RESUMEN
We report on the integration of monodisperse semiconductor nanocrystal (NC) color converters onto gallium nitride ultraviolet micro-pixelated light-emitting diodes ('micro-LEDs'). Integration is achieved in a 'self-aligned' process by forming a nanocomposite of the respective NCs in a photocurable epoxy polymer. Blue, green, yellow and red NC/epoxy blend microstructures have been successfully integrated onto micro-pixelated LEDs by this technique and utilised for color conversion, resulting in a five color emission single chip. Optical output power density of up to about 166 mW/cm2 is measured; spectral emission at 609 nm gives an estimated optical-to-optical conversion as high as 18.2% at 30 mA driving current.
Asunto(s)
Compuestos Epoxi/química , Iluminación/instrumentación , Nanoestructuras/química , Nanotecnología/instrumentación , Semiconductores , Diseño Asistido por Computadora , Cristalización/métodos , Diseño de Equipo , Análisis de Falla de Equipo , Galio/química , Indio/química , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Procesamiento de Señales Asistido por Computador/instrumentaciónRESUMEN
Carbon- and boron-oxide-encapsulated iron nanocapsules have been synthesized by arc discharge in methane (CH4) and diborane (B2H6) atmospheres respectively. The characterization and magnetic properties of carbon- and boron-oxide-encapsulated iron nanocapsules [abbreviated as Fe(C) and Fe(B) respectively] were investigated and compared. The structure of the Fe(B) nanocapsules is different from that of the Fe(C) nanocapsules. The Fe(C) nanocapsules consist of a crystalline graphite shell and a core of alpha-Fe and/or Fe3C. The Fe(B) nanocapsules consist of an amorphous boron-oxide layer and a core of Fe(B) solid solution, alpha-Fe, gamma-Fe, FeB, and/or Fe3B phases. The saturation magnetizations of both the Fe(C) and the Fe(B) nanocapsules below 300 K decrease monotonically with increasing temperature. The coercivities of the Fe(C) and Fe(B) nanocapsules are almost 2 orders of magnitude higher than that of bulk Fe. The temperature dependence of magnetization at high temperatures indicates the existence of some phase transformations.
Asunto(s)
Compuestos de Boro/química , Carbono/química , Composición de Medicamentos/métodos , Hierro/química , Magnetismo , Nanotecnología/métodos , Borohidruros/química , Compuestos de Boro/síntesis química , Compuestos de Boro/aislamiento & purificación , Carbono/aislamiento & purificación , Hierro/aislamiento & purificación , Sustancias Macromoleculares , Metano/química , Microscopía Electrónica , Microesferas , Conformación Molecular , Tamaño de la Partícula , Temperatura , Difracción de Rayos XRESUMEN
There have been few morphometric studies on the size of the motoneurons of the human spinal cord. The purpose of the present study is to report the differences in the size of the motoneurons between males and females in the human spinal cord. We examined numbers and transverse cell body areas of the motoneurons of the anterior horn using 16 male and 21 female human spinal cords at levels C5 and L3. The sizes of the motoneurons were larger in males than in females, but their numbers were practically the same. These results can be of great importance in setting standard values for the understanding of morphological and functional correlations.