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Periodic event-triggered secure consensus for networked mechanical systems under Denial-of-Service attacks

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Control Theory and Technology 2024年第1期22卷 1-13页

作者： shiqi Zheng Zhipeng Li Chao Zhai peng shi School of Automation China University of GeosciencesWuhan430074HubeiChina School of Electrical and Electronic Engineering The University of AdelaideAdelaideSA5005Australia School of Electronic Electrical Engineering and PhysicsFujian University of TechnologyFuzhou350100FujianChina

This paper concentrates on the secure consensus problem of networked mechanical/Euler–Lagrange systems.First,a new periodic event-triggered(PET)secure distributed observer is proposed to estimate the leader information.The proposed distributed observer only relies on the PET data from its neighbors,which can significantly reduce the communication and computational burden.More importantly,it is secure in the sense that it can work normally regardless of the Denial-of-Service(DoS)attacks.Second,based on the proposed distributed observer,an adaptive fuzzy control law is proposed for each Euler–Lagrange system.A PET mechanism is integrated into the controller,which can reduce the control update.This is helpful for both energy saving and fault tolerance of actuators.Moreover,the PET mechanism naturally makes the controller easy to be implemented in digital platform.The property of fuzzy logic systems and Gronwall inequality are skillfully utilized to show the stability of the closed-loop system.Finally,the proposed control scheme is verified on real Euler–Lagrange systems,which contain a robot manipulator and several servo motors.

关键词： Output regulation Mechanical/Euler-Lagrange systems Periodic event-triggered mechanism Denial-of-Service attacks

Optimal Cooperative Secondary Control for Islanded DC Microgrids via a Fully Actuated Approach

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 405-417页

作者： Yi Yu Guo-Ping Liu Yi Huang peng shi IEEE Shenzhen Key Laboratory of Control Theory and Intelligent Systems Southern University of Science and TechnologyShenzhen 518055China School of Electrical Engineering and Automation Wuhan UniversityWuhan 430072China School of Electrical and Mechanical Engineering the University of AdelaideSA 5005Australia Research and Innovation Centre Obuda University1034 BudapestHungary

DC-DC converter-based multi-bus DC microgrids(MGs) in series have received much attention, where the conflict between voltage recovery and current balancing has been a hot topic. The lack of models that accurately portray the electrical characteristics of actual MGs while is controller design-friendly has kept the issue active. To this end, this paper establishes a large-signal model containing the comprehensive dynamical behavior of the DC MGs based on the theory of high-order fully actuated systems, and proposes distributed optimal control based on this. The proposed secondary control method can achieve the two goals of voltage recovery and current sharing for multi-bus DC MGs. Additionally, the simple structure of the proposed approach is similar to one based on droop control, which allows this control technique to be easily implemented in a variety of modern microgrids with different configurations. In contrast to existing studies, the process of controller design in this paper is closely tied to the actual dynamics of the MGs. It is a prominent feature that enables engineers to customize the performance metrics of the system. In addition, the analysis of the stability of the closed-loop DC microgrid system, as well as the optimality and consensus of current sharing are given. Finally, a scaled-down solar and battery-based microgrid prototype with maximum power point tracking controller is developed in the laboratory to experimentally test the efficacy of the proposed control method.

关键词： DC microgrids distributed control high-order fully actuated system approach linear quadratic regulator microgrid modeling secondary control

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MIDNet:Deblurring Network for Material Microstructure Images

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Computers, Materials & Continua 2024年第4期79卷 1187-1204页

作者： Jiaxiang Wang Zhengyi Li peng shi Hongying Yu Dongbai Sun National Center for Materials Service Safety University of Science and Technology BeijingBeijing100083China School of Materials Sun Yat-Sen UniversityShenzhen518107China School of Materials Science and Engineering Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Sun Yat-Sen UniversityGuangzhou510006China

Scanning electron microscopy(SEM)is a crucial tool in the field of materials science,providing valuable insightsinto the microstructural characteristics of materials.Unfortunately,SEM images often suffer from blurrinesscaused by improper hardware calibration or imaging automation errors,which present challenges in analyzingand interpretingmaterial characteristics.Consequently,rectifying the blurring of these images assumes paramountsignificance to enable subsequent analysis.To address this issue,we introduce a Material Images DeblurringNetwork(MIDNet)built upon the foundation of the Nonlinear Activation Free Network(NAFNet).MIDNetis meticulously tailored to address the blurring in images capturing the microstructure of materials.The keycontributions include enhancing the NAFNet architecture for better feature extraction and representation,integratinga novel soft attention mechanism to uncover important correlations between encoder and decoder,andintroducing newmulti-loss functions to improve training effectiveness and overallmodel performance.We conducta comprehensive set of experiments utilizing the material blurry dataset and compare them to several state-of-theartdeblurring methods.The experimental results demonstrate the applicability and effectiveness of MIDNet in thedomain of deblurring material microstructure images,with a PSNR(Peak Signal-to-Noise Ratio)reaching 35.26 dBand an SSIM(Structural Similarity)of 0.946.Our dataset is available at:https://***/woshigui/MIDNet.

关键词： Image deblurring material microstructure attention mechanism deep learning

Occurrence and risk assessment of azole fungicides during the urban water cycle:A year-long study along the Yangtze River,China

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Journal of Environmental Sciences 2024年第7期141卷 16-25页

作者： Yangyang Zhang Xinjie Gu Xiuwen Li Qiuyun Zhao Xiaodong Hu Rui Huang Jixiong Xu Zilong Yin Qing Zhou Aimin Li peng shi State Key Laboratory of Pollution Control and Resource Reuse School of the EnvironmentNanjing UniversityNanjing 210023China Jiangsu Province Hydraulic Research Institute Nanjing 210023China

Azole fungicides(AFs)play an important role in the prevention and treatment of fungal diseases in agricultural crops.However,limited studies are addressing the fate and ecological risk of AFs in the urban water cycle at a large watershed scale.To address this gap,we investigated the spatiotemporal distribution and ecological risk of twenty AFs in the lower reaches of the Yangtze River across four seasons.Carbendazim(CBA),tebuconazole(TBA),tricyclazole(TCA),and propiconazole(PPA)were found to be the dominant compounds.Their highest concentrations were measured in January(188.3 ng/L),and November(2197.1 ng/L),July(162.0 ng/L),and November(1801.9 ng/L),respectively.The comparison between wastewater treatment plants(WWTPs)effluents and surface water suggested that industrial WWTPs are major sources of AFs in the Yangtze River.In particular,TBA and PPA were found to be the most recalcitrant AFs in industrial WWTPs,while difenoconazole(DFA)was found to be the most potent pollutant in municipal WWTPs,with an average removal rate of less than60%.The average risk quotient(RQ)for the entire AFs was 6.45 in the fall,which was higher than in January(0.98),April(0.61),and July(0.40).This indicates that AFs in surface water posed higher environmental risks during the dry season.Additionally,the exposure risk of AFs via drinking water for sensitive populations deserves more attention.This study provides benchmark data on the occurrence of AFs in the lower reaches of the Yangtze River,and offers suggestions for better reduction of AFs.

关键词： Azole fungicides Spatiotemporal distribution Ecological risk Urban water cycle the Yangtze River

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Analysis of large datasets for identifying molecular targets in intestinal polyps and metabolic disorders

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BIOCELL 2024年第3期48卷 415-429页

作者： SHAN OU YUN XU QINGLAN LIU TIANWEN YANG WEI CHEN XIU YUAN XIN ZUO peng shi JIE YAO Department of Gastroenterology The First Affiliated Hospital of Chongqing Medical and Pharmaceutical CollegeChongqingChina

Background:The interrelation between intestinal polyps,metabolic syndrome(MetS),and colorectal cancer(CRC)is a critical area of study.This research focuses on pinpointing potential molecular targets to understand the link between intestinal polyp formation,metabolic irregularities,and CRC progression.Methods:We examined clinical samples from patients with intestinal polyps coexisting with MetS and compared them with samples from patients with standard intestinal polyps.Transcriptome sequencing and public database analysis were employed to identify significant pathways and genes.These targets were then validated through immunohistochemistry(IHC).Following the RNA interference of key target expression,a series of experiments,including the cell counting kit-8 assay,colony formation,wound healing,and Transwell assays,were conducted.Results:Comparative analysis revealed 75 up-regulated and 61 down-regulated differentially expressed genes(DEGs)in the MetS polyp group vs.the control.Kyoto encyclopedia of genes and genomes(KEGG)pathway enrichment suggested these DEGs were primarily associated with cell cycle and mitosis.Integration with comparative toxicogenomics database(CTD)and the cancer genome atlas(TCGA)databases highlighted 44 key CRC-related genes.Protein interaction networks indicated connections of purkinje cell protein 4(PCP4),olfactomedin 1(OLFM1),fibronectin 1(FN1),and transforming growth factor beta 3(TGF-β3)with the mitogen-activated protein kinase(MAPK)pathway.Tumor correlation studies suggested higher risk associations with FN1,PCP4,and TGF-β3,while OLFM1 was identified as a lower risk gene.Immunohistochemical analysis revealed a decrease in OLFM1 in MetS-associated intestinal polyps.Upon interference with OLFM1 in polyp epithelial cells,there was a significant enhancement in cell proliferation,colony formation,and cell migration and invasion capabilities.Conclusion:Our study highlights a significant decrease in OLFM1 expression in MetS-associated intestinal polyps.And,this reduction in OLFM1 is associate

关键词： Colorectal cancer Metabolic syndrome Intestinal polyp OLFM1 Exosome

Clinical features and prognostic factors of duodenal neuroendocrine tumours:A comparative study of ampullary and nonampullary regions

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World Journal of Gastrointestinal Oncology 2024年第3期16卷 907-918页

作者： Sa Fang Yu-peng shi Lu Wang Shuang Han Yong-Quan shi Department of Gastroenterology Honghui HospitalXi’an Jiaotong UniversityXi'an 710054Shanxi ProvinceChina Department of Gastroenterology The Second Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710032Shaanxi ProvinceChina Department of Gastroenterology Xijing Hospital Affiliated to Air Force Medical UniversityXi'an 710032Shaanxi ProvinceChina

BACKGROUND Duodenal neuroendocrine tumours(DNETs)are rare neoplasms.However,the incidence of DNETs has been increasing in recent years,especially as an incidental finding during endoscopic studies.Regrettably,there is no consensus regarding the ideal treatment of DNETs.Even there are few studies on the clinical features and survival analysis of DNETs.AIM To analyze the clinical characteristics and prognostic factors of patients with duodenal neuroendocrine tumours.METHODS The clinical data of DNETs diagnosed in the First Affiliated Hospital of Air Force Military Medical University from June 2011 to July 2022 were collected.Neuroen-docrine tumours located in the ampulla area of the duodenum were divided into the ampullary region group;neuroendocrine tumours in any part of the duo-denum outside the ampullary area were divided into the nonampullary region group.Using a retrospective study,the clinical characteristics of the two groups and risk factors affecting the survival of DNET patients were analysed.RESULTS Twenty-nine DNET patients were screened.The male to female ratio was 1:1.9,and females comprised the majority.The ampullary region group accounted for 24.1%(7/29),while the nonampullary region group accounted for 75.9%(22/29).When diagnosed,the clinical symptoms of the ampullary region group were mainly abdominal pain(85.7%),while those of the nonampullary region groups were mainly abdominal distension(59.1%).There were differences in the composition of staging of tumours between the two groups(Fisher's exact probability method,P=0.001),with nonampullary stage II tumours(68.2%)being the main stage(P<0.05).After the diagnosis of DNETs,the survival rate of the ampullary region group was 14.3%(1/7),which was lower than that of 72.7%(16/22)in the nonampullary region group(Fisher's exact probability method,P=0.011).The survival time of the ampullary region group was shorter than that of the nonampullary region group(P<0.000).The median survival time of the ampullary region group was 10.0 months and that of the no

关键词： Duodenum Neuroendocrine Tumour Ampullary Nonampullary Clinical features Prognostic

Recent progress in the development of dielectric elastomer materials and their multilayer actuators

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第3期25卷 183-205页

作者： Shengchao JIANG Junbo peng Lvting WANG Hanzhi MA Ye shi ZJU-UIUC Institute Zhejiang UniversityJiaxing 314400China College of Mechanical Engineering Zhejiang UniversityHangzhou 310058China Department of Polymer Science and Engineering Zhejiang UniversityHangzhou 310058China

Dielectric elastomers(DEs)have emerged as one of the most promising artificial muscle technologies,due to their exceptional properties such as large actuation strain,fast response,high energy density,and flexible processibility for various configurations.Over the past two decades,researchers have been working on developing DE materials with improved properties and exploring innovative applications of dielectric elastomer actuators(DEAs).This review article focuses on two main topics:recent material innovation of DEs and development of multilayer stacking processes for DEAs,which are important to promoting commercialization of DEs.It begins by explaining the working principle of a DEA.Then,recently developed strategies for preparing new DE materials are introduced,including reducing mechanical stiffness,increasing dielectric permittivity,suppressing viscoelasticity loss,and mitigating electromechanical instability without pre-stretching.In the next section,different multilayer stacking methods for fabricating multilayer DEAs are discussed,including conventional dry stacking,wet stacking,a novel dry stacking method,and micro-fabrication-enabled stacking techniques.This review provides a comprehensive and up-to-date overview of recent developments in high-performance DE materials and multilayer stacking methods.It highlights the progress made in the field and also discusses potential future directions for further advancements.

关键词： Dielectric elastomer actuator(DEA) Dielectric elastomer(DE) Material svnthesis Multilaver stacking method

Promoted surface charge density from interlayer Zn–N_(4) configuration in carbon nitride for enhanced CO_(2) photoreduction

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Nano Research 2024年第4期17卷 2400-2409页

作者： Xianjin shi Yu Huang Gangqiang Zhu Wei peng Meijuan Chen State Key Laboratory of Loess and Quaternary Geology(SKLLQG) Key Laboratory of Aerosol Chemistry and PhysicsInstitute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China Center of Excellence in Quaternary Science and Global Change Chinese Academy of SciencesXi’an 710061China University of Chinese Academy of Sciences Beijing 100049China School of Physics and Information Technology Shaanxi Normal UniversityXi’an 710062China School of Human Settlements and Civil Engineering Xi’an Jiaotong UniversityXi’an 710049China

The solar-driven reduction of CO_(2) into valuable products is a promising method to alleviate global environmental problems and energy crises.However,the low surface charge density limits the photocatalytic conversion performance of CO_(2).Herein,a polymeric carbon nitride(PCN)photocatalyst with Zn single atoms(Zn1/CN)was designed and synthesized for CO_(2) photoreduction.The results of the CO_(2) photoreduction studies show that the CO and CH_(4) yields of Zn1/CN increased fivefold,reaching 76.9 and 22.9μmol/(g·h),respectively,in contrast to the unmodified PCN.Ar+plasma-etched X-ray photoelectron spectroscopy and synchrotron radiation-based X-ray absorption fine structure results reveal that Zn single atom is mainly present in the interlayer space of PCN in the Zn–N_(4) configuration.Photoelectrochemical characterizations indicate that the interlayer Zn–N_(4) configuration can amplify light absorption and establish an interlayer charge transfer channel.Light-assisted Kelvin probe force microscopy confirms that more photogenerated electrons are delivered to the catalyst surface through interlayer Zn–N_(4) configuration,which increases its surface charge density.Further,in-situ infrared spectroscopy combined with density functional theory calculation reveals that promoted surface charge density accelerates key intermediates(*COOH)conversion,thus achieving efficient CO_(2) conversion.This work elucidates the role of internal single atoms in catalytic surface reactions,which provides important implications for the design of single-atom catalysts.

关键词： single-atom catalysts photocatalytic CO_(2)reduction interlayer modification charge transfer dynamics surface charge density

Review on the design of high-strength and hydrogen-embrittlement-resistant steels

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International Journal of Minerals,Metallurgy and Materials 2024年第7期31卷 1572-1589页

作者： Zhiyu Du Rongjian shi Xingyu peng Kewei Gao Xiaolu Pang Beijing Advanced Innovation Center for Materials Genome Engineering School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China Institute for Materials Intelligent Technology Liaoning Academy of MaterialsShenyang 110010China

Given the carbon peak and carbon neutrality era,there is an urgent need to develop high-strength steel with remarkable hydrogen embrittlement resistance.This is crucial in enhancing toughness and ensuring the utilization of hydrogen in emerging iron and steel materials.Simultaneously,the pursuit of enhanced metallic materials presents a cross-disciplinary scientific and engineering challenge.Developing high-strength,toughened steel with both enhanced strength and hydrogen embrittlement(HE)resistance holds significant theoretical and practical implications.This ensures secure hydrogen utilization and further carbon neutrality objectives within the iron and steel sector.Based on the design principles of high-strength steel HE resistance,this review provides a comprehensive overview of research on designing surface HE resistance and employing nanosized precipitates as intragranular hydrogen traps.It also proposes feasible recommendations and prospects for designing high-strength steel with enhanced HE resistance.

关键词： hydrogen embrittlement surface design hydrogen traps nanosized precipitates

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