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Experimental study on combustion characteristics of supersonic combustor based on alternating-wedge strut

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Chinese Journal of Aeronautics 2024年第5期37卷 214-227页

作者： Jie li Wenyan song Yuhang WANg School of Power Energy Northwestern Polytechnical UniversityXi’an 710129China

Acetone Planar Lase-induced Fluorescence(PliF)and OH-PliF were employed to capture the fuel distribution and OH distribution downstream for the supersonic combustor based on the alternating-wedge *** combustion establishment process and combustion mode in the combustor under different fuel injection methods and different equivalence ratios were *** with the kerosene-PliF and OH-PliF results in the cavity combustor,a comparative analysis was conducted to understand the combustion characteristics and combustion modes between the alternating-wedge strut-based combustor and the cavity-based *** results show that the combustor is in weak combustion mode in the case of low equivalence ratio,and the combustor is in intensive combustion mode in the case of high equivalence *** lower limit of the equivalence ratio of the combustor to maintain the intensive combustion mode varies based on different fuel injection *** OH distribution under reacting condition has a strong correlation with the fuel distribution under non-reacting *** OH fluorescence signal near the injector is weaker when the fuel distribution is more *** injector position located at the base of the strut rear has better mixing performance,enabling the combustor to be in intensive combustion mode at a lower equivalence *** combustion reaction in the alternating-wedge strut-based combustor is not necessarily dominated by mass transfer due to the mixing enhancement and premixed zone downstream of strut,while the combustion reaction process in the cavity-based combustor is mainly influenced by mass transfer.

关键词： Supersonic combustor Alternating-wedge strut Cavity PliF Fuel injection Fuel distribution Combustion characteristics Combustion mode

Achieving given Precision Within Prescribed Time yet With guaranteed Transient Behavior via Output Based Event-Triggered Control

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iEEE/CAA Journal of Automatica Sinica 2024年第10期11卷 2059-2067页

作者： Zeqiang li Yujuan Wang Yongduan song international Joint Laboratory on Safety and Control of Autonomous Unmanned Systems School of AutomationChongqing UniversityChongqing 400044China iEEE

it is interesting yet nontrivial to achieve given control precision within user-assignable time for uncertain nonlinear *** underlying problem becomes even more challenging if the transient behavior also needs to be accommodated and only system output is available for *** key design innovations are proposed to circumvent the aforementioned technical difficulties,including the employment of state estimation filters with event-triggered mechanism,the construction of a novel performance scaling function and an error *** contrast to most existing performance based works where the stability is contingent on initial conditions and the maximum allowable steady-state tracking precision can only be guaranteed at some unknown(theoretically infinite)time,in this work the output of the system is ensured to synchronize with the desired trajectory with arbitrarily pre-assignable convergence rate and arbitrarily pre-specified precision within prescribed time,using output only with lower cost of sensing and *** addition,all the closed-loop signals are ensured to be globally uniformly bounded under the proposed control *** merits of the designed control scheme are confirmed by numerical simulation on a ship model.

关键词： Adaptive control nonlinear systems output feedback prescribed performance

High-lattice-adapted surface modifying Na_(4)MnV(PO_(4))_(3) for better sodium storage

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Nano Research 2024年第4期17卷 2728-2735页

作者： Chongran song Shiyu li Ying Bai international Joint Research Laboratory of New Energy Materials and Devices of Henan Province School of Physics and ElectronicsAcademy for Advanced Interdisciplinary StudiesHenan UniversityKaifeng 475004China

Sodium-ion batteries(SiBs)are required to possess long cycle life when used for large-scale energy *** polyanionic Na_(4)MnV(PO_(4))_(3)(NMVP)reveals good cyclic stability due to its unique three-dimensional(3D)frame structure,but it still faces the challenge of interfacial degradation in practical *** this work,NASiCON-type Na_(1.3)Al_(0.7)Ti_(1.3)(PO_(4))_(3)(NATP)was deposited on the surface of NMVP to promote interface stability by surface modification and gradient *** a result,the optimized NMVP@2%NATP released a capacity retention of 44.8%after 1000 cycles at 5 C,much higher than that of the initial NMVP(28.9%).The enhanced electrochemical performance was mainly attributed to NATP coating acting as a fast ion transport carrier and physical barrier,significantly facilitating the Na^(+)diffusion and isolating side reaction at the electrode/electrolyte *** the other hand,Ti_(4)^(+)and Al^(3+)cations from the NATP were partially doped inside the NMVP surface to boost the transport of Na^(+),and the perfect lattice matching of NVMP and NATP improved the interface and structural stability accompanying long *** work demonstrated the effectiveness of surface modification with high lattice match material and provided new perspectives for high energy density solid-state SiBs.

关键词： high-lattice-adapted cathode surface modification sodium-ion batteries

Trial application of the envelope method to the potential ambiguity problem

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Nuclear Science and Techniques 2024年第1期35卷 73-80页

作者： li-Yuan Hu Yu-Shou song Fundamental Science on Nuclear Safety and Simulation Technology Laboratory Harbin Engineering UniversityHarbin 150001China College of Nuclear Science and Technology Harbin Engineering UniversityHarbin 150001China Key Laboratory of Nuclear Safety and Advanced Nuclear Energy Technology Ministry of Industry and Information TechnologyHarbin 150001China

The optical potential ambiguity is a long-standing problem in the analysis of elastic scattering *** a specific collid-ing system,ambiguous potential families can lead to different behaviors in the nearside and farside scattering *** contrast,the envelope method can decompose the experimental data into two components with negative and positive deflection angles,***,a question arises as to whether the comparison between the calculated nearside(or farside)component and the derived positive-deflection-angle(or negative-deflection-angle)component can help analyze the potential ambiguity *** this study,we conducted a trial application of the envelope method to the potential ambiguity *** envelope method was improved by including uncertainties in the experimental *** colli.i.g systems of 16O+28Si at 215.2 MeV and 12C+12C at 1016 MeV were considered in the *** each colli.i.g system,the angular distribution experimental data were described nearly equally well by two potential sets,one of which is“surface transpar-ent”and the other is *** calculated angular distributions were decomposed into nearside and farside scattering *** the improved envelope method,the experimental data were decomposed into the positive-deflection-angle and negative-deflection-angle components,which were then compared with the calculated nearside and farside *** capability of the envelope method to analyze the potential ambiguities was also discussed.

关键词： Elastic scattering Optical potential ambiguities Envelope method Nearside/farside decomposition

Cooperative guidance law with maneuverability awareness:A decentralized solution

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Chinese Journal of Aeronautics 2024年第7期37卷 450-457页

作者： Shuyang XU Xun song Chaoyong li College of Electrical Engineering Zhejiang UniversityHangzhou 310027China Beijing institute of Electronic System Engineering Beijing 100074China

in this paper,we propose a cooperative guidance law aimed to achieve coordinated impact angles with limited observation on target *** primary challenge lies in establishing an appropriate communication graph among all missiles and devising an algorithm to estimate target acceleration information during *** address this,we propose a specific communication topology and employ a numerical integration-based estimation ***,a distributed algorithm is introduced to facilitate consensus on target acceleration *** upon these foundations,we design an optimal-control-based distributed guidance law for each *** of the proposed guidance law is validated through numerical simulations.

关键词： Cooperative guidance Target maneuver estimation Distributed estimation Consensus Optimal control

gravitational waves and primordial black hole productions from gluodynamics by holography

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Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 31-42页

作者： song He li li Zhibin li Shao-Jiang Wang Center for Theoretical Physics and College of Physics Jilin UniversityChangchun 130012China Max Planck institute for gravitational Physics(Albert Einstein institute) Golm 14476Germany CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China Peng Huanwu Collaborative Center for Research and Education Beihang UniversityBeijing 100191China School of Physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China

Understanding the nature of quantum chromodynamics(QCD)matter is important but challenging due to the presence of nonperturbative dynamics under extreme *** construct a holographic model describing the gluon sector of QCD at finite temperatures in the non-perturbative *** equation of state as a function of temperature is in good accordance with the lattice QCD ***,the Polyakov loop and the gluon condensation,which are proper order parameters to capture the deconfinement phase transition,also agree quantitatively well with the lattice QCD *** obtain a strong first-order confinement/deconfinement phase transition at Tc=276.5 Me V that is consistent with the lattice QCD *** on our model for a pure gluon hidden sector,we compute the stochastic gravitational waves and primordial black hole(PBH)productions from this confinement/deconfinement phase transition in the early *** resulting stochastic gravitational-wave backgrounds are found to be within detectability in the international Pulsar Timing Array and Square Kilometre Array in the near future when the associated productions of PBHs saturate the current observational bounds on the PBH abundances from the ligO-Virgo-Collaboration O3 data.

关键词： AdS/QCD confinement/deconfinement phase transition gravitational wave primordial black hole

Multiscale feature learning and attention mechanism for infrared and visible image fusion

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Science China(Technological Sciences) 2024年第2期67卷 408-422页

作者： gAO li LUO Delin WANg song School of Aerospace Engineering Xiamen UniversityXiamen 361102China Electric Power Research institute China Southern Power GridGuangzhou 510063China

Current fusion methods for infrared and visible images tend to extract features at a single scale,which results in insufficient detail and incomplete feature *** address these issues,we propose an infrared and visible image fusion network based on a multiscale feature learning and attention mechanism(MsAFusion).A multiscale dilation convolution framework is employed to capture image features across various scales and broaden the perceptual ***,an attention network is introduced to enhance the focus on salient targets in infrared images and detailed textures in visible *** compensate for information loss during convolution,jump connections are utilized during the image reconstruction *** fusion process utilizes a combined loss function consisting of pixel loss and gradient loss for unsupervised fusion of infrared and visible *** experiments on the dataset of electricity facilities demonstrate that our proposed method outperforms nine state-of-theart methods in terms of visual perception and four objective evaluation metrics.

关键词： infrared and visible images image fusion attention mechanism CNN feature extraction

Adaptive Consensus of Uncertain Multi-Agent Systems With Unified Prescribed Performance

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iEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1310-1312页

作者： Kun li Kai Zhao Yongduan song The authors are with the School of Automation Chongqing UniversityChongqing 400044China

Dear Editor,An adaptive consensus control algorithm for uncertain multi-agent systems(MAS),capable of guaranteeing unified prescribed performance,is presented in this *** many existing prescribed performance related works,the developed control exhibits some ***,a distributed prescribed time observer is introduced so that not only each follower is able to estimate the leader’s signal within a predetermined time,but also the control design for each agent is independent with its neighbors.

关键词： agent prescribed Uncertain

Surface morphologies of Mg-gd alloy particle during its reactions with O_(2) and Teflon

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Defence Technology（防务技术） 2024年第3期33卷 209-221页

作者： Yifan li Hongtao Yang Aifeng Jiang Dongming song Yanchun li Department of Chemical Engineering Nanjing University of Science and TechnologyNanjing 210097China Xi'an Modern Chemistry Research institute Xi'an 710065China Southwest Technology and Engineering Research institute Chongqing 400039China

Mg-gd alloy particle has exhibited its unique combustion properties as the fuel of Mg/Teflon/Viton(MTV).Mg-gd alloy/Teflon/Viton(MgTV)could burn at lower ambient pressure than *** further investigate the reaction of MgTV in air,it was investigated via thermo gravity-differential scanning calorimetry(Tg-DSC).Meanwhile,the morphologies and element distributions on the alloy surface during the reaction of MgTV in air were investigated via scanning electronic microscope-mapping-electronic differential ***,a similar experimental protocol on the Mg-gd alloy particle during oxidation was also *** results showed that owning to a protective oxide shell,the onset oxidation temperature of Mg-gd alloy is higher than ***,the onset oxidation temperature of the exceeded Mg-gd alloy in MgTV is significantly lower than that of the exceeded Mg in *** was due to the existence of gdOF,which could significantly lower the oxidation temperature of the exceeded ***,a possible reaction mechanism was *** fascinating oxidation properties of Mg-gd alloy suggested its promising applications in energetic materials.

关键词： Mg-gd alloy Energetic materials Morphology EDS gdOF