Browsing Exact and Earth Sciences by Title
Now showing items 1-20 of 4524
-
A 0.8-2.4 μm spectral atlas of active galactic nuclei
(2006) [Journal article]Aims. We present a near-infrared spectral atlas of 47 active galactic nuclei (AGN) of all degrees of activity in the wavelength interval of 0.8–2.4 μm, including the fluxes of the observed emission lines. We analyze the ... -
18 Sco : a solar twin rich in refractory and neutron-capture elements, implications for chemical tagging
(2014) [Journal article]We study with unprecedented detail the chemical composition and stellar parameters of the solar twin 18 Sco in a strictly differential sense relative to the Sun. Our study is mainly based on high-resolution (R ∼ 110,000), ... -
2006 Whole Earth Telescope observations of GD358 : a new look at the prototype DBV
(2009) [Journal article]We report on the analysis of 436.1 hr of nearly continuous high-speed photometry on the pulsating DB white dwarf GD358 acquired with the Whole Earth Telescope (WET) during the 2006 international observing run, designated ... -
2D nanoporous membrane for cation removal from water : effects of ionic valence, membrane hydrophobicity, and pore size
(2018) [Journal article]Using molecular dynamic simulations, we show that single-layers of molybdenum disulfide (MoS2) and graphene can effectively reject ions and allow high water permeability. Solutions of water and three cations with different ... -
2D stellar population and gas kinematics of the inner 1.5 kpc of the post-starburst quasar SDSS J0210−0903
(2013) [Journal article]Post-starburst quasars (PSQs) are hypothesized to represent a stage in the evolution of massive galaxies in which the star formation has been recently quenched due to the feedback of the nuclear activity. In this paper, ... -
2D stellar population and gas kinematics of the inner kiloparsec of the post-starburst quasar SDSS J0330−0532
(2014) [Journal article]We have used optical Integral Field Spectroscopy in order to map the star formation history of the inner kiloparsec of the post-starburst quasar (PSQ) J0330−0532 and to map its gas and stellar kinematics as well as the gas ... -
3-arylisoxazolyl-5-carboxylic acid and 5-(hydroxymethyl)-3-aryl-2-isoxazoline as molecular platforms for liquid-crystalline materials
(2009) [Journal article]A síntese de uma plataforma molecular para materiais líquido-cristalinos derivados do ácido 3-arilisoxazolil-5-carboxílico (1) e do 5-(hidroximetil)-3-aril-2-isoxazolina (2) é descrita. Os intermediários 1 e 2 são obtidos ... -
3-Mercaptopropionic, 4-mercaptobenzoic, and oleic acid-capped CdSe quantum dots : interparticle distance, anchoring groups, and surface passivation
(2019) [Journal article]The optoelectronic properties of quantum dots are strongly controlled by the chemical nature of their surface-passivating ligands. In this work, we present the synthesis, characterization, and surface modification of CdSe ... -
60 anos da geografia UFRGS
(2007) [Journal article] -
7-amino-4-azaheptyl grafted onto a silica gel as a sorbent for the on-line preconcentration and determination of iron(III) in water samples
(2005) [Journal article]A new sorbent was synthesized by anchoring 7-amino-4-azaheptyltrimetoxisilane, freshly prepared, to silica gel, producing 7-amino-4-azaheptyl anchored silica gel (AAHSG). This material was characterized by infrared ... -
Uma abordagem conceitual e fenomenológica dos postulados da física quântica
(2012) [Journal article]No presente trabalho, apresentamos uma discussão sobre os postulados da física quântica a partir de uma “tradução” do formalismo matemático para uma linguagem “operacional” e que envolve uma discussão conceitual e ... -
Uma abordagem de ensino de reações químicas entre compostos inorgânicos referenciada em mecanismos de reação
(2004) [Journal article]O ensino do conteúdo relacionado aos compostos inorgânicos se apresenta tradicionalmente, com uma abordagem que pode levar os alunos a uma aprendizagem memorística. Com uma metodologia referenciada na teoria da aprendizagem ... -
Abordando conceitos fundamentais da mecânica quântica no nível médio
(2004) [Journal article]A componente experimental do trabalho foi realizada em duas escolas de Ensino Médio da rede particular da cidade de Cuiabá, Brasil, envolvendo cerca 100 alunos, para os quais foram ministrados conteúdos sobre os conceitos ... -
Aborto e coerção sexual : o contexto de vulnerabilidade entre mulheres jovens
(2011) [Journal article]Neste estudo investigou-se a relação entre a prática do aborto e a declaração de coerção sexual. Os dados foram provenientes do GRAVAD, inquérito domiciliar com amostragem probabilística estratificada, realizado com jovens ... -
-
Absolutely continuous invariant mesures for a class of affine interval exchange maps
(1995) [Journal article]We consider a class A of affine interval exchange maps of the interval and we analyse several ergodic properties of the elements of this class, among them the existence of absolutely continuous invariant probability measures. ... -
Acacia bark residues as filler in polypropylene composites
(2015) [Journal article]Large amounts of acacia bark residues are produced each day after tannin extraction with hot water, being generally burned. This by-product was chemically characterized and used as filler in polypropylene (PP) composites, ... -
A acao das ongs e as novas formas de insercao profissional da geografia
(1998) [Journal article] -
Accumulation horizons and period adding in optically injected semiconductors lasers
(2007) [Journal article]We study the hierarchical structuring of islands of stable periodic oscillations inside chaotic regions in phase diagrams of single-mode semiconductor lasers with optical injection. Phase diagrams display remarkable ... -
Accuracy of the maximum entropy method
(1980) [Journal article]Although the maximum entropy method is capable of giving the period of a pure sine wave with very few data points, it is very sensitive to noise. The half power width of a spectral peak obtained by this method is proportional ...
