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11.
Two quasars SDSS J010013.02+280225.8 and J030642.51+185315.8 with redshifts z = 6.30 and z = 5.363 were recently discovered. Their apparent magnitudes in the standard cosmological model give the luminosities of Lbol ~ 4.3 × 1014L and Lbol ~ 3.4 × 1014L. In the framework of modern concepts it is accepted that the energy release of quasars is provided by the accretion onto black holes with masses of 1.24 ± 0.19 × 1010M and 1.07 ± 0.27 × 1010M. As within the standard cosmological model the ages of these objects are about one billion years, this creates serious difficulties for the scenario of formation of such objects. Here we interpret the ultra-high luminosities of quasars as the effect of lensing of their radiation by the foreground globular clusters or dwarf galaxies.  相似文献   
12.
The distribution of pairwise distances f(l) for different dependences r(z) of the metric distance is used to reveal inhomogeneities in the spatial distribution of 201 long (T 90>2s) gamma-ray bursts with measured redshifts z. For a fractal set with dimensionality D, this function behaves asymptotically as f(l) ∼ l D−1 for small l. Signs of fractal behavior with dimensionality D = 2.2–2.5 show up in all the models considered for the spatial distribution of the gamma-ray bursts. Several spatially distinct groups of gamma-ray bursts are identified. The group with equatorial coordinates ranging from 23h56m to 0h49m and δ from +19° to +23° with redshifts of 0.81–0.94 is examined separately.  相似文献   
13.
An analysis of the physical characteristics, orbital parameters, and dynamical stability of the multiple Be star HD 217675 (o And) is presented. Observations on the 6-m SAO and 1.5-m RTT telescopes are used to refine the orbital parameters of the subsystems. The spectral types, absolute magnitudes, and masses of the components are estimated. The total mass of the system is 18 ± 2 M db. It is shown that the configuration of the system is 2 + 2, where one of the subsystems is a spectral binary with a period of 33 d and the outer pair has a period of 117 yr. The parameters of the second inner subsystem are uncertain, making it difficult to draw firm conclusions about the stability of this multiple star.  相似文献   
14.
The general three-body problem with equal masses and zero initial velocities is considered. Sets of initial conditions for which the triple systems decay over comparatively short times, 10T cr < T < 20T cr, are distinguished (T cr is the mean crossing time for a component of the system). These sets form distinct families of structures in the domain of the initial conditions. The properties of trajectories of the bodies within some of these structures are described. It is shown that the set of families is no more than countable. A new classification for families of trajectories in decaying triple systems is proposed. Some problems in classifying trajectories in the three-body problem that must be addressed in the future are formulated.  相似文献   
15.
The behavior of triple systems in the transition zones located between regions of stability is studied in the framework of the general three-body problem with equal masses and zero angular momentum. It is well known that there are exist three stable periodic orbits, namely, the Schubart orbit for the rectilinear problem, the Broucke orbit for the isosceles problem, and the Moore eight-figure orbit. In the space of the initial conditions, these orbits are surrounded by sets of points where bounded motions are observed over substantial time intervals. The transition zones between the Schubart and Moore orbits and the Moore and Broucke orbits are studied. It is shown that the boundaries of the regions of stability can be either smooth and sharp or diffuse. Beyond these boundary regions, the dynamical evolution of triple systems results in a distant ejection of one of the components, or the decay of the system. The distribution of the times when the stability is lost is constructed, and obeys a power law for long time intervals. Three stages in the evolution of an unstable triple system are identified.  相似文献   
16.
Dremova  G. N.  Dremov  V. V.  Orlov  V. V.  Tutukov  A. V.  Shirokova  K. S. 《Astronomy Reports》2015,59(11):1019-1035

The probability of forming a Galactic hypervelocity star is estimated for the scenario of Hills, which describes the dynamical capture of one component of a binary star by the gravitational field of the supermassive black hole in the Galactic center, leading to the ejection of the other component. Ten thousand initial orientations of the binary orbits were considered, and the semi-major axes of the binary orbits were varied in a wide range from 11.3 R to 425 R . Two series of computations were carried out, in which the mass of the supermassive black hole was taken to be 106 M and 3.4 × 106 M . Numerical simulations of encounters of the binary and black hole in the framework of the three-body and N-body problems are used to localize regions favorable for the formation of hypervelocity stars. The motion of the ejected star in the regular field of the Galaxy is calculated, and the conditions under which the star escapes the Galaxy defined. The probability of escaping the Galaxy is caluclated as a function of various parameters the initial separation of the binary components and the distance of the binary from the black hole. On average, the probability of forming a hypervelocity star is higher for closer encounters and more tightly bound binary pairs.

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We consider the evolution of the structure of the velocity field formed by the loops of the trajectory in a generalized Hénon-Heiles model potential. Box-shaped orbits alternating with periodic trajectories are shown to dominate at low values of the energy integral. Signatures of shell-and tube-shaped structures appear as the energy increases. Tube-shaped orbits are associated with stable periodic trajectories with small resonance ratios. Zones of stochastic orbits appear at values of the energy integral close to its critical value, which corresponds to the opening of the zero-velocity contour.  相似文献   
20.
The distributionsf(z) of the redshifts for active galaxies (Seyfert galaxies, radio galaxies, and quasars) have been studied. Some statistically-significant maxima and minima are observed in the distributionsf(z) for these objects. The significance of peaks and gaps increases for the brighter objects, for which the samples are more complete. The clustering of the Seyfert galaxies is significantly different from that of the nearby normal galaxies. The distributionf(z) for the radio galaxies is similar to the analogous distribution for the galaxy clusters. Three of the five peaks in the distributionf(z) for the radio quasars may be caused by the selection effects. Two peaks within the intervalsz (0.5, 0.7) and (1.0, 1.1) are probably real. The corresponding scales of the QSO clustering along the line-of-sight are about 100h –1 Mpc (h is the Hubble constant in the units of 75 km s–1 Mpc–1). The possibility of some global quasi-periodical cycles for the processes of activity is discussed. The period of a cycle for the Seyfert and radio galaxies is about 1×108 years that corresponds to the distances of about 30h –1 Mpc between the shells.  相似文献   
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