巻号一覧
22 巻 (1988)
- 6 号 p. 237-
- 5 号 p. 183-
- 4 号 p. 143-
- 3 号 p. 89-
- 2 号 p. 47-
- 1 号 p. 1-
22 巻, 4 号
選択された号の論文の5件中1～5を表示しています
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Akira Shimoyama, Setsu Hagishita, Kaoru Harada1988 年 22 巻 4 号 p. 143-148
発行日: 1988年
公開日: 2008/04/08
ジャーナル フリーAnalysis for purines and pyrimidines was carried out with Neogene sediments in a 1600 m thick stratigraphic sequence in the Shinjo basin. Adenine, guanine, thymine, and cytosine were detected at the 100 ng/g level in the top sediment of the sequence, while guanine and occasionally adenine were chiefly detected at the 10 ng/g level in the remainder of the sediments. The assemblage of these nitrogen bases and their amounts are quite different from those found in recent sediments. These characteristics indicate that the nitrogen bases recovered survived diagenesis and are indigenous to the Neogene sediments.抄録全体を表示PDF形式でダウンロード (1741K) -
Atsushi Ando, Ken Shibata1988 年 22 巻 4 号 p. 149-156
発行日: 1988年
公開日: 2008/04/08
ジャーナル フリーData received by September, 1988 are tabulated for isotopic ratios, isotopic compositions, activity ratios and specific activities of radioactive isotopes, isotopic ages and rare gas compositions of the GSJ rock reference samples, “Igneous rock series.”抄録全体を表示PDF形式でダウンロード (2004K) -
Mitsuo Uematsu, John T. Merrill, Thomas L. Patterson, Robert A. Duce, ...1988 年 22 巻 4 号 p. 157-163
発行日: 1988年
公開日: 2008/04/08
ジャーナル フリーRadioactivity from the Chernobyl accident present on aerosols was measured at several island sites and on a ship in the North Pacific. The radioactivity arrived at the various sites located from 11°-64°N between 6-14 May 1986. Isentropic trajectory analyses and measurement of the natural radioactive species 7Be and 222Rn indicate that the continental air containing Chernobyl fission products (e.g., 131I, 137Cs) was transported to the central North Pacific through the middle troposphere. We estimate the residence time and gas-to-particle conversion times by combining the radionuclide data with surface concentration estimates in Japan. The atmospheric residence time over the North Pacific for the aerosols containing the fission products was 3-5 days. The calculated mean gas-to-particle conversion time for radioactive 131I was 2-3 weeks, with a minimum of ∼12 days. The results indicate that the radioactive submicrometer aerosol and the iodine gas from the Chernobyl explosion have residence and conversion times similar to those of naturally occurring aerosols and gases in the atmosphere.抄録全体を表示PDF形式でダウンロード (1855K) -
Jaroslav Dostal, Claude Dupuy, Mingzhe Zhai, Xiachen Zhi1988 年 22 巻 4 号 p. 165-176
発行日: 1988年
公開日: 2008/04/08
ジャーナル フリーThe Pliocene volcanic rocks of the Anhui-Jiangsu region of eastern China are composed of an alkali basaltic suite consisting of alkali basalts, basanites and nephelinites. The basalts underwent a limited degree of fractional crystallization dominated in the initial stage by olivine and subsequently by clinopyroxene. The magmas were derived from a metasomatized amphibole-bearing garnet peridotite source variously enriched in incompatible trace elements. The metasomatic enrichment of the incompatible trace elements was probably produced by a zone refining process and was superimposed on a depleted upper mantle source compositionally similar to that of mid-ocean ridge basalts.抄録全体を表示PDF形式でダウンロード (3638K) -
Yuji Sano, Hiroshi Wakita, Xu Sheng1988 年 22 巻 4 号 p. 177-181
発行日: 1988年
公開日: 2008/04/08
ジャーナル フリーThe belief that the isotope ratio of air helium is globally constant has meant that air helium is used in most laboratories as a helium isotopic standard. The well accepted air 3He/4He ratio of (1.39±0.01) × 10-6 is an average of the two isotopic determinations by Mamyrin et al. (1970) and Clarke et al. (1976). We measured absolute atmospheric 3He/4He ratio, taking into account the separation of helium from neon and possible occurrence of the helium isotope fractionation during the purification procedure. The 3He/4He ratio of (1.343±0.013)×10-6 observed at Ueno Park, Central Tokyo, Japan is apparently lower than the previous data. The discrepancy may be attributed to either experimental problems or natural phenomenon.抄録全体を表示PDF形式でダウンロード (1452K)
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