun 130025China Key Laboratory of Bionic Engineering Ministry of Education Jilin UniversityChangchun 130025China Weihai Institute for Bionics-Jilin University Weihai 264400China Institute of Structured and Architected Materials Liaoning Academy of MaterialsShenyang 110167China

Graphene(Gr)reinforced high-entropy alloy(HEA)matrix composites are expected as potential candidates for next-generation structural applications in light of outstanding mechanical properties.A deep comprehension of the underlying deformation mechanisms under extreme shock loading is of paramount importance,however,remains lacking due to experimentally technical limitations in *** the present study,by means of nonequilibrium molecular dynamics simulations,dynamic deformation behaviors and corresponding mechanisms in equiatomic FeNiCrCoCu HEA/Gr composite systems were investigated in terms of various shock *** resistance to dislocation propagation imparted by Gr was corroborated to encourage the elevated local stress level by increasing the likelihood of dislocation interplays,which facilitated the onset of twins and hexagonal close-packed(HCP)martensite ***,the advent of Gr was demonstrated to endow the HEA with an additional twinning pathway that induced a structural conversion from HCP to parent face-centered cubic(FCC)inside HCP martensite laths,different from the classical one that necessitated undergoing the intermediate procedure of extrinsic stacking fault(ESF)*** than that,by virtue of an increase in flow stress,the transformation-induced plasticity(TRIP)effect was validated to be additionally evoked as the predominant strain accommodation mechanism at higher strains on the one hand,but which only assisted plasticity in pure systems,and on the other hand,can also act as an auxiliary regulation mode together with the twinning-induced plasticity(TWIP)effect under intermediate strains,but with enhanced contributions relative to pure *** may expect that TRIP and TWIP effects promoted by introducing Gr would considerably inspire a synergistic effect between strength and ductility,contributing to the exceptional shock-resistant performance of FeNiCrCoCu HEAs under extreme regimes.

关键词： Molecular dynamics High-entropy alloy Graphene TRIP TWIP Shock

Visible Light Indoor Positioning System Based on Pisarenko Harmonic Decomposition and Neural Network

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Chinese Journal of Electronics 2024年第1期33卷 195-203页

作者： Li zhao Yi ren Qi WANG Lange DENG Feng ZHANG School of Electronic Information Engineering Xi’an Technological University

Visible-light indoor positioning is a new generation of positioning technology that can be integrated into smart lighting and optical communications. The current received signal strength(RSS)-based visible-light positioning systems struggle to overcome the interferences of background and indoor-reflected noise. Meanwhile, when ensuring the lighting, it is impossible to use the superposition of each light source to accurately distinguish light source information; furthermore, it is difficult to achieve accurate positioning in complex indoor environments. This study proposes an indoor positioning method based on a combination of power spectral density detection and a neural network. The system integrates the mechanism for visible-light radiation detection with RSS theory, to build a back propagation neural network model fitting for multiple reflection channels. Different frequency signals are loaded to different light sources at the beacon end, and the characteristic frequency and power vectors are obtained at the location end using the Pisarenko harmonic decomposition method. Then, a complete fingerprint database is established to train the neural network model and conduct location tests. Finally, the location effectiveness of the proposed algorithm is verified via actual positioning experiments. The simulation results show that, when four groups of sinusoidal waves with different frequencies are superimposed with white noise, the maximum frequency error is 0.104 Hz and the maximum power error is 0.0362 W. For the measured positioning stage, a 0.8 m × 0.8 m × 0.8 m solid wood stereoscopic positioning model is constructed, and the average error is 4.28 cm. This study provides an effective method for separating multi-source signal energies, overcoming background noise, and improving indoor visible-light positioning accuracies.

关键词： Neural networks Measurement uncertainty Position measurement Harmonic analysis Light emitting diodes Frequency estimation Indoor positioning systems

Understanding Discrepancy of Power System Dynamic Security Assessment with Unknown Faults: A Reliable Transfer Learning-based Method

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 427-431页

作者： Chao ren Han Yu Yan Xu zhao Yang Dong School of Computer Science and Engineering Nanyang Technological UniversitySingapore School of Electrical and Electronic Engineering Nanyang Technological UniversitySingapore

This letter proposes a reliable transfer learning(RTL)method for pre-fault dynamic security assessment(DSA)in power systems to improve DSA performance in the presence of potentially related unknown *** takes individual discrepancies into consideration and can handle unknown faults with incomplete *** experiment results demonstrate high DSA accuracy and computational efficiency of the proposed RTL *** analysis shows RTL can guarantee system performance.

关键词： Adversarial training dynamic security assessment maximum classifier discrepancy missing data transfer learning

Design and modification of metal sulfide-based catalysts for lithiumsulfur batteries

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Particuology 2024年第3期86卷 86-100页

作者： Yufei zhao Chuannan Geng Li Wang Haotian Yang Wei Lv quan-Hong Yang Nanoyang Group State Key Laboratory of Chemical EngineeringSchool of Chemical Engineering and TechnologyNational Industry-Education Integration Platform of Energy Storageand Collaborative Innovation Center of Chemical Science and Engineering(Tianjin)Tianjin UniversityTianjin300072China Shenzhen Geim Graphene Center Engineering Laboratory for Functionalized Carbon MaterialsTsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen518055China Haihe Laboratory of Sustainable Chemical Transformations Tianjin300192China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou350207China

Metal sulfide(MS)have good conductivity,strong adsorption ability,and excellent catalytic activity for the conversion of sulfur species,and thus,show great promise as the catalysts in LieS ***,the relationship between their properties and electrochemical performance is still ***,further in-depth discussions are required to improve their design in Li-S *** review systematically summarizes the basic structural and electrochemical properties of MSs and highlights the advantages that guarantee them as high-performance catalysts in Li-S ***,various modification strategies for MSs to enhance the catalytic activity,efficiency,and stability are also *** last,future opportunities for MS catalysts in Li-S batteries are proposed.

关键词： Lithium-sulfur battery Metal sulfide Catalysis

Urea-induced interfacial engineering enabling highly reversible aqueous zinc-ion battery

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Rare Metals 2024年第4期43卷 1599-1609页

作者： Bin-Rui Xu quan-An Li Yong Liu Guang-Bin Wang Zi-He Zhang Feng-Zhang ren School of Material Science and Engineering Henan University of Science and TechnologyLuoyang471023China School of Information Engineering Henan University of Science and TechnologyLuoyang471023China Longmen Laboratory Luoyang471023China Provincial and Ministerial Co-Construction of Collaborative Innovation Center for Non-Ferrous Metal New Materials and Advanced Processing Technology Luoyang471023China

Aqueous zinc-ion batteries(AZIBs)have been regarded as prospective rechargeable energy storage devices because of the high theoretical capacity and low redox potential of Zn ***,the uncontrollable formation of dendrites and the water-induced side reactions at the Zn/electrolyte interface,and the poor reversibility under a high current density(>2 mA·cm^(-2))and large area capacity(>2 mAh·cm^(-2))still limit the practical applications of ***,a strategy that can overcome these difficulties is urgently ***,we introduce an environmentally friendly and low-cost additive,namely urea,to the electrolyte of AZIBs to induce uniform Zn deposition and suppress the side *** of the adsorption behavior,electrochemical characterization,and observations of the morphology revealed the interfacial modification induced by urea on the Zn/electrolyte interface,demonstrating its huge potential in ***,the long-term cycling stability(over2100 h)of a Zn/Zn symmetric cell under a high current density of 5 mA·cm^(-2)and a capacity of 5 mAh·cm^(-2)was achieved with a 1 mol·L^(-1)ZnSO_(4)electrolyte with the urea ***,the assembled Zn/NH_4V_4O_(10)full cell with urea exhibited excellent cycling performance and an outstanding average Coulombic efficiency of 99.98%.These results indicate that this is a low-cost and effective additive strategy for realizing highly reversible AZIBs.

关键词： Zn anode Urea additive Interface engineering Dendrite growth Side reaction

ROS Balance Autoregulating Core-Shell CeO_(2)@ZIF-8/Au Nanoplatform for Wound Repair

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Nano-Micro Letters 2024年第8期16卷 341-361页

作者： Xi Zhou quan Zhou zhaozhi He Yi Xiao Yan Liu Zhuohang Huang Yaoji Sun Jiawei Wang Zhengdong zhao Xiaozhou Liu Bin Zhou Lei ren Yu Sun Zhiwei Chen Xingcai Zhang The Higher Educational Key Laboratory for Biomedical Engineering of Fujian Province Research Center of Biomedical Engineering of XiamenDepartment of BiomaterialsCollege of MaterialsXiamen UniversityXiamen 361005People’s Republic of China Department of Electronic Science Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance ResearchSchool of Electronic Science and EngineeringXiamen UniversityXiamen 361005People’s Republic of China John A Paulson School of Engineering and Applied Sciences Harvard UniversityCambridgeMA 02138USA Department of Otorhinolaryngology Union Hospital of Tongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022People’s Republic of China NO.1 Middle School Affiliated to Central China Normal University Wuhan 430223People’s Republic of China

Reactive oxygen species(ROS)plays important roles in living *** ROS is a double-edged sword,which can eliminate drug-resistant bacteria,but excessive levels can cause oxidative damage to cells.A core–shell nanozyme,Ce O_(2)@ZIF-8/Au,has been crafted,spontaneously activating both ROS generating and scavenging functions,achieving the multifaceted functions of eliminating bacteria,reducing inflammation,and promoting wound *** Au Nanoparticles(NPs)on the shell exhibit high-efficiency peroxidase-like activity,producing ROS to kill ***,the encapsulation of Ce O_(2) core within ZIF-8 provides a seal for temporarily limiting the superoxide dismutase and catalase-like activities of Ce O_(2) ***,as the ZIF-8 structure decomposes in the acidic microenvironment,the Ce O_(2) core is gradually released,exerting its ROS scavenging activity to eliminate excess ROS produced by the Au *** two functions automatically and continuously regulate the balance of ROS levels,ultimately achieving the function of killing bacteria,reducing inflammation,and promoting wound *** innovative ROS spontaneous regulators hold immense potential for revolutionizing the field of antibacterial agents and therapies.

关键词： Metal-organic framework(MOF) Reactive oxygen species(ROS) Cerium dioxide Au nanoparticles Wound healing