RESUMO
We report the formation of silicon and carbon hetero-nanostructures in an inductively coupled plasma system by a simultaneous growth/etching mechanism. Multi-walled carbon nanotubes were grown during one, three and five hour depositions, while tapered silicon nanowires were progressively etched. The carbon and silicon nanostructures and the interfaces between them were studied by electron microscopies and micro Raman spectroscopies. The potential of this method for large-scale controlled production of nano heterostructures without the requirement of a common catalyst is explored.
Assuntos
Carbono/química , Nanotecnologia/métodos , Silício/química , Catálise , Elétrons , Vidro , Teste de Materiais , Microscopia Eletrônica , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Nanoestruturas , Análise Espectral Raman/métodos , Propriedades de Superfície , Difração de Raios XRESUMO
We report the successful use of continuous wavelet transforms applied to atomic force microscope data sets for landmark recognition of biological features. The data sets were images of mixed red and white blood cells. Contrast enhancement followed by continuous wavelet transform of the data was used to successfully distinguish erythrocytes from neutrophil and monocyte leukocytes within the mixed cell images. All of the above are spherical objects between 6 and 8 microns in diameter, which demonstrates the ability to sort similar biological objects into distinct classes. The implications for development of on-line scanning probe recognition microscopy are discussed.
Assuntos
Algoritmos , Inteligência Artificial , Eritrócitos/ultraestrutura , Interpretação de Imagem Assistida por Computador/métodos , Leucócitos/ultraestrutura , Microscopia de Varredura por Sonda/métodos , Reconhecimento Automatizado de Padrão , Animais , Movimento Celular/fisiologia , Células Cultivadas , Técnicas de Cocultura , Eritrócitos/classificação , Eritrócitos/fisiologia , Leucócitos/classificação , Leucócitos/fisiologia , Masculino , Microscopia de Força Atômica/métodos , Ratos , Ratos WistarRESUMO
In this paper, the internal structure of novel multiphase gallium nitride nanowires in which multiple zinc-blende and wurtzite crystalline domains grow simultaneously along the entire length of the nanowire is investigated. Orientation relationships within the multiphase nanowires are identified using high-resolution transmission electron microscopy of nanowire cross-sections fabricated with a focused ion beam system. A coherent interface between the zinc-blende and wurtzite phases is identified. A mechanism for catalyst-free vapor-solid multiphase nanowire nucleation and growth is proposed.