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311.
Gravitational potential energy of Jupiter, Saturn, Uranus and Neptune has been computed on the basis of density models and compared. It has been stated that the specific potential energy per unit mass does not differ significantly. 相似文献
312.
‘Old’ water contributions to snowmelt runoff in a stream can be defined as water which was stored in the catchment prior to the start of the runoff event in question. We used mass balance techniques for natural oxygen-18 and several chemical parameters (electrical conductivity, Ca and Mg) to estimate the magnitude and timing of ‘old’ water contributions to snowmelt runoff in the Apex River watershed during the 1983 field season. The Apex River catchment is located in the southern part of Baffin Island, Northwest Territories, Canada. The watershed has an area of 60 km2, it is in the zone of continuous permafrost, and the geology is dominantly Precambrian gneiss with sporadic, thin, glacial overburden. The isotopic data indicate that for the snowmelt season of 1983 (third highest peak discharge of 11 years of record), approximately 50 per cent of the peak stream discharge consisted of ‘old’ water. Our data also suggest that about 60 per cent of the entire 1983 hydrograph was ‘old’ water. The chemical parameters give old water contributions which are at least 10 per cent less than the isotopically-derived estimate, but they are consistent with the isotopic estimate during peak flow. 相似文献
313.
Milan Burša 《Earth, Moon, and Planets》1994,64(3):265-271
The second zonal and the second sectorial Stokes parameters of the Moon's gravitational field and/or the polar and equatorial flattenings of the lunar triaxial level ellipsoid have been explained by the tidal and rotational distortions due to the Earth. The Epoch at which the Moon's figure formation was finished has been estimated as 1.6 × 109 y B. P. when the Earth-Moon distance was about 168 400 km and the orbital/rotational period of the Moon about 8 days. 相似文献
314.
Summary The parameters of the normal Earth's gravity field, determined from contemporary satellite data are discussed and compared with the parameters of the normal Helmert system (1901 to 1909).Dedicated to Academician Alois Zátopek on His 65th Birthday 相似文献
315.
Summary It has been demonstrated on the basis of recent astronomical, satellite and LLR data that the variations in the Newtonian constant of gravitation, if any, do not exceed5××10
–15 cy–1 of its relative value.
¶rt;a amuu u nmu a¶rt;u u a auu naa, m auauuaumau nm, u u um, n¶rt;m5×10 –15 mmu –1 mum au.相似文献
316.
Summary On the basis of the conservation of the Earth-Moon angular momentum, the period of the Earth's resonance rotation and Moon's revolution and the relation between tidal deceleration of the Earth's rotation and of the Moon's mean motion are derived theoretically. The comparison of the theoretical relation with the observed values indicates that a mechanism should exist which decreases the maximum principal moment of the Earth's inertia bydC/dt=–3.2×1029
kg· . m2 cy–1.
¶rt; u au ma uma ¶rt;uu um -a, ¶rt;am mmuu ¶rt; a nu¶rt;a au u u uma ¶rt;uu u mu nuu u mu au u u ¶rt; ¶rt;uu . aua mmu mu a¶rt;au auu, ¶rt;am au, m ¶rt; um m u aua ma uuu udC/dt=–3,2×1029 2 (mmu)–1.相似文献
317.
Summary The tidal decrease in the Earth's heliocentric longitude generated by the Sun has been computed. It represents the increase in the length of year10–7 s per century. The resonant angular velocity of the Earth's rotation is approximately equal to the present Earth's mean motion, however, for the model used, i.e., considering the Sun as the point-mass.
u u zumu ¶rt;m u, a nuuau m a. ¶rt; mmmm uu ¶rt;u z¶rt;a10–7 a mmu. a za m au u nu aa ¶rt; ¶rt;uu u, u, ¶rt;a, umam ¶rt;a ¶rt;u m a.相似文献
318.
The first event in the crystallization of pyroxenite in nodules from Bory was the growth of clinopyroxene at an uncertain 1,190(30)° C and 2.5(2)GPa. Lamellae of garnet and orthopyroxene in CPX nucleated slightly above 1,000° C and equilibrated at 940(20)° C and 3.9(6)GPa. The growth of lamellae was followed by crystallization of groundmass that corroded lamellar clinopyroxene. Phenocrysts of clinopyroxene and orthopyroxene in olivine pyroxenite from T?i Studně crystallized at 1,290(100)° C and 2.3(1.4)GPa. The lamellae in both phases nucleated between 1,400 and 1,200° C and equilibrated at 860(40)° C and 0.2(3)GPa, before regional metamorphism. (The temperatures of nucleation mentioned rest on uncertain assumptions in the phase-boundary theory and should be viewed with caution.) The serpentinized peridotite-pyroxenite from De?tná contains clinopyroxene relics (the only primary phase) with lamellae of a 1.42 nm sheet silicate topotactically pseudomorphing enstatite, possibly a chlorite or vermiculite. All phases in lamellae are crystallographically oriented in the hosts. The present cases suggest that when applying the theory of phase boundaries, a modified procedure of Robinson et al. should also be considered, in which identity of adjacent areas, rather than just vectors, is the basis of calculation. Spinel lamellae in CPX are bounded not only by faces parallel to coherent interfaces, but also by faces formed by accumulation of incoherent edges of growth ledges. 相似文献
319.
320.
Summary On the basis of the angular momentum balance in the Earth — Moon — Sun system and with the use of the observed secular variation in the Moon's mean motion and the variation in the second zonal geopotential harmonic, the tidal and nontidal variations in the angular velocity of the Earth's rotation are computed and different values describing the field of tidal forces estimated.
¶rt; u au m uma ¶rt;uu um —a—, um n a¶rt;u uu ¶rt; ¶rt;uu u m aauunmuaa nuu u nuu auauu mu au u u ¶rt;am ua a ¶rt;a uu, nuau n u nuu mu.相似文献