巻号一覧
9 巻 (1975)
- 4 号 p. 185-
- 3 号 p. 113-
- 2 号 p. 51-
- 1 号 p. 1-
9 巻, 2 号
選択された号の論文の6件中1～6を表示しています
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P. K. Kuroda1975 年 9 巻 2 号 p. 51-62
発行日: 1975/06/20
公開日: 2008/04/08
ジャーナル フリーAn alternative explanation for the oxygen isotope anomaly observed in high-temperature inclusions of carbonaceous chondrites is proposed. Just as the main features of the variation of the isotopic compositions of the rare gases in carbonaceous chondrites can be explained in terms of the alterations due to the processes of a) mass-fractionation and b) cosmic-ray irradiation, the pattern observed by CLAYTON et al. (1973) in their plot of δ17O v. δ18O for high temperature minerals of Allende, Murchison, Murray, etc., is explained as due to a combination of the processes a) and b), which occurred during the early history of the solar system. An ‘early’ irradiation of the solar system materials must have taken place, while the rare gases were beginning to escape from the meteorite parent bodies.抄録全体を表示PDF形式でダウンロード (2606K) -
P. K. Kuroda, R. A. Sigg, R. D. Sherrill, J. N. Beck1975 年 9 巻 2 号 p. 63-73
発行日: 1975/06/20
公開日: 2008/04/08
ジャーナル フリーThe xenon found in carbonaceous chondrites and in lunar fines is predominantly of solar origin and its isotopic composition represents that of primordial xenon, which was modified by exposure to a neutron flux during the deuterium-burning stage of the sun. The isotopic composition of atmospheric xenon, on the other hand, represents that of mass-fractionated primordial xenon, in which the heavier isotopes are systematically enriched relative to lighter isotopes. Solar xenon contains excesses of xenon isotopes, produced by neutron-capture reactions in the sun's core during the deuterium-burning stage. The enrichment of 130Xe and 132Xe in solar xenon is of special interest, because these isotopes can be enriched only through neutron-capture reactions on 129Xe and 131Xe in the sun. The ratio of excess 130Xe and 132Xe may thus provide a direct measure of the temperature of the sun during the deuterium-burning stage. Although many capture cross-section measurements over a wide neutron energy range for the four xenon isotopes, 129Xe, 130Xe, 131Xe and 132Xe, are needed before a reliable temperature scale can be established, it appears that an upper limit of roughly 1060K can be set for the temperature of the sun on the basis of existing data and our current knowledge of the general pattern of neutron-capture excitation functions.抄録全体を表示PDF形式でダウンロード (2407K) -
Yasushi Kitano, Minoru Okumura, Masatoshi Idogaki1975 年 9 巻 2 号 p. 75-84
発行日: 1975/06/20
公開日: 2008/04/08
ジャーナル フリーCalcite and/or aragonite were formed from calcium bicarbonate solutions containing sodium sulfate, sodium chloride and magnesium chloride of various concentrations. Sodium, chloride and sulfate contents of synthetic calcite or aragonite were measured. Sodium and chloride ions are incorporated into aragonitic calcium carbonate more easily than into calcitic calcium carbonate, although sodium and chloride ions in the parent solution favor the formation of calcitic calcium carbonate. On the other hand, sulfate ions are incorporated into calcitic calcium carbonate more easily than into aragonitic calcium carbonate, although sulfate ions in the parent solution favor the formation of aragonitic calcium carbonate. Sodium content of aragonite, which is precipitated from calcium bicarbonate solution containing sodium sulfate, sodium chloride and magnesium chloride, exhibits a maximum value together with sulfate content of aragonite.抄録全体を表示PDF形式でダウンロード (2368K) -
Akira Shimoyama, Cyril Ponnamperuma1975 年 9 巻 2 号 p. 85-95
発行日: 1975/06/20
公開日: 2008/04/08
ジャーナル フリーSamples of sediments at depths of 0∼10 and 50∼60cm from fresh water, brackish, and marine environments of the Chesapeake Bay were analyzed for n-fatty acids, n-alkanes, amino acids, lipids, humic substances, and total organic carbon and nitrogen. The abundance of n-fatty acids, humic substances, and total organic C and N was greatest in the fresh water environment and least in the marine. No similar trend was evident in the case of amino acids or hydrocarbons. The molecular distribution patterns of n-fatty acids and n-alkanes show maxima at a higher molecular range in the case of the fresh-water sediment and at a lower molecular range in the case of the marine sediment. The abundance of unsaturated n-fatty acids relative to that of saturated n-fatty acids decreases with sediment depth and also from the marine to the fresh-water sediment. Amino acids are readily recovered by acid hydrolysis. The distribution of individual acids in a sample is related to the chemical properties of the acids in the sediments. The concentration of lipids relative to that of humic substances appears to decrease with sediment depth. Samples of a recent oil spill in the neighborhood of the Bay exhibit a molecular distribution pattern different from those found in the Bay sediments.抄録全体を表示PDF形式でダウンロード (2780K) -
Kenji Notsu, Hisao Mabuchi1975 年 9 巻 2 号 p. 97-106
発行日: 1975/06/20
公開日: 2008/04/08
ジャーナル フリーThe 146Sm/144Sm ratio at the time of solidification of four chondrites, Abee (E4), Modoc (L6), St. Séverin (LL6) and Allende (C3), were measured. The values obtained are 0.06 ± 0.25 (Abee), 0.03 ± 0.08 (Modoc), 0.06 ± 0.05 (St. Séverin) and 1.4 ± 2.0 (Allende), where quoted errors represent 2σ of York's method. Under the assumption of simultaneous formation of these chondrites, we can set an upper limit value of (146Sm/144Sm)0 as 0.11. From this value it is concluded that “last spike” contribution was rather small for p-process nucleosynthesis.抄録全体を表示PDF形式でダウンロード (2324K) -
Tetsuro Suzuoki, Yoshimasu Kuroda, Sadao Matsuo1975 年 9 巻 2 号 p. 107-111
発行日: 1975/06/20
公開日: 2008/04/08
ジャーナル フリーFluid inclusions in olivine were extracted in vacuum by a sodium carbonate fusion method. In the present study, bulk hydrogen content and D/H ratio of the inclusion were measured. The results showed that a consistent value of δD was obtained with a standard deviation of ±2‰, when the absolute amount of hydrogen extracted was more than 40μmol (0.9ml STP H2). On the other hand, when the absolute amount of extracted hydrogen was less than 40μmol, δD value of the extract fluctuated, probably being affected by the contamination in the whole procedure.抄録全体を表示PDF形式でダウンロード (1468K)
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