Navegação Ciências Exatas e da Terra por Título
Resultados 1906-1925 de 5955
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Exploratory behavior, trap models, and glass transitions
(2004) [Artigo de periódico]A random walk is performed on a disordered landscape composed of N sites randomly and uniformly distributed inside a d-dimensional hypercube. The walker hops from one site to another with probability proportional to ... -
Exploring FSR open cluster candidates within ιΔι = 20º of the Galactic anticentre
(2008) [Artigo de periódico]Context. We investigate the nature of a sample of star cluster candidates detected as stellar overdensities towards the Galactic anticentre. Aims. Taken from the catalogue of Froebrich, Scholz, and Raftery (FSR), the sample ... -
Exploring the AGN-merger connection in Arp 245 : I: nuclear star formation and gas outflow in NGC 2992
(2021) [Artigo de periódico]Galaxy mergers are central to our understanding of galaxy formation, especially within the context of hierarchical models. Besides having a large impact on the star formation history, mergers are also able to influence gas ... -
Exploring the Barkas effect with keV-electron scattering
(2013) [Artigo de periódico]The energy loss of fast ions at close collision is mainly due to electron-ion collisions. The electrons are approximately stationary and they collidewith a fast-moving ion. Herewe study the same collision experimentally, ... -
Exploring the brown dwarf desert : new substellar companions from the SDSS-III MARVELS survey
(2017) [Artigo de periódico]Planet searches using the radial velocity technique show a paucity of companions to solar-type stars within ∼5 au in the mass range of ∼10–80 MJup. This deficit, known as the brown dwarf desert, currently has no conclusive ... -
Exploring the NΛ–NΣ coupled system with high precision correlation techniques at the LHC
(2022) [Artigo de periódico]The interaction of Λ and Σ hyperons (Y) with nucleons (N) is strongly influenced by the coupled-channel dynamics. Due to the small mass difference of the NΛ and NΣ systems, the sizable coupling strength of the NΣ ↔ NΛ ... -
Exponential estimates for "not very large deviations" and wave front propagation for class of reaction-diffusion equations
(1997) [Artigo de periódico]A Large Deviation Principle for a class of ranclom processes depending on a small parameter ε > O is established. This class of processes arises from a random perturbation of a dynamical system. Then, exponential estimates ... -
Extended gas in Seyfert 2 galaxies : implications for the nuclear source
(2003) [Artigo de periódico]We use long-slit spectroscopic optical data to derive the properties of the extended emitting gas and the nuclear luminosity of a sample of 18 Seyfert 2 galaxies. From the emissionline luminosities and ratios we derive the ... -
Extended gas in Seyfert galaxies : near-infrared observations of 15 active nuclei
(2000) [Artigo de periódico]Results from an analysis of low-resolution …(R ~ 250)† near-infrared long-slit spectra covering simultaneously the I, J, H and K bands, for a sample of 15 Seyfert galaxies and the NGC5253 starburst nucleus, are presented. ... -
Extended gas in Seyfert galaxies: near-infrared observations of NGC 2110 and Circinus
(1999) [Artigo de periódico]We present results of near-IR long-slit spectroscopy in the J and K bands of the Seyfert 2 galaxies NGC2110 and Circinus. Our goal is to investigate the gaseous distribution, excitation, reddening and kinematics, looking ... -
Extensão do método de análise de robustez para múltiplos outliers
(2016) [Artigo de periódico]Na análise de robustez, a "robustez" de uma rede geodésica é compreendida como a capacidade desta rede geodésica em "resistir" a deformações causadas por erros "não detectados" nas observações. A análise de robustez foi ... -
Extinction within 10 of the Galactic centre using 2MASS
(2003) [Artigo de periódico]We extract J and Ks magnitudes from the 2MASS Point Source Catalog for approximately 6×106 stars with 8 < - Ks < - 13 in order to build an AK extinction map within 10◦ of the Galactic centre. The extinction was determined ... -
Extração de Al(III), Cr(III) e Fe(III) de meio etanólico usando o xerogel anilinapropilsílica
(2004) [Artigo de periódico]In this study, the preparation of the xerogel anilinepropylsilica is reported. The ability of the xerogel for extracting Al(III), Cr(III) and Fe(III) from ethanol was investigated at 25 ºC. The xerogel adsorption capacities ... -
Extração semi-automática de cruzamentos de vias em áreas urbanas usando imagem de intensidade do pulso laser
(2011) [Artigo de periódico]O mapeamento de vias e malhas viárias é de fundamental importância para o desenvolvimento econômico de qualquer país, uma vez que representam os meios para o transporte convencional de bens e pessoas. Neste traballio é ... -
Extracting parameters from colour–magnitude diagrams
(2015) [Artigo de periódico]We present a simple approach for obtaining robust values of astrophysical parameters from the observed colour–magnitude diagrams (CMDs) of star clusters. The basic inputs are the Hess diagram built with the photometric ... -
Extraction kinetics and molecular size fractionation of humic substances from two brazilian soils
(1999) [Artigo de periódico]No presente trabalho foi estudada sistematicamente a extração de substâncias húmicas (SH) de um Oxisol e de um Mollisol do Sul do Brazil, empregando-se soluções de NaOH 0.1 e 0.5 mol L-1 e de Na4P2O7 0.15 mol L-1 a pH 7. ... -
Extreme and superextreme events in a loss-modulated CO2 laser : nonlinear resonance route and precursors
(2017) [Artigo de periódico]We investigate the occurrence of extreme and rare events, i.e., giant and rare light pulses, in a periodically modulated CO2 laser model. Due to nonlinear resonant processes, we show a scenario of interaction between chaotic ... -
Extreme galactic wind and Wolf-Rayet features in infrared mergers and infrared quasi-stellar objects
(2003) [Artigo de periódico]We report, as a part of a long-term study of infrared (IR) mergers and IR quasi-stellar objects (QSOs), detailed spectroscopic evidence for outflow (OF) and Wolf–Rayet (WR) features in the nearby mergers NGC4038/39 and ... -
Extremely large magnetic-field-effects on the impedance response of TiO2 quantum dots
(2019) [Artigo de periódico]Here, we report large magnetoresistance and magnetocapacitance response of undoped TiO 2 quantum dots weighting the contribution of both grain and grain boundaries by means of impedance spectroscopy. We also performed a ... -
Extrusão de compósitos de PP com fibras curtas de coco : efeito da temperatura e agentes de acoplamento
(2010) [Artigo de periódico]Compósitos de PP com fibras curtas de coco foram preparados em extrusora, com dois perfis de temperatura, visando avaliar o efeito compatibilizante de PP modificado com vinilalcoxisilano e com anidrido maleico. Foi verificado ...
