Browsing Exact and Earth Sciences by Title
Now showing items 4468-4487 of 6198
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(R)-4-Isopropyl-3-isopropylsulfanyl-5,5-diphenyl-1,3-oxazolidin-2-one
(2012) [Journal article]The title compound, C21H25NO2S, consists of a five-membered heterocyclic ring, with pendant phenyl groups, an isopropyl group and a thioether residue. The thioether bonds to the heterocycle via the N atom. The absolute ... -
Raça, gênero e classe social nas ciências físicas : o silêncio dos homens
(2024) [Journal article]Ensaio produzido a partir da palestra Questões étnico-raciais e de gênero nas ciências físicas: o silêncio dos homens, ministrada pelo autor durante a segunda edição do evento As Astrocientistas: Encontro Brasileiro de ... -
Radiation of water waves by a heaving submerged horizontal disc
(1997) [Journal article] -
Radiatively inefficient accretion flow in the nucleus of NGC 1097
(2006) [Journal article]We present a model for the accretion flow around the supermassive black hole in the LINER nucleus of NGC 1097 that fits the optical to X-ray spectral energy distribution (SED). The X-ray segment of the SED is based on ... -
Radio 88.1 - Restinga FM:
(2004) [Journal article]O presente artigo discute algumas situações vivenciadas na sociedade atual e espacializadas no Bairro Restinga. Parte do desenvolvimento desigual do solo urbano, para a compreensão das dinâmicas de segregação sócio-espacial ... -
Radio 88.1 - Restinga FM: a radiodifusão comunitária como movimento social
(2006) [Journal article]O presente artigo discute algumas situações vivenciadas na sociedade atual e espacializadas no Bairro Restinga. Parte do desenvolvimento desigual do solo urbano, para a compreensão das dinâmicas de segregação sócio-espacial ... -
Radioquímica : uma disciplina articuladora de conhecimentos pedagógicos e conhecimentos específicos na licenciatura em química
(2015) [Journal article]Trabalho realizado na disciplina Radioquímica do curso de Licenciatura em Química-Noturno da Universidade Federal do Rio Grande do Sul ao longo dos semestres letivos 2014/01, 2014/02 e 2015/01. -
Raios X, enculturamento científico, autonomia e reflexão : uma proposta didática inspirada na pedagogia dialógica
(2019) [Journal article]Neste trabalho relatamos uma experiência didática concebida no âmbito de um Mestrado Profissional em Ensino de Física e inspirada na pedagogia de Paulo Freire para abordar o tema Raios X (matéria e radiações), visando o ... -
Raios X : um tema instigante para a introdução da Física Moderna e Contemporânea na sala de aula do Ensino Básico
(2017) [Journal article]Este texto tem o objetivo de ser uma introdução ao estudo dos raios X: o que são, como são produzidos e como afetam a vida humana. É, portanto, um texto introdutório que visa oferecer subsídios para uma abordagem do tema ... -
Ralaxation times of nanoscale deformations on the surface of a polymer thin film near and below the glass transition
(2006) [Journal article]We report on measurements of relaxation times of nanometer-sized deformations resulting from the impact of individual energetic ions on poly methyl methacrylate surfaces at temperatures close to and below the glass transition ... -
Raman spectra of R2O3 (R-rare earth) sesquioxides with C-type bixbyite crystal structure : a comparative study
(2014) [Journal article]Raman spectra of R2O3 (R—Sc, Er, Y, Ho, Gd, Eu, and Sm) powders with C-type bixbyite crystal structure are measured. With the help of these data and ones, previously published for other oxides from the same structural ... -
Raman study of phonons in CaMn7O12 : effects of structural modulation and structural transition
(2014) [Journal article]Polarized Raman spectra of oriented CaMn7O12 single crystals have been studied in a broad temperature range (5–500 K) covering the crystallographic, ferroelectric, and magnetic transitions. From the spectra obtained at ... -
Random and channeling stopping powers of He and Li ions in Si
(2002) [Journal article]In this work we have measured the electronic stopping powers of ⁴He and ⁷Li ions for channeling and random directions in Si as a function of the incident ion energy. The channeling (‹100› for Li, ‹110› and ‹111› for Li and ... -
Range and thermal behavior studies of Au and Bi implanted into photoresist films
(1990) [Journal article]The Rutherford backscattering technique has been used to determine range parameters of Au and Bi íons implanted into AZ1350 photoresist films at energies from 20 to 300 keV. The experimental results are 20 to 25% higher ... -
Range measurements and thermal stability study of az111 photoresist implanted with bi ions
(1988) [Journal article]The Rutherford backscattering technique has been used to determine the range parameters of Bi ions implanted into AZ111 photoresist film at energies from 10 to 400 keY. An overaU good agreement is found between the ... -
Range study of Eu implanted into Si channeling directions : evidence for the Z/sub 1/ effect
(2001) [Journal article]Eu ions have been implanted along the Si ‹100›, ‹111›, and ‹110› directions at 623 K with energies ranging from 15 keV to 50 keV. The depth profiles have been measured using Rutherford backscattering spectroscopy (RBS). A ... -
Rapid changes in the integrated light of young star clusters
(1989) [Journal article]We discuss the occurrence of rapid red phases in the integrated colours of star clusters by comparing a colour evolution model with spectral and broad band UBVK observations in the LMC. The model is computed with a very ... -
Rapidly converging bounds for the ground-state energy of hydrogenic atoms in superstrong magnetic fields
(1989) [Journal article] -
Rare earth element and yttrium geochemistry applied to the genetic study of cryolite ore at the Pitinga mine (Amazon, Brazil)
(2008) [Journal article]Este trabalho enfoca a geoquímica de elementos terras raras (ETR) e de Y no minério criolítico disseminado, no depósito criolítico maciço e na fluorita associada na mina Pitinga. As assinaturas de ETR na criolita e fluorita ... -
Rare-earth spin-glasses with uniaxial anisotropy
(1984) [Journal article]The properties of spin-glasses with uniaxial anisotropy are investigated by magnetization measurements on single crysta1s of Y and Se doped with Er, Dy, Tb, or Gd impurities. In alloys with strong anisotropy, spin-glass ...
