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Moments of Continuous-state Branching Processes with or Without Immigration

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Acta Mathematicae Applicatae Sinica 2020年第2期36卷 361-373页

作者： li-na JI zeng-hu li Department of Mathematics Southern University of Science and TechnologyShenzhen 518055China School of Mathematical Sciences Beijing Normal UniversityBeijing 100875China

For a positive continuous function f satisfying some standard conditions,we study the f-moments of continuous-state branching processes with or without *** main results give criteria for the existence of the *** chara... 详细信息

关键词： branching process continuous-state immigration moments stochastic equation

Discretization of Continuous-time Systems with Input Delays

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自动化学报 2010年第10期36卷 1426-1431页

作者： zeng li hu Guang-Da Department of Electronics and Information Engineering School of Information Engineering University of Science and Technology Beijing Beijing 100083 P. R. China

In this paper, the Runge-Kutta (RK) method, which involves the polynomial interpolation is adopted to discretize continuous-time systems with input delay. The proposed scheme is an efficient and higher-order approach compared with conventional discretizing methods. The accuracy of the proposed conversion scheme is closely related to the order of RK as well as that of the polynomial interpolation. Both the approximate order and the maximal attainable order of the discretization are discussed. In addition, the input-to-state stability of the scheme is analyzed. In order to guarantee the stability of the corresponding discrete system, the sampling time can be chosen by investigating the absolute stability region of the RK method. Especially, when the RK method is A-stable, the sampling time can be selected without being constrained by stability considerations. A numerical experiment is provided to demonstrate the superior performance of the method

关键词：自动化系统系统稳定性研究发展

A Local-Global Attention Fusion Framework With Tensor Decomposition for Medical Diagnosis

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IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1536-1538页

作者： Peishu Wu Han li liwei hu Jirong Ge Nianyin zeng Department of Instrumental and Electrical Engineering Xiamen UniversityFujian 361005China Key Research Laboratory of Osteoporosis Syndrome Genomics Fujian Academy of Chinese Medical SciencesFuzhou 350003China

Dear Editor,In this letter,a novel hierarchical fusion framework is proposed to address the imperfect data property in complex medical image analysis(MIA)*** particular,by combining the strengths of convolutional neural networks(CNNs)and transformers,the enhanced feature extraction,spatial modeling,and sequential context learning are realized to provide comprehensive insights on the complex data *** of information in different level is enabled via a multi-attention fusion mechanism,and the tensor decomposition methods are adopted so that compact and distinctive representation of the underlying and high-dimensional medical image features can be accomplished[1].It is shown from the evaluation results that the proposed framework is competitive and superior as compared with some other advanced algorithms,which effectively handles the imperfect property of inter-class similarity and intra-class differences in diseases,and meanwhile,the model complexity is reduced within an acceptable level,which benefits the deployment in clinic *** has assumed a pivotal role in numerous critical clinical scenarios,where sophisticated image analysis techniques have proven instrumental in augmenting medical decision-making,facilitating individualized therapeutic interventions,and enhancing patient prognostication[2]−[4].

关键词： handle image property

Numerical analysis of factors affecting the range of heat transfer in earth surrounding three subways

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Journal of China University of Mining and Technology 2008年第1期18卷 67-71页

作者： hu zeng-hui li Xiao-zhao ZHAO Xiao-bao XIAO lin WU Wei Department of Earth Sciences Nanjing University Nanjing Jiangsu 210093 China

In order to examine the factors which affect the range of heat transfer in earth surrounding subways, FLAC3D was adopted in this study to analyze these factors, under different conditions, in a systematic manner. When we compare these numerical tests, the results show that the main factors, affecting the heat transfer range are the thermal properties of the surrounding earth, the initial ground temperature and the temperature in the tunnel. The heat transfer coefficient between air and linings has little effect on the temperature distribution around the tunnel. The current results can provide a reference for improving the thermal environment in subways and optimizing the design of subwav ventilation and air conditioning.

关键词： earth surrounding subways range of heat transfer factors affecting heat transfer numerical analysis

Cationic surface polarization centers on ionic carbon nitride for efficient solar-driven H_(2)O_(2) production and pollutant abatement

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Chinese Chemical Letters 2024年第10期35卷 383-388页

作者： Zhenyu hu Zhenchun Yang Shiqi zeng Kun Wang lina li Chun hu Yubao Zhao MOE Key Laboratory for Water Quality and Conservation of the Pearl River Delta Institute of Environmental Research at Greater BayGuangzhou UniversityGuangzhou510006China

Solar-driven H_(2)O_(2)production and emerging organic pollutants(EOPs)elimination are of great significance from the perspective of environmental *** efficiency of the photocatalytic reaction system is the key challenge to be *** this work,the strategy of constructing surface ionic local polarization centers to enhance the exciton dissociation of the polymeric photocatalytic is *** bipyridinium cation(TMAP)is complexed on a K^(+)-incorporated carbon nitride(CNK)framework,and the combination of local polarization centers both on the surface(bipyridinium cation)and bulk(K+cation)contributes to a superior photocatalytic H_(2)O_(2)production performance,affording a remarkable H_(2)O_(2)generation rate of 46.8μmol h^(-1)mg^(-1)and a high apparent quantum yield(AQY)value of 77.5%under irradiation of 405 nm *** substantiated experimentally by steady state/transient spectroscopy techniques,the surface local polarization centers increase the population of the long-lived trapped electrons,and thereby promote the interfacial charge transfer process for chemical conversion *** strategy is potentially applicable to the design of a wide range of efficient solar-to-chemical conversion systems.

关键词： Local polarization Oxygen reductionreaction Hydrogen peroxide production Pollutantdegradation Polymeric carbon nitride

Learning Sequential and Structural Dependencies Between Nucleotides for RNA N6-Methyladenosine Site Identification

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IEEE/CAA Journal of Automatica Sinica 2024年第10期11卷 2123-2134页

作者： Guodong li Bowei Zhao Xiaorui Su Dongxu li Yue Yang Zhi zeng Lun hu Xinjiang Technical Institute of Physics and Chemistry Chinese Academy of ScienceUrumqi 830011China College of Computer Xi’an Jiaotong UniversityXi’an 710049China IEEE

N6-methyladenosine(m6A)is an important RNA methylation modification involved in regulating diverse biological processes across multiple ***,the identification of m6A modification sites provides valuable insight into the biological mechanisms of complex diseases at the post-transcriptional *** a variety of identification algorithms have been proposed recently,most of them capture the features of m6A modification sites by focusing on the sequential dependencies of nucleotides at different positions in RNA sequences,while ignoring the structural dependencies of nucleotides in their threedimensional *** overcome this issue,we propose a cross-species end-to-end deep learning model,namely CR-NSSD,which conduct a cross-domain representation learning process integrating nucleotide structural and sequential dependencies for RNA m6A site ***,CR-NSSD first obtains the pre-coded representations of RNA sequences by incorporating the position information into single-nucleotide states with chaos game representation *** then constructs a crossdomain reconstruction encoder to learn the sequential and structural dependencies between *** minimizing the reconstruction and binary cross-entropy losses,CR-NSSD is trained to complete the task of m6A site *** experiments have demonstrated the promising performance of CR-NSSD by comparing it with several state-of-the-art m6A identification ***,the results of cross-species prediction indicate that the integration of sequential and structural dependencies allows CR-NSSD to capture general features of m6A modification sites among different species,thus improving the accuracy of cross-species identification.

关键词： Cross-domain reconstruction cross-species prediction N6-methyladenosine(m6A)modification site RNA sequence sequential and structural dependencies

A Review of Magnesium Alloys as Structure–Function Integrated Materials

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Acta Metallurgica Sinica(English Letters) 2024年第8期37卷 1301-1338页

作者： Zhenfei Jiang Bo hu Zixin li Fanjin Yao Jiaxuan Han Dejiang li Xiaoqin zeng Wenjiang Ding National Engineering Research Center of light Alloy Net Forming and State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai 200240China

Magnesium alloys have a significant advantage,lower density over the other structure materials;hence,they have been widely used in various fields such as transportation and *** the development of research and the enlargement of the research scope,more advantages have been revealed:excellent shielding efficiency,extraordinarily high damping capacity,as well as impressive thermal ***,Mg alloys have the potential to be various functional materials,such as electromagnetic shielding material,damping material,and thermal conductive *** review comprehensively summarizes the research progress and the up-to-date summary of Mg alloys as structure–function integrated materials in recent *** atoms,heat treatment,deformation,secondary phase,and temperature,which have a significant influence on the properties of magnesium alloys,are *** expect this review to be helpful for those who are working on developing structure–function integrated materials with superior comprehensive performance.

关键词： Magnesium alloys Structure-function integrated Electromagnetic shielding Damping capacity Thermal conductivity

Intelligent Predetermination of Generator Tripping Scheme: Knowledge Fusion-based Deep Reinforcement Learning Framework

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 66-75页

作者： lingkang zeng Wei Yao Ze hu Hang Shuai Zhouping li Jinyu Wen Shijie Cheng State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronics EngineeringHuazhong University of Science and TechnologyWuhan 430074China Dispatching and Control Center Central China Branch of State Grid Corporation of ChinaWuhan 430077China. Department of Electrical Engineering and Computer Science University of TennesseeKnoxvilleTN 37996USA

Generator tripping scheme(GTS)is the most commonly used scheme to prevent power systems from losing safety and ***,GTS is composed of offline predetermination and real-time scenario ***,it is extremely time-consuming and labor-intensive for manual predetermination for a large-scale modern power *** improve efficiency of predetermination,this paper proposes a framework of knowledge fusion-based deep reinforcement learning(KF-DRL)for intelligent predetermination of ***,the Markov Decision Process(MDP)for GTS problem is formulated based on transient instability ***,linear action space is developed to reduce dimensionality of action space for multiple controllable ***,KF-DRL leverages domain knowledge about GTS to mask invalid actions during the decision-making *** can enhance the efficiency and learning ***,the graph convolutional network(GCN)is introduced to the policy network for enhanced learning *** simulation results obtained on New England power system demonstrate superiority of the proposed KF-DRL framework for GTS over the purely data-driven DRL method.

关键词： Deep reinforcement learning generator tripping scheme graph convolutional network invalid action masking knowledgefusion

Single-source-precursor synthesis and air-plasma ablation behavior of(Ti,Zr,Hf)C/SiC ceramic nanocomposites at 2200℃

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Journal of Advanced Ceramics 2024年第7期13卷 1043-1059页

作者： li Lu Qingbo Wen Jinrun hu Tianxing Jiang Xiangchao Ren Yalei Wang Yi zeng Xiang Xiong State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China

Dense monolithic(Ti,Zr,Hf)C/SiC ceramic nanocomposites with four different molar ratios of metallic elements in the(Ti,Zr,Hf)C phase(i.e.,Ti:Zr:Hf=1:1:1,2:3:5,2:3:3,and 1:2:1)were prepared upon pyrolysis of novel(Ti,Zr,Hf)-containing single-source precursors(SSPs),followed by spark plasma sintering(SPS).A thorough characterization was conducted to elucidate the synthesis of the SSPs,polymer-to-ceramic transformation,chemical/phase compositions,and microstructure of the SiTiZrHfC-based *** results revealed the feasibility of synthesizing nanocomposites with high(Ti,Zr,Hf)C contents using the SSP *** nanocomposites were characterized by a unique microstructure with in situ generated(Ti,Zr,Hf)C@C core-shell nanoparticles homogeneously mixed withβ-*** ablation behavior of the nanocomposites was evaluated on an air-plasma device for 60 ***,the nanocomposites exhibited excellent ablation resistance,and the lowest linear ablation rate reached−0.58μm/s at 2200°***,the ablation resistance can be dramatically improved by precisely tailoring the atomic ratios of metal elements within the(Ti,Zr,Hf)C phase via the molecular design of the *** formation of a multiple-oxide layer with both a high-meltingpoint phase((Ti,Zr,Hf)O_(2))and low-melting-point phases((Zr,Hf)TiO_(4))and glassy SiO_(2),as well as their structure,played a critical role in the enhanced ablation *** uniform distribution of the high-melting-point(Ti,Zr,Hf)O_(2)nano/microparticles throughout the glassy SiO_(2)matrix significantly enhanced the viscosity and stability of the oxide layer by the pinning effect,offering superior protection against the ingress of oxygen atoms and excellent resistance to mechanical erosion.

关键词： ultrahigh-temperature ceramics(UHTCs) multicomponent carbide nanocomposites ablation behavior multiple oxides