Navegação Ciências Exatas e da Terra por Título
Resultados 4270-4289 de 5955
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Quantum electrodynamics with zero bare ferminon mass
(1964) [Artigo de periódico] -
Quantum phase transitions in an interacting atom-molecule boson model
(2010) [Artigo de periódico]We study the quantum phase transitions of a model that describes the interconversion of interacting bosonic atoms and molecules. Using a classical analysis, we identify a threshold coupling line separating a molecular phase ... -
Quantum phase transitions in Bose–Einstein condensates from a Bethe ansatz perspective
(2012) [Artigo de periódico]We investigate two solvable models for Bose–Einstein condensates and extract physical information by studying the structure of the solutions of their Bethe ansatz equations. A careful observation of these solutions for the ... -
Quantum Physics teaching and the theory of Social representations : investigating the presence of quantum mysticism concepts among high school students in the south of Brazil
(2023) [Artigo de periódico]The present work deals with possibilities for contribution of the Theory of Social Representations (TSR) as a reference for group learning, with techniques and methodologies that are specific to it, to facilitate the ... -
Quantum spherical spin glass : supersymmetry and annealing
(2007) [Artigo de periódico]We show that the effective action of the quantum spherical spin glass is invariant under a generalized form of Becchi-Rouet-Stora-Tyutin supersymmetry. The Ward identities associated with this invariance indicate that the ... -
Quantum spin glass : a replica-symmetric theory with positive entropy
(1986) [Artigo de periódico]In the present paper we present a detailed analysis of quantum effects in the spin-glass transition as described by a quantum Heisenberg analogue of the Sherrington-Kirkpatrick model. The spin operators are represented in ... -
A quantum toy-model for inelastic scattering and catalysis based on Bäcklund transformations
(2022) [Artigo de periódico]This work presents a scalar self-consistent quantum model for molecular simulation. This model employs Bäcklund transformations to eliminate the wave function from Klein-Gordon and Schrödinger-type equations. The nonlinear ... -
Quarkonium photoproduction in pp and AA collisions at the LHC
(2016) [Artigo de periódico]In this contribution we report on the investigations of the exclusive production of quarkonium states in proton-proton and nucleus-nucleus reactions at the LHC using the theoretical framework of the light-cone dipole ... -
Quarkonium plus prompt-photon associated hadroproduction and nuclear shadowing
(2010) [Artigo de periódico]Quarkonium hadroproduction in association with a photon at high energies provides a probe of the dynamics of the strong interactions as it is dependent on the nuclear gluon distribution. Therefore, it could be used to ... -
Quasi-free scattering of polarized electrons by polarized nuclear protons
(1977) [Artigo de periódico]It Is shown that quasi-free electron scattering in a suitable geometry takes place on strongly polarized nuclear protons. A calculation for the single particle model of 160 predicts large asymmetries for the scattering of ... -
Quasilinear analysis of loss-cone driven weakly relativistic electron cyclotron maser instability
(1995) [Artigo de periódico]This paper presents a quasilinear analysis of the relativistic electron cyclotron maser instability. Two electron popUlations are assumed: a low-temperature background component and a more energetic loss-cone population. ... -
Quasilinear evolution of cyclotron maser instability
(1995) [Artigo de periódico]A quasilinear analysis of the relativistic electron cyclotron maser instability is presented. A background plasma is assumed to support the wave motion, while the instability is driven by a tenuous population of energetic ... -
Quasilinear evolution of the weakly relativistic electron cyclotron maser instability
(1997) [Artigo de periódico]This paper presents a quasilinear analysis of the relativistic electron cyclotron maser instability in which the self-consistent set of equations governing the evolution of the particle distribution function and the energy ... -
Quasinormal modes and stability of accelerating Reissner-Norsdtröm AdS black holes
(2022) [Artigo de periódico]We investigate the numerical stability of accelerating AdS black holes against linear scalar perturbations. In particular, we study the evolution of a probe non-minimally coupled scalar field on Schwarzschild and ... -
Quasi-one-dimensional magnetic properties of NiNb2−xVxO6 compounds synthesized at high pressure in a nonstandard columbite-type structure
(2021) [Artigo de periódico]We report on the low-dimensional magnetic behavior of the series of compounds NiNb2−xVxO6 (0 x 2), with a columbite-type crystal structure stabilized at high pressure and temperature. Based on susceptibility, magnetization, ... -
Quasistationary trajectories of the mean-field XY Halmitonian model : a topological perspective
(2005) [Artigo de periódico]We employ a topological approach to investigate the nature of quasistationary states of the mean-field XY Hamiltonian model. We focus on the quasistationary states reached when the system is initially prepared in a fully ... -
O que a Geografia (Política) deve ser. A Geografia Política entre a paz e a guerra
(2017) [Artigo de periódico]O texto resgata autores clássicos da Geografia Política (Kropotkin, Mackinder, Hartshorne) para ilustrar as profundas relações entre a história da Geografia Política e a construção da paz, ainda que as suas origens e ... -
Quem são os formadores de professores que ensinam matemática no Rio Grande do Sul?
(2021) [Artigo de periódico]O artigo apresenta uma proposta de pesquisa sobre formadores de professores que ensinam Matemática no Rio Grande do Sul. Reflexões sobre formação de professores e debates realizados em fóruns da Sociedade Brasileira de ... -
A questão das ênfases curriculares e a formação do professor de ciências
(1986) [Artigo de periódico]Resumo não disponível -
A questão de redação no concurso vestibular à universidade : validade e poder decisório
(2001) [Artigo de periódico]Apresentam-se análises de validade e do poder decisório da questão de Redação nos concursos vestibular da Universidade Federal do Rio Grande do Sul e da Pontifícia Universidade Católica do Rio Grande do Sul, envolvendo ...