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Your search keyword '"Kawamura, Masayuki"' showing total 44 results
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44 results on '"Kawamura, Masayuki"'

2. Stark spectroscopy of the 6s5d1D2 – 5d2 1D2 forbidden transition in atomic barium.

Author

Suto, Keisuke, Motohashi, Takuma, Miyauchi, Shun, Kawamura, Masayuki, and Jin, Wei-Guo

Subjects
LASER spectroscopy, STARK effect, ATOMIC transitions, ELECTRIC fields, BARIUM
Abstract

We report an observation of the 6s5d1D2 – 5d2 1D2 forbidden transition in Ba atom by means of high-resolution atomic-beam laser spectroscopy. Stark shifts and splittings of this forbidden transition were measured for 136Ba and 138Ba using the Stark-induced interference method, increasing as the applied electric field increases. From measured spectra at various electric fields, scalar and tensor polarizabilities of the forbidden transition were obtained and found to be much larger than those of other levels. The forbidden transition with large electric polarizabilities, resulting from strong mixing between the two closely lying levels of 5d2 1D2 and 5d6p1D2, provides a good candidate for atomic parity non-conservation study. [ABSTRACT FROM AUTHOR]

Published
2024
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3. A New 100-GHz Band Front-End System with a Waveguide-Type Dual-Polarization Sideband-Separating SIS Receiver for the NRO 45-m Radio Telescope

Author

Nakajima, Taku, Kawamura, Masayuki, Kimura, Kimihiro, Yonekura, Yoshinori, Ogawa, Hideo, Sakai, Takeshi, Kuno, Nario, Tsuboi, Masato, Asayama, Shin'ichiro, Noguchi, Takashi, and Kawabe, Ryohei

Subjects
Astrophysics
Abstract

We developed a waveguide-type dual-polarization sideband-separating SIS receiver system of the 100-GHz band for the 45-m radio telescope at the Nobeyama Radio Observatory, Japan. This receiver is composed of an ortho-mode transducer and two sideband-separating SIS mixers, which are both based on the waveguide technique. The receiver has four intermediate frequency bands of 4.0--8.0 GHz. Over the radio frequency range of 80--120 GHz, the single-sideband receiver noise temperatures are 50--100 K and the image rejection ratios are greater than 10 dB. We developed new matching optics for the telescope beam as well as new IF chains for the four IF signals. The new receiver system was installed in the telescope, and we successfully observed the 12CO, 13CO and C18O emission lines simultaneously toward the Sagittarius B2 region to confirm the performance of the receiver system. The SSB noise temperature of the system, including the atmosphere, became approximately half of that of the previous receiver system. The Image Rejection Ratios (IRRs) of the two 2SB mixers were calculated from the 12CO and HCO+ spectra from the W51 giant molecular cloud, resulting in > 20 dB for one polarization and > 12 dB for the other polarization., Comment: 10 pages, 13 figures, Accepted for publication in PASJ, version with high resolution figures is available via http://www.nro.nao.ac.jp/library/report/list.html

Published
2008
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6. Induced emission cross section of a possible laser line in Nd:Y2O3 ceramics at 1.095 μm.

Author

Fukabori, Akihiro, Sekita, Masami, Ikegami, Takayasu, Iyi, Nobuo, Komatsu, Toshiki, Kawamura, Masayuki, and Suzuki, Makoto

Subjects
MEASUREMENT, CHANGE, OPTICS, TRANSMISSOMETERS, TEMPERATURE, LASERS
Abstract

In this study, we measured the change of the optical transmittance for calcination temperatures, in steps of 10°, at two different sintering temperatures. It was found that the optical transmittance is highly dependent on the calcination temperature. The highest optical transmittance obtained was 70% for the transparent Y2O3 (yttria) ceramics produced without the use of additives and high injection presure in this study, higher than the highest reported value of 65%. Optical absorption and emission spectra of Nd:Y2O3 obtained from a low temperature synthesis process were measured. The energy level structure of Nd3+ in the Y2O3 ceramics was determined for a 1 mol % Nd concentration. The induced emission cross section was calculated to be in the range of 3.2×10-19–1.1×10-17 cm2 for the 1 mol % Nd-doped Y2O3 ceramics. Furthermore, a laser line possibly has been identified in this study, in the Nd:Y2O3 ceramic at 1.095 μm. [ABSTRACT FROM AUTHOR]

Published
2007
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7. Induced emission cross section of a possible laser line in Nd:[Y.sub.2][O.sub.3] ceramics at 1.095 [micro]m

Author

Fukabori, Akihiro, Sekia, Masami, Ikegami, Takayasu, Iyi, Nobuo, Komatsu, Toshiki, Kawamura, Masayuki, and Suzuki, Makoto

Subjects
Ceramic materials -- Optical properties, Ceramic materials -- Thermal properties, Ceramics -- Optical properties, Ceramics -- Thermal properties, Polycrystalline semiconductors -- Optical properties, Polycrystalline semiconductors -- Thermal properties, Sintering -- Analysis, Physics
Abstract

The change of the optical transmittance for calcinations temperatures are measured at two different sintering temperatures in Nd:[Y.sub.2][O.sub.3]. It is found that optical transmittance is highly dependent on the calcination temperature and hence the calcinations at 1080 and 1100 degree Celsius are suitable to fabricate [Y.sub.2][O.sub.3] and Nd:[Y.sub.2][O.sub.3].

Published
2007

13. Development of TES Bolometer Camera for ASTE Telescope: II. Performance of Detector Arrays

Author

Hirota, Akihiko, primary, Westbrook, Ben, additional, Suzuki, Kenta, additional, Izumi, Takuma, additional, Takekoshi, Tatsuya, additional, Sato, Tatsuhiro, additional, Oshima, Tai, additional, Minamidani, Tetsuhiro, additional, Kawamura, Masayuki, additional, Suzuki, Aritoki, additional, Lee, Adrian T., additional, Holzapfel, William L., additional, Kohno, Kotaro, additional, and Kawabe, Ryohei, additional

Published
2013
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16. Optics Design and Optimizations of the Multi-Color TES Bolometer Camera for the ASTE Telescope

Author

Takekoshi, Tatsuya, primary, Minamidani, Tetsuhiro, additional, Nakatsubo, Shunichi, additional, Oshima, Tai, additional, Kawamura, Masayuki, additional, Matsuo, Hiroshi, additional, Sato, Tatsuhiro, additional, Halverson, Nils W., additional, Lee, Adrian T., additional, Holzapfel, William L., additional, Tamura, Yoichi, additional, Hirota, Akihiko, additional, Suzuki, Kenta, additional, Izumi, Takuma, additional, Sorai, Kazuo, additional, Kohno, Kotaro, additional, and Kawabe, Ryohei, additional

Published
2012
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24. A New 100-GHz Band Front-End System with a Waveguide-Type Dual-Polarization Sideband-Separating SIS Receiver for the NRO 45-m Radio Telescope

Author

Nakajima, Taku, primary, Sakai, Takeshi, additional, Asayama, Shin’ichiro, additional, Kimura, Kimihiro, additional, Kawamura, Masayuki, additional, Yonekura, Yoshinori, additional, Ogawa, Hideo, additional, Kuno, Nario, additional, Noguchi, Takashi, additional, Tsuboi, Masato, additional, and Kawabe, Ryohei, additional

Published
2008
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37. PETITIONS AND REQUESTS AS A COLLECTIVE BEHAVIOR

Author

Mitsui, Hirotaka and Kawamura, Masayuki

Abstract

これまで請願・陳情は住民運動への手掛りのーつとして扱われてきたが，ここでは集団行動として捉えることにした。これは請願・陳情に伴う署名活動を都市住民の所属集団の研究と関連づけて分析するためであり，更にはそのプロセスに焦点をあてるためであった。具体的には，過去4年間にわたる請願・陳情の内容分析とともに，その代表者に対する面接調査を行なった。その結果，次の点が明らかにされた。(1) 請願・陳情の約80%が何らかの組織を介したものであること，(2) 近年の動向として，既成の組織にとらわれない組織活動が増加していること，(3) なかでも，自己啓発・社会参加を目的とした婦人の活動が目立つていること，(4) このような組織のリーダーの間には，既成の組織や政治関係者に対する不信がみられること，勿論，これらは断定的な結論ではなく，今後とも検討すべき問題である。, We have been taking the signatory lists of petitions and requests as a clue to community action. As a result，some findings were obtained. However，in one view，petitions and requests are considered to reflect the social power of groups which are concerned with relevant issues. From this，the content of petitions and requests over four years were analysed and representatives of each group were interviewed. The following results were obtained: 1) About eighty per cent of all petitions and requests were conducted through some sort of organization. 2) In recent years，the increment of newly formed groups (voluntary) has been determined. 3) In particular，the activities of women who purpose self discipline and social participation are worthy of note. 4) Leaders of these groups have distrust for existing groups and political parties.

Published
1978

38. Abstraktheit and Provision

Author

Kawamura, Masayuki and 一橋大学一橋学会

Abstract

論文タイプ||研究ノート

Published
1973

43. Development of Medical Communication Support System 'Health Life Passport'.

Author

Takizawa, Kiyomi, Takesako, Kazumi, Kawamura, Masayuki, and Sakamaki, Tetsuo

Abstract

Today, the number of foreign residents in Japan is increasingdue to globalization. However, Japan is behind other advanced countries in accepting oversea patients. Japan has to improve medical institutions' readiness to accept foreign patients, and nurture medical interpreters. To address these issues, we developed a language support application for smart phones. Anyone can download it freely. [ABSTRACT FROM AUTHOR]

Published
2013
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