巻号一覧
29 巻 (1995)
- 2 号 p. 63-
- 1 号 p. 1-
29 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
- |<
- <
- 1
- >
- >|
特集：地球環境の中に見る地域環境化学
-
寺井 久慈1995 年 29 巻 2 号 p. 63-66
発行日: 1995/12/25
公開日: 2016/12/16
ジャーナル フリーPDF形式でダウンロード (429K) -
高 春心, 小倉 紀雄1995 年 29 巻 2 号 p. 67-74
発行日: 1995/12/25
公開日: 2016/12/16
ジャーナル フリーThe atmospheric deposition of fluoride (F-) was observed at Fuchu, in a Tokyo suburb, from February 1992 through November 1994. Dry and wet depositions of F- were in the range of 8.6-57 and 9.9-214 μg m-2day-1, with the weighted mean values of 26 and 76 μg m-2day-1, respectively. Weighted mean value for total (dry + wet) deposition of F- was 102 μg m-2day-1. Dry fall-out amounted to 27% of the total F^- deposition, which was in the same range as other observed elements derived from soils. However, chemical analysis indicated neither soil particles nor sea salt to be a major source of F- deposition. This result suggests contributions other than these two; probably a fossil fuel combustion source. In the case of dry deposition, an increase in F- deposition during the spring period resulted in higher F-/nss-SO42- (nss = non sea salt) than that for the remainder of the time. Such periodical changes in F-/nss-SO42- was not obtained with wet deposition, because the wet depositions of F- and nss-SO42- depended largely on the amount of rainfall. A stationary source emitting fluoride to atmosphere was not observed near the sampling site. Therefore, transportation of suspended particles rich in fluoride was suggested as a possible mechanism to increase the F-/nss-SO42- of dry deposition in the spring.抄録全体を表示PDF形式でダウンロード (702K) -
大塚 治子, 井上 広史, 吉田 恭司, 早川 清子1995 年 29 巻 2 号 p. 75-84
発行日: 1995/12/25
公開日: 2016/12/16
ジャーナル フリーAtmospheric methane concentration was continually monitored for two years (April 1992-March 1994) at 29 stations in Aichi Prefecture. Possible causes for variability in the data were evaluated. The annual means of methane concentration were higher by about 0.1 ppm than the value of background concentration at Ryori. Monthly mean concentrations showed two distinctive peaks a year, in July and early winter. The former peak was presumed to result mainly from rice cultivation in southwestern Owari, while the latter was due to urban activities around Nagoya City. At the stations with high mean concentration, a clear diurnal variation was observed; methane concentration increased from midnight to early morning, corresponding well with a decrease in wind speed. The night peaks appeared concurrently over an area of some 10 km2 with an irregular periodicity of several days. The periodicity seemed to be affected by rainfall as well as wind speed; the night peak tended to disappear just after rainfall of more than about 10 mm/d. From the annual variation pattern of high methane levels at night, the 29 stations could roughly be classified into 4 types: background, paddy field, semi-urbanized (industrial), and highly urbanized. Each was considered to have been affected by different sources of methane.抄録全体を表示PDF形式でダウンロード (1040K) -
南 秀樹, 加藤 義久, 和田 秀樹, 岡部 史郎1995 年 29 巻 2 号 p. 85-97
発行日: 1995/12/25
公開日: 2016/12/16
ジャーナル フリーFour cores, which penetrated into the Holocene, were collected in 1985-1986 from the center to mouth of Lake Hamana, Japan. Sediments were analyzed for the concentrations of organic C, total N, biogenic SiO2, Mg, Al, Fe, Mn, V and P. The age of the sediment near the bottom part of each core, which exhibited a higher C/N mole ratio, changed from 11,000 yr B. P. at the mouth to 7,000 yr B. P. at the center part of the lake. This indicated a higher sedimentation of land plants enriched in carbon, which probably took place during a period of high sealevel. After 4,000 yr B. P. in the inner part of the lake there were some distinctive changes in the distributions of elements, as related to their 14C ages : (1) higher content and large fluctuations in both the sediment, organic carbon and biogenic SiO2, and (2) an excess organic carbon over biogenic SiO2. Yet, in contrast, the C/N mole ratio≈12 remained constant. These observations suggested that an eutrophic and productive lake was formed when the seawater exchange was restricted. The contents of Fe and Mg also increased remarkably after 4,000 yr B. P. These changes are due to increasing of the transport ation of particles, originating from ultra-basic rocks carried by the Miyakoda River in the northern part of the lake. Before this period marine silt was predominantly transported from the Pacific sea side.抄録全体を表示PDF形式でダウンロード (1215K) -
森泉 純, 永峰 康一郎, 飯田 孝夫, 池辺 幸正, 中村 俊夫1995 年 29 巻 2 号 p. 99-111
発行日: 1995/12/25
公開日: 2016/12/16
ジャーナル フリーCarbon-14 isotopic measurements of atmospheric methane (CH4) provide useful information on its sources and behavior. We have assembled a preparation line to concentrate and purify low levels (〜2 ppmv) of methane for the measurement of 14C content with accelerator mass spectrometry (AMS). In this system, trace amounts of methane in nearly 1 m3 of air sample are cryogenically adsorbed on active carbon, purified by gas chromatography, combusted and collected as carbon dioxide. The mean yield of this procedure is 88.6±5.8 (1σ) %. Carbon dioxide, obtained from the above procedure, is divided into two parts : one portion is converted to graphite for AMS, and the other is used for δ13C measurement. Sample contamination is negligible compared with the precision of 〜1 pM (1σ) for AMS. The effect of isotopic fractionation in this procedure is also smaller than any of the source of contamination. The overall error of this procedure is lower than 1 ‰ for the δ13C measurement. From isotopic measurements of atmospheric methane in Nagoya City at the beginning of 1994, we found a high methane concentration air sample in which 14C content of methane was lower. This implies the contribution of fossil methane to the urban atmosphere.抄録全体を表示PDF形式でダウンロード (1249K) -
田中 剛, 川邊 岩夫, 山本 鋼志, 岩森 光, 平原 靖大, 三村 耕一, 浅原 良浩, 伊藤 貴盛, 米澤 千夏, ドラグシャヌ クリ ...1995 年 29 巻 2 号 p. 113-125
発行日: 1995/12/25
公開日: 2016/12/16
ジャーナル フリーStream sediments in and around Seto City, Aichi Prefecture, were examined for geoenvironmental assessment of the area. New 157 samples were analysed for seventeen elements including Al, Ca, Ce, Co, Cr, Cu, Fe, K, Mn, Mg, Na, Ni, P, Sr, Ti, V and Zn. ICP atomic emission spectrometry and atomic absorption spectrometry were employed for the analyses. The representativeness of the analysed data for the sampling locality is examined by means of duplicate or triplicate samplings from the same place and by repeated analyses of the singly bottled sample. The data show ±100% variations in the abundance of Ti and ±50% or less variations for the other elements. This variation may have been caused by heterogeneous distribution of small accessory minerals bearing Ti. The stream sediments from the area where granitic rocks are exposed are rich in Al, Ca, Na, K and Sr. On the contrary, Co, Cr, Fe, Ni, V, Mn and Zn are enriched in the sediments from the area where the Tertiary sediments are dominant. Correlation coefficients higher than 0.6 are found between abundances of Ca-Na-Sr-Al, Ni-Co, P-Cu-Zn and Ti-Ce. The coefficients are remarkably higher for the samples took from the area of the Tertiary sediments than for the samples from granitic region. Although one sample shows a high Cr-abundance (785 ppm), which is 20 times the abundance of the average value for the Tertiary sediments, no clear evidence for artificial pollution of any elements examined here is found.抄録全体を表示PDF形式でダウンロード (1450K) -
高橋 和志1995 年 29 巻 2 号 p. 127-136
発行日: 1995/12/25
公開日: 2016/12/16
ジャーナル フリーWater and nitrogen are usually considered to be the limiting factors for growth of trees on urban streets. We demonstrated that the leaf carbon isotope ratio (δ13C) is a good indicator of long-term water stress of various species (Zelkowa serrata, Platanus occidentalis, Cinnamomun camphora, Sophora japonica, Ginkgo biloba), resulting from low intercellular carbon dioxide concentrations in water stress treatments in green house experiments. It is well known that the leaf carbon isotope ratio is negatively correlated with intercellular carbon dioxide concentrations in various kinds of plants. On the other hand, leaf nitrogen content is thought to be an indicator of nitrogen supply for street trees, because leaf nitrogen content increases as soil nutrients become enriched. The simultanuous measurements of δ13C and nitrogen content of leaves by automatic stable isotope analyzer suggested that the growth of street trees was limited by soil nitrogen, rather than soil water, during June to September, 1994, in Toyota city.抄録全体を表示PDF形式でダウンロード (838K) -
鹿角 孝男, 宮島 勲, 塩澤 憲一1995 年 29 巻 2 号 p. 137-145
発行日: 1995/12/25
公開日: 2016/12/16
ジャーナル フリーRiver sediment is thought to show average composition of the upstream watershed. We examined a method, using exchangeable aluminum Ex-Al, and the effects of acid deposition on influencing water composition. An index of acidification was established. First, the most useful method for measuring Ex-Al in sediment was evaluated. According to the contact tests with atmospheric precipitation and sediments, H+ and SO42- in the precipitation samples were adsorbed to biotite, and the amount of Ex-Al in the sediments increased. Acid deposition, river water composition and Ex-Al in sediments were measured at a mountain region site in southwest Nagano Prefecture, where granite was the basement rock. High acid deposition was measured at this site in the comparison with the mean value at 20 stations in Nagano Prefecture, and the alkalinity of river water was below 0.2 meq/l in this upstream region. Because of this, it was suggested that the experiment catchment area was highly sensitive to acid rain. Ex-Al was detected but quite variable from sediments in this area which received the influence of acid deposition. So sediment Ex-Al is thought to be a good index to show influence of acid deposition on river waters.抄録全体を表示PDF形式でダウンロード (779K)
- |<
- <
- 1
- >
- >|