19 resultados para 506
em Cambridge University Engineering Department Publications Database
Resumo:
The fabrication of carbon nanomaterials usually calls for expensive vacuum systems to generate plasmas and yields are disappointingly low. Here we describe a simple method for producing high-quality spherical carbon nano-'onions' in large quantities without the use of vacuum equipment. The nanoparticles, which have C60 cores surrounded by onion-like nested particles, are generated by an arc discharge between two graphite electrodes submerged in water. This technique is economical and environmentally benign, and produces uncontaminated nanoparticles which may be useful in many applications.
Field emission properties of self-assembled silicon nanostructures formed by electron beam annealing
Resumo:
In this article, we develop a new Rao-Blackwellized Monte Carlo smoothing algorithm for conditionally linear Gaussian models. The algorithm is based on the forward-filtering backward-simulation Monte Carlo smoother concept and performs the backward simulation directly in the marginal space of the non-Gaussian state component while treating the linear part analytically. Unlike the previously proposed backward-simulation based Rao-Blackwellized smoothing approaches, it does not require sampling of the Gaussian state component and is also able to overcome certain normalization problems of two-filter smoother based approaches. The performance of the algorithm is illustrated in a simulated application. © 2012 IFAC.
Resumo:
We demonstrate a dual-wavelength, carbon nanotube mode-locked Er fiber laser. The laser outputs two wavelengths at 1549nm and 1562nm, and each wavelength corresponds to pulse duration of ∼1.3ps and repetition rate of ∼11.27MHz. © 2012 IEEE.