Institution
University of Electro-Communications
Education•Tokyo, Japan•
About: University of Electro-Communications is a education organization based out in Tokyo, Japan. It is known for research contribution in the topics: Laser & Robot. The organization has 8041 authors who have published 16950 publications receiving 235832 citations. The organization is also known as: UEC & Denki-Tsūshin Daigaku.
Topics: Laser, Robot, Fiber laser, Mobile robot, Control theory
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TL;DR: In this paper, the authors studied the dynamics of O+ ions during the superstorm that occurred on 29-31 October 2003, using energetic (9-210 keV/e) ion flux data obtained by the energetic particle and ion composition (EPIC) instrument on board the Geotail satellite and neutral atom data in the energy range of 10 eV to a few keV acquired by the low-energy neutral atom (LENA) imager on board IMAGE satellite.
Abstract: [1] We studied dynamics of O+ ions during the superstorm that occurred on 29–31 October 2003, using energetic (9–210 keV/e) ion flux data obtained by the energetic particle and ion composition (EPIC) instrument on board the Geotail satellite and neutral atom data in the energy range of 10 eV to a few keV acquired by the low-energy neutral atom (LENA) imager on board the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) satellite. Since the low-energy neutral atoms are created from the outflowing ionospheric ions by the charge exchange process, we could examine variations of ionospheric ion outflow with the IMAGE/LENA data. In the near-Earth plasma sheet of XGSM ∼ −6 RE to −8.5 RE, we found that the H+ energy density showed no distinctive differences between the superstorm and quiet intervals (1–10 keV cm−3), while the O+ energy density increased from 0.05–3 keV cm−3 during the quiet intervals to ∼100 keV cm−3 during the superstorm. The O+/H+ energy density ratio reached 10–20 near the storm maximum, which is the largest ratio in the near-Earth plasma sheet ever observed by Geotail, indicating more than 90% of O+ in the total energy density. We argued that such extreme increase of the O+/H+ energy density ratio during the October 2003 superstorm was due to mass-dependent acceleration of ions by storm-time substorms as well as an additional supply of O+ ions from the ionosphere to the plasma sheet. We compared the ion composition between the ring current and the near-Earth plasma sheet reported by previous studies and found that they are rather similar. On the basis of the similarity, we estimated that the ring current had the O+/H+ energy density ratio as large as 10–20 for the October 2003 superstorm.
83 citations
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Nagoya University1, Kanazawa University2, Kyoto University3, National Institute of Information and Communications Technology4, National Institute of Polar Research5, Japan Aerospace Exploration Agency6, Tohoku University7, Osaka Electro-Communication University8, Aichi University9, University of Tokyo10, University of Electro-Communications11, Athabasca University12, Virginia Tech13, Augsburg College14, University of Oulu15, Finnish Meteorological Institute16, Russian Academy of Sciences17, University of Alaska Fairbanks18
TL;DR: The PWING project as mentioned in this paper has been carried out since April 2016 to provide the global distribution and quantitative evaluation of the dynamical variation of these plasmas and waves in the inner magnetosphere.
Abstract: The plasmas (electrons and ions) in the inner magnetosphere have wide energy ranges from electron volts to mega-electron volts (MeV). These plasmas rotate around the Earth longitudinally due to the gradient and curvature of the geomagnetic field and by the co-rotation motion with timescales from several tens of hours to less than 10 min. They interact with plasma waves at frequencies of mHz to kHz mainly in the equatorial plane of the magnetosphere, obtain energies up to MeV, and are lost into the ionosphere. In order to provide the global distribution and quantitative evaluation of the dynamical variation of these plasmas and waves in the inner magnetosphere, the PWING project (study of dynamical variation of particles and waves in the inner magnetosphere using ground-based network observations, http://www.isee.nagoya-u.ac.jp/dimr/PWING/
) has been carried out since April 2016. This paper describes the stations and instrumentation of the PWING project. We operate all-sky airglow/aurora imagers, 64-Hz sampling induction magnetometers, 40-kHz sampling loop antennas, and 64-Hz sampling riometers at eight stations at subauroral latitudes (~ 60° geomagnetic latitude) in the northern hemisphere, as well as 100-Hz sampling EMCCD cameras at three stations. These stations are distributed longitudinally in Canada, Iceland, Finland, Russia, and Alaska to obtain the longitudinal distribution of plasmas and waves in the inner magnetosphere. This PWING longitudinal network has been developed as a part of the ERG (Arase)-ground coordinated observation network. The ERG (Arase) satellite was launched on December 20, 2016, and has been in full operation since March 2017. We will combine these ground network observations with the ERG (Arase) satellite and global modeling studies. These comprehensive datasets will contribute to the investigation of dynamical variation of particles and waves in the inner magnetosphere, which is one of the most important research topics in recent space physics, and the outcome of our research will improve safe and secure use of geospace around the Earth.
83 citations
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TL;DR: In this article, three types of bimetallic Pt nanoparticles with different core-shell structures besides Pt and Pd nanoparticles were synthesized by coreduction and sequential reduction methods in ethylene glycol.
Abstract: Three types of bimetallic Pt–Pd nanoparticles with different core–shell structures besides Pt and Pd nanoparticles were synthesized by coreduction and sequential reduction methods in ethylene glycol. The synthesized nanoparticles were supported on carbon to prepare five different electrocatalysts Pt/C, Pd/C, PdPt alloy/C, Pd(core)–Pt(shell)/C, and Pt(core)–Pd(shell)/C for oxygen reduction reaction (ORR) in fuel cells. The nanoparticles and supported catalysts were characterized by means of transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), extended X-ray absorption fine structure (EXAFS), and cyclic voltammetry (CV). It was proposed by these characterizations that the PdPt alloy/C, Pd(core)–Pt(shell)/C, and Pt(core)–Pd(shell)/C catalysts constituted Pd4Pt1(core)–Pt(two-layers shell), Pd (core)–Pd2Pt1(three-layers)–Pt(three-layers shell), and Pt(core)–Pt2Pd1(two-layers)–Pd (microcrystal shell), respectively. The Pt surface-enriched catal...
82 citations
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TL;DR: In this paper, the authors used simultaneous ground-based, all-sky camera observations from a geomagnetically conjugate Iceland-Syowa Station pair to demonstrate that the auroral beads, whose wavelength is ∼30-50 km, evolve synchronously in the northern and southern hemispheres and have remarkable interhemispheric similarities.
Abstract: [1] Auroral beads, i.e., azimuthally arrayed bright spots resembling a pearl necklace, have recently drawn attention as a possible precursor of auroral substorms. We used simultaneous, ground-based, all-sky camera observations from a geomagnetically conjugate Iceland-Syowa Station pair to demonstrate that the auroral beads, whose wavelength is ∼30–50 km, evolve synchronously in the northern and southern hemispheres and have remarkable interhemispheric similarities. In both hemispheres: 1) they appeared almost at the same time; 2) their longitudinal wave number was similar ∼300–400, corresponding bead separation being ∼1° in longitude; 3) they started developing into a larger scale spiral form at the same time; 4) their propagation speeds and their temporal evolution were almost identical. These interhemispheric similarities provide strong evidence that there is a common driver in the magnetotail equatorial region that controls the major temporal evolution of the auroral beads; thus, the magnetosphere plays a primary role in structuring the initial brightening arc in this scale size.
82 citations
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TL;DR: In this paper, the use of Raman spectroscopy to elucidate the vibrational and electronic structure of single wall carbon nanotubes is reviewed and the special role played by single nanotube spectroscopic techniques in the structural characterization of individual carbon-nanotubes and in the elucidation of the spectra of nanotub bundles is emphasized.
Abstract: The use of Raman spectroscopy to elucidate the vibrational and electronic structure of single wall carbon nanotubes is reviewed. The special role played by single nanotube spectroscopy in the (n,m) structural characterization of individual nanotubes and in the elucidation of the spectra of nanotube bundles is emphasized.
82 citations
Authors
Showing all 8079 results
Name | H-index | Papers | Citations |
---|---|---|---|
Mildred S. Dresselhaus | 136 | 762 | 112525 |
Matthew Nguyen | 131 | 1291 | 84346 |
Juan Bisquert | 107 | 450 | 46267 |
Dapeng Yu | 94 | 745 | 33613 |
Riichiro Saito | 91 | 502 | 48869 |
Shun-ichi Amari | 90 | 495 | 40383 |
Shigeru Nagase | 76 | 617 | 22099 |
Ingrid Verbauwhede | 72 | 575 | 21110 |
Satoshi Hasegawa | 69 | 708 | 22153 |
Yu Qiao | 69 | 484 | 29922 |
Yukio Tanaka | 68 | 744 | 19942 |
Zhijun Li | 68 | 614 | 14518 |
Iván Mora-Seró | 67 | 235 | 23229 |
Kazuo Tanaka | 63 | 535 | 27559 |
Da Xing | 63 | 624 | 14766 |