6 research outputs found

    730-nm optical parametric conversion from near- to short-wave infrared band

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    A record 730 nm parametric conversion in silica fiber from the near-infrared to the short-wave infrared band is reported and analyzed. A parametric gain in excess of 30 dB was measured for a signal at 1300 nm (with corresponding idler at 2030 nm). This conversion was performed in a travelling single-pass one-pump parametric architecture and high efficiency is achieved by a combination of high peak power and a nonlinear fiber with a reduced fourth-order dispersion coefficient

    Comparação das categorias espaciais por meio de sistemas lingüístico e pictórico em pré-escolares de diferentes grupos sócio-econômico-culturais Comparison of spacial categories in preschool children by means of linguistic and pictorial methods in three different socio-economic-cultural groups

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    Foi investigado um sistema discriminativo relacionado à psicolingüística a ser aplicado no Programa Centro de Educação e Alimentação de Pré-Escolar (CEAPE). Optou-se por explorar a representação espacial por meio de sistemas lingüístico e pictórico. A amostra estudada foi constituída de 105 crianças de 3 a 6 anos e meio pertencentes a três grupos: do Programa CEAPE, de um grupo controle "Não-Ceapense" e de um outro de nível sócio-econômico alto da cidade de São Paulo. Estudou-se o poder discriminativo das perguntas nos três grupos de pré-escolares. Em relação às variáveis, nível sócio-econômico-cultural e estimulação, houve diferenças significativas para testes de compreensão lingüística em favor do grupo de alto nível sócio-econômico-cultural. As percentagens de categorias dominadas por 100% dos componentes dos três grupos foram, respectivamente: 41,7% (São Paulo), 30,6% (CEAPE) e, 25,0% (não CEAPE); 95% dos componentes dos três grupos dominaram, respectivamente, 50,0% (São Paulo), 47,2% (CEAPE) e 36,1% (não CEAPE) das categorias.<br>A research into a system, related to psycholinguistics, which is to be applied to a CEAPE program for preschool-age children is described. The choice fell upon spacial representation through linguistic and pictorial systems. A cross-section of ages was studied (from 3 to 6). Sample children came from 3 groups: those from a CEAPE program, a control group of children not covered by CEAPE and a high level socio-economic group from the city of S. Paulo, Brazil. The differentiating power of the items was studied in the 3 groups. With regard to socio-economic-cultural level and stimulation, significant differences in linguistic understanding to the advantage of the high level socio-economic-cultural group were observed Percentages of categories in which all subjects, answered correcty were respectively: 41.7% (S. Paulo), 30.6% (CEAPE) and 25.0% (non-CEAPE). Ninety-five percent of the members of the 3 groups gave correct answers to 50.0% (S. Paulo), 47.2% (CEAPE) and 36.1% (non-CEAPE) of the items, respectively
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