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<i>Spitzer</i>IRAC Colors of Nebulae Associated with Star-Forming Regions

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International Journal of Astronomy and Astrophysics 2019年第1期9卷 39-50页

作者： Yoichi Itoh yumiko oasa Nishi-Harima Astronomical Observatory Center for Astronomy University of Hyogo Sayo Hyogo Japan Faculty of Education Saitama University Saitama Japan

Star-forming regions are often associated with nebulosity. In this study, we investigated infrared diffuse emission in Spitzer IRAC images. The infrared nebula L1527 traces outflows emanating from a low-mass protostar. The nebular color is consistent with the color of a stellar photosphere with large extinction. Nebulae around the HII region W5-East are bright in the infrared. These colors are consistent with the model color of dust containing polycyclic aromatic hydrocarbon (PAH). The strength of ultraviolet irradiation of the nebulae and the small dust fraction were deduced from the infrared colors of the nebulae. We found that the edges of the nebulae are irradiated by strong ultraviolet radiation and have abundant small dust. Dust at the surface of the molecular cloud is thought to be destroyed by ultraviolet radiation from an early-type star.

关键词： Interstellar Medium Dust Extinction HII Regions

Spectroscopic Survey of Hα Emission Line Stars Associated with Bright Rimmed Clouds

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International Journal of Astronomy and Astrophysics 2019年第2期9卷 154-171页

作者： Kensuke Hosoya Yoichi Itoh yumiko oasa Ranjan Gupta Asoke Kumar Sen Nishi-Harima Astronomical Observatory Center for AstronomyUniversity of HyogoKobeJapan Faculty of Education Saitama UniversitySaitamaJapan Inter University Center for Astronomy and Astrophysics(IUCAA) PuneIndia Department of Physics Assam UniversitySilcharIndia

The results of a spectroscopic survey of Hα emission line stars associated with fourteen bright rimmed clouds are presented. Slit-less optical spectroscopy was carried out with the Inter University Centre for Astronomy and Astrophysics (IUCAA) 2 m telescope and IUCAA Faint Object Spectrograph and Camera (IFOSC). Hα emission line was detected from 173 objects. Among them 85 objects have a strong Hα emission line with its equivalent width larger than 10 ?. Those are classical T Tauri stars. 52 objects have a weak Hα emission line with its equivalent width less than 10 ? and do not show intrinsic near-infrared excess. Those are weak-line T Tauri stars. On the other hand, 36 objects have a weak Hα emission line (?), although they show intrinsic near-infrared excess. Such objects are not common in low-mass star forming regions. Those are misfits of the general concept on formation process of a low-mass star, in which it evolves from a classical T Tauri star to a weak-line T Tauri star. Those might be weak-line T Tauri stars with a flared disk in which gas is heated by ultraviolet radiation from a nearby early-type star. Alternatively, we propose pre-transitional disk objects as their evolutional stage.

关键词： Star Formation Pre-Main Sequence Stars T Tauri Stars

Near-infrared polarimetry of the GG Tauri A binary system

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Research in Astronomy and Astrophysics 2014年第11期14卷 1438-1446页

作者： Yoichi Itoh yumiko oasa Tomoyuki Kudo Nobuhiko Kusakabe Jun Hashimoto Lyu Abe Wolfgang Brandner Timothy D.Brandt Joseph C.Carson Sebastian Egner Markus Feldt Carol A.Grady Olivier Guyon Yutaka Hayano Masahiko Hayashi Saeko S.Hayashi Thomas Henning Klaus W.Hodapp Miki Ishii Masanori Iye Markus Janson Ryo Kandori Gillian R.Knapp Masayuki Kuzuhara Jungmi Kwon Taro Matsuo Michael W.McElwain Shoken Miyama Jun-Ichi Morino Amaya Moro-Martin Tetsuo Nishimura Tae-Soo Pyo Eugene Serabyn Takuya Suenaga Hiroshi Suto Ryuji Suzuki Yasuhiro H.Takahashi Naruhisa Takato Hiroshi Terada Christian Thalmann Daigo Tomono Edwin L.Turner Makoto Watanabe John Wisniewski Toru Yamada Satoshi Mayama Thayne Currie Hideki Takami Tomonori Usuda Motohide Tamura Nishi-Harima Astronomical Observatory Center for AstronomyUniversity of Hyogo407-2NishigaichiSayoHyogo 679-5313Japan Faculty of Education Saitama University255 Shimo-OkuboSakuraSaitamaSaitama338-8570Japan Subaru Telescope National Astronomical Observatory of Japan650 North Ahoku PlaceHiloHI 96720USA National Astronomical Observatory of Japan 2-21-1OsawaMitakaTokyo181-8588Japan H.L.Dodge Department of Physics & Astronomy University of Oklahoma440 W Brooks St.NormanOK 73019USA Laboratoire Lagrange (UMR 7293) Universit de Nice-Sophia AntipolisCNRSObservatoire de la Cote d’Azur28 avenue Valrose06108 Nice Cedex 2France Max Planck Institute for Astronomy Knigstuhl 1769117 HeidelbergGermany Department of Astrophysical Science Princeton UniversityPeyton HallIvy LanePrincetonNJ 08544USA Department of Physics and Astronomy College of Charleston58 Coming St.CharlestonSC29424USA Subaru Telescope National Astronomical Observatory of Japan650 North A’ohoku PlaceHiloHI 96720USA Exoplanets and Stellar Astrophysics Laboratory Code 667Goddard Space Flight CenterGreenbeltMD 20771USA Eureka Scientific 2452 DelmerSuite 100Oakland CA 96002USA Goddard Center for Astrobiology GreenbeltMD 20771USA Institute for Astronomy University of Hawaii640 N.Aohoku PlaceHiloHI 96720USA Department of Earth and Planetary Sciences Tokyo Institute of TechnologyOokayamaMeguro-kuTokyo 152-8551Japan Department of Astronomy Kyoto UniversityKitashirakawa-Oiwake-choSakyo-kuKyotoKyoto 606-8502Japan Hiroshima University 1-3-2KagamiyamaHigashihiroshimaHiroshima 739-8511Japan Department of Astrophysics CAB-CSIC/INTA28850 Torrejón de ArdozMadridSpain Jet Propulsion Laboratory California Institute of TechnologyPasadenaCA91109USA Department of Astronomical Science The Graduate University for Advanced Studies2-21-1OsawaMitakaTokyo181-8588Japan Department of Astronomy The University of Tokyo7-3-1HongoBunkyo-kuTokyo113-0033Japan Astronomical Institute "Anton Pannekoek" University

A high angular resolution near-infrared image that shows the intensity of polarization for the GG Tau A binary system was obtained with the Subaru Telescope. The image shows a circumbinary disk scattering the light from the central binary. The azimuthal profile of the intensity of polarization for the circumbinary disk is roughly reproduced by a simple disk model with the Henyey-Greenstein phase function and the Rayleigh function, indicating there are small dust grains at the surface of the disk. Combined with a previous observation of the circumbinary disk, our image indicates that the gap structure in the circumbinary disk orbits counterclockwise, but material in the disk orbits clockwise. We propose that there is a shadow caused by material located between the central binary and the circumbinary disk. The separations and position angles of the stellar components of the binary in the past 20 yr are consistent with the binary orbit with a = 33.4 AU and e = 0.34.

关键词： stars individual (GG Tauri) -- stars pre-maln sequence - techniques high angular resolution

Small molecular decoys in Alzheimer's disease

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Neural Regeneration Research 2024年第8期19卷 1658-1659页

作者： Sho oasa Valentina L.Kouznetsova Igor F.Tsigelny Lars Terenius Department of Clinical Neuroscience Center for Molecular MedicineKarolinska InstitutetStockholmSweden San Diego Supercomputer Center University of California San DiegoLa JollaCAUSA Department of Neurosciences University of California San DiegoLa JollaCAUSA Department of Clinical Neuroscience Karolinska University HospitalKarolinska InstitutetStockholmSweden

Recent progress in the treatment of Alzheimer’s disease(AD)using antibodies against amyloid sustains amyloid generation as a key process in *** formation starts with two amyloidbeta(Aβ)molecules interacting(dimer formation)followed by an accelerating build-up of socalled protofibrils,which turn into fibrils,which accumulate in the characteristic plaques.

关键词： Alzheimer decoy Aβ

Hand-holding and releasing between the anion and cation to change their macroscopic behavior in water

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Green Energy & Environment 2019年第2期4卷 127-130页

作者： Kosuke Kuroda yumiko Shimada Kenji Takahashi Faculty of Biological Science and Technology Institute of Science and Engineering Kanazawa University

Despite the similarity of ionic liquid and zwitterion, their some properties such as conductivity and hydrophobicity are different. Here we developed a novel phosphonium salt having a dynamic covalent bond between anion and cation, enabling reversible structural shift between free ion pair and zwitterion. With the phosphonium salt, control of the macroscopic phase behavior in aqueous solution, i.e. forming mono-or biphasic systems, upon exposure to an acid or base was reversibly achieved, based on the structural shift of the phosphonium salt. CO_2/N_2 bubbling reversibly changed the phase behavior as well as acid/base, leading to green separation systems.

关键词： Ionic liquid Zwitterion Phase separation Dynamic covalent bond

Effect of Plate Position and Size for Self-Induced Flow Oscillation of Underexpanded Supersonic Jet Impinging on Perpendicular Plate

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Journal of Thermal Science 2011年第3期20卷 238-241页

作者： Tsuyoshi Yasunobu yumiko Otobe Hideo Kashimura Department of Control & Information Systems Engineering Kitakyushu College of Technology Sii Kokuraminami-ku Kitakyushu-shiFukuoka 802-0985 Japan

When the underexpanded supersonic jet impinges on the obstacle, it is well known that the self-induced flow oscillation occurs at the specific condition of the pressure ratio in the flowfield, the position of an obstacle and so on. This oscillation is related with the noise problems of aeronautical and other industrial engineering so that the characteristic and the mechanism of self-induced flow oscillation have to be cleared to control the various noise problems. But, it seems that the characteristics of the oscillated flowfield and the mechanism of oscillation have to be more clear to control the oscillation. This paper aims to clarify the effect of the plate position and the width for the self-induced flow oscillation of an underexpanded supersonic jet impinging on the perpendicular plate by the experiment and the numerical analysis. From the results, it is clear that the occurring domain of the self-induced flow oscillation and its dimension strongly depend on the plate position and the width.

关键词： Compressible Flow Supersonic Jet Mach Disk Barrel Shock Flow Oscillation

Shock Wave in Supersonic Moist Air Jet for a Low Pressure Ratio

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Journal of Thermal Science 2011年第4期20卷 289-293页

作者： yumiko OTOBE Hideo KASHIMURA Toshiaki SETOGUCHI Kitakyushu National College of Technology Saga University

In the present study,a computational fluid dynamics work was performed to investigate the occurrence of the shock wave by condensation in supersonic moist air *** unsteady,compressible axisymmetric Navier-Stokes equation is solved by TVD(Total Variation Diminishing) scheme in this *** numerical simulations have been performed for low pressure ratio and various *** results show the occurrence of the shock wave in supersonic moist air jet for a low pressure ratio when Mach disk does not occur,depending on humidity of the air.

关键词： compressible flow axisymmetric flow shock wave condensation humidity

Characteristic and Mechanism of Pressure Fluctuation Caused by Self-Induced Oscillation of Supersonic Impinging Jet

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Journal of Thermal Science 2013年第2期22卷 123-127页

作者： Tsuyoshi Yasunobu yumiko Otobe Hideo Kashimura Department of Control & Information Systems Engineering Kitakyushu College of Technology

When the underexpanded supersonic jet impinges on the obstacle, it is well known that the self-induced flow os- cillation occurs. This oscillation depends on the pressure ratio in the flowfield, the position of an obstacle and is related with the noise problems of aeronautical and other industrial engineering. The characteristic and the mechanism of self-induced flow oscillation, have to be clarified to control various noise problems. But, it seems that the characteristics of the oscillated flowfield and the mechanism of an oscillation have to be more cleared to control the oscillation. This paper aims to clarify the effect of the pressure ratio and the obstacle position and the mechanism of self-induced flow oscillation by numerical analysis and experiment, when the underexpanded su- personic jet impinges on the cylindrical body. From the result of this study, it is clear that occurrence of the self-induced flow osciUation depends on the pressure balance in the flowfield.

关键词： Supersonic Jet Mach Disk Barrel Shock Flow Oscillation Flow Visualization Numerical Analysis

History of Incarnations (’Khrung rabs) of Sangs rgyas rgya mtsho

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中国藏学 1992年第S1期 307-314页

作者： yumiko Ishihama

1. Introduction As is generally known, after the 1642’ s triumph of the dGe lugs sect, a sect of the TibetanBuddhism, against the opposing, the Karma sect, three important figures appeared upon the sceneof Tibetan history. One of them was, of course, Gusi Khan from the Oyirad tribe of Mongol, whosupported the dGe lugs sect militarily. Another was the Regent who was originally the treasurer of

关键词： of Sangs rgyas rgya mtsho History of Incarnations Khrung rabs