994 resultados para Retz, cardinal de (1613-1679)
Resumo:
Comprend : Incendium Londinense
Resumo:
Comprend : Notice
Resumo:
Banco del conocimiento
Resumo:
Banco del conocimiento
Resumo:
Using the Physical Vapor Transport method, single crystals of Cd2Re207 have been grown, and crystals of dimensions up to 8x6x2 mm have been achieved. X-ray diffraction from a single crystal of Cd2Re207 has showed the crystal growth in the (111) plane. Powder X-ray diffraction measurements were performed on ^^O and ^^O samples, however no difference was observed. Assigning the space group Fd3m to Cd2Re207 at room temperature and using structure factor analysis, the powder X-ray diffraction pattern of the sample was explained through systematic reflection absences. The temperatiure dependence of the resistivity measurement of ^^O has revealed two structural phase transitions at 120 and 200 K, and the superconducting transition at 1.0 K. Using Factor Group Analysis on three different structiures of Cd2Re207, the number of IR and Raman active phonon modes close to the Brillouin zone centre have been determined and the results have been compared to the temperature-dependence of the Raman shifts of ^^O and ^*0 samples. After scaling (via removing Bose-Einstein and Rayleigh scattering factors from the scattered light) all spectra, each spectrum was fitted with a number of Lorentzian peaks. The temperature-dependence of the FWHM and Raman shift of mode Eg, shows the effects of the two structurjil phase transitions above Tc. The absolute reflectance of Cd2Re207 - '^O single crystals in the far-infrared spectral region (7-700 cm~^) has been measured in the superconducting state (0.5 K), right above the superconducting state (1.5 K), and in the normal state (4.2 K). Thermal reflectance of the sample at 0.5 K and 1.5 K indicates a strong absorption feature close to 10 cm~^ in the superconducting state with a reference temperature of 4.2 K. By means of Kramers-Kronig analysis, the absolute reflectance was used to calculate the optical conductivity and dielectric function. The real part of optical conductivity shows five distinct active phonon modes at 44, 200, 300, 375, and 575 cm~' at all temperatures including a Drude-like behavior at low frequencies. The imaginary part of the calculated dielectric function indicates a mode softening of the mode 44 cm~' below Tc.
Resumo:
The purpose of this study was to examine the experiences of adult only-child educators. The researcher explored the extent to which the experiences of growing up in a one-child family influenced the participants' professional experiences. This was a qualitative study. A narrative case study approach was used, and data were collected from 4 participants through 1 -to- 1 interviews. The narratives were analyzed, and common themes were identified. The findings showed that many of the participants' only-child experiences have influenced their professional roles as educators. This was largely with respect to their interactions with students. These participants valued positive relationships founded on genuine care and concern for their students. The participants also fostered a positive educational environment that provided high levels of support for the social learning and character development of their students. There are several implications for educational practice resulting from this study. Educators and other school personnel must be critically aware of meeting the socialization needs of their students. Consideration must be given to developing schoolwide initiatives related to the social skills development and character education of students. In addition, preservice and inservice teacher education programs must ensure that educators are prepared to provide rich environments where relationships with students are central and social learning opportunities are prevalent.