巻号一覧
39 巻 (2005)
- 6 号 p. 481-
- 5 号 p. 397-
- 4 号 p. 301-
- 3 号 p. 201-
- 2 号 p. 113-
- 1 号 p. 1-
39 巻, 2 号
選択された号の論文の8件中1～8を表示しています
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Dexian Li, Zhenmin Gao, Yongxuan Zhu, Yunmei Yu, Hua Wang2005 年 39 巻 2 号 p. 113-119
発行日: 2005年
公開日: 2006/03/23
ジャーナル フリーThe valence state of thallium determines its toxicity, distribution and mobility. Tl(I) can be oxidized to Tl(III) under photoirradiation of the high-pressure mercury arc lamp and solar light. A photooxidation experiment of thallium showed that the photooxidation rate could be affected by the pH of the solution, and the intensity and wavelength of the light source. Lowering the pH and increasing the light intensity have the effect of increasing the photooxidation rate. UV radiation (UVB and UVC regions) plays an important role in the photooxidation of Tl(I). However, the microbial effect is not obvious in comparison with photooxidation effect in this experiment. The study can provide important scientific groundwork for handling of thallium pollution.抄録全体を表示PDF形式でダウンロード (64K) -
Zhi-Nong Gao, Li-Bo Zeng, Fei Niu2005 年 39 巻 2 号 p. 121-130
発行日: 2005年
公開日: 2006/03/23
ジャーナル フリーGas chromatography (GC), gas chromatography-mass spectrometry (GC/MS), supercritical fluid chromatography (SFC), elemental analysis, infrared absorption spectroscopy (IR), thermal analysis (TG/DTA), Rock-Eval pyrolysis, as well as viscosity and density analysis revealed that oil sands from Qaidam basin, Qinghai Province of China, are highly concentrated in light components (≤C23), with saturated hydrocarbons (including most n-alkanes) comprising between 49.6 to 71.4% of total organics (wt.%). Their physicochemical characteristics are very similar to those of heavy oils, rather than other oil sand bitumens. The above analyses suggest that Qinghai oil sands originate from a terrigenous source, similar to oils from the surrounding area. Additionally, the existence of n-alkanes shows that the oil sands are weakly biodegraded, and that the formation of these unusual oil sands is related to the particular geographic/climatic conditions of Qaidam basin. No other known oil sands with chemical composition and distribution similar to that in Qinghai have been documented. Exploitation should be initiated with drilling wells followed by open pit mining.抄録全体を表示PDF形式でダウンロード (96K) -
Ahmet Sasmaz, Ayten Önal, Ahmet Sagiroglu, Mehmet Önal, Buny ...2005 年 39 巻 2 号 p. 131-139
発行日: 2005年
公開日: 2006/03/23
ジャーナル フリーThe Çelikhan fluorite mineralization is concentrated in the thrust zone between the Pinarbasi Formation, which forms the hanging wall, and the Kalecik Limestone foot wall. Fluorite occurs as fracture fills in the thrust zone and as replacement of the foot wall. The wall rock alteration consists of calcite, barite, quartz and kaolinite. The total REE contents of the country rocks, especially the mica- and calc-schists of the Pinarbasi formation at 519 ppm, are higher than those of fluorites. The chondrite normalized REE patterns of country rock and fluorites display generally identical trends. However, fluorite patterns show positive Eu and negative Ce anomaly indicative of low temperature and high fo2 conditions. Cross plots of the Tb/Ca - Tb/La, (La/Yb)n - (Tb/Yb)n and (La/Yb)n (Eu/Eu*)n ratios of the fluorites indicate deposition by low temperature hydrothermal waters. The REE and F were probably leached from the Pinarbasi Formation by the mineralizing solutions. The mineralizing fluids are probably meteoric and formation waters heated at depth along the thrust zone by the natural thermal gradient and/or formation waters heated and mobilized by thrusting.抄録全体を表示PDF形式でダウンロード (221K) -
Surendra P. Verma, Ignacio S. Torres-Alvarado, Muharrem Satir, Patrick ...2005 年 39 巻 2 号 p. 141-163
発行日: 2005年
公開日: 2006/03/23
ジャーナル フリーWe present new major and trace elements and Sr, Nd, Pb, and O isotopic data on basaltic andesite to rhyolitic volcanic rocks from surface outcrops as well as drill wells from the Los Azufres geothermal field (LAGF). With a total installed capacity for electricity production of about 100 MW, LAGF is the second most important geothermal field in Mexico. Hydrothermal alteration has affected most subsurface (drill well) rocks, ranging from partial to complete alteration. The alteration mineralogy with increasing depth (and temperature) is: argillitization/silicification, zeolite/calcite formation, sericitization/chloritization, chloritization/epidotization. The Sr, Nd and Pb isotopic ratios from the LAGF show the following ranges: for surface rocks (87Sr/86Sr)i ≈ 0.70344-0.7048; (143Nd/144Nd)i ≈ 0.512745-0.512908; 206Pb/204Pb ≈ 18.695-18.725; 207Pb/204Pb ≈ 15.585-15.612; 208Pb/204Pb ≈ 38.406-38.522; whereas for drill well rocks (87Sr/86Sr)i ≈ 0.70374-0.70462; (143Nd/144Nd)i ≈ 0.512675-0.512862; 206Pb/204Pb ≈ 18.643-18.770; 207Pb/204Pb ≈ 15.590-15.621; 208Pb/204Pb ≈ 38.390-38.595. An objective statistical methodology, based on F-ratio and Student-t tests, used for the comparison of chemistry of surface fresh rocks (from the LAGF and the surrounding area), to that of shallow (<1000 m depth) drill well altered rocks reveals that hydrothermal alteration causes a loss of total alkalis in most rock types. High-field strength elements such as Zr, TiO2, and P2O5, generally considered as immobile elements, also show significant hydrothermal alteration-related changes. Finally, Pb isotopic ratios of drill well altered rocks significantly decrease and 143Nd/144Nd significantly increase with increasing SiO2. Such a trend of decreasing Pb isotopic ratios and increasing 143Nd/144Nd is also observed for hydrothermally-altered rhyolites as compared to fresh rhyolites.抄録全体を表示PDF形式でダウンロード (313K) -
Jie-Dong Yang, Jun Chen, Jian-Xin Zhang2005 年 39 巻 2 号 p. 165-171
発行日: 2005年
公開日: 2006/03/23
ジャーナル フリー87Sr/86Sr ratios of acid-washed residues of the loess and paleosols since 40 ka B.P. from the Huanxian profile of the Loess Plateau, China, were determined. The investigation shows that 87Sr/86Sr ratios of the residues from the loess levels are generally lower than those from the paleosol levels. It is thought that the paleosol contain a higher proportion of the fine grain size parts (<2 um) than the loess. A correlation occurs among the variations in 87Sr/86Sr ratios, Zr/Rb ratios and mean grain size and, collectively they, imply that the East Asian winter monsoon was weak about from 40 ka B.P. to 30 ka, but it became stronger from about 30 ka B.P. to 10 ka B.P. Heinrich events of the North Atlantic region and Greenland correspond well to low 87Sr/86Sr ratios of residues of the Huanxian profile, which demonstrates that Heinrich events also influnced the east Asian region, including the Loess Plateau of China, and 87Sr/86Sr ratios of residues of the Loess Plateau can record information on high-frequency oscillations of the east Asian winter monsoon strength.抄録全体を表示PDF形式でダウンロード (82K) -
Mayumi Seto, Tasuku Akagi2005 年 39 巻 2 号 p. 173-183
発行日: 2005年
公開日: 2006/03/23
ジャーナル フリーThe concentration of Fe in stream water and groundwater was measured monthly during a whole year. The study fields were Ozenuma lake and Senjougahara peatland, which snow covers for more than 5 months in winter. Iron concentration in water increased during snow-covered and thaw seasons with the synchronized decrease in Eh and pH for both stream water and groundwater. In snow-covered seasons, it is hypothesized that supply of melt water and/or coverage with ice layers during this period could cause the development of an anaerobic zone in underlying soil. This study suggests that change in the amount of snowfall or in the length of snow season may influence the geochemical cycle of iron.抄録全体を表示PDF形式でダウンロード (259K) -
Naotatsu Shikazono, Akitsugu Takino, Haruhiro Ohtani2005 年 39 巻 2 号 p. 185-196
発行日: 2005年
公開日: 2006/03/23
ジャーナル フリーCompositional and mineralogical (primary silicate minerals, volcanic glass, secondary minerals) properties of weathered basaltic ash soil ("Andisol") derived from Mt. Fuji, central Japan, with an age of ca. 6,000 y.B.P. to 240 y.B.P. were studied. X-ray fluorescence analysis indicates that the order of relative elemental mobilities during the weathering is Na, Ca > K > Mg > P > Si > Ti, Fe > Al > Mn. The trends of soil water chemistry (H4SiO4 concentration) with depth were calculated based on a dissolution (volcanic glass)-precipitation (allophane) kinetics-fluid flow coupling model. In order to calculate the trends, the data on present-day annual rainfall, solubility of basalt glass, porosity and specific gravity of the soil, deposition rate of volcanic ash and grain size of volcanic glass were used. The calculated results were compared with analytical trends of soil water chemistry. From this comparison, the dissolution rate constant of basalt glass was estimated to be 10-10.2±0.5 (mole Si m-2s-1). This value is consistent with previously determined experimental long-term dissolution rate constant of basalt glass reported in the literature (Berger et al., 1994).抄録全体を表示PDF形式でダウンロード (265K)
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Shigeru Ohde, Alexis Aguino Ramos, John W. Morse2005 年 39 巻 2 号 p. 197-200
発行日: 2005年
公開日: 2006/03/23
ジャーナル フリーPrecipitation experiments were carried out using chemo-stat technique in order to determine the effect of humic acid on the precipitation rate and composition of magnesian calcite from seawater under laboratory conditions (25°C, 1 atm). Results of our study clearly show that the presence of humic acid in seawater reduces the precipitation rate of magnesian calcite. However, MgCO3 composition in magnesian calcite overgrowths is not influenced by the presence of up to 9.2 mg C/l of humic acid.抄録全体を表示PDF形式でダウンロード (45K)
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