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781.
782.
Vladimír Čermák Louise Bodri Jan Šafanda Milan Krešl Petr Dědeček 《Studia Geophysica et Geodaetica》2014,58(3):403-424
Long-term observations of air, near-surface (soil) and ground temperatures, collected between 1994 and 2011, monitored in the Geothermal Climate Change Observatory at Spo?ilov, Prague (GCCO) are analyzed to better understand the relationship between these quantities and to describe the mechanism of heat transport at the land-atmosphere boundary layer. The 17 years long monitoring series provided a surprisingly small mean ground-air temperature offset of only 0.31 K with no clear annual course and with the offset value changing irregularly even on a daily scale. Such value is substantially lower than similar values (1–2 K and more) found elsewhere, but it may be well characteristic for a mild temperate zones, when all so far available information referred rather to more southern locations. As many other observed geophysical data, temperature time series consist of a systematic pattern (usually a set of identifiable components) contaminated by random noise, which makes the identification of the proper pattern difficult. To identify the existing systematic patterns (cycles) of the temperature-time series at several depth levels in the investigated depth interval 0–40 m, the observed data were processed with the help of the Fast Fourier Transform (FFT) and Recurrence Quantification Interval (RQI) analysis. The latter represents recently developed powerful technique to uncover hidden periodicities in a noisy time environment. At low frequency band the RQI may provide far finer resolution than the conventional FFT technique. The results proved considerable similarity for all investigated depth levels. In addition to the annual wave all measured series proved to have a more complex pattern including predominantly 8-year and 11 years long periodicities. The results were compared with similar analysis of the meteorological air temperature series as well as with the results of other similar studies. The potential dynamics explaining the occurrence of the 8-year wave is briefly discussed. 相似文献
783.
Pavel Koten Jiří Borovička Pavel Spurný Stephen Evans Rostislav Štork Andrew Elliott 《Earth, Moon, and Planets》2008,102(1-4):151-156
We carried out double station observations of the Leonid meteor shower outburst, which occurred in the morning hours of November
19, 2006. Using image-intensified cameras we recorded approximately 100 Leonid meteors. As predicted, the outburst was rich
especially in fainter meteors. The activity profile shows that the peak of the outburst occurred at 4:40 ± 0:05 UT. The maximum
reached flux was 0.03 meteoroids km−2 hod−1 for meteors brighter than +6.5 magnitude. 相似文献
784.
785.
786.
Atmospheric waves influence the dynamics and energetic budget of the upper atmosphere. Using the continuous HF Doppler sounder,
we study the wave activity in the ionosphere during tropospheric convective storms in western and central part of the Czech
Republic. The study is focused on acoustic-gravity waves in the period range 2–30 minutes. We discuss possible methods of
distinguishing the waves emitted by meteorological sources from waves of different origin, particularly waves of geomagnetic
origin. In two cases out of twenty-five analysed, we found waves in the infrasonic period range which might be generated by
exceptionally intense meteorological activity in the troposphere. The results differ considerably from those previously obtained
in North America. In the central part of the United States, infrasonic waves were frequently observed during convective storms.
As a possible reason, we discuss different intensity and dynamics of weather systems in both regions. 相似文献
787.
Eva Holtanová Jaroslava Kalvová Jiří Mikšovský Petr Pišoft Martin Motl 《Studia Geophysica et Geodaetica》2010,54(3):513-528
In this study we present results of uncertainty analysis in eight regional climate model (RCM) outputs over the area of the
Czech Republic. The RCM simulations come from the EU 5th Framework program project PRUDENCE (Prediction of Regional scenarios
and Uncertainties for Defining EuropeaN Climate change risks and Effects). Using the analysis of variance we have found that
the main source of uncertainty in projected changes of mean seasonal air temperature is the driving global climate model.
In case of precipitation changes, the RCM is the largest source of uncertainty in all seasons except for the spring. With
the second method, the Reliability Averaging method, we have focused on the uncertainty coming from the RCM itself. The results
of both methods showed that the relative contribution of the regional climate model to the uncertainty of simulated mean seasonal
air temperature and precipitation changes is largest in summer and smallest in winter. 相似文献
788.
Soejono Igor Janoušek Vojtěch Žáčková Eliška Sláma Jiří Konopásek Jiří Machek Matěj Hanžl Pavel 《International Journal of Earth Sciences》2017,106(6):2109-2129
International Journal of Earth Sciences - Cadomian magmatic complexes of the Brunovistulian Domain crop out at the eastern termination of the Bohemian Massif. However, the age, nature and... 相似文献
789.
Ulrych Jaromír Krmíček Lukáš Teschner Claudia Řanda Zdeněk Skála Roman Jonášová Šárka Fediuk Ferry Adamovič Jiří Pokorný Richard 《Mineralogy and Petrology》2017,111(5):761-775
Mineralogy and Petrology - Tachylytes from rift-related volcanic rocks were recognized as: (i) irregular veinlets in host alkaline lava flows of the Kozákov volcano, Czech Republic, (ii)... 相似文献
790.
The first results of the almost one year drop size distribution (DSD) measurement in the Czech Republic are summarised in this study. The ESA-ESTEC 2D videodistrometer was used to measure the rain drop parameters. The average DSD is shown to be of the gamma type. One minute DSDs were evaluated to test the accuracy of analytical DSD models. Parameters of gamma distribution and exponential distribution functions were evaluated for the whole data set as well as for the various rain rate intervals. Regression technique and the method of moments were applied to estimate the parameters of DSD. It is shown that the parameter value strongly depends on the method of computation as well as on the rain type. Its average value is about 0.59 for the average (smooth) one minute DSD while an average value of un-smoothed DSD is 11.0 (moment method) or 5.4 (regression technique). The Joss's shape parameter and the Tokay-Short's parameter CS estimating roughly the rain type are also discussed (if CS>1, the event should be convective). The tendency of increasing numerical value of the CS parameter with the increasing rain rate was observed (the DSDs were distributed into classes respecting the rain rate value) and thus the idea of the convectivity occurrence bounded with the higher CS parameter value was supported. The study also compares the parameters of the average DSD with the averages of parameter values of all 4 183 one minute DSDs. 相似文献