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The novel fabrication of multi-walled carbon nanotube (MWCNT)/cementite (Fe3C) nanocomposites was demonstrated via the calciothermic reduction of carbon dioxide (CO2) through electrolysis in molten CaCl2/CaO with iron additives at 1173 K. In this technique, CO2 generated from a graphite anode is reduced to carbon with a metallic calcium reductant formed on a graphite cathode via electrolysis in molten salt. Calciothermic reduction without iron additives resulted in the formation of onion-like carbons (OLCs) with spherical graphite layers and thin graphite sheets. In contrast, MWCNT/Fe3C nanocomposites and OLCs were successfully fabricated via calciothermic reduction with iron additives through their catalytic activities

We demonstrate the efficient coupling (99.5%) of a silica whispering gallery mode microresonator directly with a silicon chip by using a silicon photonic crystal waveguide as a coupler. The efficient coupling is attributed to the small effective refractive index difference between the two devices. The large group index of the photonic crystal waveguide mode also contributes to the efficient coupling. A coupling Q of 2.68×10 6 is obtained, which allows us to achieve the critical coupling of a silica whispering gallery mode with an intrinsic Q of close to 10 7 with a Si chip.

It is a common view that ballistic transport is enhanced by channel length scaling because of a decreased scattering number. On the other hand, the acoustic phonon (AP) scattering rate is higher in silicon-on-insulator (SOI) MOSFETs than in bulk Si-MOSFETs; moreover, surface roughness (SR) scattering caused by spatial fluctuation of quantized subbands emerges in extremely scaled SOI channels. Therefore, the influences of these scattering mechanisms on ballistic transport in ultrathin-body Si-MOSFETs are examined in this paper using a Monte Carlo simulation technique. First of all, the effect of increased AP scattering rate on the drain current and ballistic efficiency is found to be negligible. Furthermore, contrary to the common view, ballistic transport in double-gate MOSFETs is shown to be degraded when the channel length decreases to less than 10 nm, mainly owing to SR scattering intensified by the spatial fluctuation of quantized subbands. The gate and drain bias voltage dependencies of ballistic efficiency are also discussed.