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Science China(Information Sciences) 2020年第5期63卷 48-60页

作者： Lulu LI xiaoyang liu Wei HUANG School of Mathematics Hefei University of Technology School of Computer Science and Technology Jiangsu Normal University

This paper mainly concentrates on the event-based bipartite consensus(BCs) in multi-agent networks(MANs) with partial information transmission(PIT) and communication delays. Two types of communication constraints, i.e., time delays and partial information transmission, make the BCs problem in MANs more challenging and practical. A distributed event-triggered scheme(ETS) is proposed for the considered MANs. Based on the proposed ETS, it is observed that the addressed MANs reaches BCs provided that the network is balanced. A numerical example is presented to demonstrate the effectiveness of the theoretical results.

关键词： bipartite consensus event-triggered control communication delays partial information transmission

Stability of Delayed Switched Systems With State-Dependent Switching

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IEEE/CAA Journal of Automatica Sinica 2020年第3期7卷 872-881页

作者： Chao liu Zheng Yang xiaoyang liu Xianying Huang School of Computer Science and Engineering Chongqing University of TechnologyChongqing 400054China Hubei Key Laboratory of Applied Mathematics(Hubei University) Wuhan 430062China

This paper investigates the stability of switched systems with time-varying delay and all unstable subsystems. According to the stable convex combination, we design a state-dependent switching rule. By employing Wirtinger integral inequality and Leibniz-Newton formula, the stability results of nonlinear delayed switched systems whose nonlinear terms satisfy Lipschitz condition under the designed state-dependent switching rule are established for different assumptions on time delay. Moreover,some new stability results for linear delayed switched systems are also presented. The effectiveness of the proposed results is validated by three typical numerical examples.

关键词： Stability statedependent switching switched system time delay

Ferroelectricity induced by non-symmetry of A-site cations in hexagonal antiferromagnetic In_(1-x)Yb_(x)FeO_(3)(x=0.1,0.2,0.3) perovskites

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Journal of Rare Earths 2023年第12期41卷 1990-1995,I0006页

作者： Yong Zhou Peng liu Yang Chen Bin Yang Bing Li Fuyang liu xiaoyang liu State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of ChemistryJilin UniversityChangchun30012China Center for High Pressure Science and Technology Advanced Research Changchun130012China Center for High Pressure Science and Technology Advanced Research Beijing100094China

A new series of multiferroic In_(1-x)Yb_(x)FeO_(3)(x=0.1,0.2,0.3) compounds were prepared using the traditional synthesis method for the first *** substituting In ions in InFeO3with Yb ions results in the weak ferroelectricity of the compound.A dielectric relaxation peak is found at ~500 K in the temperature dependence of the dielectric properties of the resulted *** dielectric constant of In_(0.8)Yb_(0.2)FeO_(3)displays an anomaly at -500 K,and the ferroelectric hysteresis loop reveals its weak ferroelectric behaviors below this *** to InFeO_(3),the compounds crystallize in space group P63/*** increase in the Yb content leads to an increment in a and a reduction in c *** temperature dependence of magnetization for In_(0.8)Yb_(0.2)FeO_(3)gives a Néel temperature of -150 *** hysteresis loops at 10 and 100 K indicate its weak ferromagnetic characteristics above room ***,In_(1-x)Yb_(x)FeO_(3)(x=0.1,0.2,0.3) compounds show both weak ferroelectricity and weak *** non-symmetry of Yb cations causes the ferroelectricity of the compounds.

关键词： Solid phase synthesis Perovskite structure Multiferroic properties Doping InFeO_(3) Rareearths

New stability results of generalized impulsive functional differential equations

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Science China(Information Sciences) 2022年第2期65卷 248-250页

作者： Chao liu xiaoyang liu Zheng YANG Hongyu YANG Junjian HUANG School of Computer Science and Engineering Chongqing University of Technology Key Laboratory of Machine Perception and Children's Intelligence Development Chongqing University of Education

Dear editor,An impulsive functional differential equation (IFDE) is a hybrid dynamical system including both continuous-time dynamics exhibited via a functional differential equation and discrete-time dynamics which are shown by *** the best of our knowledge,impulsive phenomena,which are presented in the form of instantaneous jump,exist in the fields of engineering and *** recent years,

关键词： Stability Impulsive functional differential equation Uniformly stable function Razumikhin technique Lyapunov function

Dynamic model of computer viruses under the effect of removable media and external computers

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The Journal of China Universities of Posts and Telecommunications 2018年第4期25卷 86-93页

作者： Cai Xiumei liu Chao Huang Xianying liu xiaoyang Cao Qiong Yang Hongyu School of Computer Science and Engineering Chongqing University of Technology

This paper investigates the propagation of computer viruses and establishes a novel propagation model. In contrast to the existing models,this model can directly indicate the impact of removable media and external computers on the propagation of computer virus. The stability results of equilibrium point are derived by Hurwitz criterion and Bendixson Dulac criterion. The effectiveness of the proposed results is shown by numerical simulation. In order to show the superiority of the proposed model,some comparisons with the existing models are presented. The acceptable threshold and the reasonable strategies for suppressing the propagation of computer virus are also suggested,respectively.

关键词： computer virus external computer removable medium viral equilibrium point global stability

Developing Mechanical Metamaterials Under an Adaptable Topology Optimization Design Framework

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Acta Mechanica Solida Sinica 2023年第2期36卷 306-316页

作者： Zhengtong Han Kai Wei xiaoyang liu Yuhang Long Jialong Li Xinglin Chen State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan UniversityChangsha 410082China State Key Laboratory of High Performance Complex Manufacturing Central South UniversityChangsha 410083China

Developing mechanical metamaterials through topology optimization attracts high attention in both computational design and engineering ***,most of the studies in the literature are of quite limited applicability and poor ***,this work originally established an adaptable metamaterial topology optimization framework through integrating a commercial finite element analysis(FEA)***,the sensitivity analysis was derived and simplified to avoid the complex extraction of internal FEA information according to the strain-energy-based homogenization method.A series of two-and three-dimensional metamaterials with different properties,i.e.,bulk and shear moduli,negative Poisson’s ratio,were subsequently *** optimized metamaterials were fabricated and experimentally tested based on the additive manufacturing,firmly demonstrating the effectiveness of the developed design *** well-structured design framework can be conveniently extended to the systematic design of metamaterials with various other exclusive performances,fulfilling the urgent need for metamaterial design methods.

关键词： Metamaterial Topology optimization Mechanical properties Tensile experiments

Constructing temporal and spatial water vapor figures by GPS remote sensing along slant rays

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Science China Earth Sciences 2007年第2期50卷 296-305页

作者： MAO Hui MAO JieTai BI YanMeng LI ChengCai liu xiaoyang Department of Atmospheric Sciences School of PhysicsPeking UniversityBeijing 100871China Shenzhen Meteorological Bureau Shenzhen 518001China

A Global Positioning System (GPS) receiver can generally track 5-7 rays from GPS satellites at any moment, and water vapor along these ray paths (slant-path water vapor, SWV) may be retrieved using the methods developed in recent years. This paper suggests two new parameters-absolute vertical SWV (VSWV) and relative VSWV derived from SWV, and their temporal and spatial figures can reflect the heterogeneous distribution and variation of water vapor field. This approach has been applied to the weather diagnoses in a severe storm event in Beijing during July 2004, and it is concluded that the temporal and spatial figures of absolute VSWV and relative VSWV can be useful in monitoring the evolution of water vapor field and be potential in better understanding the precipitation process.

关键词： GPS absolute VSWV relative VSWV water vapor precipitation

Regulation of the pore structure of carbon nanosheets based electrocatalyst for efficient polysulfides phase conversions

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Journal of Materials Science & Technology 2024年第4期171卷 37-46页

作者： xiaoyang liu Jingbo Zhang Kangli liu Shijie Zhang Rouhan Hou Xiaoyi Hu Peng Zhang Guosheng Shao State Center for International Cooperation on Designer Low-Carbon&Environmental Materials(CDLCEM) School of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450001China Zhengzhou Materials Genome Institute(ZMGI) Xingyang 450100China

The practical applications of lithium-sulfur(Li-S)batteries are hampered by the sluggish redox kinetics and polysulfides shuttle in the cyclic process,which leads to a series of problems including the loss of active materials and poor cycling *** this paper,the pore structures of carbon nanosheets based electrocatalysts were precisely controlled by regulating the content of water-soluble KCl *** relationship between pore structures and Li-S electrochemical behavior was studied,which demonstrates a key influence of pore structure in polysulfides phase *** the liquid-sloid redox reaction of polysulfides,the micropores and small mesopores(d20 nm)and macropores played a decisive *** a typical exhibition,the nickel-embedded carbon nanosheets(Ni-CNS)with a high content of large mesopores and macropores can aid Li-S batteries in exhibiting stable cycling performance(760.1 mAh g^(-1)at 1 C after 300 cycles)and superior rate capac-ity(847.8 mAh g^(-1)at 2 C).Furthermore,even with high sulfur loading(8 mg cm^(−2))and low electrolyte(E/S is around 6μL mg^(-1)),the high area capacity of 7.7 mAh cm^(−2)at 0.05 C could be *** work can provide a guideline for the design of the pore structure of carbon-based electrocatalysts toward high-efficiency sulfur species redox reactions,and afford a general,controllable,and simple approach to constructing high performance Li-S batteries.

关键词： Hierarchical porous carbon network Electrocatalyst Molten salt templating method Modified separators Li-S batteries

HMTA-assisted One-pot Synthesis of Greigite Nano-platelet and Its Magnetic Properties

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Journal of Materials Science & Technology 2015年第9期31卷 895-900页

作者： Tuoquan Liao Wei Wang Yongli Song Xianjie Wang Yanqiang Yang xiaoyang liu Academy of Fundamental and Interdisciplinary Sciences Harbin Institute of Technology Department of Physics Harbin Institute of Technology State Key Lab of Inorganic Synthesis and Preparative Chemistry College of Chemistry Jilin University

A facile one-pot hydrothermal procedure for the synthesis of magnetic greigite was investigated in this work, by using FeSO4, thioacetamide, and a tiny amount of hexamethylenetetramine （HMTA） as starting materials. The HMTA molecule, which acted as a chelating agent and an oxidant, could not only tune the valence fluctuation of iron ions, but also direct the hydrothermal reaction towards the exclusive for- mation of greigite platelets with hundreds of nanometers in lateral size. In the presence of a static magnetic field during this synthesis, the greigite nano-platelets were apt to congregate to form 3D flower-like microspheres. A set of experiments suggested that the ferrous ions were at first partly oxidized by HMTA to form ferric intermediates, i.e., Fe（OH）3 and Fe2O3. Then excessive ferrous ions, along with the solid in- termediates, reacted with sulfide ions, and finally evolved into greigite, Taken into consideration that a similar process occurred in magnetotactic bacteria, our results may give a hint at the design of biomimetic synthesis strategies to produce nanomaterials, especially the magnetosome-like greigite.

关键词： GreigiteNano-plateletHydrothermal synthesisMagnetic materials

Negative Magnetism in Perovskite Manganites Gd1-xSrxMnO3（0.1 ≤x≤0.3）

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Chemical Research in Chinese Universities 2015年第5期31卷 699-703页

作者： ZHANG Yingnan LI Junjia ZHANG Ziqing liu Fuyang ZHAO Xudong liu xiaoyang State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of Chemistry Jilin University Changchun 130012 P. R. China

A series of Sr-substituted Gd1-xSrxMnO3（0.1 ≤x≤0.3） materials was prepared via a standard method involving solid-state reaction. Their crystal structure within the entire doping region was determined to be orthorhombic perovskite type. The magnetic properties of the perovskite Gd1-xSrxMnO3（0.1 ≤x≤0.3） were thoroughly investigated. It appears that Mn ions with high valence state can induce stronger magnetization, and negative magnetization is evident in the manganites with x=0.1 and x=0.2, suggesting that valence fluctuation plays an important role in such systems. The result of XPS analysis indicates that the valence state of Mn ions is 3.25 and there seems to be excess amounts of oxygen in the structure of Gd0.8Sr0.2MnO3＋δ. In addition, the results of magnetization measurements demonstrate that spin reversal occurs only when the applied field is less than 1.99× 10^5 A/m, which presumably could be due to the negative exchange interaction between Mn sub-lattice and Gd sites.

关键词： Perovskite manganite Solid-state reaction Negative magnetization Spin reversal