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Orbital magneto-optical response of periodic insulators from first principles

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npj Computational Materials 2019年第1期5卷 874-882页

作者： Irina V.Lebedeva David A.Strubbe Ilya V.Tokatly Angel rubio Nano-Bio Spectroscopy Group and ETSF Departamento de Física de MaterialesUniversidad del País Vasco UPV/EHU20018 San SebastiánSpain Department of Physics School of Natural SciencesUniversity of CaliforniaMercedCA 95343USA Donostia International Physics Center(DIPC) Manuel de Lardizabal 520018 San SebastiánSpain IKERBASQUE Basque Foundation for Science48011 BilbaoSpain Max Planck Institute for the Structure and Dynamics of Matter and Center for Free-Electron Laser Science Luruper Chaussee 14922761 HamburgGermany

Magneto-optical response,*** response in the presence of a magnetic field,is commonly used for characterization of materials and in optical ***,quantum mechanical description of electric and magnetic fields in crystals is not straightforward as the position operator is ill *** present a reformulation of the density matrix perturbation theory for time-dependent electromagnetic fields under periodic boundary conditions,which allows us to treat the orbital magneto-optical response of solids at the ab initio *** efficiency of the computational scheme proposed is comparable to standard linearresponse calculations of absorption spectra and the results of tests for molecules and solids agree with the available experimental data.A clear signature of the valley Zeeman effect is revealed in the continuum magneto-optical spectrum of a single layer of hexagonal boron *** present formalism opens the path towards the study of magneto-optical effects in strongly driven low-dimensional systems.

关键词： periodic magneto solids

The Behavior of Solutions of Multidimensional Aggregation Equations with Mildly Singular Interaction Kernels

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Chinese Annals of Mathematics,Series B 2009年第5期30卷 463-482页

作者： Andrea L.BERTOZZI Thomas LAURENT Department of Mathematics University of California-Los AngelesLos Angeles

The authors consider the multidimensional aggregation equation tρ-div(ρ▽K*ρ)=0 in which the radially symmetric attractive interaction kernel has a mild singularity at the origin (Lipschitz or better),and review recent results on this problem concerning well-posedness of nonnegative solutions and finite time blowup in multiple space dimensions depending on the behavior of the kernel at the *** problem with bounded initial data,data in Lp∩L1,and measure solutions are also considered.

关键词：奇异性相互作用行为方程聚集多维径向对称有限时间

Network platform for remote structural testing and shared use of laboratories

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Progress in Natural Science:Materials International 2005年第12期15卷 1135-1142页

作者： XIAO Yan,HU Qing,GUO Yurong,ZHU Pingsheng and YI Weijian Department of Civil Engineering,University of Southern california,los Angeles ca90089,USA School of Civil Engineering,Hunan University,Changsha 410082,China FutureNet Technologies Corporation,Monrovia,california,USA,and Nanchang,China Department of Civil Engineering University of Southern California Los Angeles CA90089 USA United States School of Civil Engineering Hunan University Changsha 410082 China FutureNet Technologies Corporation Monrovia California and Nanchang China

This paper presents a network platform developed for remote testing of scaled model or prototype structures and structural *** network platform,NetSLab,was developed based on the client/server concept along with a proposed data model and the communication *** platform is capable of transferring the control and feedback data as well as signals among remotely located structural testing laboratories or computers connected by *** concepts were introduced to develop the platform and to provide relatively easy and friendly interface for applications and further *** and actual tests were successfully carried out at the Hunan University,China and the University of Southern california,*** simulating bridge piers and piles or building substructures were subjected to recorded earthquake ground motions,and the tests were controlled remotely over the Internet using the platform.

关键词： communication protocol data model earthquake simulation Internet remote testing

A NEW ALGORITHM FOR COMPUTING LARGEST REAL PART EIGENVALUE OF MATRICES:COLLATZ & PERRON-FROBERNIUS' APPROACH

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Acta Mathematica Scientia 2011年第3期31卷 1189-1202页

作者： Tedja Santanoe Oepomo Science Technology Engineering and Mathematics Division los Angeles Harbor/West LA Colleges National University and california International University 1301Las Riendas Drive Units:15 Las Habra

This paper describes a new method and algorithm for the numerical solution of eigenvalues with the largest real part of positive *** method is based on a numerical implementation of Collatz＇s eigenvalue inclusion theorem for non-negative irreducible *** are analyzed for the studies of the stability of linear ***, a numerical discussion is given to derive the required number of mathematical operations of the new algorithm. Comparisons between the new algorithm and several well known ones, such as Power, and QR methods, are discussed.

关键词： Collatz’s theorem Perron-Frobernius’theorem eigenvalue

Dynamics and Synchronization of Semiconductor Lasers

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Dynamics and Synchronization of Semiconductor Lasers

INVESTIGATION ON RESONANT TUNNELING IN GaAs/Al_xGa_(1-x)As DBD USING TUNNELING SPECTROSCOPY

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作者： Jia-Ming Liu Electrical Engineering Department.University of california los Angeles. los Angeles ca 90095. USA

＜正＞A complete picture of the nonlinear dynamics and unidirectionally coupled chaos synchronization of single-mode semiconductor lasers is presented in this paper. Synchronization for chaotic optical communications is *** concepts and theoretical framework are *** results are presented to demonstrate the fundamental *** computations are employed for mapping the dynamical states and for illustrating certain detailed characteristics of the chaotic *** different semiconductor laser systems,namely the optical injection system,the optical feedback system,and the optoelectronic feedback system,that are of most interest for high-bit-rate chaotic optical communications are *** optical injection system is a nonautonomous system that follows a period-doubling route to *** optical feedback system is a phase-sensitive delayed-feedback autonomous system for which all three known routes, namely period-doubling,quasiperiodicity,and intermittency,to chaos can be *** optoelectronic feedback system is a phase-insensitive delayed-feedback autonomous system that follows a quasiperiodicity route to chaotic *** synchronization in unidirectionally coupled configurations is the focus of discussions for chaotic *** optical injection and optical feedback systems,the frequency,phase,and amplitude of the optical fields of both transmitter and receiver lasers are all locked in synchronism when complete synchronization is *** the optoelectronic feedback system,chaos synchronization involves neither the locking of the optical frequency nor the synchronization of the optical *** both optical feedback and optoelectronic feedback systems,where the transmitter is configured with a delayed feedback loop, anticipated and retarded synchronization can be observed as the difference between the feedback delay time and the propagation time from the transmitter laser to the receiver las

关键词： Semiconductor lasers dynamics chaos synchronization and chaotic communications

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Journal of Electronics(China) 1990年第1期7卷 70-76页

作者：陈弘毅 K.L.Wang Institute of Microelectronies Tsinghua UniversityBeijing100084 Device Research Laboratory Electrical Engineering DepartmentUniversity of California at Los AngelesLos AngelesCA.90024U.S.A

Experimental investigation on resonant tunneling in various GaAs/AlxGa1-xAsdouble barrier single well structures has been performed by using tunneling spectroscopy atdifferent *** results show that in addition to resonant tunneling via GaAs wellstate confined by AlxGa1-xAs Γ-point barrier there exists resonant tunneling via GaAs well stateconfined by AlxGa1-xAs X-point barrier for both indirect（x>0.4）and direct（xcases.

关键词： Resonant tunneling Quantum well Energy band profile

THE EARLY INFLUENCE OF PETER LAX ON COMPUTATIONAL HYDRODYNAMICS AND AN APPLIcaTION OF LAX-FRIEDRICHS AND LAX-WENDROFF ON TRIANGULAR GRIDS IN LAGRANGIAN COORDINATES

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Acta Mathematica Scientia 2011年第6期31卷 2195-2202页

作者： Richard Liska Mikhail Shashkov Burton Wendroff Faculty of Nuclear Sciences and Physical Engineering Czech Technical University in Prague Group XCP-4 MS-F644Los Alamos National Laboratry Group T-5 MS-B284Los Alamos National Laboratry

We give a brief discussion of some of the contributions of Peter Lax to Com- putational Fluid Dynamics. These include the Lax-Friedrichs and Lax-Wendroff numerical schemes. We also mention his collaboration in the 1983 HLL Riemann solver. We de- velop two-dimensional Lax-Friedrichs and Lax-Wendroff schemes for the Lagrangian form of the Euler equations on triangular grids. We apply a composite scheme that uses a Lax- Friedrichs time step as a dissipative filter after several Lax-Wendroff time steps. Numerical results for Noh＇s infinite strength shock problem, the Sedov blast wave problem, and the Saltzman piston problem are presented.

关键词： Lax-Friedrichs Lax-Wendroff conservation laws Lagrangian coordinates,triangular grid

Lichenicolous fungi of the genus Abrothallus (Dothideomycetes: Abrothallales ordo nov.) are sister to the predominantly aquatic Janhulales

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Fungal Diversity 2014年第1期64卷 295-304页

作者： Sergio Pérez-Ortega Ave Suija Ana Crespo Asunción de los Ríos Departamento Biología Ambiental Museo Nacional de Ciencias Naturales(CSIC)c/Serrano 115 dpdo28006 MadridSpain Institute of Ecology and Earth Sciences University of Tartu40 Lai str.51005 TartuEstonia Facultad de Farmacia Departamento Biología Vegetal IIUniversidad Complutense de MadridPlaza Ramón y Cajal s/n28040 MadridSpain

This study provides new insights on the phylogenetic position of the lichenicolous fungal genus Abrothallus based on six molecular markers(nuSSU,nuLSU,mtSSU,RPB1,RPB2 and TEF-α).In a broad-scale analysis,we detected high support for inclusion of the genus within Dothideomycetes.A further analysis provided support for Abrothallus as a member of the subclass Pleosporomycetidae as a sister group of Jahnulales,an order of aquatic *** the exclusive characters of this group of apotheciate fungi within the Dothidiomycetes,a new monotypic order Abrothallales is here introduced together with the new family *** a multi-locus analysis(based on the six loci indicated above plus ITS)restricted to 12 putative Abrothallus species,two clearly separated clades were observed:one comprising species growing on lichens of the families Parmeliaceae and Ramalinaceae,and the second including species that live on lichens of the order Peltigerales and the family Cladoniaceae.

关键词： Lichenicolous Multi-locus analysis Taxonomy Pleosporomycetidae Jahnulales

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

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Acta Metallurgica Sinica(English Letters) 2015年第7期28卷 809-816页

作者： Chao Yang He-Fei Huang Massey de los Reyes Long Yan Xing-Tai Zhou Tian Xia De-Liang Zhang Shanghai Institute of Applied Physics Chinese Academy of Science (CAS) Institute of Materials Engineering Australian Nuclear Science and Technology Organisation State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong University

Silicon carbide nanoparticle-reinforced nickel-based composites（Ni–Si CNP）,with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma *** addition,unreinforced pure nickel samples were also prepared for comparative *** characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy（TEM） was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile *** results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was *** homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain *** the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si ***,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling *** all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening（Orowan effects） and particle strengthening（Hall–Petch effects）.For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased *** to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.

关键词： Ni-SiCNP composite Mechanical alloying Spark plasma sintering Transmission electron microscopy Tensile test