巻号一覧
40 巻 (1979)
- 4 号 p. 169-
- 3 号 p. 115-
- 2 号 p. 61-
- 1 号 p. 1-
40 巻, 3 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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今里 哲久1979 年 40 巻 3 号 p. 115-122
発行日: 1979/07/30
公開日: 2009/10/21
ジャーナル フリーIt is qualitatively well known that a seiche of a lake loses its energy due to friction and proceeds to decay. Another possibility for the decay of a seiche due to nonlinear interaction is discussed on the basis of bispectral analysis of seiches in Lake Biwa with periods longer than 30 minutes. A significantly non-zero bispectral density B(f1, f2) indicates the nonlinear interaction among three constituents of seiche with a relation in their frequencies such as f1+f2+f3=0.
Nonlinearity in the surface oscillation in Lake Biwa is in the order of magnitude of 5-10% of that in wind-waves. Significant bispectral peaks appear at the frequency regions corresponding to the constituents of the seiche with dominant power spectral densities. It must be noted that the nonlinear interaction does not occur among three constituents of a seiche, i.e. at least one of the three constituents nonlinearly interacting is not a constituent of the characteristic oscillation in Lake Biwa. Therefore, energy is transported from the seiches to a constituent which does not have a characteristic period of Lake Biwa, and the latter loses its energy not only due to friction but also from breaking on the lake shore. As the result of this fact, the seiche proceeds to decay.抄録全体を表示PDF形式でダウンロード (920K) -
松永 勝彦, 米田 義昭, 深瀬 茂1979 年 40 巻 3 号 p. 123-128
発行日: 1979/07/30
公開日: 2009/10/21
ジャーナル フリーAn investigation in the lake was made from June 1977 to May 1978. The average value of primary production was below 0.2 g C/m2 day from April to October. The concentrations of nitrate and phosphate were almost zero in summer, and phosphate in particular showed a value of almost zero throughout the year. Transparency was below 2m in all stations throughout the year. From the measurement of C/N ratio of suspended matter in lake and river waters, it was suggested that much of the suspended matter in the lake derived from the river flowing into and this had caused a decrease in transparency. The suspended matter scarcely settled because of the active vertical and horizontal movement of the lake water. The nutrient supply from waste water was less than 10 % of the total nutrient supply.抄録全体を表示PDF形式でダウンロード (749K) -
中島 淳, 鎗田 功, 小林 節子, 小倉 久子1979 年 40 巻 3 号 p. 129-136
発行日: 1979/07/30
公開日: 2009/10/21
ジャーナル フリーFractionation of phosphorus was carried out ; organic P, calcium P, aluminum P, iron P and residual P were determined in sediments of Lake Inbanuma, a eutrophic lake, and the Shinkawa River, an organic polluted river entering the lake. Large differences between the lake and the river were observed in both the concentration and percentage of fractionated P in the surface sediments. The enrichment in aluminum P and iron P observed in the river surface sediments seemed to result from domestic sewage entering the river. Changes of fractionated P in the surface sediments with the water flow from the river to the lake corresponded to those in the overlying water. From these correspondences the sedimentation process of P and the possibility of P release from the sediment into the overlying water were considered. Vertical profiles of fractionated P indicated a recent marked increase of P loading which is attributed to domestic sewage entering the river.抄録全体を表示PDF形式でダウンロード (990K) -
高久 武雄, 高橋 正征, 大槻 晃1979 年 40 巻 3 号 p. 137-144
発行日: 1979/07/30
公開日: 2009/10/21
ジャーナル フリーDecrease of an organophosphorus insecticide, Fenitrothion, dispersed by a helicopter was determined daily in paddy fields and a surrounding river by using reversed phase adsorption liquid chromatography. Fenitrothion was found to be at a level of 554 ppb in a paddy field immediately after the dispersion, and then decreased exponentially with time. The level reduced to 5 ppb after 3 days of the dispersion.
By dispersing Fenitrothion, a crustacean Moina sp. prevalent in paddy fields was noticed to disappear immediately, but its population density was regained within 10 days after the dispersion. Planktonic algal growth was stimulated by the Fenitrothion dispersion.抄録全体を表示PDF形式でダウンロード (1021K) -
Distribution of Total Ni and Cr多田 史, 鈴木 静夫1979 年 40 巻 3 号 p. 145-152
発行日: 1979/07/30
公開日: 2009/10/21
ジャーナル フリーIt was observed from the analysis of Cr and Ni in the bottom mud of Japanese rivers that mud normally contained 1-50 ppm of total Ni and 1-80 ppm of total Cr. Chromium content was plentiful in the lower stream mud.
The bottom mud of rivers flowing through Hokkaido, Shikoku, and the Pacific coast districts was high in total Ni and Cr compared with those of other districts. These districts geologically belong to the serpentine belt or Outer zone.
The correlation coefficient between total Ni and Cr was 0.91 for the mud of serpentine rock areas and 0.54 for the mud of urban rivers polluted artificially.抄録全体を表示PDF形式でダウンロード (845K) -
Distribution of Extractable Ni and Cr多田 史, 鈴木 静夫1979 年 40 巻 3 号 p. 153-161
発行日: 1979/07/30
公開日: 2009/10/21
ジャーナル フリーTo examine the distribution of extractable Ni and Cr in mud of rivers, mud extraction was carried out with 0.5N HCl, 0.2M EDTA, and 2N CH3COONH4, respectively. The mud samples were collected from upper and lower streams of Japanese rivers of the first category.
It was consequently demonstrated that bottom mud in rivers contained 1-5 ppm Ni and Cr soluble in 0.5N HCl and 0.2M EDTA, and not soluble in 2N CH3COONH4. The bottom mud of rivers, which run through densely populated and industrial areas, contained much extractable Cr. On the other hand, only small amounts of Cr and Ni were extracted with various extractants from the mud of rivers in the serpentine belt containing a relatively large concentrations of these two metals.抄録全体を表示PDF形式でダウンロード (877K)
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