There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

THE large-scale use of photovoltaic devices for electricity generation is prohibitively expensive at present: generation from existing commercial devices costs about ten times more than conventional methods1. Here we describe a photovoltaic cell, created from low-to medium-purity materials through low-cost processes, which exhibits a commercially realistic energy-conversion efficiency. The device is based on a 10-µm-thick, optically transparent film of titanium dioxide particles a few nanometres in size, coated with a monolayer of a charge-transfer dye to sensitize the film for light harvesting. Because of the high surface area of the semiconductor film and the ideal spectral characteristics of the dye, the device harvests a high proportion of the incident solar energy flux (46%) and shows exceptionally high efficiencies for the conversion of incident photons to electrical current (more than 80%). The overall light-to-electric energy conversion yield is 7.1-7.9% in simulated solar light and 12% in diffuse daylight. The large current densities (greater than 12 mA cm-2) and exceptional stability (sustaining at least five million turnovers without decomposition), as well as the low cost, make practical applications feasible.

A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films

To use solar irradiation or interior lighting efficiently, we sought a photocatalyst with high reactivity under visible light. Films and powders of TiO 2- x N x have revealed an improvement over titanium dioxide (TiO 2 ) under visible light (wavelength 2 has proven to be indispensable for band-gap narrowing and photocatalytic activity, as assessed by first-principles calculations and x-ray photoemission spectroscopy.

/pdf/visible-light-photocatalysis-in-nitrogen-doped-titanium-np6nklr9gh.pdf

Visible-Light Photocatalysis in Nitrogen-Doped Titanium Oxides

Titanium Dioxide Nanomaterials: Synthesis, Properties, Modifications, and Applications

Ammonium ions were formed by electrochemical oxidation of urea with a boron-doped diamond (BDD) electrode. Almost complete decomposition of urea was achieved. When the BDD electrode was used together with a mesoporous titanium dioxide photocatalyst, the amount of ammonium ions produced increased.

/pdf/formation-of-ammonium-ions-by-electrochemical-oxidation-of-3zptbziubd.pdf

Formation of ammonium ions by electrochemical oxidation of urea with a boron-doped diamond electrode

We have prepared yttrium (Y)-doped hydrogen titanate nanorods (HTN) by a microwave-assisted hydrothermal method. Y-doped HTN showed much improved photocatalytic activities for both H2 evolution and...

One-Pot Synthesis of Anatase, Rutile-Decorated Hydrogen Titanate Nanorods by Yttrium Doping for Solar H2 Production

Fabrication of a Nanostructured Diamond Honeycomb Film.

Boron-doped diamond (BDD) electrodes were used to investigate the possibility of detecting N-hydroxysuccinimide (NHS) by linear sweep anodic voltammetry. By increasing the pH the peak potential corresponding to NHS oxidation gradually decreases, suggesting that the electroactive species are the deprotonated ones. An exponential enhancement of the peak current with increasing pH was also observed, indicating that the overall process involves OH--mediated regeneration of these species. The sweep rate effect, together with digital simulation, allowed ascribing the anodic peak to a mechanism consisting of a slow uptake of an electron from the deprotonated NHS species, followed by their catalytic regeneration through a fast chemical reaction. It was also found that in alkaline media the voltammetric response is suitable for analytical applications. A method was proposed for the determination of NHS in the concentration range 5 μM to 10 mM. The good analytical performance characteristics and the wide dynamic range of analytically useful response are also meaningful as they might come in useful in providing a basis for new, electrochemical, approaches for NHS quantification.

Voltammetric determination of N-hydroxysuccinimide at conductive diamond electrodes

PROBLEM TO BE SOLVED: To provide a negative electrode for stationary energy storage that has functions as a secondary battery and an electric double-layer capacitor and can set output density and energy density freely. SOLUTION: The electrode has a conductive substrate; and a conductive material that is carried on the surface of the conductive substrate, and has a gap capable of incarnation of anode ions in an electrolyte and a gap capable of bringing the conductive substrate into contact with the electrolyte. Even if a negative voltage for causing incarnation of the anode ions in the conductive material is applied to the electrode in the electrolyte, charge is accumulated without causing incarnation of the anode ions in the conductive substrate. COPYRIGHT: (C)2006,JPO&NCIPI

Akira Fujishima

Papers

Formation of ammonium ions by electrochemical oxidation of urea with a boron-doped diamond electrode

One-Pot Synthesis of Anatase, Rutile-Decorated Hydrogen Titanate Nanorods by Yttrium Doping for Solar H2 Production

Fabrication of a Nanostructured Diamond Honeycomb Film.

Voltammetric determination of N-hydroxysuccinimide at conductive diamond electrodes

Electrode for stationary energy storage, stationary energy storage, and stationary energy storage method