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Construction of Dulac functions for mathematical models in population biology

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International Journal of Biomathematics 2015年第3期8卷 135-154页

作者： Osvaldo Osuna Cruz Vargas-de-Leon Instituto de fisica y Matematicas Universidad MichoacanaEdif. C-3 Cd. Universitaria CP 58040 Morelia Michoacan Mexico Unidad de Medicina Experimental Hospital General de Mexico "Dr. Eduardo Liceaga" DF 06726 Mdxieo

In this paper, we present a method for constructing a Dulac function for mathematical models in population biology, in the form of systems of ordinary differential equations in the plane.

关键词： Population models epidemic models chemostat models Dulac function nonexistence of periodic orbits.

debye's temperature and heat capacity for Sr_(0.15)Ba_(0.85)Bi_(2)Nb_(2)O_(9) relaxor ferroelectric ceramic

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Journal of Advanced Dielectrics 2016年第4期6卷 1-4页

作者： A.Pelaiz-Barranco Y.Gonzalez-Abreu P.Saint-Gregoire J.D.S.Guerra F.Calderón-Piñar Facultad de fisica-IMRE Universidad de La Habana San Lazaro y LVedadoLaHabana 10400Cuba department of Sciences and Arts University of Nîmes 30021 Nîmes Cedex 01France Grupo de Ferroeletricos e Materiais Multifuncionais Instituto de Fisica Universidade Federal de Uberlandia.38400-902Uberlandia-MGBrazil

A lead-free relaxor ferroelectric,Sr_(0.15)Ba_(0.85)Bi_(2)Nb_(2)O_(9),was synthesized via solid-state reaction and the temperature-dependence of the heat capacity was measured in a wide temperature *** dielectric permittivity was also measured between 500 Hz and 5 MHz in the same temperature *** anomaly has been detected in the heat capacity curve for the whole temperature range covered in the present experiments,while broad peaks have been observed in the dielectric permittivity with high frequency dispersion.A typical relaxor behavior has been observed from the dielectric *** debye's temperature has showed a minimum value near the freezing *** results are discussed considering the spin-glass model and the high frequency dispersion,which has been observed for the studied relaxor system.

关键词： Relaxors ferroelectrics heat capacity ceramics

1.3 μm emitting SrF2：Nd^3＋ nanoparticles for high contrast in vivo imaging in the second biological window

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Nano Research 2015年第2期8卷 649-665页

作者： Irene Villa Anna Vedda Irene Xochilt Cantarelli Marco Pedroni Fabio Piccinelli Marco Bettinelli Adolfo Speghini Marta Quintanilla Fiorenzo Vetrone Ueslen Rocha Carlos Jacinto Elisa Carrasco Francisco Sanz Rodrfguez Angeles Juarranz Blanca del Rosal Dirk H. Ortgies Patricia Haro Gonzalez Jose Garcia Sole Daniel Jaque Garcia department of Materials Science University of Milano-Bicocca Via R. Cozzi 55 20125 Milano Italy Dipartimento di Biotecnologie Universita di Verona and INSTM UdR Verona Strada le Grazie 15 37134 Verona Italy Institut National de la Recherche Scientifique-Energie Materiaux et Telecommunications Universitd du Quebec Varennes QC PQ J3X 1S2 Canada Grupo de Fotonica e Fluidos Complexos Instituto de Fisica Universidade Federal de Alagoas 57072-970 Maceio Alagoas Brazil departamento de Biologia Facultad de Ciencias Campus de Cantoblanco Universidad Autdnoma de Madrid Madrid 28049 Spain Fluorescence Imaging Group Departamento de Fisica de Maferiales Facultad de Ciencias Campus de Cantoblanco Universidad Aut6noma de Madrid Madrid 28049 Spain

Novel approaches for high contrast, deep tissue, in vivo fluorescence biomedical imaging are based on infrared-emitting nanoparticles working in the so-called second biological window （1,000-1,400 nm）. This allows for the acquisition of high resolution, deep tissue images due to the partial transparency of tissues in this particular spectral range. In addition, the optical excitation with low energy （infrared） photons also leads to a drastic reduction in the contribution of autofluorescence to the in vivo image. Nevertheless, as is demonstrated here, working solely in this biological window does not ensure a complete removal of autofluorescence as the specimens diet shows a remarkable infrared fluorescence that extends up to 1,100 nm. In this work, we show how the 1,340 nm emission band of Nd3. ions embedded in SrF2 nanoparticles can be used to produce autofluorescence free, high contrast in vivo fluorescence images. It is also dem- onstrated that the complete removal of the food-related infrared autofluorescence is imperative for the development of reliable biodistribution studies.

关键词： fluorescence imaging rare earth dopednanoparticles nanomedicine

Features of the motion of gel particles in a three-phase bubble column under foaming and non-foaming conditions

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Chinese Journal of Chemical Engineering 2018年第6期26卷 1370-1382页

作者： Gabriel Salierno Mauricio Maestri Stella Piovano Miryan Cassanello Maria Angelica Cardona Daniel Hojman Hector Somacal Laboratorio de Reactores y Sistemas para la lndustria-LARSl Dep. lndustrias FCEyN Universidad de Buenos Aires Int. GiJiraldes 2620 CI428BGA Buenos Aires Argentina Laboratorio de Diagnóstico por Radiaciones-LADiR Dep. de Fisica Experimental. Comision National de Energia Atomica (CNEA) San Martin Buenos Aires Argentina Universidad de San Martin San Martin Buenos Aires Argentina

Features of the motion of gel particles in a three-phase bubble column with non-foaming and foaming gas–liquid systems,determined by using experiments of radioactive particle tracking(RPT),have been *** tracer used is a gel particle which resembles typical immobilized *** tracer trajectory is analyzed to extract relevant information for design *** solid velocity field,turbulence parameters,dispersion coefficients,mixing times and flow transitions are determined and *** presence of foam significantly affects many quantified parameters,especially within the heterogeneous flow *** hydrodynamic stresses are reduced in the presence of foam,especially close to the *** dispersion coefficients also decrease,and the solid mixing time is only slightly affected by the presence of *** holdup,inferred both from RPT experiments and from gamma ray scanning,is higher for foaming systems and leads to a shift in the transition gas velocity towards higher values.

关键词： Bubble columns Solid motion Gel beads Foaming Particle tracking Mixing

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Analysis of microscopic properties of radiative shock experiments performed at the Orion laser facility

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High Power Laser Science and Engineering 2018年第2期6卷 189-201页

作者： R.Rodriguez G.Espinosa J.M.Gil E Suzuki-Vidal T.Clayson C.Stehle E Graham IUNAT Departamento de FisicaUniversidad de Las Palmas de Gran Canaria35017 Las Palmas de Gran CanariaSpain Instituto de Fusion Nuclear Universidad Politecnica de Madrid28040 MadridSpain Blackett Laboratory Imperial CollegeLondon SW7 2AZUK LERMA Sorbonne UniversitesUPMCObservatoire de ParisPSL Research UniversityCNRSF-75006 ParisFrance AWE AldermastonReading RG7 4PRUK

In this work we have conducted a study on the radiative and spectroscopic properties of the radiative precursor and the post-shock region from experiments with radiative shocks in xenon performed at the Orion laser facility. The study is based on post-processing of radiation-hydrodynamics simulations of the experiment. In particular, we have analyzed the thermodynamic regime of the plasma, the charge state distributions, the monochromatic opacities and emissivities, and the specific intensities for plasma conditions of both regions. The study of the intensities is a useful tool to estimate ranges of electron temperatures present in the xenon plasma in these experiments and the analysis performed of the microscopic properties commented above helps to better understand the intensity spectra. Finally, a theoretical analysis of the possibility of the onset of isobaric thermal instabilities in the post-shock has been made, concluding that the instabilities obtained in the radiative-hydrodynamic simulations could be thermal ones due to strong radiative cooling.

关键词： high-power lasers laboratory experiments on radiative shocks plasma radiative properties spectroscopy

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Erratum to:Influence of metal support in-plane symmetry on the corrugation of hexagonal boron nitride and graphene monolayers

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Nano Research 2019年第5期12卷 1217-1218页

作者： Antonio J.Martinez-Galera Jose M.Gomez-Rodriguez departamento de fisica de la Materia Condensada Universidad Autonoma de MadridMadrid E-28049Spain Condensed Matter Physics Center(IFIMAC) Universidad Autonoma de MadridMadrid E-28049Spain Instituto Nicolas Cabrera Universidad Autonoma de MadridMadrid E-28049Spain

The writings of the text on the last line,left column on the 4^th page and the text on lines 8^th,10^th,11^th and 16^th in the 4^th paragraph,left column and on lines from 1st to 8^th in the 1st paragraph,right column on the 5^th page,and the text on line 4^th in the 1^st paragraph,left column on the 9^th page,and Fig.3 and its caption on the 5^th page in the original version of this article were unfortunately incorrect.

关键词： corrugation hexagonal boron nitride graphene monolayers

Short-term solar eruptive activity prediction models based on machine learning approaches: A review

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Science China Earth Sciences 2024年

作者： Xin HUANG Zhongrui ZHAO Yufeng ZHONG Long XU Marianna B.KORSóS R.ERDéLYI Faculty of Electrical Engineering and Computer Science Ningbo University State Key Laboratory of Space Weather National Space Science Center Chinese Academy of Sciences School of Astronomy and Space Science University of Chinese Academy of Sciences Beijing Cellular Exploration Science and Technology Center Dipartimento di fisica e Astronomia “Ettore Majorana” Università di Catania department of Astronomy E?tv?s Loránd University Hungarian Solar Physics Foundation Solar Physics & Space Plasma Research Center (SP2RC) School of Mathematics and Statistics University of Sheffield

Solar eruptive activities, mainly including solar flares, coronal mass ejections (CME), and solar proton events (SPE),have an important impact on space weather and our technosphere. The short-term solar eruptive activity prediction is an active field of research in the space weather prediction. Numerical, statistical, and machine learning methods are proposed to build prediction models of the solar eruptive activities. With the development of space-based and ground-based facilities, a large amount of observational data of the Sun is accumulated, and data-driven prediction models of solar eruptive activities have made a significant progress. In this review, we briefly introduce the machine learning algorithms applied in solar eruptive activity prediction, summarize the prediction modeling process, overview the progress made in the field of solar eruptive activity prediction model, and look forward to the possible directions in the future.

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Central nucleus-nucleus collisions at relativistic energies with a new method based on Random Matrix Theory

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Chinese Physics C 2010年第8期34卷 1076-1081页

作者： Z.Wazir R.G.Nazmitdinov E.I.Shahaliev M.K.Suleymanov department of Physics COMSATS Institute of Information Technology department de fisica Universitat de les Illes Balears Bogoliubov Laboratory of Theoretical Physics Joint Institute for Nuclear Research High Energy Physics Laboratory Joint Institute for Nuclear Research Institute of Radiation Problems

Using the method based on Random Matrix Theory （RMT）, the results for the nearest-neighbor distributions obtained from the experimental data on ^12C-C collisions at 4.2 AGeV/c have been discussed and compared with the simulated data on ^12C-C collisions at 4.2 AGeV/c produced with the aid of the Dubna Cascade Model. The results show that the correlation of secondary particles decreases with an increasing number of charged particles Nch. These observed changes in the nearest-neighbor distributions of charged particles could be associated with the centrality variation of the collisions.

关键词： random matrix theory experimental data Dubna cascade model central collisions

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Comparison of Different Formulations for the Numerical Calculation of Unsteady Incompressible Viscoelastic Fluid Flow

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Advances in Applied Mathematics and Mechanics 2010年第4期2卷 483-502页

作者： L.J.Amoreira P.J.Oliveira departamento de fisica Unidade de Detecccao RemotaUniversidade da Beira InteriorP6201-001 CovilhãPortugal departamento de Engenharia Electromecânica Unidade de Materiais Têxteis e PapeleirosUniversidade da Beira InteriorP6201-001 CovilhãPortugal

In this paper we compare different methods currently used in the stabilization of numerical simulations of time-dependent viscoelastic fluid flows described with the Oldroyd-B and related *** methods under consideration,based on the separation of newtonian-like components from the stress tensor,are applied to a finite volume analysis of two simple benchmark problems(the plane Poiseuille startup and pulsated flows),for which analytical solutions are *** relative performances of each method are evaluated regarding stability,accuracy and efficiency.

关键词： Time-dependent viscoelastic flows oscilating flow start-up flow computational rheology