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Spectroscopic Determination of C,N,and O Abundances of Solar-analog Stars Based on the Lines of Hydride Molecules

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Research in Astronomy and Astrophysics 2023年第2期23卷 107-120页

作者： yoichi Takeda 11-2 Enomachi Naka-kuHiroshima-shi730-0851Japan

Photospheric C,N,and O abundances of 118 solar-analog stars were determined by applying the synthetic-fitting analysis to their spectra in the blue or near-UV region comprising lines of CH,NH,and OH molecules,with an aim of clarifying the behaviors of these abundances in comparison with[Fe/H].It turned out that,in the range of-0.6■[Fe/H]■+0.3,[C/Fe]shows a marginally increasing tendency with decreasing[Fe/H]with a slight upturn around[Fe/H]~0,[N/Fe]tends to somewhat decrease toward lower[Fe/H],and[O/Fe]systematically increases (and thus[C/O]decreases) with a decrease in[Fe/H].While these results are qualitatively consistent with previous determinations mostly based on atomic lines,the distribution centers of these[C/Fe],[N/Fe],and[O/Fe]at the near-solar metallicity are slightly negative by several hundredths of dex,which is interpreted as due to unusual solar abundances possibly related to the planetary formation of our solar ***,clear anomalies are not observed in the[C,N,O/Fe]ratios of planet-host *** out of four very Be-deficient stars were found to show anomalous[C/Fe]or[N/Fe]which may be due to mass transfer from the evolved companion,though its relation to the Be depletion mechanism is still unclear.

关键词： Galaxy evolution-planet-star interactions-stars abundances-stars atmospheres-stars solar-type

Measurements of the Ca II infrared triplet lines of young stellar objects

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Research in Astronomy and Astrophysics 2013年第10期13卷 1189-1201页

作者： yoichi Itoh Keiko Moto'oka yoichi Itoh The Saga Prefecture Space & Science Museum 16351 Nagashima Takeo Takeo Saga 843-0021 Japan Nishi-Harima Astronomical Observatory Center for Astronomy University of Hyogo 407-2 Nishigaichi Sayo Hyogo 679-5313 Japan yitoh @nhao.jp

Equivalent widths and line widths of Ca II infrared triplet emission lines were measured in the high-resolution optical spectra of 39 young stellar *** found that the equivalent widths of the emission lines decrease with stellar *** has often been claimed that strong chromospheric activity is generated by a dynamo process caused by fast rotation of the ***,we found no clear correlation between the strength of the Ca II lines and the stellar rotation ***,we found that the objects with high mass accretion rates had stronger Ca II emission *** correlation supports the turbulent chromosphere model or the magnetic accretion theory for classical T Tauri *** also noticed that the equivalent widths of Ca II lines in transitional disk objects are one-tenth of those in classical T Tauri stars,even if the masses of the circumstellar disks are comparable.

关键词： stars:pre-main sequence stars:emission lines

Degradation behaviors of nonylphenol ethoxylates by isolated bacteria using improved isolation method

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Journal of Environmental Sciences 2008年第9期20卷 1025-1027页

作者： Hideyuki Tamaki yoichi Kamagata Institute for Biological Resources and Functions National Institute of Advanced Industrial Science and Technology

Nonylphenol ethoxylate (NPEO)-degrading bacteria were isolated from activated sludge using an improved isolation method, and the corresponding degradation behaviours were investigated. Eight NPEO-degrading strains distributed in genera Pseudomonas, Sphingomonas, Sphingobium, Cupriavidus, Ralstonia, Achromobacter, and Staphylococcus were acquired. The latter five genera have never been reported for the degradation of NPEOs. Four degradation patterns were observed for the eight pure strains. In pattern A, NPE...

关键词： nonylphenol ethoxylate (NPEO) biodegradation ssolation method

Cultivating the unseen:Lessons from James Tiedje

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mLife 2023年第3期2卷 217-223页

作者： yoichi Kamagata National Institute of Advanced and Industrial Science and Technology(AIST) TsukubaJapan

In recounting *** ***'s outstanding research achievements spanning the past 55 years,it is easy to overlook his early and mid-career ***,his contribution to the aerobic degradation of pesticides and other chemicals,as well as methanogenic degradation of those compounds retains their *** researchers in environmental microbiology have gained invaluable knowledge from these studies,which have been applied to the elucidation of previously uncultivated microorganisms.

关键词： cultivated gained pesticides

Numerical analysis of surface plasmons excited on a thin metal grating

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第1期7卷 55-70页

作者： OKUNO yoichi SUYAMA Taikei Graduate School of Science and Technology Kumamoto University Kumamoto 860-8555 Japan Department of Electrical and Computer Engineering Kumamoto University Kumamoto 860-8555 Japan

The authors numerically investigated the characteristics of surface plasmons excited on a thin metal grating placed in planer or conical mounting. After formulating the problem, the solution method, Yasuura＇s method （a modal expansion approach with least-squares boundary matching） was described. Although the grating is periodic in one direction, coupling between TE and TM waves Occurs because arbitrary incidence is assumed. This requires the employment of both TE and TM vector modal functions in the analysis. Numerical computations showed：（l） the excitation of surface plasmons with total or partial absorption of incident light; （2） the resonance character of the coefficient of an evanescent order that couples the plasmon surface wave; （3） the field profile and Poynting＇s vector. The plasmons excited on the surfaces of a thin metal grating are classified into three types： SISP, SRSP, and LRSP, different from each other in the feature of field profile and energy flow. In addition, the eigenvalue of a plasmon mode was obtained by solving a sequence of diffraction problems with complex-valued angles of incidence and using the quasi-Newton algorithm to predict the real angle of incidence at which the absorption occurs.

关键词： Thin metal grating Plasmon modes Resonance absorption Numerical analysis

Storage-efficient reconstruction framework for planar contours

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Geo-Spatial Information Science 2017年第1期20卷 14-28页

作者： Hiroyuki Goto yoichi Shimakawa Department of industrial and system engineering Hosei UniversitytokyoJapan Department of computer science and technology salesian polytechniquetokyoJapan

A storage-efficient reconstruction framework for cartographic planar contours is *** a smaller number of control points,we aim to calculate the area and perimeter as well as to reconstruct a smooth *** input data forms an oriented contour,each control point of which consists of three values:the Cartesian coordinates(x,y)and tangent angleθ.Two types of interpolation methods are developed,one of which is based on an arc spline while the other one is on a cubic Hermite *** arc spline-based method reconstructs a G1 continuous curve,with which the exact area and perimeter can be *** benefit of using the Hermite spline-based method is that it can achieve G2 continuity on most control points and can obtain the exact area,whereas the resulting perimeter is *** a numerical experiment for analytically defined curves,more accurate computation of the area and perimeter was achieved with a smaller number of control *** another experiment using a digital elevation model data,the reconstructed contours were smoother than those by a conventional method.

关键词： Oriented contour arc spline cubic Hermite spline geometric continuity storage efficient

High-Resolution Spectroscopy of Winds Associated with T Tauri Stars

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Research in Astronomy and Astrophysics 2016年第2期16卷 89-96页

作者： Naoto Iguchi yoichi Itoh Graduate School of Science Kobe University1-1 Rokkodai-choNada-kuKobeHyogo 657-8501Japan Nishi-Harima Astronomical Observatory Center for AstronomyUniversity of Hyogo407-2NishigaichiSayoHyogo 679-5313Japan

We carried out optical high-resolution spectroscopy of T Tauri stars using the Subaru Telescope. Using archived data from the Keck Telescope and the Very Large Telescope, we detected forbidden lines of [S II] at 4069A, in addition to those of [O I] at 5577 A and 6300A, for 13 T Tauri stars. We consider that low-velocity components of these forbidden lines emanate from the wind associated with T Tauri stars. Using two flux ratios of the three lines, we simultaneously determined the hydrogen density and temperature of the winds. The winds ofT Tauri stars have a hydrogen density of 2.5 × 106 cm^-3 - 2.5 × 10^9 cm^-3 and a temperature of 10 800 -18 000 K. The mass loss rates by the wind are estimated to lie in the range from 2.0 × 10^-10 M⊙ yr-1 to 1.4× 10^-9 M⊙ yr-1. The mass loss rates are found to increase with increasing mass accretion rates. The ratio of the mass loss rate to the mass accretion rate is 0.001-0.1 for classical T Tauri stars and 0.1-1 for transitional disk objects.

关键词： stars pre-main sequence -- stars emission lines

Unsteady Flow at Low Flow-rate Region in a Semi-open Propeller Fan (Velocity Fluctuation outside of Blade Tip)

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Journal of Thermal Science 2011年第3期20卷 218-223页

作者： Norimasa SHIOMI yoichi KINOUE Toshiaki SETOGUCHI Department of Mechanical Engineering Saga UniversityHonjo-machi 1Saga-shiSaga840-8502Japan

In order to clarify the unsteady flow fields at low flow-rate region with positive gradient on pressure-flow-rate curve,the experimental investigation was carried out at rotor inlet and outside of rotor blade tip without casing in a semi-opened propeller fan using a hot-wire anemometer.A single I-type hot-wire probe was used,and the data obtained were processed by the use of phase-locked averaging,ensemble averaging and FFT *** flow fields at rotor inlet and outside of rotor blade tip were discussed mainly using the results from distributions of velocity fluctuations and power spectrum *** was found from these results that there are the two types of different periodical fluctuations and both of those frequencies were not the same of rotor rotating frequency(RRF;15Hz).One was observed at relatively high flow-rate region at relatively downstream area in measurement and its frequency was approximately 7Hz(47% of RRF).The other was observed at relatively low flow-rate region at relatively upstream area in measurement and its frequency was approximately 10Hz(67% of RRF)".As the velocity fluctuations with the flow fields are rapidly increased by the former fluctuation,it is thought that its fluctuation is the trigger of blade stall.

关键词： Semi-opened fan Propeller fan Unsteady flow measurement and FFT analysis

Fukuititan nipponensis,A New Titanosauriform Sauropod from the Early Cretaceous Tetori Group of Fukui Prefecture,Japan

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Acta Geologica Sinica(English Edition) 2010年第3期84卷 454-462页

作者： yoichi AZUMA Masateru SHIBATA Fukui Prefectural Dinosaur Museum 51-11 TeraoMurokoKatsuyamaFukui 911-8601Japan

A titanosauriform dinosaur： Fukuititan nipponensis gen. et sp. nov. is erected based on the incomplete skeleton. It is characterized by elongated asymmetric tooth crown with a weak or absent labial groove and without lingual concavity; stalk-like epipophysis of cervical vertebra; the transverse width of the proximal end of the humerus approximately 32% of the humerus length; metacarpal longer, approximately 48 % of the radius and the distal end of the ischia slightly expanded. It represents the first relatively complete titanosauriform skeleton found from Japan. The discovery of Fukuititan indicates that the diversity and geographical distribution of Titanosauriformes are much higher than the previous thought.

关键词： Fukuititan Titanosauriformes Early Cretaceous Japan