Navegação Ciências Exatas e da Terra por Título

Resultados 5802-5821 de 6034

    • Unconventional singlet-triplet superconductivity 

      Möckli, David (2022) [Artigo de periódico]
      Have you been lying awake wondering what symmetries determine whether a superconductor is spin-singlet, triplet, or both? We show that if one supplies additional degrees of freedom to BCS theory, spin-singlet can coexist ...

    • Unconventional superconducting granularity of the Y/sub 1-x/Pr/sub x/Ba/sub 2/Cu/sub 3/O/sub 7-[delta]/ compound 

      Barros, Fábio Martins; Pureur Neto, Paulo; Schaf, Jacob; Fabris, Frederik Wolff; Vieira, Valdemar das Neves; Jurelo, Alcione Roberto; Cantão, Mauricio Pereira (2006) [Artigo de periódico]
      We report on fluctuation magnetoconductivity and magnetic irreversibility of Y1−xPrxBa2Cu3O7− single crystals and a polycrystalline sample. Although our samples are all single phase orthorhombic and the single crystals ...

    • Uncovering the chemical structure of the pulsating low-mass white dwarf SDSS J115219.99+024814.4 

      Romero, Alejandra Daniela; Ramos, Gabriel Lauffer; Istrate, Alina G.; Parsons, Steven (2022) [Artigo de periódico]
      Pulsating low-mass white dwarf (WD) stars are WDs with stellar masses between 0.30 and 0.45 M⊙ that show photometric variability due to gravity-mode pulsations. Within this mass range, they can harbour both a helium core ...

    • Underlying-event properties in pp and p–Pb collisions at √sNN = 5.02 TeV 

      Acharya, Shreyasi; Gay Ducati, Maria Beatriz; Pereira, Luis Gustavo; ALICE Collaboration (2023) [Artigo de periódico]
      We report about the properties of the underlying event measured with ALICE at the LHC in pp and p–Pb collisions at √ sNN = 5.02 TeV. The event activity, quantified by charged-particle number and summed-pT densities, is ...

    • Underlying event properties in pp collisions at √s = 13 TeV 

      Acharya, Shreyasi; Gay Ducati, Maria Beatriz; Pereira, Luis Gustavo; Pezzi, Rafael Peretti; ALICE Collaboration (2020) [Artigo de periódico]
      This article reports measurements characterizing the Underlying Event (UE) associated with hard scatterings at midrapidity (|η| < 0.8) in pp collisions at √s = 13 TeV. The hard scatterings are identified by the leading ...

    • Underscreened Kondo lattice model applied to heavy fermion uranium compounds 

      Perkins, Natalia B.; Núñez-Regueiro, M.D.; Coqblin, Bernard; Iglesias, Jose Roberto (2007) [Artigo de periódico]
      We present theoretical results for the underscreened Kondo lattice model with localized S=1 spins coupled to a conduction band through a Kondo coupling, JK, and interacting among them ferromagnetically. We use a fermionic ...

    • Understanding the cool DA white dwarf pulsator G29-38 

      Kleinman, Scot James; Nather, R. Edward; Winget, Donald Earl; Clemens, J. Christopher; Bradley, Paul A.; Kanaan Neto, Antonio Nemer; Provencal, Judith L.; Claver, C.F.; Watson, Todd K.; Yanagida, K.; Nitta, Atsuko; Dixson, James S.; Wood, Matthew A.; Grauer, Albert D.; Hine, B.P.; Fontaine, Gilles; Liebert, James; Sullivan, Denis J.; Wickramasinghe, D.T.; Achilleos, Nicholas; Marar, T.M. Krishnan; Seetha, S.; Ashoka, B.N.; Meistas, Edmundas G.; Leibowitz, Elia M.; Moskalik, Pawel; Krzesinski, Jerzy; Solheim, Jan-Eric; Bruvold, A.; O'Donoghue, Darragh; Kurtz, Donald W.; Warner, B.; Martinez, Peter; Vauclair, Gérard; Dolez, Noël; Chevreton, Michel; Barstow, Martin A.; Kepler, Souza Oliveira; Giovannini Junior, Odilon; Augusteijn, T.; Hansen, Carl J.; Kawaler, Steven D. (1998) [Artigo de periódico]
      The white dwarfs are promising laboratories for the study of cosmochronology and stellar evolution. Through observations of the pulsating white dwarfs, we can measure their internal structures and compositions, critical ...

    • Understanding the two-dimensional ionization structure in luminous infrared galaxies : a near-IR integral field spectroscopy perspective 

      Colina, Luis; Piqueras López, Javier; Arribas Mocoroa, Santiago; Riffel, Rogério; Riffel, Rogemar André; Rodriguez-Ardila, Alberto; Pastoriza, Miriani Griselda; Storchi-Bergmann, Thaisa; Alonso-Herrero, Almudena; Sales, Dinalva Aires de (2015) [Artigo de periódico]
      We investigate the two-dimensional excitation structure of the interstellar medium (ISM) in a sample of luminous infrared galaxies (LIRGs) and Seyferts using near-IR integral field spectroscopy. This study extends to the ...

    • Une generalisation de l'invariant de malgrange 

      Sebastiani Artecona, Marcos Antonio Arturo (1992) [Artigo de periódico]

    • Un enfoque epistemológico de la enseñanza de la física : una contribución para el aprendizaje significativo de la física, con muchas cuestiones sin respuesta 

      Massoni, Neusa Teresinha; Moreira, Marco Antonio (2010) [Artigo de periódico]
      Este trabajo relata un estudio de caso con un profesor de Física de enseñanza secundaria cuyas concepciones epistemológicas, ya identificadas en dos estudios anteriores, fueron consideradas claramente concordes con las ...

    • Unfolding of antiferromagnetic phases and multicritical points in a two-orbital model for uranium compounds under pressure and magnetic field 

      Magalhães, Sergio Garcia; Lausmann, Ana Claudia; Calegari, Eleonir João; Riseborough, Peter S. (2020) [Artigo de periódico]
      We investigate the occurrence of multicritical points under pressure and magnetic field in a model that describes two 5 f bands (of either α or β characters), which hybridize with a single itinerant conduction band. The 5 ...

    • Unhealthy food commercials on brazilian TV 

      Viacava, Keitiline Ramos; Simões, Reinaldo Augusto Gomes; Santolim, Ricardo Ribas; Weydmann, Gibson Juliano; Damasceno, Betina Vidal; Tietze, Arthur Weinmann; Vigo, Álvaro; Araujo, Lisiane Bizarro (2016) [Artigo de periódico]
      Determining and monitoring the amount of unhealthy food commercials on TV is relevant to the prevention and control of obesity. The aim of this study was to determine the proportion of unhealthy food commercials on Brazilian ...

    • A unidade (divisao) da geografia e o sentido da pratica 

      Rego, Nelson (1995) [Artigo de periódico]

    • Unified formulation for inhomogeneity-driven instabilities in the lower-hybrid range 

      Silveira, Omar Junior Garcia; Ziebell, Luiz Fernando; Gaelzer, Rudi; Yoon, Peter H. (2002) [Artigo de periódico]
      A local dispersion relation that describes inhomogeneity-driven instabilities in the lower-hybrid range is derived following a procedure that correctly describes energy exchange between waves and particles in inhomogeneous ...

    • Unified line profiles for hydrogen perturbed by collisions with protons : satellites and asymmetries 

      Pelisoli, Ingrid Domingos; Santos, Marcio Gabriel dos; Kepler, Souza Oliveira (2015) [Artigo de periódico]
      We present new calculations of unified line profiles for hydrogen perturbed by collisions with protons. We report on new calculations of the potential energies and dipole moments which allow the evaluation of profiles for ...

    • Uniform detection of the pre-main-sequence population in the five embedded clusters related to the HII region NGC2174 (Sh2-252) 

      Bonatto, Charles Jose; Bica, Eduardo Luiz Damiani (2011) [Artigo de periódico]
      We investigate five embedded clusters (ECs) and the extended stellar group itself of the prominent HII region NGC2174 (Sh2-252), which presents scarce and heterogeneous information coming from the optical and infrared. ...

    • Unique ergodicity of interval exchange maps 

      Rocha, Luiz Fernando Carvalho da (1992) [Artigo de periódico]
      Necessary and suffi cient conditions are given in order that an in terval excha.nge map satisfying Keane's infinite a.nd di stinct orbit COlldition be uniquely ergodi c. This is done through the dcvelopment of a t heory ...

    • Uniqueness of the functional approach 

      Girotti, Horacio Oscar; Simoes, Tiago Josue Martins (1980) [Artigo de periódico]
      It is shown that the phase-space Schwinger equations can only be appropriately formulated in terms of a specific discrete procedure. Nevertheless, the solutions to Schwinger equations turn out to be independent of the ...

    • Unitarity boundary for deep inelastic structure functions 

      Ayala Filho, Alvaro Leonardi; Gay Ducati, Maria Beatriz; Levin, Eugene Marcovich (1996) [Artigo de periódico]
      In this letter we derive the unitarity boundaries in QCD for the deep inelastic structure function in low x kinematic region: the Froissart boundary and a more restricted one, linked with experiment and based on additional ...

    • Unitarity corrections to the structure functions through the dipole picture 

      Gay Ducati, Maria Beatriz; Machado, Magno Valério Trindade (2002) [Artigo de periódico]
      We study the dipole picture for the description of deep inelastic scattering, focusing on the structure functions which are driven directly by the gluon distribution. One performs estimates using the effective dipole cross ...