7 resultados para 64098
Resumo:
An electroabsorption modulator using an intra-step quantum well (IQW) active region is fabricated for a radio over fibre system. The strain-compensated InGaAsP/InGaAsP IQW shows good material quality and improved modulation properties, high extinction ratio efficiency (10 dB V-1) and low capacitance (< 0.42 pF), with which high frequency (> 15 GHz) can be obtained. High-speed measurement under high-power excitation shows no power saturation up to an excitation power of 21 dBm. To our knowledge, the input optical power is the highest reported for a multi-quantum well EAM without a heat sink.
Resumo:
Cumple con los objetivos docentes para la etapa 3 (key stage 3) del nivel de secundaria del plan de estudios inglés. Se estructura en varias secciones: un repaso del curso anterior, una introducción ó avance de las nuevas ideas del curso presente, las propias unidades de estudio y los objetivos que se han de cumplir con la realización de ejercicios de evaluación. También, se considera un reto en el aprendizaje de las ciencias, la utilización de un vocabulario específico por parte de los estudiantes. Se acompaña de una guía-recurso para el profesor.
Resumo:
Counts of colony forming units of actinomycetes, bacteria and filamentous fungi were determined in cerrado soil treated with vinasse (processed sugar cane effluent) for 5 yr, using doses of 20 l m-2a-1 and 50 l m-2a-1. A temporary increase in the counts of actinomycetes and bacteria for some months after the addition of vinasse was observed. An increased number of fungi was detected throughout the experiment together with qualitative changes in the population. The most abundant fungi in cerrado soil not treated with vinasse (control soil) were Chaetomium, yeasts, Mucor, Penicillium and Trichoderma, while in vinasse treated soils, the same genera adding Verticillium, with the exception of yeasts, were the most common fungi. -Author
