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Minoru Itoh

Publications and source records attributed to Minoru Itoh.

6 recordsLinked to original sources
PubMed2006

Infrared absorption change in single-walled carbon nanotubes observed by combination spectroscopy of synchrotron radiation and laser.

The Drude tail due to photo-excited carriers in single-walled carbon nanotubes (SWNTs) has been observed in the mid-infrared region by using combination spectroscopy of synchrotron radiation and Ti:sapphire laser. It is found that the density of photo-excited carriers increases as the sample temperature is raised from 12 to 300 K, and their lifetime is of the order of minutes at 300 K. These facts suggest that the movement of photo-excited carriers is largely affected by some extrinsic defect, thus resulting in the long-lasting Drude reflection in SWNTs.

Absorption↗
PubMed2005

Two-photon spectroscopy of core excitons in barium fluoride using synchrotron radiation and laser light.

We have conducted two-photon spectroscopy of core excitons in BaF(2). Synchrotron radiation and laser light were used for 5p core-electron excitation and Auger-free luminescence was detected as the signal. Two-photon excitation enables access to f and p orbitals that cannot be reached by one-photon excitation of electrons in p orbitals. It has been found that the spin-orbit splittings of 4f and 6p states of the Ba ion in BaF(2) are 0.7 +/- 0.1 and 1.4 +/- 0.1 eV, respectively.

Journal Article↗
PubMed2004

Self-assembly patterning of colloidal crystals constructed from opal structure or NaCl structure.

We developed a novel self-assembly process to fabricate an orderly array of particle wires constructed from a close-packed colloidal crystal without preparation of patterned templates. A substrate was immersed vertically into a SiO2 colloidal solution, and the liquid surface moved downward upon evaporation of solution. Particles formed a mono-/multiparticle layer, which was cut by the periodic drop-off of solution. The orderly array of particle wires was successfully fabricated, showing the suitability of the self-assembly process for the fabrication of nano-/microstructures constructed from nano-/microparticles or blocks. The mechanism of the assembly process and control of thickness, width, and interval of particle wires were further discussed. Moreover, an array of particle wires constructed not from close-packed face-centered cubic (or hexagonal close packed) structure but from two kinds of particles was realized to fabricate an array of particle wires with NaCl structure by this self-assembly process.

Journal Article↗
PubMed2003

Time-resolved Auger decay in CsBr using high harmonics.

The temperature-dependent decay dynamics of innershell holes in CsBr was measured by using high harmonics. The measured lifetime was as short as 1.5 ps at 340 K due to increasing the Auger-allowed final state density in the Urbach exciton tail, whereas it is 1.1 ns at 10 K, determined by radiative recombination. The temperature-dependent Auger lifetime extrapolated to a high temperature corresponds to the fully energy-allowed Auger decay. In the model to be presented, this yields an interatomic Auger decay lifetime of 2.4+3.8/-1.5 fs, in line with a theoretical calculation for NaF.

Journal Article↗
PubMed2002

Effects of running exercise with increasing loads on tibialis anterior muscle fibres in mice.

Cross-sectional areas and succinate dehydrogenase (SDH) activities of type identified fibres in the deep, middle and superficial regions of the tibialis anterior muscle in mice were examined after 4 weeks of voluntary running exercise with increasing loads. Nineteen-week-old male mice were assigned randomly to either a control or exercise group. The mean cross-sectional areas of all types (IIa, IIx and IIb) of fibres in the superficial region of the muscle were greater in the exercise group than in the control group. The mean SDH activities of type IIx and type IIb fibres in the middle region and of all types (IIa, IIx and IIb) of fibres in the superficial region of the muscle were greater in the exercise group than in the control group. These results suggest that voluntary running exercise with increasing loads causes hypertrophy and/or an increase in the SDH activity of fibres in the specific muscle region where fibres with a high threshold and a low-oxidative enzyme activity are distributed, and these fibres are recruited to adapt to changes in exercise conditions.

Animals↗