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1.
Zhao  Juan  Han  Yanben  Li  Zhian 《Earth, Moon, and Planets》2000,88(3):123-129
This paper considers the relationship between 21 major earthquakes(Ms ≥ 7.0) in land and the offshore area of Taiwan island in the 20th century and thevariance ratio of the lunar-solar tidal force. The result indicates that the time of these earthquakes is closely related to the variance ratio of the lunar-solar tidal force, and therefore that the tidal force possibly plays an important role in triggering earthquakes. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

2.
A well known theorem of relativistic hydrodynamics states that the streamlines of an isentropic perfect fluid are the future-pointing timelike (FPT) curves extremizing the integral J = ∫ S1 S2 fds, where f is the so-called index function and s the proper time on the world line of the fluid particle. The integral is taken over all possible FPT curves with regular representations xi = xi (s) joining the fixed end events E1, E2. The purpose of this note is to show that the streamlines of an adiabatic perfect fluid can likewise be regarded as extremizing curves of the functional J provided the class of admissible curves consists of those FPT curves satisfying the side condition ui∂iS = 0, ui unit 4-velocity and S the specific proper entropy of the fluid, with the first end point fixed and the second being the end point variable. __________ Published in Astrofizika, Vol. 48, No. 4, pp. 641–647 (October–December, 2005).  相似文献   

3.
Dealing with moon theory and tidal dynamics and checking lists of earthquake data one can take the following two observations: 1) The first extreme proxigean spring tide in the new millennium happened on 2005 January 10, in new moon phase, and half a synodic month earlier, when the Moon was full on 2004 December 26, the Christmas Tsunami was triggered in the Indian Ocean. The next extreme tide in new moon phase will occur after one Saros cycle, on 2023 January 21. 2) The second observation is connected with the lunar evection anomaly. The time between the Whitsun Quake in China on 2008 May 12 and the Christmas Tsunami amounts to 1233 days. On the other hand, three lunar evectional cycles take 3 × Ue = 3 × 411.8 = 1235 days. These observations hint at lunisolar structures in the earthquake distribution. In the present treatise we will reveal such structures by composing lunisolar ephemerides and earthquake Tables. In particular, we use Student's t‐test and show that there is a significant relationship between the beat period Ue and the earthquake statistics (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

4.
Previously published solar abundances of oxygen and carbon can be corrected to be logN(O) = 8.93 and logN(C) = 8.60 on the hydrogen log-scale when new accurate forbidden electric quadrupole transition probabilities A Q(s–1) are used. Such A Q's, based on the new atomic structure and electron correlation theory, developed recently by Sinanolu and coworkers, are reported for the (1 S 0-1 D 2) lines of [C i], [N ii, [O i] and [O iii] and the (2 P-2 D) lines of [N i] and [O ii]. The available experimental values are also given for comparison.Work supported by Grant No. GP-29471 from the U.S. National Science Foundation.  相似文献   

5.
天文潮汐与地震   总被引：6，自引：0，他引：6  
从三个方面综述了天文潮汐与地震关纱的研究，内容包括，日、月、地球的相对位置与地震，天文潮汐的周期，相位与地震，天文潮汐应力与地震，日、月、地球的相对位置与地震和天文潮汐周期与地城的研究均属于从体积力的角度考虑问题，主要是从宏观角度揭示地震发生时的日月位置分布有何规律性，揭示地震发生时间丛集在潮汐周期变化过程中的相位或时段以及地城牟潮汐周期，天文潮汐应力与震的研究从引潮力在地震内部地震源处产生的潮汐应力角度出发，着重研究不同类型性质的发震断层与潮汐应力触发的关系，从物理意义上讲，该研究较深 次地切入了问题的实质，分析了采用某些方法和样本研究结果不一致性的原因，并提出了进一步研究的方向。  相似文献   

6.
Coordinated observations involving ion composition, thermal plasma, energetic particle, and ULF magnetic field data from GEOS 1 and 2 often reveal the presence of electromagnetic ion cyclotron and magnetosonic waves, which are distinguished by their respective polarization characteristics and frequency spectra. The ion cyclotron waves are identified by a magnetic field perturbation that lies in a plane perpendicular to the Earth's magnetic field B0 and propagate along B0. They are associated with the abundance of cold He+ in the presence of anisotropic pitch angle distributions of ions having energies E > 20 keV, and were observed at frequencies near the He+ gyrofrequency. The magnetosonic waves are characterized by a magnetic field perturbation parallel to B0 and thus seem to be propagating perpendicular to the Earth's magnetic field. They often occur at harmonics (not always including the fundamental) at the proton gyrofrequency and are associated with phase-space-density distributions that peak at energies E ～ 5–30 keV and at a pitch angle of 90°. Such a ring-like distribution is shown to excite instability in the magnetosonic mode near harmonics of the proton gyrofrequency. Magnetosonic waves are associated in other cases with sharp spatial gradients in energetic ion intensity. Such gradients are encountered in the early afternoon sector (as a consequence of the drift shell distortion caused by the convection electric field) and could likewise constitute a source of free energy for plasma instabilities.  相似文献   

7.
The energy spectra of solar ions (H, He, C, O. Fe) for 23 events in the 23-rd solar activity cycle are analyzed in order to clarify the parameters for classifying these events. The analysis shows that the evens are distributed within three groups according to the energy at the knee of the ion spectrum. 7 events were included in the first group, for which Ek(A)/Ek(P) = A, where Ek(A) is the total kinetic energy at the knee of the spectrum for ions with atomic number A and Ek(P) is the energy at the knee for the proton spectrum. For the second group (7 events) Ek(A)/Ek(P) = QA, where QA is the ionic charge. For the third group (9 events) Ek(A)/Ek(P) = A/QA. The curves for the second and third groups can also be used for a highly accurate determination of the ionic charges.__________Translated from Astrofizika, Vol. 48, No. 2, pp. 247–260 (May 2005).  相似文献   

8.
Newtonian tidal theory and PPN metric theory. Variable G and earthquakes,II   总被引：1，自引：0，他引：1  
The tidal accelerations due to the Moon and the Sun can be computed at the same time and place of the earthquake events. The search for an earthquake-tide correlation has been referred to small Greek regions and in certain magnitude range. The events correlating with the tides are functions of the angles of the place with respect to the sublunar and subsolar points. A significant correlation has been obtained between the earthquake events and the gravity tide which means that tides are one of the most important triggering mechanism, or in other words, triggering appears as function of Newtonian or Post-Newtonian gravity. Any tidal correlation of earthquakes, which has been examined in this paper, is explicitly given by Tables and Figures as a function of Newtonian and Post-Newtonian gravity.The present paper completes the previous one.This work has been supported by the Greek General Secretariat of Research and Technology under Grant No. 89E160.  相似文献   

9.
The detailed study of the possible presence of four [Niii] lines in solar absorption leads to an abundanceA ni = logN ni = 6.30±0.30 (in the usual scale where logN H = 12.00), in agreement with the coronal and meteoritic values.On leave from Institut d'Astrophysique, Université de Liège.  相似文献   

10.
Modified similarity method has been used to study the propagation of spherical-variable energy blast waves through a self-gravitating gas. For an energy inputE =E 0t4/3, whereE is the energy released up to timet andE 0 is a functional constant, the similarity solutions correct up to third approximation have been obtained. It is found that the effects of self-gravitational forces are of third order. An increase in the parameterA 2 (characterising the gravitational field) increases the shock velocity.  相似文献   

11.
本文在潮汐应力、构造应力、地震断层和岩石破裂滑动理论的基础上 ,建立了潮汐应力对地震断层作用的力学模式 ,该模式将潮汐应力与地震应力作用相结合 ,描述了沿地震主压应力和地震主张应力方向的附加潮汐应力对发震断层的力学作用方式 ,从而切入潮汐应力触发地震的物理机制 ,认为潮汐对地震的触发作用在实质上归结为潮汐应力对地震断层的促滑作用 ,这种促滑作用分增压型和减压型。在此模式基础上 ,对中国大陆及邻区的不同类型地震的潮汐触发性进行了研究 ,内容包括 :计算了中国及邻区一千多个地震震源处沿主压应力P轴和主张应力T轴方向的附加潮汐应力分量 ,分析了这些量对发震断层的作用方式 ,按纬度区域统计了受到潮汐应力促滑作用的发震断层类型以及它们与潮汐应力作用方式的关系 ,得到了如下结论 :受到潮汐应力促滑作用的发震断层的比例随区域纬度增加有减小趋势 ,其中 ,走滑型断层的比例在低纬区较大 ,而倾滑斜型断层的比例在中高纬度区较大 ;对整个统计区域而言 ,受增压型潮汐应力促滑作用的发震断层数比例大于受减压型潮汐应力促滑作用的发震断层 ;对不同的纬度区域 ,不同的潮汐应力作用方式与之促滑的发震断层类型也有不同的分布特征。最后 ,本文将中国及邻区受到潮汐触发作用的地震按构造应力  相似文献   

12.
In this paper we use a new approach to derive the system of first-order coupled equations governing the propagation of electromagnetic waves in an inhomogeneous magnetized plasma for normal incidence. In this new approach we employ a step model and use Maxwell's equations indirectly. The method we present here possesses simplicity in mathematical manipulation and gives a clearer physical picture of the mechanism of mode-coupling. The variablesE i used in the coupled equations are directly related to experimental measurements. Our result is shown to be equivalent to that obtained by Budden and Clemmow (1957).  相似文献   

13.
A mathematical analysis of the Newtonian and parametrized Post-Newtonian tidal stresses is applied to tidal triggering mechanism for earthquakes. We investigate a possible correlation.The procedure used for calculating the solid earth tidal stress is described by the Newtonian theory and the parametrized Post-Newtonian metric. We calculate tidal stress histories for earthquakes between 1908 and 1991 in Greek area. Although no significant tidal correlation was found for the entire data set, which contained earthquakes of magnitudeM 6.0, a fairly striking correlation was observed for an earthquake-tide correlation by computing tidal functions at the time and place of the earthquake events. A successful correlation as used in this paper means that: earthquake events occur during a certain part of the tidal cycle.Also, we have studied a variation of the gravitational constant according to the variation of the velocity of the Earth and the uniform velocity of the Solar System with respect to a preferred Universal rest frame.This work has been supported by the Greek General Secretariat of Research and Technology under Grant No. 89e160.  相似文献   

14.
Coronal radio-sounding experiments were carried out using two-way coherent dual-frequency carrier signals of the ESA spacecraft Rosetta (ROS) in 2006. Frequency measurements recorded at both NASA and ESA tracking stations (sample rate: 1 Hz) are analyzed in this work. Spectral analysis of the S-band, X-band, and differential frequency records has shown that the mean frequency fluctuation of each signal can be described by a radial power-law function of the form σ i =A i (R/R⊙)?mi , where i=x,s,sx. The ratio of the coefficients A s and A x is not the expected theoretical value A s/A x=f s/f x. This occurs because the X-band fluctuations underlie a two-way propagation mode while the S-band fluctuations are essentially the product of a one-way propagation experiment. Results are compared with similar, but not identical, two-way radio propagation experiments performed during the 1991 solar conjunction of the Ulysses spacecraft.  相似文献   

15.
Individual tidal torque λ 2,E 2 and apsidal-motion k 2 constants were calculated for 112 close eclipsing binaries (CEBs) with Detached components belonging to the Main Sequence (DMS-type) from the catalogue by Svechnikov and Perevozkina (Catalogue of orbital elements, masses and luminosities of variable stars of DMS-type and some results of its statistical treatment, Ural State University Press, Yekaterinburg, pp. 1–5, 1999) and for 95 detached binaries taken from the catalogue by Torres et al. (Astron. Astrophys. Rev. 18:67, 2010) on the base of theoretical evolutionary stellar models including tidal torque constants by Claret (Astron. Astrophys. 424:919, 2004). A method of the inversion of model track grid into isochrones was formulated as a complex interpolation procedure for DMS-binaries data. Sets of isochrones were computed in k 2–M, k 2–R, λ 2–M, λ 2–R, E 2–M, and E 2–R planes. Calculated tidal torque constants allow to test stellar structure theory by comparing observed and estimated values of apsidal motion period and analyzing the correlation between timescales of synchronization, circularization, magnetic braking, as well as nuclear burning of DMS-components.  相似文献   

16.
Korteweg-de-Vries-Burger (K-dVB) equation is derived for ion acoustic shock waves in electron-positron-ion plasmas. Electrons and positrons are considered superthermal and are effectively modeled by a kappa distribution in which ions are as cold fluid. The analytical traveling wave solutions of the K-dVB equation investigated, through the (G′/G)-expansion method. These traveling wave solutions are expressed by hyperbolic function, trigonometric functions are rational functions. When the parameters are taken special values, the shock waves are derived from the traveling waves. It is observed that the amplitude ion acoustic shock waves increase as spectral index κ and kinematic viscosity η i,0 increases in which with increasing positron density β and electron temperature σ the shock amplitude decreases. Also, numerically the effect different parameters on the nonlinearity A and dispersive B terms and wave velocity V investigated.  相似文献   

17.
Joanna Furno 《Icarus》2007,189(1):246-255
The equilibrium tide-generating forces in the lunar orbital plane of a planet of radius R are calculated for the case of N moons of mass Mi orbiting the planet at instantaneous polar coordinates (Di, αi). For the case of a single moon, there are only two high tides. For the case of two moons, it is found that there can exist a critical lunar orbital distance at which two high tides become unstable with respect to formation of three high tides. Bifurcation diagrams are presented which depict how the angular positions of the high and low tides on the planet vary with the lunar distances and lunar separation angle. Tidal stability diagrams, which illustrate the stability regions for various tidal patterns as a function of lunar distances and lunar separation angle, are presented for various values of D2/D1 and M2/M1. Generally speaking, the aforementioned tidal instability, and hence the propensity for formation of three high tides on a two-moon planet, exists over a significant range of lunar distances and separation angles provided that M2/M1∼3(D2/D1). For the case of N>2 moons, the tidal stability diagram becomes more complex, revealing a diversity of potential tidal patterns.  相似文献   

18.
We have analyzed the intermediate-term periodicities in soft X-ray flare index (FISXR) during solar cycles 21, 22 and 23. Power-spectral analysis of daily FISXR reveals a significant period of 161 days in cycle 21 which is absent during cycles 22 and 23. We have found that in cycle 22 periodicities of 74 and 83 days are in operation. A 123-day periodicity has been found to be statistically significant during part of the current solar cycle 23. The existence of these periodicities has been discussed in the light of earlier results.  相似文献   

19.
We present the results of our photometric and spectroscopic studies of the new eclipsing cataclysmic variable star 1RXS J180834.7+101041. Its spectrum exhibits double-peaked hydrogen and helium emission lines. The Doppler maps constructed from hydrogen lines show a nonuniform distribution of emission in the disk similar to that observed in IP Peg. This suggests that the object can be a cataclysmic variable with tidal density waves in the disk. We have determined the component masses (M WD = 0.8 ± 0.22M ⊙ and M RD = 0.14 ± 0.02M ⊙) and the binary inclination (i = 78° ± 1.5°) based on well-known relations between parameters for cataclysmic variable stars. We have modeled the binary light curves and showed that the model of a disk with two spots is capable of explaining the main observed features of the light curves.  相似文献   

20.
W.W. Mullins 《Icarus》1978,33(3):624-629
A previous analysis of a stochastic model of lunar-type impact cratering is extended to utilize geological age data by defining a more general statistic Ωi(t) to be the number of equivalent whole craters of original diameter di and age ≤t in an observational area A; each crater is taken to be equivalent to the fraction of its rim (or area) that is in A and not occluded by later craters. By integration of a new gain-loss differential equation, a generalization of the previous basic equation is obtained that relates the expected value ωi(t) = E[Ωi(t)] to the process functions specifying the size distribution and flux of craters (primary or secondary) as they form. The results are specialized to the plausible case in which the cratered body can be subdivided into geological provinces of increasing ages t1, t2, …, ti … and the size probability distribution can be approximated as constant within each of the periods ti+1 - ti. It is shown that use of the Ωi permits, in principle, a reconstruction of the historical values of the process functions and correctly compensates for the effect of overlap by removing the false bias favoring large craters that results from the usual method of crater counting. Possible generalizations of the gain-loss equation are indicated.  相似文献   

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