No abstract

Nanogranular films and lines, which are composed of size-selected Au, Ni, and Pt nanoparticles (NPs) and which exhibit an intermediate structure between that of the individual NPs and that of polycrystalline ones, were produced by a fully physical process. By using a combination of techniques such as lithography, lift-off, size selection, and aerosol deposition, well-designed Au lines (linewidth W=80 nm) and thickness-controlled rectangular patterns could be produced, while Ni and Pt NPs did not form continuous lines if the linewidth was less than W=150 nm. This difference might be explained by the extent of collision-induced surface melting during NP deposition onto the substrate.

Increased amounts of secondary copper resources with higher levels of impurities are being fed to copper smelters. To avoid passivation problems, low-grade copper that is derived from secondary resources is dissolved in sulfuric-acid solution, and the dissolved copper is recovered by electrowinning. Electrowinning is disadvantageous because of its higher power consumption compared with electrorefining. Based on an electroplating technique that uses basket electrolysis with a ball-shaped anode and another experimental approach of copper-scrap electrorefining in a basket, we investigated an electrorefining method that uses small low-grade copper shots (diameter of several millimeters) as an anode. It is expected that the copper-dissolution ratio will be higher, even with a small elution depth, because of the small primary-anode size and the effect of the three-dimensional shape. In addition, the current density for a shot-shaped anode can be lower than that for a plate-shaped anode at the same current and for the same occupied area, and would result in the inhibition of passivation. Rotating-disk-electrode equipment was used in the electrolysis experiments. Single-layered copper shots that contained 0.9 « 0.2 mass% Pt (18 shots) in a platinum basket were used as an anode, and a copper rotating-disk electrode (7-mm diameter) was used as a cathode. The temporal changes in anode potential were measured at a constant current to investigate the electrolytic properties of a small shot-shaped anode during the electrorefining experiments. The current efficiency and final anode-dissolution ratio exceeded 90% up to an initial anode current density of ³673 A/m 2. Stable electrolysis could be carried out with a copper shot-shaped anode that contained high levels of platinum.

We have used time-resolved imaging to examine the effect of incident radiation wavelength in the range 2.75–3.75 μm on the shattering of water microdroplets by single and dual lasers. Dye sensitization of microdroplets was induced by using the water-soluble dye sulforhodamine G; this enabled us to observe both the forward and backward components of fragmented droplets and splashes. Compared with employing a single IR laser, simultaneous illumination by two IR lasers can effectively compress the spatial distribution of small fragments around the absorption maximum for the OH-stretching vibration of liquid water (

No abstract