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Progress of Pattern Dynamics in Plasma Waves

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communications in computational Physics 2008年第10期4卷 1129-1150页

作者： B.Qiao c.t.zhou X.t.He c.H.Lai center for Plasma Physics Department of Physics and AstronomyQueen’s University BelfastBelfast BT71NNUK Department of Physics National University of SingaporeSingapore 117542 Institute of Applied Physics and computational Mathematics P.O.Box 8009Beijing 100088China center for Applied Physics and technology Peking UniversityBeijing 100871China Institute for Fusion theory and Simulation Zhejiang UniversityHangzhou 310027China Beijing-Hong Kong-Singapore Joint centre for Nonlinear&complex Systems(Singapore) National University of SingaporeSingapore 117542.

this paper is concerned with the pattern dynamics of the generalized nonlinear Schrodinger equations(NSEs)relatedwith various nonlinear physical problems in *** theoretical and numerical results show that the higher-order nonlinear effects,acting as a Hamiltonian perturbation,break down the NSE integrability and lead to chaotic ***,coherent structures are destroyed and replaced by complex *** orbit crossings in the phase space and stochastic partition of energy in Fourier modes show typical characteristics of the stochastic *** investigations show that nonlinear phenomena,such as wave turbulence and laser filamentation,are associated with the homoclinic *** particular,we found that the unstable manifolds W(u)possessing the hyperbolic fixed point correspond to an initial phase θ=45° and 225° ,and the stable manifolds W(s)correspond toθ=135° and 315° .

关键词： Pattern dynamics homoclinic chaos nonlinear Schrodinger equations plasma waves

the preface: Interplay of topological and magnetic orders in the Mn-Bi-te family

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National Science Review 2024年第2期11卷 6-7页

作者： Fu-chun Zhang Hai-zhou Lu X.c.Xie Kavli Institute for theoretical Sciences University of Chinese Academy of Sciences Department of Physics Southern University of Science and Technology (SUSTech) International center for Quantum Materials School of Physics Peking University

the discovery and synthesis of MnBi2te4in 2013 initially garnered little attention [1]. Yet, the revelation of its topological properties in 2019 [2–6] sparked a surge of research into the MnBite family. these extensive studies are primarily driven by two objectives:the realization of a high-temperature quantum anomalous Hall effect （QAHE） and the exploration of exotic phases born from the interplay of topological and magnetic orders,

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Nonlinear branched flow of intense laser light in randomly uneven media

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Matter and Radiation at Extremes 2023年第2期8卷 25-32页

作者： K.Jiang t.W.Huang c.N.Wu M.Y.Yu H.Zhang S.Z.Wu H.B.Zhuo A.Pukhov c.t.zhou S.c.Ruan college of Applied Sciences Shenzhen UniversityShenzhen 518060People’s Republic of China Shenzhen Key Laboratory of Ultraintense Laser and Advanced Material technology Center for Advanced Material Diagnostic Technologyand College of Engineering PhysicsShenzhen Technology UniversityShenzhen 518118People’s Republic of China Institut für theoretische Physik I Heinrich-Heine-Universität Düsseldorf40225 DüsseldorfGermany

Branched flow is an interesting phenomenon that can occur in diverse *** is usually linear in the sense that the flow does not alter the properties of the *** flow of light on thin films has recently been *** is therefore of interest to know whether nonlinear light branching can also ***,using particle-in-cell simulations,we find that in the case of an intense laser propagating through a randomly uneven medium,cascading local photoionization by the incident laser,together with the response of freed electrons in the strong laser fields,triggers space–time-dependent optical *** resulting branching pattern depends dramatically on the laser *** is,the branching here is distinct from the existing linear *** observed branching properties agree well with theoretical analyses based on the Helmholtz *** branched propagation of intense lasers potentially opens up a new area for laser–matter interaction and may be relevant to other branching phenomena of a nonlinear nature.

关键词： laser intense flow

Spatial distributions of soil nutrients affected by land use,topography and their interactions,in the Loess Plateau of china

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International Soil and Water conservation Research 2024年第1期12卷 227-239页

作者： Wenxin zhou changjia Li Wenwu Zhao Lindsay c.Stringer Bojie Fu State Key Laboratory of Earth Surface Processes and Resource Ecology Faculty of Geographical ScienceBeijing Normal UniversityBeijingChina Institute of Land Surface System and Sustainable Development Faculty of Geographical ScienceBeijing Normal UniversityBeijingChina Department of Environment and Geography University of YorkYorkUK York Environmental Sustainability Institute University of YorkYorkUK

Soil nutrient availability and their spatial distributions are strongly related to land use and landscape *** study aims to address the knowledge gap regarding the interaction between these factors and the underlying *** selected five land uses(grassland with Artemisia gmelinii,woodland with Robinia pseudoacacia,shrubland with caragana korshinskii and Hippophae rhamnoides,and apple orchard with Malus pumila)and nine slope positions across hillslopes in the Loess Plateau,china,to investigate their combined effects on the contents and stocks of soil organic carbon(SOc),total nitrogen(tN)and total phosphorus(tP).Parametric and non-parametric statistical tests were conducted to determine the significant differences in the means or the medians of the soil nutrient *** showed that the SOc and tN contents of shrubland with caragana korshinskii were statistically significantly greater than those of the grassland(pc and tN contents generally decreased from the upper slope to the middle slope,and to the foot slope for the grassland,woodland and shrublands,and on the contrary,an increasing trend from the upper slope,to the middle slope,and to the foot slope was identified for the apple *** study highlights that land use,slope position and their interaction have significant effects on the spatial distributions of soil *** provides essential empirical evidence for the identification of the optimal vegetation type and slope positions in land management and vegetation restoration activities.

关键词： Soil organic carbon total nitrogen total phosphorus Slope position Vegetation restoration

Progress on the antiferromagnetic topological insulator MnBi2te4

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National Science Review 2024年第2期11卷 33-49页

作者： Shuai Li tianyu Liu chang Liu Yayu Wang Hai-zhou Lu X.c.Xie Department of Physics Harbin Institute of Technology Shenzhen Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and Technology(SUSTech) Quantum Science center of Guangdong-Hong Kong-Macao Greater Bay Area(Guangdong) Shenzhen Key Laboratory of Quantum Science and Engineering International Quantum Academy Beijing Academy of Quantum Information Sciences Beijing Key Laboratory of Optoelectronic Functional Materials&Micro-Nano Devices Department of Physics Renmin University of China State Key Laboratory of Low Dimensional Quantum Physics Department of PhysicsTsinghua University Frontier Science center for Quantum Information Hefei National Laboratory International center for Quantum Materials School of Physics Peking University Institute for Nanoelectronic Devices and Quantum computing Fudan University

topological materials, which feature robust surface and/or edge states, have now been a research focus in condensed mather physics. they represent a new class of materials exhibiting nontrivial topological phases,and provide a platform for exploring exotic transport phenomena, such as the quantum anomalous Hall effect and the quantum spin Hall effect. Recently, magnetic topological materials have attracted considerable interests due to the possibility to study the interplay between topological and magnetic *** particular, the quantum anomalous Hall and axion insulator phases can be realized in topological insulators with magnetic order. MnBi2te4, as the first intrinsic antiferromagnetic topological insulator discovered, allows the examination of existing theoretical predictions; it has been extensively studied, and many new discoveries have been made. Here we review the progress made on MnBi2te4from both experimental and theoretical aspects. the bulk crystal and magnetic structures are surveyed first, followed by a review of theoretical calculations and experimental probes on the band structure and surface states, and a discussion of various exotic phases that can be realized in MnBi2te4. the properties of MnBi2te4thin films and the corresponding transport studies are then reviewed, with an emphasis on the edge state transport. Possible future research directions in this field are also discussed.

关键词： MnBi2te4 magnetic topological insulator antiferromagnetic quantum anomalous Hall effect axion insulator

Phase field modeling of ferroelastic variant switching in yttria-stabilized t'zirconia with strain gradient elasticity and interface tension

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Science china(technological Sciences) 2024年第5期67卷 1443-1457页

作者： zhou QianQian WEI YueGuang zhou Yichun YANG Li college of Engineering BIC-ESATPeking UniversityBeijing100871China School of Advanced Materials and Nanotechnology Xidian UniversityXi’an710126China Frontier Research center of thin Films and coatings for Device Applications Academy of Advanced Interdisciplinary ResearchXidian UniversityXi’an710126China

the 6–8 wt%yttria-stabilized zirconia with a tetragonal structure(t’-YSZ)is extensively employed in thermal barrier *** exceptional fracture toughness of t’-YSZ can be attributed to its distinctive ferroelastic toughening *** and interface tension play a critical role in ferroelastic variant switching at the micro-and *** paper presents an original thermodynamically consistent phase field(PF)theory for analyzing ferroelastic variant switching at the micro-and nano-scale of t’-*** theory incorporates strain gradient elasticity using higher-order elastic energy and interface tension tensor via geometric nonlinearity to represent biaxial tension resulting from interface ***,a mixed-type formulation is employed to implement the higher-order theory through the finite element *** an interface in equilibrium,the effects of strain gradient elasticity result in a more uniform distribution of stresses,whereas the presence of interface tension tensor significantly amplifies the stress magnitude at the *** introduction of an interface tension tensor increases the maximum value of stress at the interface by a factor of 4 to *** nucleation and evolution of variants at a pre-existing crack tip in a mono-phase t’-YSZ have also been *** strain gradient elasticity is capable of capturing the size effect of ferroelastic variant switching associated with microstructures in ***,when the grain size approaches that of the specimen,the critical load required for variant switching at the crack tip increases,resulting in greater dissipation of elastic energy during ferroelastic variant ***,the interface tension accelerates the evolution of *** presented framework exhibits significant potential in modeling ferroelastic variant switching at the micro-and nano-scale.

关键词： thermodynamics strain gradient elasticity interface tension phase field method ferroelastic variant switching

track-before-detect for bistatic radar based on pseudo-spectrum

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chinese Journal of Aeronautics 2024年第1期37卷 236-246页

作者： tao HAN Gongjian zhou School of Electronics and Information Engineering Harbin Institute of TechnologyHarbin 150001China Key Laboratory of Marine Environmental Monitoring and Information Processing Ministry of Industry and Information TechnologyHarbin 150001China

track-Before-Detect(tBD) is an efficient method to detect dim targets for radars. conventional tBD usually follows an approximate motion model of the target, which may cause an inaccurate integration of the target energy. A tBD technique on basis of pseudo-spectrum in mixed coordinates adopting an accurate motion model for bistatic radar system is developed in this *** predicted position in bistatic polar plane is derived according to a nonlinear function that exactly describes the constant cartesian velocity motion. then around the predicted position, a pseudo-spectrum is formulated and its samples are accumulated to the integration frame for energy integration. the evolution of the state and the procedure of accumulation of the target energy are derived elaborately. the superior performance of the proposed method is demonstrated by some simulations.

关键词： Weak target detection Bistatic radar track-before-detect Pseudo-spectrum Multiframe integration

Effects of layer interactions on instantaneous stability of finite Stokes flows

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 69-84页

作者： chen ZHAO Zhenli cHEN c.t.MUtASA Dong LI School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China

the stability analysis of a finite Stokes layer is of practical importance in flow control. In the present work, the instantaneous stability of a finite Stokes layer with layer interactions is studied via a linear stability analysis of the frozen phases of the base flow. the oscillations of two plates can have different velocity amplitudes, initial phases, and frequencies. the effects of the Stokes-layer interactions on the stability when two plates oscillate synchronously are analyzed. the growth rates of two most unstable modes when δ t equal, and δ = δ*/h*, where δ*and h*are the Stokes-layer thickness and the half height of the channel, respectively. However, their vorticities are different. the vorticity of the most unstable mode is symmetric, while the other is asymmetric. the Stokes-layer interactions have a destabilizing effect on the most unstable mode when δ tabilizing effect when δ > 0.68. However, the interactions always have a stabilizing effect on the other unstable mode. It is explained that one of the two unstable modes has much higher dissipation than the other one when the Stokes-layer interactions are strong. We also find that the stability of the Stokes layer is closely related to the inflectional points of the base-flow velocity profile. the effects of inconsistent velocity-amplitude, initial phase, and frequency of the oscillations on the stability are analyzed. the energy of the most unstable eigenvector is mainly distributed near the plate of higher velocity amplitude or higher oscillation frequency. the effects of the initial phase difference are complicated because the base-flow velocity is extremely sensitive to the initial phase.

关键词： finite Stokes layer instantaneous stability Stokes-layer interaction asynchronous oscillation

Urbanity mapping reveals the complexity,diffuseness,diversity,and connectivity of urbanized areas

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Geography and Sustainability 2024年第3期5卷 357-369页

作者： Dawa Zhaxi Weiqi zhou Steward t.A.Pickett chengmeng Guo Yang Yao State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of chinese Academy of Sciences Beijing 100049China Beijing Urban Ecosystem Research Station Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Beijing-tianjin-Hebei Urban Megaregion National Observation and Research Station for Eco-Environmental change Chinese Academy of SciencesBeijing 100085China cary Institute of Ecosystem Studies MillbrookNY 12545USA

there are urgent calls for new approaches to map the global urban conditions of complexity,diffuseness,diversity,and ***,existing methods mostly focus on mapping urbanized areas as bio physical ***,based on the continuum of urbanity framework,we developed an approach for cross-scale urbanity map-ping from town to city and urban megaregion with different spatial resolutions using the Google Earth *** approach was developed based on multi-source remote sensing data,Points of Interest-Open Street Map(POIs-OSM)big data,and the random forest regression *** approach is scale-independent and revealed significant spatial variations in urbanity,underscoring differences in urbanization patterns across megaregions and between urban and rural *** was observed transcending traditional urban boundaries,diffusing into rural settlements within non-urban *** finding of urbanity in rural communities far from urban areas challenges the gradient theory of urban-rural development and *** mapping livelihoods,lifestyles,and connectivity simultaneously,urbanity maps present a more comprehensive characterization of the complex-ity,diffuseness,diversity,and connectivity of urbanized areas than that by land cover or population density *** helps enhance the understanding of urbanization beyond biophysical *** approach can provide a multifaceted understanding of urbanization,and thereby insights on urban and regional sustainability.

关键词： continuum of Urbanity Big data Mapping Spatial regression Multiscale