A5043208579- Earthquake Detection and Analysis
- Chalcogenide Semiconductor Thin Films
- Seismic Waves and Analysis
- earthquake and tectonic studies
- Ionosphere and magnetosphere dynamics
- Geomagnetism and Paleomagnetism Studies
- Geophysical and Geoelectrical Methods
- Phase-change materials and chalcogenides
- Seismology and Earthquake Studies
- Semiconductor materials and interfaces
- Thermography and Photoacoustic Techniques
- Geophysics and Gravity Measurements
- GNSS positioning and interference
- Geophysical Methods and Applications
- Silicon and Solar Cell Technologies
- Quantum Dots Synthesis And Properties
- Solid-state spectroscopy and crystallography
- Semiconductor materials and devices
- Advanced Semiconductor Detectors and Materials
- Crystal Structures and Properties
- High-pressure geophysics and materials
- Silicon Nanostructures and Photoluminescence
- Solar and Space Plasma Dynamics
- Optical and Acousto-Optic Technologies
- Nonlinear Optical Materials Studies
The University of Tokyo
2000-2024
Association for the Development of Earthquake Prediction
2004-2024
Earthquake Engineering Research Institute
2015-2020
Nihon University
2006
University of Tsukuba
1980-1998
Japan Atomic Energy Agency
1998
Fujitsu (Japan)
1987-1991
Earth Science Institute of the Slovak Academy of Sciences
1983
Kyoto University
1983
Osaka Kyoiku University
1970-1974
Correlated magnetic noise from Schumann resonances threatens to contaminate the observation of a stochastic gravitational-wave background in interferometric detectors. In previous work, we reported on first effort eliminate global correlated using Wiener filtering, demonstrating as much factor two reduction coherence between magnetometers different continents. this present results dedicated magnetometer measurements at Virgo and KAGRA sites, which are for subtraction data detector sites. We...
Abstract Intraplate earthquakes occur more frequently in the Japanese islands than other regions. Large intraplate island arc preferentially strain concentration zones detected by geological and geodetic studies. Crustal heterogeneity plays a crucial role generating large concentrations. Thus, we elucidated crustal heterogeneities beneath area on back‐arc side of northeastern Japan Arc based electrical resistivity, which is sensitive to weak crust. By deploying wideband magnetotelluric...
Triaxial deformation experiments were performed to compare electromagnetic emissions (EMEs) from dry and wet granite specimens associated with acoustic (AEs). Cylindrical of initially intact tested at room temperature. We measured both high‐frequency (10 kHz 1 MHz) low‐frequency (DC 500 Hz) components the electric potential variations. In general, it is difficult detect EMEs in conditions because rock has very short relaxation time, which proportional its resistivity. However, experiment...
The previous model for the low-energy anharmonic excitation of interstitial oxygen in silicon [D. R. Bosomworth, W. Hayes, A. L. Spray, and G. D. Watkins, Proc. Soc. London, Ser. A 317, 133 (1970)] is expanded so that coupling to local phonon included. result calculation explains previously observed absorption peaks $^{16}\mathrm{O}$ $^{18}\mathrm{O}$ 30-, 1100-, 1200-${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ bands, confirming energy-level scheme transition assignment Bosomworth et al....
Change in the electronic state due to size confinement was studied for CdS cluster embedded GeO 2 glass by photoacoustic, optical absorption and photoluminescence spectroscopies. The increases with increasing annealing temperature time. activation energy of ion diffusion during growth is 0.45 eV. When becomes less than about twice exciton size, bands become discrete. energies 1st 2nd excited states increase decreasing size. dependence ist determined experimentally coincides calculation....
Some size effects of the relaxation mechanism optically excited electrons in CdS fine particles were investigated by means photoacoustic and luminescence spectroscopies. The intensity green (∼2.47 eV) decreased its peak position shifted to lower-energy side upon decreasing particle size. impurity which appears longer-wavelength region, red emission (∼1.7 eV), did not vary as much ∼40 nm diameter. absorption spectrum intrinsic energy region for a small-size particle, was determined from...
Abstract Effects of the initial concentration and amount fraction on molecular weight distribution (mol. wt. distr.) were examined atactic polystyrene in methylcyclohexane. The phase separation was caused by lowering temperature dilute solution. A constant (about 1/9 total polymer dissolved) first precipitated from solutions various concentrations ranging 0.1 to 2.0%. In addition, varied 1/2 1/5 for (1.0 2.0%). mol. distr. thus obtained determined gel permeation chromatography. It is...
Phase diagrams for the CaO-SiO2-FeOx-Al2O3 or -MgO systems at various oxygen partial pressures are necessary design of raw material ironmaking, analysis smelting reaction and sintering process. To clarify effect Al2O3 MgO content on formation melts in process is important development new sinter. In this study, liquidus were observed 1 573 K by using chemical equilibration technique. The liquid phase area changed with adding MgO. Fe3+/Fe2+ ratio melting mechanism discussed.
A resistivity section based on magnetotelluric data was obtained for the Shonai Plain fault in northeastern Honshu, Japan. Faults this area were created as normal faults during opening of Japan Sea Miocene but are now reactivated high‐angle reverse under compressional tectonics. Geological interpretations support proposed reactivation. An estimated east‐dipping conductor along a deep part system probably represents fluid‐rich zone around zone. The high 3 He/ 4 He ratio near indicates...
This paper presents acase study of Electromagnetic (EM) signals associated with earthquakes due to the piezoelectricity crustal rocks. For a simple model structure subsurface piezoelectric body, mathematical expression was obtained that describes behavior EM incidence teleseismic body wave. Using this expression, we evaluated expected physical parameters reasonable for Results frequency domain analysis suggested intensity signal decreases decreasing stress rate at lower frequencies, and...
The effects of germanium doping on the 30-, 1100-, and 1200-${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ bands Si-O-Si were investigated. centers, perturbed by nearby Ge atoms, caused absorptions at largely shifted positions in each band. oscillator strengths peak separations between 1100-${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ reduced from corresponding unperturbed ones. Our previously obtained model consistently explains both energies these absorptions. oscillator-strength peak-separation...
Abstract On 25 March 2007, a damaging earthquake ( M j 6.9) occurred near the west coast of Noto Peninsula, Central Japan. A wideband magnetotelluric (MT) survey was carried out in onshore area source region immediately after mainshock, with aim imaging heterogeneity crustal resistivity structure. The final observation network had consisted 26 sites. As preparatory step for three-dimensional features around focal region, we constructed two-dimensional models along five profiles using only TM...
We optimized Ge+ and Si+ preimplantation to eliminate the channeling tail prevent rapid diffusion of boron formation serious defects. examined dependence microchanneling BF+2 implantation or lattice disorder preimplanted silicon using secondary-ion mass spectroscopy grazing exit Rutherford backscattering spectroscopy. The optimum doses are about 25% those for full amorphization, i.e., preamorphization. is eliminated by disordered layers containing 60% atoms on irregular sites.
The infrared reflectivity spectra have been observed for sintered MCr 2 S 4 (M=Zn, Cd, Hg) near normal incidence in the range from 30 to 900cm -1 . effective charges of Cr and ions are determined frequencies transverse longitudinal modes within small error. Szigetieffective e s * per valency Z eff anions show correlation with low frequency electronic dielectric constant ε ∞ which has established selenide oxide spinels expressed as -1=2.0/(( / )+( ) ). By using this empirical relationship,...
Abstract The Network-Magnetotelluric (NMT) method is well-suited for investigating deep and large-scale conductivity structure; however, application of the strongly dependent on availability telecommunication facilities (specifically, metallic transmission cables). To overcome problem posed by progressive replacement cables with fiber cables, we developed a modified NMT (modified NMT) consisting purpose-built electrodes, making use local lines, without cable. We first applied this over Kii...
逐次分別沈殿法による重合度分別のシミュレーションな電子計算機な用いて実施した。現在までに発表されているこの種の研究では, 希薄相と濃厚相の体積比 (R) とこれら2相への高分子の分配率のパラメーター (σ) は各々独立変数であると仮定しているが, この仮定は厳密には理論的に誤りである。そこで, 本論文ではFlory-Hugginsの相平衡理論を基礎にしてRとσ との相関関係な考慮して逐次分別沈殿法による重合度分別の計算な行なった。原試料の重合度分布として最も確からしい分布 (most probable distribution) な仮定し, これを等重量の15区分に分別した。分別区分はほぼ左右対称の重合度分布なもち, Schulz-Zimm型分布よりむしろ正規分布で精度よく近似できた。第1区分を含めて低次の分別区分はかなり低重合度領域まで裾 (すそ) を引く分布をもつが, いわゆるすそ効果は第1区分だけに見られる特異性ではない。この場合, 分別区分の重合度と重量を利用してSchulzの方法に従って原試料の重合度分布を評価したが,...
Abstract An attempt has been made to study the following refractionation method proposed by K AMIDE and his coworkers: The first fraction precipitated from a solution of comparatively high initial concentration is divided into several subfractions. polymer‐lean phase obtained in last stage returned that fractionation step. As above described, followed repeated adequate times. Taking F LORY ‐H UGGINS theory as basic principle, hypothetical refractionations were performed an electronic...
Abstract The Atotsugawa fault is one of the most active faults in Japan, and strain accumulation at considered to be caused by an aseismic shear zone fluid‐rich lower crust. To identify investigate origin aqueous fluid crust, we deployed a Network‐MT survey addition conventional wideband‐MT around performed inversion combining both MT data sets. In inversion, modifying algorism, accurately represented kilometer‐scale dipoles measurement provide constraints on electrical resistivity...
A single crystal of MgIn 2 S 4 was grown by Bridgman method. The structure the measured powdered X-ray diffractometer. By comparison integrated diffraction intensity between experimental and calculated, partially inverse best fit to experimental. fundamental absorption edge is positioned at 2.14 eV. using interference fringes thin sample prism method, accurate dispersion curve obtained over wavelength range 2.5–16µ. Five vibrational modes were observed in lattice vibration spectrum. High...
Abstract In order to examine the method of fractionation into summative fractions proposed by S PENCER , a complete mathematical was carried out using an electronic computer according procedure K AMIDE O GAWA and their coworkers. Various amounts precipitates were separated from 1.0% solution polymer having most probable size distribution with number‐average degree polymerization (P)X̄ = 150. The theory FLORY HUGGINS employed as principle basis fractionation. data obtained in this manner...
Temperature dependence of absorption, photoacoustic(PA), photoluminescence excitation(PLE) and photoluminescence(PL) spectra were measured for filter glasses which include sulfur-rich CdS x Se 1- microcrystals. Absolute quantum efficiency radiative recombination was obtained by comparing photoacoustic with spectra. Quantum small microcrystals is found to be higher than that large By solving the rate equations, very band-to-band nonradiative transition suggested in these We regarded this as...
Infrared reflection spectra of InS single crystals are observed in the wavenumber range between 50 and 900 cm -1 for each polarization c -plane. The vibrational frequencies longitudinal (ω L ) transverse T modes determined by Kramers-Kronig analyses as follows: ω =309 =217 E // a , =110, 236, 322, =104, 196, 296 b polarizations. Almost same obtained from fitting procedure using classical oscillator model. It is confirmed that dispersion parameters more explicit values than those previous...