巻号一覧
29 巻 (1995)
- 2 号 p. 63-
- 1 号 p. 1-
29 巻, 1 号
選択された号の論文の4件中1～4を表示しています
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報文
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河村 公隆, 小坂 真由美, サンペレ リシャール1995 年 29 巻 1 号 p. 1-15
発行日: 1995/05/29
公開日: 2016/12/15
ジャーナル フリーIn order to understand the source and behavior of organic matter in urban atmosphere, normal alkanes (C15-C43 ; 31-320 ngm-3), hopanoid hydrocarbons (C29-C32 : 0.7-15 ngm-3) and unresolved complex mixture of hydrocarbons (UCM : 270-3000 ngm-3) were determined in urban and rural aerosols as well as rainwaters by using capillary GC and GC-MS. Total carbon and nitrogen contents were also determined in the aerosols. During spring to summer seasons, n-alkanes in Tokyo aerosols were dominated with higher plant-derived species such as C27, C29 and C31, whereas they were overwhelmed in winter by anthropogenic hydrocarbons with no odd/oven carbon number predominance. Hopanoid and UCM hydrocarbons mainly derived from petroleum combustion residue, showed higher concentrations in winter, however, their concentrations significantly decreased in new year holidays. The results of urban rainwater samples indicated distributions similar to aerosols. Time series rainwater samples showed that their concentrations decreased as a function of time, indicating a continuous wet scavenging of particulate organic matter. However, odd/even ratios (CPI) of n-alkanes and n-alkanes/ UCM ratios showed a gradual decrease during precipitation event, suggesting a preferential scavenging of plant-derived n-alkanes over anthropogenic hydrocarbons, the former being enriched in coarser particles.抄録全体を表示PDF形式でダウンロード (1285K) -
猪狩 俊一郎1995 年 29 巻 1 号 p. 17-23
発行日: 1995/05/29
公開日: 2016/12/15
ジャーナル フリーA system to measure C2+ light hydrocarbons (CnHm, n≧2) in methane-rich gases is reported. Until now, measurement of trace C2+ light hydrocarbons by gas chromatography (GC) has been difficult, because C2+ hydrocarbons could not be separated well from methane. In this system, C2+ hydrocarbon concentration column (stainless hollow pipe) is equipped between GC injection and GC column. With the C2+ hydrocarbon concentration column, only C2+ hydrocarbons are concentrated and methane is removed. After the removal of methane, precise measurement of C2+ hydrocarbons by GC becomes possible.抄録全体を表示PDF形式でダウンロード (458K) -
寺島 滋, 片山 肇, 中嶋 健, 池原 研1995 年 29 巻 1 号 p. 25-36
発行日: 1995/05/29
公開日: 2016/12/15
ジャーナル フリーThree-hundred argillaceous marine sediments collected from off Niigata, southeastern coastal margin of the Japan Sea were analyzed for mercury by cold vapor atomic absorption spectrometry. Anomalously high mercury content of more than 300 ppb is found in the sediments around Sado Island. This anomalous mercury is likely to have originated from gold-silver mining activities in the island. In this case, mercury is probably presented in the form of Au-Ag-Hg amalgam. As for the other samples, the mercury is generally enriched in the fine sediment fraction and positively correlated with gold, copper, lead, sulfur and organic carbon. The inverse correlation between the mercury content and redox potential of the sediment suggests that mercury is enriched in reducing environments. In general, mercury is concentrated clearly in the uppermost layer of the core sediments. This may be caused by recent anthropogenic inputs because the mercury enrichment during early diagenesis is assumed to be negligible.抄録全体を表示PDF形式でダウンロード (890K) -
林 正人, 田中 剛, 上岡 晃1995 年 29 巻 1 号 p. 37-50
発行日: 1995/05/29
公開日: 2016/12/15
ジャーナル フリーTrace element abundances were determined by INAA for forty-nine inclusions of various sizes in the Allende meteorite, especially medium-to-small-sized inclusions were emphasized to analyze. All of the refractory elements in coarse grained inclusions analyzed in the present study were enriched by a factor of only eight relative to their concentrations in Cl chondrites though in the previous studies enriched by a factor of twenty. The concentrations of refractory elements in the coarse grained inclusions, the amoeboid olivine aggregates and magnetite rich inclusions correlate positively to the sizes of inclusions. This suggests that these inclusions suffered secondary alteration and the refractory elements were diluted. As the refractory elements in the coarse grained inclusions were more enriched than in the amoeboid olivine aggregates, the coarse grained inclusions are considered to have been removed from equilibrium with the gas before the amoeboid olivine aggregates removed. On the other hand, the abundances of refractory elements in the fine grained inclusions were nearly identical with those reported in the earlier works, irrespective of the size; the light REEs are enriched by a factor of twenty and heavy REEs enriched by less than three. This suggests that the fine grained inclusions suffered no alteration. Some possible models for the formation mechanism of CAI were discussed in the light of the size and chemical composition. It has been made clear that the difference between coarse and fine grained inclusion is not only their appearance but also their fomation environment.抄録全体を表示PDF形式でダウンロード (3489K)
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