巻号一覧
4 巻 (1951)
- 2 号 p. 48-
- 1 号 p. 1-
前身誌
4 巻, 1 号
選択された号の論文の5件中1～5を表示しています
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島津 康男1951 年 4 巻 1 号 p. 1-8
発行日: 1951/09/15
公開日: 2010/03/11
ジャーナル フリーIn his theory of density distribution in the mantle of the earth, K. E. Bullen assumed the existence of a density discontinuity at 400km depth. He also assumed the chemical homogeneities on both sides of this depth, for the continuous and homogeneous mantle leads us to an unreasonable result as to the state of the core.
Recently, H. Brown who studied the chemical compositions of the earth's interior inferred from those of meteorites, concluded that the concentration of the metal phase would increase linearly with depth. The concentration of metallic materials will also have influence upon the density distribution.
A possible density distribution of the model having such a concentration is discussed in this paper.
The main results are as follows:
(1) the density at the bottom of the mantle may be 6.289 (Table 3, Fig. 3),
(2) the metal phase contents at the bottom of the mantle may be 20.4per cent by weight (Table 3, Fig. 4),
(3) the total contents of metal phase in the mantle may be 11.4per cent by weight,
(4) the atomic ratio of iron to silicate in the whole earth will be 1.559, this number is not affected by iron contents in the mantle.抄録全体を表示PDF形式でダウンロード (616K) -
吉山 良一1951 年 4 巻 1 号 p. 9-16
発行日: 1951/09/15
公開日: 2010/03/11
ジャーナル フリーExamining the seismological data for the Fukui Earthquake, June 28. 1948, the author obtained the travel-time curves of P, P* and Pn and determined the depth of the origin of P-wave of the earthquake together with the layered structure of the earth's crust in Japan. The latter result does not agree with those obtained previously by other authors. The layers corresponding to P and P* were respectively found to be 35km and 14km in thickness.抄録全体を表示PDF形式でダウンロード (851K) -
竹山 謙三郎1951 年 4 巻 1 号 p. 17-22
発行日: 1951/09/15
公開日: 2010/03/11
ジャーナル フリーSeismic factors for structural design of buildings relating to geological ground condition were recently prescribed by Building Code in Japan. The map in the text shows the reduction coefficient to be multiplied to the basic seismic factor, 0.2 in every prefecture in Japan. The table indicated the reduction coeficient for each kind of structure (Wooden bldg. Steel bldg. Reinforced-concrete bldg. and Masonry bldg. from the left to the right column) and of geological ground condition (from the 1st. to the 4th).抄録全体を表示PDF形式でダウンロード (674K) -
田治米 鏡二1951 年 4 巻 1 号 p. 23-35
発行日: 1951/09/15
公開日: 2010/03/11
ジャーナル フリーThe apparatus which was used in this experiment was what was previously described by C. TSUBOI. It consists of a bifilar pendulum and a synchronous motor driven electrically by the pendulum. It was attempted to improve the accuracy obtainable by this apparatus. The present study consists of two parts, the one concerning the bifilar-pendulum, and the other concerning the synchronous motor. The fluctuation in the period of the pendulum in relation to the phase of the exciting electric current was investigated. It was found that the fluctuation was 10-6 sec when the motor is excited at the most preferable phase. As the period of the pendulum was 10-1 sec, the relative accuracy was 10-5.抄録全体を表示PDF形式でダウンロード (3766K) -
西部 照雄1951 年 4 巻 1 号 p. 38
発行日: 1951年
公開日: 2010/03/11
ジャーナル フリーPDF形式でダウンロード (103K)
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