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31.
Summary The Banach theorem is applied to the Lagrange planetary equation for the semimajor axis of a geostationary satellite orbit to estimate the stability of near-geostationary satellite orbits. To achieve a graveyard (disposal) orbit, which will not interfere (=cross) the initial geostationary orbit, the geostationary semi-major axis ag have to be increased at least by 50 km. Numerical results for a variety of graveyard orbits show that the increase of ag by about 100 km will yield sufficiently stable orbits (accounting for the Earth's gravitational perturbations only) during the next 150 years.Dedicated to the 75th Birthday of Professor Academician Tibor Kolbenheyer 相似文献
32.
Summary The dependence of Pn-wave velocities on the heat flow, temperature at the crustmantle boundary and the thickness of the Earth's crust in Europe was investigated in relation to the problem of lateral inhomogeneities in the upper mantle. A map was constructed of the distribution of Pn-wave velocities on the territory of Europe. The relations these investigations yielded, were compared with the results of laboratory experiments and all the results are discussed from the physical point of view. The conclusion drawn is that that temperature and pressure effect provide a sufficient explanation of the observed regional changes of Pn-wave velocities for the European continent.
auum ¶rt;auu mu n¶rt; ¶rt; nmu uua (Pn) u mn nm, mnam a nmu amuu u m a mumuu n a u¶rt;aa u numa ¶rt;¶rt;m amuu. mumuu n a maa a uu m Pn- a nmu uua. u¶rt;u umam ¶rt;a mama aam u¶rt;au uuu m n¶rt; amuu u u ¶rt;au u mnam mmmm mama n¶rt;aa am. ¶rt;a ¶rt;, m ua uu m Pn- a n mum ¶rt;mam um uuu mnam u ¶rt;au a nmu uua.相似文献
33.
Velocity determination of 131 head echoes recorded during Perseid meteor shower observations by the Canadian 2 MW radar, has
been performed under the assumption of either their constant velocity or of its linear change with time. Even though the constant
velocities concentrated at 60 km s-1 generally accepted for the Perseids, a substantial number of echoes had velocities either
lower than 60 km s-1 or greater than this value. The inclusion of variable velocity into considerations led to surprising
result that a great portion of the head echoes accelerated (3 possibly decelerating echoes in comparison with 33 accelerating
cases on the level of relative standard deviations of output parameters not exceeding 10%). It seems that the allocation of
the ionization responsible for the head echo is not entirely identical with the instantaneous meteoroid position. As a consequence,
the velocity derived from the measured head echo coordinates can differ from the velocity of parent body. We are not able
to explain this finding at present.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
34.
Karel Prikner Jaroslav Střeštík Karel Dobeš Reviewer M. Hvoždara 《Studia Geophysica et Geodaetica》1972,16(3):262-270
Summary The spectral analysis of samples of beating-type pc3 pulsations, recorded at the Budkov Observatory during the summer months of 1968 and 1969 was carried out in the frequency interval10 mHz100 mHz. The average limits of the pulsation frequency range are roughly20 mHz60 mHz. The centre of the occurrence frequency graphs for both components is at the frequency fg 41 mHz. The analysis of three separated daily intervals showed a very slight tendency to a systematic decrease in the frequency of the centre from the morning to the afternoon. The study of the sense of rotation of the pulsation disturbance vector in the (X, Y)-plane showed an overall predominancy of L over R-types during daytime, particularly during the morning. 相似文献
35.
36.
37.
Jaroslav Souček 《Astrophysics and Space Science》1986,121(1):161-191
By combining two two-dimensional subspaces, closed into themselves due to curvature, it is possible to create a model of three-dimensional space of the same properties. If the Universe is a space of this type, its effect is that of a monstrous lens. Close objects are observed to diminish according to the normal law of perspective; however, the remote galaxies are seen to be very highly magnified.The apparent angular size2 of a galaxy is more than the size1 in flat space according to relation:2 =1 cosec , where is the angular distance from the observer to the galaxy. The diameter2
d of a galaxy in curved space must be in the same relation to a diameter1
d with no curvature of space:2
d=1
d cosec . The apparent angular size2 and diameter2
d are distorted shapes in consequence of an optical illusion caused by the spatial curvature.It is necessary to distribute the multitude of galaxies into two parts in accordance with their location on the close or reverse hemihypersphere of the Universe. The minimum of apparent angular size2 of a galaxy of diameter1
d is at the equatorial zone.The most likely candidates for location in the reverse hemi-hypersphere are cD's of apparent supergiant sizes due, probably, to the curvature of space. The existence of supergiant sizes of galaxies is the second indirect proof, besides superluminal velocities, that the Universe is closed into itself through curvature. The third indirect evidence, i.e., inductive confirmation of the same fact, is the superposition of galaxies which need not inevitably be a new alternative to the present theories of collisions, cannibalism, merger, etc.The fourth indirect proof of the positive curvature of the Universe is the occurrence of background radiation, because that must vanish in hyperbolic space irrespective of its origin. The gravitational lens effect acquires another theoretical form, as usual, in the case of remote galaxies, because it is impossible to distinguish between gravitator and lensing image. 相似文献
38.
Jaroslav Weiser 《Aquatic Sciences - Research Across Boundaries》1949,11(1-2):65-71
Ohne Zusammenfassung 相似文献
39.
Jaroslav Hofierka Juraj Parajka Helena Mitasova & Lubos Mitas 《Transactions in GIS》2002,6(2):135-150
Regularized Spline with Tension (RST) is an accurate, flexible and efficient method for multivariate interpolation of scattered data. This study evaluates its capabilities to interpolate daily and annual mean precipitation in regions with complex terrain. Tension, smoothing and anisotropy parameters are optimized using the cross-validation technique. In addition, smoothing and rescaling of the third variable (elevation) is used to minimize the predictive error. The approach is applied to data sets from Switzerland and Slovakia and interpolation accuracy is compared to the results obtained by several other methods, expert-drawn maps and measured runoff. The results demonstrate that RST performs as well or better than the methods tested in the literature. The incorporation of terrain improves the spatial model of precipitation in terms of its predictive error, spatial pattern and water balance. 相似文献
40.
nma nu SS u nmau u nau a¶rt;a ¶rt;u nma u u a au 11-mu ua. u ¶rt; nm ¶rt; n. a¶rt;am nuu nu SS u. 相似文献