Ami Yoshida Junko Shikimori Takeshi Ohno Yuta Ijichi Yusuke Fukami Masahiro Sakata Takafumi Hirata
Journal of environmental radioactivity 255 107011-107011 2022年9月 [査読有り]
We examine the historical changes of 236U/238U and 235U/238U in a sediment core collected in Tokyo Bay and elucidate the anthropogenic sources of uranium in the 1960s-2000s. Uranium-236 was detected in samples deposited in the 1960s-2000s, and the...
Geochimica et Cosmochimica Acta 318 279-291 2022年2月 [査読有り]
We present the first report of the concentrations and stable isotope compositions of Te in the surface layer of ferromanganese crusts collected from the slope of two seamounts in the Northwest Pacific Ocean, Takuyo-Daigo and Takuyo-Daisan, which c...
Takeshi Ohno Naoki Sato Junko Shikimori Yuta Ijichi Yusuke Fukami Yasuhito Igarashi
Science of the Total Environment 2021年 [査読有り]
We examine the temporal changes of 236U/238U and 235U/238U in atmospheric deposition from samples collected in Tokyo and Akita from 1963 to 1979 and elucidate the spatial distribution and historical changes of the anthropogenic sources of uranium ...
Nickel (Ni), copper (Cu), and zinc (Zn) are commonly used in human activities and pollute aquatic environments including rivers and oceans. Recently, Ni, Cu, and Zn isotope ratios have been measured to identify their sources and cycles in environm...
<p>半減期1570万年である放射性ヨウ素-129は放射性ヨウ素の環境トレーサーとして用いられてきた。環境試料中のヨウ素-129の濃度を迅速に調べる手法の一つとして、溶液試料導入法を用いたICP質量分析計による測定法が提案されている(Ohno et al., 2013)。しかしこの手法では、127Iの水素化物イオンによる質量数129への干渉を完全には除去できず、測定の感度も十分とは言えないという問題点がある。そこで本研究では試料溶液中のヨウ素を酸化気化しICP質量分析...
人文科学研究科
理学部