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Deep reinforcement learning based active surge control for aeroengine compressors

Chinese Journal of Aeronautics 2024年第7期37卷 418-438页

作者： Xinglong zhang Zhonglin LIN Runmin JI Tianhong zhang College of Energy and Power Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China School of Mechanical Engineering and Automation Fuzhou UniversityFuzhou 350108China

This study proposes an active surge control method based on deep reinforcement learning to ensure the stability of compressors when adhering to the pressure rise command across the wide operating range of an ***,the study establishes the compressor dynamic model with uncertainties,disturbances,and Close-Coupled Valve(CCV)actuator *** upon this foundation,a Partially Observable Markov Decision Process(POMDP)is defined to facilitate active surge *** address the issue of unobservability,a nonlinear state observer is designed using a finite-time high-order sliding ***,an Improved Soft Actor-Critic(ISAC)algorithm is developed,incorporating prioritized experience replay and adaptive temperature parameter techniques,to strike a balance between exploration and convergence during *** addition,reasonable observation variables,error-segmented reward functions,and random initialization of model parameters are employed to enhance the robustness and generalization ***,to assess the effectiveness of the proposed method,numerical simulations are conducted,and it is compared with the fuzzy adaptive backstepping method and Second-Order Sliding Mode Control(SOSMC)*** simulation results demonstrate that the deep reinforcement learning based controller outperforms other methods in both tracking accuracy and ***,the proposed active surge controller can effectively ensure stable operation of compressors in the high-pressure-ratio and high-efficiency region.

关键词： Aeroengine surge Active surge control Moore-Greitzer model Deep reinforcement learning Soft actor-critic Nonlinear observer

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Polystyrene microplastics disrupted physical barriers, microbiota composition and immune responses in the cecum of developmental Japanese quails

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Journal of Environmental Sciences 2024年第10期144卷 225-235页

作者： Lingyang Jing Yuxin zhang Qingyu zhang Hongfeng Zhao College of Life Sciences Shaanxi Normal UniversityXi’an 710119China

Microplastics,a new type of emerging pollutant,is ubiquitous in terrestrial and water *** have become a growing concern due to their impacts on the environment,animal,and human *** also suffer from microplastics *** this study,we examined the toxic effects of polystyrene microplastics(PS-MPs)exposure on physical barrier,microbial community,and immune function in the cecum of a model bird species—Japanese quail(Coturnix japonica).The one-week-old birds were fed on environmentally relevant concentrations of 20μg/kg,400μg/kg,and 8 mg/kg PS-MPs in the diet for 5 *** results showed that microplastics could cause microstructural damages characterized by lamina propria damage and epithelial cell vacuolation and ultrastructural injuries including microvilli breakage and disarrangement aswell asmitochondrial vacuolation in the cecum of *** particular,blurry tight junctions,wider desmosomes spacing,and gene expression alteration indicated cecal tight junction ***,mucous layer breakdown andmucin decrease indicated that chemical barrier was disturbed by ***-MPs also changed cecal microbial *** addition,structural deformation of cecal tonsils and increasing proinflammatory cytokines suggested cecal immune disorder and inflammation responses by PS-MPs *** results suggested that microplastics negatively affected digestive system and might pose great health risks to terrestrial birds.

关键词： Microplastics Gut barrier Histology Inflammation Immunity Oxidative stress

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Multi-circular formation control with reinforced transient profiles for nonholonomic vehicles:A path-following framework

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Defence Technology（防务技术） 2024年第1期31卷 278-287页

作者： Jintao zhang Xingling Shao Wendong zhang Zongyu Zuo School of Instrument and Electronics North University of ChinaTaiyuan 030051China State Key Laboratory of Dynamic Measurement Technology North University of ChinaTaiyuan 030051China Seventh Research Division School of Automation Science and Electrical EngineeringBeihang UniversityBeijing 100191China

This article investigates a multi-circular path-following formation control with reinforced transient profiles for nonholonomic vehicles connected by a digraph.A multi-circular formation controller endowed with the feature of spatial-temporal decoupling is devised for a group of vehicles guided by a virtual leader evolving along an implicit path,which allows for a circumnavigation on multiple circles with an anticipant angular *** addition,notice that it typically imposes a stringent time constraint on time-sensitive enclosing scenarios,hence an improved prescribed performance control(IPPC)using novel tighter behavior boundaries is presented to enhance transient capabilities with an ensured appointed-time convergence free from any *** significant merits are that coordinated circumnavigation along different circles can be realized via executing geometric and dynamic assignments independently with modified transient ***,all variables existing in the entire system are analyzed to be *** and experimental results are provided to validate the utility of suggested solution.

关键词： Multi-circular formation Reinforced transient profiles Nonholonomic vehicles Path following

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Accumulated-state-error-based event-triggered sampling scheme and its application to H∞ control of sampled-data systems

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Science China(Information Sciences) 2024年第6期67卷 328-341页

作者： Xian-Ming zhang Qing-Long HAN Bao-Lin zhang Xiaohua GE Dawei zhang School of Science Computingand Engineering TechnologiesSwinburne University of Technology College of Automation and Electronic Engineering Qingdao University of Science & Technology School of Mathematics Shandong University

This paper is concerned with event-triggered H∞control of sampled-data systems. Its novelties lie in three aspects:（i） A novel accumulated-state-error-based event-triggered scheme is introduced by comparing the integral of the state error from tk to t with the system state sampled at tk. This condition works well due to the fact that the so-called Zeno behaviour does not occur.（ii） A novel Lyapunov functional is constructed to establish a criterion to ensure some certain H∞performance of the closed-loop system. This Lyapunov functional is dependent on the integral of the state error involved in the event-triggered scheme.（iii） Under the event-triggered sampling scheme, suitable state-feedback controllers can be designed rather than be given a priori. Moreover, a self-triggered implementation of the proposed event-triggered sampling scheme is presented as well. Finally, a batch reactor model and an inverted pendulum system are given to demonstrate the effectiveness of the proposed method.

关键词： event-triggered sampling self-triggered implementation $H_\infty$ control looped-functional

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On the Pathwise Uniqueness of Solutions of One-dimensional Reflected Stochastic Differential Equations with Jumps

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 149-163页

作者： Hua zhang School of Statistics and Data Science&Key Laboratory of Data Science in Finance and Economics Jiangxi University of Finance and EconomicsNanchang330013China

In this paper, we are concerned with the problem of the pathwise uniqueness of one-dimensional reflected stochastic differential equations with jumps under the assumption of non-Lipschitz continuous coefficients whose... 详细信息

关键词： reflected diffusion processes with jumps pathwise uniqueness local time Meyer It?'s formula

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Dynamics of a Reaction-diffusion-ODE System in a Heterogeneous Media

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 275-301页

作者： Cong-hui zhang Hai-feng zhang Mei-rong zhang School of Science Beijing University of Civil Engineering and ArchitectureBeijing 102616China Institute of Applied System Analysis Jiangsu UniversityZhenjiang 212013China Department of Mathematical Sciences Tsinghua UniversityBeijing 100084China

The existence and stability of stationary solutions for a reaction-diffusion-ODE system are investigated in this *** first show that there exist both continuous and discontinuous stationary *** a good understanding of the stability of discontinuous stationary solutions is gained under an appropriate *** addition,we demonstrate the influences of the diffusion coefficient on stationary *** results we obtained are based on the super-/sub-solution method and the generalized mountain pass ***,some numerical simulations are given to illustrate the theoretical results.

关键词： reaction-diffusion-ODE system discontinuous stationary solutions stability asymptotic behavior monotone solutions

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Structure characterization of the oxide film on FGH96 superalloy powders with various oxidation degrees

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International Journal of Minerals,Metallurgy and Materials 2024年第9期31卷 2037-2047页

作者： Yang Liu Yufeng Liu Sha zhang Lin zhang Peng zhang Shaorong zhang Na Liu Zhou Li Xuanhui Qu Beijing Advanced Innovation Center for Materials Genome Engineering Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China Institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang 110004China Science and Technology on Advanced High Temperature Structural Materials Laboratory AECC Beijing Institute of Aeronautical MaterialsBeijing 100095China

The structure of the oxide film on FGH96 alloy powders significantly influences the mechanical properties of *** this study,FGH96 alloy powders with various oxygen contents were investigated using high-resolution transmission electron microscopy and atomic probe technology to elucidate the structure evolution of the oxide *** dispersive spectrometer analysis revealed the presence of two distinct components in the oxide film of the alloy powders:amorphous oxide layer covering the γ matrix and amorphous oxide particles above the *** alloying elements within the oxide layer showed a laminated distribution,with Ni,Co,Cr,and Al/Ti,which was attributed to the decreasing oxygen equilibrium pressure as oxygen diffused from the surface into the γ *** the other hand,Ti enrichment was observed in the oxide particles caused by the oxidation and decomposition of the carbide *** analysis of the oxide film with oxygen contents of 140,280,and 340 ppm showed similar element distributions,while the thickness of the oxide film varies approximately at 9,14,and 30 nm,*** findings provide valuable insights into the structural analysis of the oxide film on FGH96 alloy powders.

关键词： Ni-based superalloys surface structure oxide layer thickness oxidation behavior element distribution

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A design and manufacturing methodology for encoded soft-textile robots

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 212-213页

作者： Yihui zhang Applied Mechanics Laboratory Department of Engineering MechanicsTsinghua UniversityBeijing 100084China

The development of programmable soft robots with bioinspired morphing capabilities has attracted considerable *** mode and complexity of morphing capabilities are essential to the manipulation and movement abilities o... 详细信息

关键词： environments robots manipulation

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Heterostructure Cu_(3)P-Ni_(2)P/CP catalyst assembled membrane electrode for high-efficiency electrocatalytic nitrate to ammonia

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Nano Research 2024年第6期17卷 4872-4881页

作者： Meng Jin Jiafang Liu Xian zhang Shengbo zhang Wenyi Li Dianding Sun Yunxia zhang Guozhong Wang Haimin zhang Laboratory of Materials Physics Centre for Environmental and Energy NanomaterialsAnhui Key Laboratory of Nanomaterials and NanotechnologyCAS Center for Excellence in NanoscienceInstitute of Solid State PhysicsHefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China Anhui Contango New Energy Technology Co. Ltd.Hefei 230031China

Electrochemical nitrate reduction reaction(NO_(3)RR)is a promising means for generating the energy carrier ***,we report the synthesis of heterostructure copper-nickel phosphide electrocatalysts via a simple vapor-phase hydrothermal *** resultant catalysts were evaluated for electrocatalytic nitrate reduction to ammonia(NH_(3))in three-type electrochemical *** detail,the regulation mechanism of the heterogeneous Cu_(3)P-Ni_(2)P/CP-x for NO_(3)RR performance was systematically studied through the H-type cell,rotating disk electrode setup,and membrane-electrode-assemblies(MEA)*** a result,the Cu_(3)P-Ni_(2)P/CP-0.5 displays the practicability in an MEA system with an anion exchange membrane,affording the largest ammonia yield rate(RNH_(3))of 1.9 mmol·h^(−1)·cm^(−2),exceeding most of the electrocatalytic nitrate reduction electrocatalysts reported to *** theoretical calculations and in-situ spectroscopy characterizations uncover that the formed heterointerface in Cu_(3)P-Ni_(2)P/CP is beneficial for promoting nitrate adsorption,activation,and conversion to ammonia through the successive hydrodeoxygenation pathway.

关键词： electrocatalytic nitrate reduction to ammonia three-type reactors membrane-electrode-assemblies system operando ATR-IRRAS successive hydrodeoxygenation pathway

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Integration of Multiple Spectral Data via a Logistic Regression Algorithm for Detection of Crop Residue Burned Areas:A Case Study of Songnen Plain,Northeast China

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Chinese Geographical Science 2024年第3期34卷 548-563页

作者： zhang Sumei zhang Yuan ZHAO Hongmei College of Mining and Engineering Taiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Wetland Ecology and Environment Northeast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun 130102China

The burning of crop residues in fields is a significant global biomass burning activity which is a key element of the terrestrial carbon cycle,and an important source of atmospheric trace gasses and *** estimation of cropland burned area is both crucial and challenging,especially for the small and fragmented burned scars in *** we developed an automated burned area mapping algorithm that was implemented using Sentinel-2 Multi Spectral Instrument(MSI)data and its effectiveness was tested taking Songnen Plain,Northeast China as a case using satellite image of *** employed a logistic regression method for integrating multiple spectral data into a synthetic indicator,and compared the results with manually interpreted burned area reference maps and the Moderate-Resolution Imaging Spectroradiometer(MODIS)MCD64A1 burned area *** overall accuracy of the single variable logistic regression was 77.38%to 86.90%and 73.47%to 97.14%for the 52TCQ and 51TYM cases,*** comparison,the accuracy of the burned area map was improved to 87.14%and 98.33%for the 52TCQ and 51TYM cases,respectively by multiple variable logistic regression of Sentind-2 *** balance of omission error and commission error was also *** integration of multiple spectral data combined with a logistic regression method proves to be effective for burned area detection,offering a highly automated process with an automatic threshold determination *** method exhibits excellent extensibility and flexibility taking the image tile as the operating *** is suitable for burned area detection at a regional scale and can also be implemented with other satellite data.

关键词： crop residue burning burned area Sentinel-2 Multi Spectral Instrument(MSI) logistic regression Songnen Plain,China

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