Zobrazeno 1 - 10
of 15
pro vyhledávání: '"U. A. Leitão"'
Autor:
Marcelo Knobel, Cibele Konzen, Javier Ellena, L.C. Meira-Belo, Humberto O. Stumpf, Antonio C. Doriguetto, Cynthia L. M. Pereira, U. A. Leitão, A.L. Brandl, Nelson G. Fernandes, Yvonne Primerano Mascarenhas
Publikováno v:
European Journal of Inorganic Chemistry. 2005:5018-5025
The compound [CoCu(opba)(DMSO)3] (1) [opba = ortho-phenylenebis(oxamato)] has been synthesized and characterized. Its crystal structure has been analyzed by X-ray diffraction techniques at 100 and 298 K. A structural phase-transition has been detecte
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::8205af8e302092c9cee1d3fea65038a3
https://doi.org/10.1002/ejic.200500474
https://doi.org/10.1002/ejic.200500474
Autor:
U. A. Leitão, Natália Cristina Trindade do Nascimento, Lilian Mara Benedita da Cruz Gervásio, Antonio dos Anjos Pinheiro da Silva
Publikováno v:
Physics Education. 52:015024
In this paper we report an investigative activity on hydrodynamics, in the context of an inquiry-based learning project. The aim is to analyse the experiment of a bullet shot underwater. Using Tracker, a video analysing and modelling software, the di
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::e54aaaf1a8faf343cc84d5ff641e19bc
https://doi.org/10.1088/1361-6552/52/1/015024
https://doi.org/10.1088/1361-6552/52/1/015024
Publikováno v:
Physical Review B. 62:215-222
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::2df148aa96a2646d35366bd865e3b854
https://doi.org/10.1103/physrevb.62.215
https://doi.org/10.1103/physrevb.62.215
Publikováno v:
Ferroelectrics. 184:289-292
LiK1−xRbxSO4 solid solutions have been obtained for different concentrations x. Crystals with x = 0.10 and 0.50 have been investigated by Raman spectroscopy, in the temperature range 80 - 300K. The room temperature spectra show that the sample with
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::5ba6ddcfaa7e412124e4d01cb5c5a4cb
https://doi.org/10.1080/00150199608230278
https://doi.org/10.1080/00150199608230278
Autor:
L. C. M. Belo, Ariete Righi, Roberto L. Moreira, U. A. Leitão, Patrice Bourson, Marcos A. Pimenta
Publikováno v:
Physical Review B. 52:12591-12600
The low-temperature phase transitions of ${\mathrm{LiK}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Rb}}_{\mathit{x}}$${\mathrm{SO}}_{4}$ mixed crystals have been studied by Raman spectroscopy (x=0.10 and 0.50) and birefringence measurements (x=0
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::fa56dbef9b13f96a1d539264e352ed7c
https://doi.org/10.1103/physrevb.52.12591
https://doi.org/10.1103/physrevb.52.12591
Publikováno v:
Journal of Physics: Condensed Matter. 7:8445-8452
X-ray diffraction studies on solution-grown LiKSO4 have been performed between 70 K and 300 K. The lattice parameters have been obtained as a function of the temperature. The hexagonal to trigonal phase transition at 205 K is seen by a slight increas
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::807ccd4afd296c6ea012aee693031bce
https://doi.org/10.1088/0953-8984/7/44/013
https://doi.org/10.1088/0953-8984/7/44/013
Publikováno v:
Ferroelectrics. 157:245-250
The polar low-temperature phase of weakly doped KTa1-xNbxO3 with x ≥ 0.012 seems to be ferroelectric as shown by Raman data, but simultaneously exhibits glass-like disorder according to recent X-ray studies. Very probably this is due to the occurre
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::30e4fbdb9b78d639dcadc16b6e1d26c1
https://doi.org/10.1080/00150199408229513
https://doi.org/10.1080/00150199408229513
Autor:
Antonio C. Doriguetto, U. A. Leitão, Humberto O. Stumpf, Nelson G. Fernandes, L.C. Meira-Belo, Cynthia L. M. Pereira
Publikováno v:
Journal of Magnetism and Magnetic Materials. :2018-2020
The present paper reports on a study of the magnetic anisotropy of the Co-based chain molecular magnet CoCu(opba)(DMSO)3. The magnetic anisotropy measurements were performed on microgram monocrystalline samples using a cantilever magnetometer at low
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::31ae2ee833633f5ff9ebdb3502c6682b
https://doi.org/10.1016/s0304-8853(00)01094-5
https://doi.org/10.1016/s0304-8853(00)01094-5
Autor:
G. A. M. Sáfar, L.C. Meira-Belo, U. A. Leitão, Alvaro V. Teixeira, Pedro Licinio, M.S. Andrade
Publikováno v:
Journal of Magnetism and Magnetic Materials. :1945-1947
Nanosize magnetic particles in dispersions should be strongly stabilized in order to avoid flocculation. Even with the use of steric surfactants or ionic peptization of particle surface, potential minima due to magnetic interaction may result in temp
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::9e29f41c16b44736ff7cf50276728f72
https://doi.org/10.1016/s0304-8853(00)00928-8
https://doi.org/10.1016/s0304-8853(00)00928-8
Autor:
U. A. Leitão
Publikováno v:
Education Policy Analysis Archives, Vol 23, Iss 0 (2015)
In this article, I propose an index, called the Social Index of Educational Effectiveness (SIEE), which allows the establishment of an objective criterion to define the school’s profile concerning the promotion of educational equity. It makes it po
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::de1eac5e23b25d0885fd4ee595891dff
https://doi.org/10.14507/epaa.v23.1915
https://doi.org/10.14507/epaa.v23.1915