巻号一覧
45 巻 (1984)
- 4 号 p. 253-
- 3 号 p. 173-
- 2 号 p. 93-
- 1 号 p. 1-
45 巻, 4 号
選択された号の論文の9件中1～9を表示しています
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遠山 英一1984 年 45 巻 4 号 p. 253-259
発行日: 1984/10/30
公開日: 2009/11/13
ジャーナル フリーThe suspended sediment delivered by the Makiminato stream during a flood period consists of about 40 percent clay, 58 percent silt and 2 percent sand in terms of weight. The chemical composition of the sediment is more analogous to that of terrigenous clay than red clay and nearshore marine clay. In comparison to the terrigenous clay, it is relatively low in SiO2 and significantly high in CaO which is traceable to the calcareous fossils within the Shimajiri formation and the Ryukyu limestones accumulated from place to place along the formation.
The mineral composition of the sediment is calculated by recasting the chemical oxide components into standard minerals plagioclase, K-feldspar, Ca-feldspar, calcite, dolomite, enstatite, anhydrite, chlorite, montmorillonite, kaolinite, illite, ilmenite, quartz and hematite.抄録全体を表示PDF形式でダウンロード (848K) -
入江 敏勝1984 年 45 巻 4 号 p. 260-268
発行日: 1984/10/30
公開日: 2010/11/22
ジャーナル フリーThe concentrations of 7 minor heavy metallic elements (Cd, Cr, Cu, Mn, Ni, Pb and Zn) were determined by the A.A.S. method in 116 river water samples, of which 13 samples were collected from the granitic region and others from the green tuff region in Yamagata Prefecture. High concentration areas of the metallic elements were found in the east, southeast and central part of the survey area. In consideration of their flow rate, the mean concentrations of the metallic elements in river water were obtained. The mean values of 0.35 ppb of Cd, 3.74 ppb of Cr, 6.92 ppb of Cu, 15.39 ppb of Mn, 3.32 ppb of Ni, 5.45 ppb of Pb and 17.26 ppb of Zn were found in the green tuff region. The mean values of these elements in the granitic region was lower than that of the green tuff region except for Cr.
Since it can be considered that these river water sampling sites are not affected by human activities, these values, except for lead, represent the minor metal concentration in close to its natural state.抄録全体を表示PDF形式でダウンロード (1298K) -
-内部波に対する湖盆形態の影響小泊 重能1984 年 45 巻 4 号 p. 269-278
発行日: 1984/10/30
公開日: 2010/11/22
ジャーナル フリーUsing the two-layer model, numerical calculations were made for 24 small lake models. Two types of internal wave are noted dominantly. The one rotates counterclockwise round the basin by the effect of the earth's rotation, and the other clockwise. The former is characterized by the uninodal longitudinal mode in the zero-rotation case and the latter is the uninodal transverse one. Due to the lake basin shape, the period of the counterclockwise internal wave is prolonged. The island makes the period of the clockwise internal wave longer. When the length of the minor axis is shortened by the lake basin shape, the clockwise internal wave is not dominant in the complex figure model or its period becomes shorter than that of the rectangular lake model. There are cases where the magnitude of displacement of two internal waves is reversed at some position in the lake. The effect of the lake basin shape is larger on the clockwise internal wave than on the counterclockwise one.抄録全体を表示PDF形式でダウンロード (1423K) -
中西 昇, 名越 誠1984 年 45 巻 4 号 p. 279-288
発行日: 1984/10/30
公開日: 2009/11/13
ジャーナル フリーThe stomach contents of the Isaza, Chaenogobius isaza TANAKA, were investigated in Lake Biwa from 1962 to 1982. In the present study, yearly fluctuation of food habits was observed.
The fish of age 0 fed mainly on zooplankters, such as Daphnia longispina, Diaphanosoma brachyurum, Mesocyclops leuckarti, Leptodora kindtii, throughout the year before 1970. However, they fed mainly on gammarids from winter to spring after 1970.
The fish of age 1 also fed mainly on zooplankters, gammarids and chironomid larvae throughout the year before 1970. However, they fed mainly on gammarids after 1970. The frequency rate of gammarids in stomach contents was about 45% to 84%, and the rates were always higher than for other stomach contents.
The authors noted that the yearly change of food habits of the Isaza was affected by the eutrophication of Lake Biwa.抄録全体を表示PDF形式でダウンロード (1021K) -
実測流と地衡流の比較-遠藤 修一1984 年 45 巻 4 号 p. 289-295
発行日: 1984/10/30
公開日: 2009/11/13
ジャーナル フリーIn order to determine the validity of applying a geostrophic relationship to the circular currents in Lake Biwa, a series of quasi-simultaneous observations of currents and water temperature were carried out. The current measurements were made using the drifters with cross-board placed at several depths. The vertical profiles of water temperature were measured by a bathythermograph at four points about 500 m away from the current station.
The comparisons between the directly measured current and estimated geostrophic current show that the geostrophic approximation is not so valid for the current observed at a specified time and space. On the other hand, the current averaged over a time long enough to cancel the effect of the slowest internal wave, can serve as the baroclinic geostrophic current including the centrifugal force.抄録全体を表示PDF形式でダウンロード (1030K) -
多田 史, 鈴木 潤三, 鈴木 静夫1984 年 45 巻 4 号 p. 296-303
発行日: 1984/10/30
公開日: 2009/11/13
ジャーナル フリーIn order to clarify the distribution pattern of heavy metals contained in the bottom mud of urban rivers, the metals were fractionated by extraction with 2N CH3COONH4 and 0.5N HCl. The total metal content was determined after the decomposition with HNO3-H2O2. A part of the Cu, Zn, and Cd in the bottom mud of urban rivers was extracted with 2N CH3COONH4, but the Pb, Ni and Cr were unextractable. This result indicated that the forms of metals in bottom mud differed from one another. The metal content increased in the lower reaches of the urban river, and the amount of the increased metals was approximately equal to those of the metals extracted with 0.5N HCl. The increase of metals downstream was also correlated to the grain size and the organic matter content of bottom mud. These results suggested that a significant part of the metals in the bottom mud of urban rivers were weakly bound to fine grain size sand and organic matter.抄録全体を表示PDF形式でダウンロード (931K) -
According to the Degree of River Water Pollution真山 茂樹, 小林 弘1984 年 45 巻 4 号 p. 304-312
発行日: 1984/10/30
公開日: 2009/11/13
ジャーナル フリーThe ecological characteristics of Achnanthes minutissima KUETZ. var, saprophila H. KOB. & MAYAM., reported as one of the most pollution-tolerant diatoms by the present authors in 1982, were investigated in detail in the river waters of Tokyo and vicinity. In contrast to the distribution of the nominate variety, var. saprophila was found only in heavily to excessively polluted waters and even occurred as dominant or subdominant taxon in some samples. Vigorous growth was observed in the strongly polluted stretch of the Minamiasa-kawa (Minamiasa River), as shown by cell numbers in a given area.抄録全体を表示PDF形式でダウンロード (1368K) -
伊藤 富子, 川村 洋司1984 年 45 巻 4 号 p. 313-317
発行日: 1984/10/30
公開日: 2010/11/22
ジャーナル フリーFinal instar larva, young larva and pupa of Oxyethira acuta KOBAYASHI are described. Young larvae do not make the case. Final instar larvae bear bottle-shaped cases made entirely of silk. The larvae live on the stems and leaves of higher water plants and feed on the filamentous green algae. They break the cell walls of the algae by their mandibles and suck out the cell contents. O. acuta has a one year life cycle in Lake Utonai, Hokkaidô, northern Japan; young larvae occur in late summer, final instar larvae are found from early autumn to next summer, and pupae occur in summer.抄録全体を表示PDF形式でダウンロード (631K) -
佐藤 泰哲, 東海林 浩子, 伊藤 倫子1984 年 45 巻 4 号 p. 318-321
発行日: 1984/10/30
公開日: 2009/11/13
ジャーナル フリーInorganic carbonate is eliminated by passing CO2 and organic free air through acidified samples for DOG analysis. The air is supplied from a manual rubber air pump by way of two gas washing bottles containing concentrated sulfuric acid and 1N-NaOH and a sodalime tube. The precision of the present method is the same as that of the standard method, which removes inorganic carbonate by high quality nitrogen gas supplied from a high pressure nitrogen gas tank. The present method is especially useful in remote areas such as alpine lakes.抄録全体を表示PDF形式でダウンロード (410K)
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