巻号一覧
26 巻 (1974)
- 6 号 p. 515-
- 5 号 p. 449-
- 4 号 p. 365-
- 3 号 p. 285-
- 2 号 p. 105-
- 1 号 p. 1-
26 巻, 4 号
選択された号の論文の7件中1～7を表示しています
- |<
- <
- 1
- >
- >|
-
Hiroshi MATSUMOTO, Kozo HASHIMOTO, Iwane KIMURA1974 年 26 巻 4 号 p. 365-383
発行日: 1974年
公開日: 2010/03/12
ジャーナル フリーImportance of the “phase bunching” of resonant electrons in the whistler mode (WM) wave-particle interactions was pointed out by Brice. In this paper, we call attention on the point that there are two different types of phase bunching with two physically distinct phasing mechanisms in the case of the WM wave-particle interaction. One is a longitudinal phase bunching (the Brice type) which is caused by a longitudinal acceleration, while the other is a transverse phase bunching which is caused by a transverse acceleration. The both types are considered separately and examined mathematically and physically. In order to visualize the different characteristics of the two, numerical results on the phasing patterns and the resultant resonant current are shown by computing the nonlinear motion of electrons in a monochromatic WM wave with various initial velocities (36 different initial phase angles ×15 different speed |υ|).抄録全体を表示PDF形式でダウンロード (1807K) -
J. Hanumath SASTRI, C. V. SUBRAHMANYAM1974 年 26 巻 4 号 p. 385-391
発行日: 1974年
公開日: 2010/03/12
ジャーナル フリーHF Doppler data over two long low latitude radio paths (ATA-Haringhata and JJY-Haringhata) for the period June, 1966 to December 1972 has been examined for effects of sudden commencements. It is noticed that for the same type of sudden commencement, i. e., SC (+), four distinct types of ferequency deviations exist, designated as SCFD (+), SCFD (-), SCFD (+-) and SCFD (-+). The occurrence and the nature of the frequency deviation effect due to sudden commencement is independant of the amplitude of the sudden commencement. A positive correlation between the amplitude of the maximum positive frequency deviation and maximum negative frequency deviation is noticed in composite events: SCFD (+-) and SCFD (-+).抄録全体を表示PDF形式でダウンロード (598K) -
Leroy R. ALLDREDGE, Charles O. STEARNS1974 年 26 巻 4 号 p. 393-404
発行日: 1974年
公開日: 2010/03/12
ジャーナル フリーThe problem of collecting data for making geomagnetic charts including secular change is reviewed. Satellite data gives excellent coverage, but the satellite total field intensity data is not sufficient to properly define the field components. In constructing charts, the specific time and space filtering that is used should be specified so the user can make needed corrections in the use of the charts. An attempt should be made to include time variations having periods of one year or greater. In the space domain spherical harmonic coefficients up to degree 12 or 13 should probably be included. Adequate charts n the future will likely require the use of some external coefficients.抄録全体を表示PDF形式でダウンロード (1300K) -
Victor I. METCHNIK, Michael T. GLADWIN, Frank D. STACEY1974 年 26 巻 4 号 p. 405-415
発行日: 1974年
公開日: 2010/03/12
ジャーナル フリーThe mechanical (or magnetic) energy available in principle from convection in a fluid body with an adiabatic temperature gradient is shown to be related to the convective heat transport by the efficiency of an ideal thermodynamic engine working across the adiabatic temperature difference. The temperature gradient at any level within the core is presumed to take either the adiabatic value or the diffusive gradient corresponding to the heat flux at that level, whichever is less. Then the convective power is calculable in terms of the assumed distribution of heat sources, the values of thermal conductivity K and the thermodynamic Grüneisen ratio, γ. Numerical results are presented for the case of heat sources uniformly distributed through the outer core, with γ=1.15. These indicate that with K=28Wm-1deg-1 (our preferred value) and an inner core temperature of 4000°K the thermodynamic efficiency of core convection rises from zero at a total heat generation Q0=2.5×1012W to 6.4% at Q0=7.5×1012W, but increases only slowly with further heat input. The efficiency is scaled in terms of the ratio K/Q0. The upper limit of plausible convective power in the core is about 7×1011W.抄録全体を表示PDF形式でダウンロード (1014K) -
S. O. OGUNADE, V. RAMASWAMY, H. W. DOSSO1974 年 26 巻 4 号 p. 417-427
発行日: 1974年
公開日: 2010/03/12
ジャーナル フリーD'YAXONOV's (1959) general solution for the problem of induction in a conducting sphere embedded in a uniform conducting half-space by a spherically symmetric source has been evaluated numerically for the particular case of an overhead vertical magnetic dipole source. The validity of the numerical results are examined by comparing the results for several cases with analogue model measurements. Numerical results for a range of source frequencies, sphere radii, depths of burial, and conductivity contrasts of geophysical interest are presented.抄録全体を表示PDF形式でダウンロード (1082K) -
C. AMERIGIAN, N. D. WATKINS, B. B. ELLWOOD1974 年 26 巻 4 号 p. 429-441
発行日: 1974年
公開日: 2010/03/12
ジャーナル フリーA paleomagnetic study of 30 lavas from Marion Island, situated on the Indian-Atlantic ridge yields a value for Brunhes epoch secular variation with confidence limits so broad that no distinction can be made with present geomagnetic field behavior. When combined with similar results from the nearby Crozet Islands, however, data for over 100 separate lavas become available for analysis, facilitating an estimate of regional secular variation with narrow confidence limits. The result, which suggests that Brunhes epoch geomagnetic secular variation in this region was (at the 95 percent confidence level) higher than at present, could be explained if the present secular variation maximum south of South Africa persisted during at least the past half million years. It is concluded that values of Brunhes epoch geomagnetic secular variation may depend not only on latitude, experimental methods, and coverage of the geological interval involved, but also on proximity to long term isoporic foci. Incidental results for the survey include detection of excursions attributable to non-dipole behavior in some instances, and possible dipole tilting in other cases.抄録全体を表示PDF形式でダウンロード (1460K) -
The Secular Variation of Components of the Geomagnetic Field as Measured at Hong Kong from 1884-1973M. R. NEIGHBOUR, D. G. RIVERS, G. O. WALKER1974 年 26 巻 4 号 p. 443-447
発行日: 1974年
公開日: 2010/03/12
ジャーナル フリーPDF形式でダウンロード (376K)
- |<
- <
- 1
- >
- >|