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981.
S. V. Shestov S. V. Kuzin A. M. Urnov A. S. Ul’yanov S. A. Bogachev 《Astronomy Letters》2010,36(1):44-58
Plasma temperature diagnostics in solar flares and active regions has been carried out using data from the SPIRIT spectroheliograph onboard the CORONAS-F satellite. The temperature distribution of the differential emission measure (DEM) has been determined from the relative intensities of spectral lines recorded in the spectral range 280–330 Å in the period from 2001 to 2005. Analysis of these distributions has led to the conclusion about the existence of active regions with various “characteristic” temperature compositions. The presence of a hot plasma with temperatures logT = 6.8?7.2 in active regions has been established for the first time from XUV spectroscopic data and monochromatic X-ray line images. The DEM distribution for intense long-decay flares has also been obtained for the first time and a similarity of the temperature compositions for flares of different classes at the decay phase has been found. The spectra have been modeled on the basis of the calculated DEMs. The systematic discrepancies between the calculated and measured line intensities are discussed. 相似文献
982.
M.L. Moriconi J.I. Lunine A. Adriani E. D’Aversa A. Negrão G. Filacchione A. Coradini 《Icarus》2010,210(2):823-831
Liquid hydrocarbons were long predicted on Titan’s surface before the RADAR instrument onboard Cassini detected lakes poleward of 70°N in July 2006. Before that the Cassini Imaging Science Subsystem (ISS) observed a lake-like feature in the South Pole, named Ontario Lacus, in July 2004. Here we analyze one observation of Ontario Lacus taken by the Visual and Infrared Mapping Spectrometer (VIMS) on 2007 December 5, during the T 38 flyby. This is the best spatially resolved image of a Titan lake to date by an imaging spectrometer, and has been previously reported in Brown et al. (Brown, R.H., Soderblom, L.A., Soderblom, J.M., Clark, R.N., Jaumann, R., Barnes, J.W., Sotin, C., Buratti, B., Baines, K.H., Nicholson, P.D. [2008]. Nature 454, 607–610) and in Barnes et al. (Barnes, J.W. et al. [2009]. Icarus 201, 217–225). The observing geometry and our data processing will be explained, followed by a discussion of the main characteristics of the image. The analyzed image covers a small portion of Ontario Lacus and shows what appears from RADAR data to be a region of modest slope (“ramp”) adjacent to the dark lake itself. Our analysis of 5.0 μm spectral data suggests that the previously reported absorption feature of ethane seen at shorter wavelengths may be produced by damp sediments adjacent to the main liquid basin. The latter appears to be absorbing all of the photons incident upon it in the 5 μm spectral region and shows no discernible absorption features. A characterization of the basin composition and morphology is developed with the help of ISS and RADAR observations. The simplest model consistent with the data is an optically deep lake surrounded by a region in which ethane, propane, possibly methane, and other, less volatile hydrocarbons and nitriles are present mixed into spectroscopically neutral sediments. The dominance of relatively low vapor pressure organics outside the lake itself suggests a retreat of Ontario Lacus associated with evaporation on seasonal or longer timescales, consistent with analysis of RADAR and ISS images. 相似文献
983.
V.?V.?Prokof’eva-MikhailovskayaEmail author A.?N.?Abramenko G.?V.?Baida A.?V.?Zakrevskii L.?G.?Karachkina E.?A.?Sergeeva E.?A.?Zhuzhulina 《Bulletin of the Crimean Astrophysical Observatory》2010,106(1):68-81
Properties of the surfaces of Jupiter’s satellites—Ganymede and Callisto—are shortly described. Their images acquired in space
missions are shown. Causes of the discrepancy between orbital lightcurves of the satellites obtained from the earth and spaceborne
maps of the satellites are considered. The groundbased observations were carried out under phase angles of solar illumination
ranging from 0° to 12°, and the maps were built from images acquired from spacecraft in a wide interval of solar phase angles.
We suggest that the main cause of the discrepancies between the lightcurves is the coherent backscattering effect observed
only at small phase angles of the sun. 相似文献
984.
Photometric observations of the over-contact binary ER ORI were performed during November 2007 and February to April 2008
with the 51 cm telescope of Biruni Observatory of Shiraz University in U, B and V filters (Johnson system) and an RCA 4509
photomultiplier. We used these data to obtain the light curves and calculate the newtimes of minimum light in each filter
and plot the O-C diagram of ER ORI. Using theWilson’s computer code with the help of an auxiliary computer program to improve
the optimizations, the light curve analyses were carried out to find out the photometric elements of the system. 相似文献
985.
M. M. Bisi A. R. Breen B. V. Jackson R. A. Fallows A. P. Walsh Z. Mikić P. Riley C. J. Owen A. Gonzalez-Esparza E. Aguilar-Rodriguez H. Morgan E. A. Jensen A. G. Wood M. J. Owens M. Tokumaru P. K. Manoharan I. V. Chashei A. S. Giunta J. A. Linker V. I. Shishov S. A. Tyul’bashev G. Agalya S. K. Glubokova M. S. Hamilton K. Fujiki P. P. Hick J. M. Clover B. Pintér 《Solar physics》2010,265(1-2):49-127
We report the results of a multi-instrument, multi-technique, coordinated study of the solar eruptive event of 13 May 2005. We discuss the resultant Earth-directed (halo) coronal mass ejection (CME), and the effects on the terrestrial space environment and upper Earth atmosphere. The interplanetary CME (ICME) impacted the Earth’s magnetosphere and caused the most-intense geomagnetic storm of 2005 with a Disturbed Storm Time (Dst) index reaching ?263 nT at its peak. The terrestrial environment responded to the storm on a global scale. We have combined observations and measurements from coronal and interplanetary remote-sensing instruments, interplanetary and near-Earth in-situ measurements, remote-sensing observations and in-situ measurements of the terrestrial magnetosphere and ionosphere, along with coronal and heliospheric modelling. These analyses are used to trace the origin, development, propagation, terrestrial impact, and subsequent consequences of this event to obtain the most comprehensive view of a geo-effective solar eruption to date. This particular event is also part of a NASA-sponsored Living With a Star (LWS) study and an on-going US NSF-sponsored Solar, Heliospheric, and INterplanetary Environment (SHINE) community investigation. 相似文献
986.
987.
M. A. Vashkov’yak 《Solar System Research》2010,44(6):527-540
A new analytical solution of the system of differential equations describing secular perturbations and long-period solar perturbations
of mean orbits of outer satellites of giant planets was obtained. As distinct from other solutions, the solution constructed
using von Zeipel’s method approximately takes into account, in the secular part of the perturbing function, the totality of
fourth order with respect to the small parameter m of the ratio of the mean motions of the primary planet and the satellite. This enables us to describe more accurately the
evolution of satellite orbits with large apocentric distances, which in the course of evolution may exceed the halved radius
of the Hill sphere of the planet with respect to the Sun. Among these are the orbits of the two outermost Neptunian satellites
N10 (Psamathe) and N13 (Neso). For these satellites, the parameter m amounts to 0.152 and 0.165, respectively. Different from a purely analytical solution, the proposed solution requires preliminary
calculations for each satellite. More precisely, in doing so, we need to construct some simple functions to approximate more
complex ones. This is why we use the phrase “constructive analytical.” To illustrate the solution, we compare it with the
results of the numerical integration of the strict motion equations of the satellites N10 and N13 over time intervals 5–15
thousand years. 相似文献
988.
G. A. Avanesov R. V. Gordeev V. A. Grishin B. S. Zhukov S. B. Zhukov E. V. Kolomeets E. B. Krasnopevtseva M. I. Kudelin A. A. Krupin V. M. Murav’ev A. A. Forsh 《Solar System Research》2010,44(5):444-450
A TV system for navigation and guidance (TVSNG) has been designed for solving the navigation and scientific tasks of the Phobos-Grunt mission. It consists of two narrow-angle and two wide-angle television cameras. Each camera has a built-in processor for the real-time processing of received images. The program of TVSNG observations includes three modes: Imaging of Stars, Sequential Imaging, and Landing. The first two modes will be used to calibrate the TVSNG against the stars, to take images of Phobos and Mars, and to detect the dust rings of Mars. In the Landing mode, the height and velocity components of the spacecraft during the landing on Phobos will be measured, and an autonomous selection of the landing site will be made. 相似文献
989.
S. Degl’Innocenti 《Astrophysics and Space Science》2010,328(1-2):201-208
In this contribution I will review the present knowledge about helium and metal diffusion efficiency in the Sun and in old cluster stars and the influence of the uncertainties still present on these mechanisms concerning the stellar characteristics in different evolutionary phases. I will also discuss the relevance of the current uncertainties on the assumed chemical composition for the main evolutionary features of population II stars. 相似文献
990.