巻号一覧
34 巻, 1 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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Mihoko Hareyama, Noriyoshi Tsuchiya, Masahiro Takebe, Tadashi Chida2000 年 34 巻 1 号 p. 1-9
発行日: 2000/02/20
公開日: 2008/04/08
ジャーナル フリーTwo-dimensional measurement of radiation produced by natural irradiation of granitic rocks was performed by the use of an imaging plate, which is a storage film coated with photostimulated phosphor (BaFBr:Eu2+). Radiation images of small volume specimens, such as thin sections were obtained with the imaging plate. Irradiation images of granitic rocks are inhomogeneous and the intensity of photostimulated luminescence per unit area, which is principally converted into the integrated dose, increases with the increasing potassium content in the rocks. The results of the present study indicate that the disintegration of 40K is the dominant radiation source of granitic rocks. The imaging plate is a new research tool for the evaluation of the natural radioactive properties of geological materials and is applicable as a semi-quantitative two-dimensional dosimeter for natural radioactivity.抄録全体を表示PDF形式でダウンロード (812K) -
Keiji Misawa, Fumie Yamazaki, Nami Ihira, Noboru Nakamura2000 年 34 巻 1 号 p. 11-21
発行日: 2000/02/20
公開日: 2008/04/08
ジャーナル フリーA new separation scheme for rare earth elements (REE) and strontium, and its application to REE determination of chondrites and terrestrial rocks along with isotopic analysis of strontium in chondritic meteorites are presented. The miniaturized extraction chromatography scheme using RE and Sr Resins provide simple and effective methods for the isolation of REE and strontium from chondritic meteorites. Chemical yields of up to 90% of the desired elements and low procedural blanks enable us to use the resins for small-size chondritic meteorite samples, weighing one to five milligrams. The techniques presented here are fully applicable to Rb-Sr isotopic systematics and to REE geochemistry and cosmochemistry. A separation procedure of lead from total rock basalt samples using Sr Resin is also briefly described.抄録全体を表示PDF形式でダウンロード (230K) -
Masahiro Sakata, Masaki Kurata, Nobuyuki Tanaka2000 年 34 巻 1 号 p. 23-32
発行日: 2000/02/20
公開日: 2008/04/08
ジャーナル フリーIn this study, we measured the lead isotope ratios as well as trace metal concentrations (As, Cd, Cr, Ni, Pb and Zn) in the airborne particles collected at the Tokyo metropolitan area, where 9 municipal solid waste (MSW) incinerators locate nearby. Relationship between the concentrations of lead and other trace metals was investigated using data obtained both at the study site and at the 16 monitoring stations of the National Air Surveillance Network (NASN) of Japan sited mainly in urban areas. The results showed that lead isotope ratios were almost constant at the study site. The lead isotope ratios were very close to those for 7 cities throughout the whole country and also the fly ashes from MSW incinerators. This means that MSW incineration can account for the major portion of the lead in most Japanese urban atmosphere. The results also suggested that there are no significant differences in the concentration ratios of Cd, Zn and As to Pb in the airborne particles emitted from MSW incinerators across the country. Based on these results, the contributions from MSW incineration to the atmospheric metal concentrations were estimated to be 94% for Cd, 78% for Zn and 71 % for As.抄録全体を表示PDF形式でダウンロード (281K) -
Chu-Nan Hsu, Ju-Chin Chen, Kung-Suan Ho2000 年 34 巻 1 号 p. 33-58
発行日: 2000/02/20
公開日: 2008/04/08
ジャーナル フリーThe major volcanic activity in Kirin Province, northeast China occurred in Changpaishan area and lasted from the Miocene to Holocene. The volcanic rocks include basanite, alkali basalt, tholeiite, trachyte, and rhyolite. Ultramafic xenoliths and megacrysts occur in the basanite and alkali basalt. The compatible (Ni, Cr, Sc, V, Co) and incompatible elements (Rb, Li, Th, Hf, La, Lu, Nb, Zr, Y) vary systematically with 100MgO/(MgO + ΣFeO) in the volcanic rocks. Fractional crystallization clearly was important in the magmatic evolution. The volcanic rocks and their ultramafic xenoliths have characteristic Sr and Nd isotopic ratios which fall between DMM and EM-I or EM-II. There are two types of spinel-lherzolite xenoliths in the basalts from Kirin Province: (1) an E-type enriched in LREE with (La/Yb)N varying from 6.6 to 8.15; (2) a D-type depleted in LREE with (La/Yb)N varying from 0.2 to 0.7 indicating of mantle heterogeneity in the Kirin region. The E-type lherzolites contain higher TiO2, K2O, P2O5, Rb, Sr, Ba, Y, Nb, Ta, Th and U than the D-type lherzolites. The former may have resulted from mantle metasomatic processes. The tholeiite, alkali basalt and basanite may have been derived from an isotopically similar mantle source through different degree of partial melting at different P-T conditions. The trachyte may be derived from the basalt through fractional crystallization of plagioclase, olivine, clinopyroxene and magnetite.抄録全体を表示PDF形式でダウンロード (1208K) -
Tomohisa Irino, Ryuji Tada2000 年 34 巻 1 号 p. 59-93
発行日: 2000/02/20
公開日: 2008/04/08
ジャーナル フリーIn order to reconstruct past variations in the aeolian dust (Kosa) contribution to the Japan Sea, and to establish a direct link between terrestrial and marine climatic records, we have applied statistical procedures to distinguish and quantify detrital subcomponents within the detrital fraction of the late Quaternary hemipelagic sediments in the Japan Sea. Q-mode factor analysis with varimax and oblique rotation of the factors followed by multiple-regression analysis between mineral composition and factor loadings was conducted using six “detrital” elements. Four detrital subcomponents were defined, which are attributed to Kosa derived from “typical” loess, Kosa from “weathered” loess, and fine and coarse arc-derived detritus, respectively, based on comparisons with the chemical and mineral compositions of probable source materials. Using these detrital subcomponents, the variation in Kosa fraction was reconstructed for the last 200 ky. The results reveal millennial-scale as well as glacial-interglacial scale variations in Kosa contribution. Especially, millennial-scale variability of Kosa contribution suggests the presence of high frequency variation in summer monsoon precipitation in the central to east Asia during the last 200 ky.抄録全体を表示PDF形式でダウンロード (7007K) -
J. W. Smith2000 年 34 巻 1 号 p. 95-99
発行日: 2000/02/20
公開日: 2008/04/08
ジャーナル フリーIn the direct hydrolysis of elemental sulfur, immediate precipitation of the sulfide as the copper salt allows measurement of the initial sulfur isotopic compositions of product sulfide and sulfate. δ34S values for product sulfide and sulfate and for parent elemental sulfur at reaction temperatures of 50 to 200°C differ by less than 3‰ and demonstrate that only minor sulfur isotope fractionation accompanies hydrolysis. These data suggest that the larger values commonly reported reflect, not hydrolysis reactions, but other secondary equilibration processes.抄録全体を表示PDF形式でダウンロード (46K)
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