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Li, W.*; Yamada, Shinya*; Hashimoto, Tadashi; Okumura, Takuma*; Hayakawa, Ryota*; Nitta, Kiyofumi*; Sekizawa, Oki*; Suga, Hiroki*; Uruga, Tomoya*; Ichinohe, Yuto*; et al.
Analytica Chimica Acta, 1240, p.340755_1 - 340755_9, 2023/02
Times Cited Count:1 Percentile:42.63(Chemistry, Analytical)no abstracts in English
Kobayashi, Keita; Yamaguchi, Akiko; Okumura, Masahiko
Applied Clay Science, 228, p.106596_1 - 106596_11, 2022/10
Times Cited Count:4 Percentile:79.38(Chemistry, Physical)no abstracts in English
Yamaguchi, Akiko; Nagata, Kojiro*; Kobayashi, Keita; Tanaka, Kazuya; Kobayashi, Toru; Tanida, Hajime; Shimojo, Kojiro; Sekiguchi, Tetsuhiro; Kaneta, Yui; Matsuda, Shohei; et al.
iScience (Internet), 25(8), p.104763_1 - 104763_12, 2022/08
Times Cited Count:3 Percentile:45.22(Multidisciplinary Sciences)no abstracts in English
Yamaguchi, Akiko; Nagata, Kojiro*; Tanaka, Kazuya; Kobayashi, Keita; Kobayashi, Toru; Shimojo, Kojiro; Tanida, Hajime; Sekiguchi, Tetsuhiro; Kaneta, Yui; Matsuda, Shohei; et al.
Hosha Kagaku, (45), p.28 - 30, 2022/03
no abstracts in English
Yamaguchi, Akiko; Kobayashi, Keita; Takahashi, Yoshio*; Machida, Masahiko; Okumura, Masahiko
Chemical Physics Letters, 780, p.138945_1 - 138945_5, 2021/10
Times Cited Count:4 Percentile:42.08(Chemistry, Physical)no abstracts in English
Konagaya, Rimi*; Kawamura, Naomi*; Yamaguchi, Akiko; Takahashi, Yoshio*
Chemistry Letters, 50(8), p.1570 - 1572, 2021/08
Times Cited Count:3 Percentile:27.22(Chemistry, Multidisciplinary)no abstracts in English
Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.
Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03
Times Cited Count:30 Percentile:96.42(Astronomy & Astrophysics)Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200
C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.
Kobayashi, Keita; Nakamura, Hiroki; Yamaguchi, Akiko; Itakura, Mitsuhiro; Machida, Masahiko; Okumura, Masahiko
Computational Materials Science, 188, p.110173_1 - 110173_14, 2021/02
Times Cited Count:12 Percentile:75.78(Materials Science, Multidisciplinary)no abstracts in English
Yamaguchi, Akiko; Asano, Ikumi*; Kitagawa, Yuri*; Meng, C.*; Nakao, Atsushi*; Okumura, Masahiko
Proceedings of Joint International Conference on Supercomputing in Nuclear Applications + Monte Carlo 2020 (SNA + MC 2020), p.127 - 130, 2020/10
no abstracts in English
Nagasawa, Makoto*; Qin, H.-B.*; Yamaguchi, Akiko; Takahashi, Yoshio*
Chemistry Letters, 49(8), p.909 - 911, 2020/08
Times Cited Count:2 Percentile:11.21(Chemistry, Multidisciplinary)Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Arai, Takehiko*; Nakauchi, Yusuke*; Nakamura, Tomoki*; Matsuoka, Moe*; et al.
Science, 364(6437), p.272 - 275, 2019/04
Times Cited Count:233 Percentile:99.75(Multidisciplinary Sciences)The near-Earth asteroid 162173 Ryugu, the target of Hayabusa2 sample return mission, is believed to be a primitive carbonaceous object. The Near Infrared Spectrometer (NIRS3) on Hayabusa2 acquired reflectance spectra of Ryugu's surface to provide direct measurements of the surface composition and geological context for the returned samples. A weak, narrow absorption feature centered at 2.72 micron was detected across the entire observed surface, indicating that hydroxyl (OH)-bearing minerals are ubiquitous there. The intensity of the OH feature and low albedo are similar to thermally- and/or shock-metamorphosed carbonaceous chondrite meteorites. There are few variations in the OH-band position, consistent with Ryugu being a compositionally homogeneous rubble-pile object generated from impact fragments of an undifferentiated aqueously altered parent body.
Yamaguchi, Akiko*; Honda, Tasuku*; Tanaka, Masato*; Tanaka, Kazuya; Takahashi, Yoshio*
Geochemical Journal, 52(5), p.415 - 425, 2018/00
Times Cited Count:11 Percentile:55.16(Geochemistry & Geophysics)Ion-adsorption type REE deposits in weathered granite are main sources of REE essential for high-technology industries. However, these type deposits have not been searched in Japan. In this study, Bulk REE abundances (= REE), ion-exchangeable REE (= REE
) by ammonium chloride solution, and percentage of REE
relative to REE
(= REE
) in fresh and weathered granite samples in Southwest Japan (i.e., Hiroshima and Shimane Prefectures) were determined. The REE
and REE
were comparable to those of ion-adsorption type REE deposits in China. Extended X-ray adsorption fine structure (EXAFS) spectra of REE in original samples and samples after the extraction of ion-exchangeable REE showed that (i) REE in samples with high REE
mainly forms outer-sphere complexes and (ii) the remaining REE in the rocks after the extraction forms inter-sphere complexes.
Masuda, Toshiyuki*; Arase, Junko*; Inagaki, Yusuke*; Kawahara, Masatoshi*; Yamaguchi, Kentaro*; Ohara, Takashi; Nakao, Akiko*; Momma, Hiroyuki*; Kwon, E.*; Setaka, Wataru*
Crystal Growth & Design, 16(8), p.4392 - 4401, 2016/08
Times Cited Count:27 Percentile:88.4(Chemistry, Multidisciplinary)Yamasaki, Chisato*; Murakami, Katsuhiko*; Fujii, Yasuyuki*; Sato, Yoshiharu*; Harada, Erimi*; Takeda, Junichi*; Taniya, Takayuki*; Sakate, Ryuichi*; Kikugawa, Shingo*; Shimada, Makoto*; et al.
Nucleic Acids Research, 36(Database), p.D793 - D799, 2008/01
Times Cited Count:51 Percentile:71.65(Biochemistry & Molecular Biology)Here we report the new features and improvements in our latest release of the H-Invitational Database, a comprehensive annotation resource for human genes and transcripts. H-InvDB, originally developed as an integrated database of the human transcriptome based on extensive annotation of large sets of fulllength cDNA (FLcDNA) clones, now provides annotation for 120 558 human mRNAs extracted from the International Nucleotide Sequence Databases (INSD), in addition to 54 978 human FLcDNAs, in the latest release H-InvDB. We mapped those human transcripts onto the human genome sequences (NCBI build 36.1) and determined 34 699 human gene clusters, which could define 34 057 protein-coding and 642 non-protein-coding loci; 858 transcribed loci overlapped with predicted pseudogenes.
Ozawa, Akira*; Matsuta, Kensaku*; Nagatomo, Takashi*; Mihara, Mototsugu*; Yamada, Kazunari*; Yamaguchi, Takayuki*; Otsubo, Takashi*; Momota, Sadao*; Izumikawa, Takuji*; Sumikama, Toshiyuki*; et al.
Physical Review C, 74(2), p.021301_1 - 021301_4, 2006/08
Times Cited Count:41 Percentile:89.05(Physics, Nuclear)no abstracts in English
Yamaguchi, Akiko*; Kurihara, Yuichi*; Tanaka, Kazuya; Ohara, Yoshiyuki; Kozai, Naofumi; Takahashi, Yoshio*
no journal, ,
Kuribara, Yuichi; Yamaguchi, Akiko*; Higaki, Shogo*; Ohara, Yoshiyuki; Takahashi, Yoshio*
no journal, ,
In order to investigate the behavior of radium in the Ningyo-toge Environmental Engineering Center, radium in the core sample in the center was analyzed with HPGe semiconductordetector. As a result, concentrate of radium was observed in the weathered granite in the lower part of the core sample.
Yamaguchi, Akiko; Kuribara, Yuichi; Okumura, Masahiko; Takahashi, Yoshio*
no journal, ,
no abstracts in English
Takahashi, Yoshio*; Tsuboi, Hiroyuki*; Yamaguchi, Akiko
no journal, ,
no abstracts in English
Kuribara, Yuichi; Yamaguchi, Akiko*; Higaki, Shogo*; Ohara, Yoshiyuki; Takahashi, Yoshio*
no journal, ,
In order to investigate the behavior of radium (Ra) in the Ningyo-toge Environmental Engineering Center, Ra/
U activity ratio in two boring core samples in the center was analyzed with HPGe semiconductor detector. The
Ra/
U ratio was below 1 and over 1 in the U enriched and contained clay mineral layers, respectively. Based on the radioactive equilibrium and mass balance calculation, it was suggested that Ra and U eluted to groundwater migrated from the U enriched layer to the contained clay minerals layer when Ra was selectivity fixed on the contained clay mineral layer. EXAFS and micro-XRF-XANES-XRD for Ba, used as an analog of Ra, confirmed that Ba
was adsorbed on clay minerals as IS complex, and Ra was expected to show similar behavior. Therefore, it was indicated that Ra migrated from U concentrated layer was adsorbed and fixed on clay minerals in the environment of the Ningyo-toge Environmental Engineering Center.