巻号一覧
21 巻 (1987)
- 6 号 p. 253-
- 5 号 p. 197-
- 4 号 p. 139-
- 3 号 p. 85-
- 2 号 p. 43-
- 1 号 p. 1-
21 巻, 2 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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D. N. Sandoval, E. Greaves, S. Melendez1987 年 21 巻 2 号 p. 43-49
発行日: 1987年
公開日: 2008/04/08
ジャーナル フリーDeviations from the natural isotopic composition of the 234U/238U and 228Th/232Th activity ratios have been determined for nine different hot spring water samples from Venezuela. The 234U/238U activity ratios range from 1.13 ± 0.07Ci/Ci to 9.94 ± 2.53 Ci/Ci in the samples Quebrada la Colonia and Aguas Calientes Ure=a, respectively. The 228Th/232Th activity ratios range from 3.20 ± 0.25 Ci/Ci to 21.60 ± 1.81 Ci/Ci in the Quebrada la Colonia and Las Trincheras hot spring samples. A linear relationship was found between 228Th/232Th activity ratio and the amount of dissolved SiO2 in mg/l which follows the relationship 228Th/232Th=0.2397 SiO2 + 0.5402. The wide deviations in the activity ratios measured were attributed to mechanisms of differential solubility of the intermediate short lived daughters in the decay chain of uranium and thorium (234Th, 234Pa, 229Ra, 228Ac) and to the effect of recoil of the decaying nuclei during alpha and beta emissions.抄録全体を表示PDF形式でダウンロード (1748K) -
R. Fukai, A. Yamato, M. Thein, H. Bilinski1987 年 21 巻 2 号 p. 51-57
発行日: 1987年
公開日: 2008/04/08
ジャーナル フリーThe measurements of the oxidation states of fallout plutonium in rain water collected at Monaco indicate that plutonium exists predominantly in the higher oxidation states (Pu (V) and Pu (VI)). The results obtained show that the percentage of the higher valency fraction of plutonium ranges from 38 to 89 % of the total soluble plutonium in rain. The percentage tends to be lower when the storage time before the chemical treatment becomes longer. A thermodynamical computation supports these findings. The occurrence of plutonium in the higher oxidation states in rain is considered to be one of the major causes of the characteristic geochemical stability of fallout plutonium observed in the Mediterranean Sea.抄録全体を表示PDF形式でダウンロード (2079K) -
Tamotsu Oomori, Yasushi Kitano1987 年 21 巻 2 号 p. 59-65
発行日: 1987年
公開日: 2008/04/08
ジャーナル フリーProtodolomite was synthesized from sea water containing dioxane by adding 0.4M Na2CO3 solution at 40°C. The presence of dioxane in moderate concentrations (3 to 8vol%) in a parent solution favors the formation of CaCO3(calcite)-MgCO3 solid solution. Optimal condition for protodolomite synthesis was established. The mineral synthesized from sea water containing dioxane was very superior in size and crystallinity as compared to that from highly saline but dioxane-free solutions.抄録全体を表示PDF形式でダウンロード (1668K) -
Yasuhiro Kiyosu1987 年 21 巻 2 号 p. 67-73
発行日: 1987年
公開日: 2008/04/08
ジャーナル フリーD/H ratios of molecular hydrogen and chemical composition were analyzed for well and fumarole steam from the Matsukawa, Takinoue and Onikobe active geothermal fields in Northeast Japan. The δD values ranged from -364 to -594‰. The temperatures estimated from the hydrogen-water deuterium isotope equilibrium fractionation are 200 to 300°C for most samples. The relationship between H2/H2S ratios and the hydrogen isotope geothermometer suggests that hydrogen and hydrogen sulfide concentrations in geothermal waters are controlled by equilibria with iron mineral buffers.抄録全体を表示PDF形式でダウンロード (1741K) -
N. M. S. Rock1987 年 21 巻 2 号 p. 75-84
発行日: 1987年
公開日: 2008/04/08
ジャーナル フリーA potpourri of mutually inconsistent normalized multi-element diagrams (‘spider-diagrams’) has been used in geochemistry, on the basis of different choices of: (i) element order; (ii) normalizing materials (chondrite, ‘primitive’ mantle, MORB, composite shale, etc.); (iii) normalizing values (many incompatible sets are used for conventional chondrite-normalized rare-earth element (REE) plots, which generate ‘enrichments’ varying by as much as 65 % from a single rock, and Eu anomalies of quite divergent strengths). Standardization is urgently required, not least because (1) many published diagrams are unnecessarily difficult to compare; (2) different element orders can drastically affect patterns, or lead to artificial ‘pseudo-anomalies’ lacking petrogenetic significance. One type of chondrite- and MORB-normalized spider-diagram (each based on one set of normalizing values) should suffice to represent most igneous rocks. Arguments favouring the chondrite-normalizing REE values of Nakamura (1974), the chondrite-normalized 19-element plot of Thompson (1982), and the MORB-normalized 15-element plot of Pearce (1982, 1983) are preferred, hopefully as an impetus to wider discussion. Consistently ordered sub-sets can be chosen from either multi-element plot if fewer elements are in fact analysed. A FORTRAN77 program has been written to realize these suggestions.抄録全体を表示PDF形式でダウンロード (3039K)
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