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931.
The aim of this work was to study seasonal variation of histopathological and histochemical markers in blue mussels (Mytilus edulis L.) exposed to pyrogenic PAH contaminants. Mussels were collected in January, June, September and October from a sampling site in the vicinity of the discharge from an aluminium smelter and from a clean reference site. Histopathological analysis was carried out on the digestive gland (DG) and the gonads, lipofuscin and neutral lipids were analysed in the DG. Clear responses in lipofuscin and neutral lipids were detected in the DG of mussels collected from the polluted site at some sampling times. Moreover, these mussels presented atrophy in digestive tubules and haemocytic aggregates in the gonad and DG. However, in all parameters studied, the magnitude of the response showed clear seasonal variation. 相似文献
932.
V. S. Rakitin E. V. Fokeeva E. I. Grechko A. V. Dzhola R. D. Kuznetsov 《Izvestiya Atmospheric and Oceanic Physics》2011,47(1):59-66
The results of the carbon monoxide total content measurements over Moscow and Zvenigorod for 2005–2008 are compared with the same data sets for Moscow 1986–2005 and Beijing, 1992–2007. Two identical medium resolution diffraction spectrometers (resolution 0.2 cm?1) with solar tracking system were used. The CO total content measured simultaneously over the city and over Zvenigorod Scientific Station (ZSS) of the Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences (60 km west from Moscow). This method allows to isolate an urban part of CO content. The acoustic locator SODAR LATAN-3 measurements permitted us to study the influence of the carbon monoxide ventilation conditions upon level of pollution. Correlation coefficients between the urban part of CO content and average wind speed for cold and warm seasons were obtained. The data sets analysis showed a preeminent effect of the wind within boundary layer (up to 300 m) over the CO ventilation. The urban part of the CO content hasn’t increased in spite of more than quintuple increase of the motor-vehicles number in Moscow. An increase of the rural CO total column for the 1970–1985 has transformed into its virtually stable amount in between of 1986 to 2000, changed then to a decrease for 2001–2008. We noted the 2008 as “the year of the CO total column minimum” over the past decade. The effect of urban CO sources influence on the CO total column in rural area is small, i.e. on a level of 3% of the total number of measurements. The number of extremal daily values for Moscow is estimated as 5%, and 20% for Beijing. 相似文献
933.
L. P. Golobokova V. E. Pavlov I. V. Khvostov T. V. Khodjer 《Izvestiya Atmospheric and Oceanic Physics》2011,47(3):329-335
We consider the resemblance between the ion composition of the fraction of soluble aerosols and gaseous admixtures in the atmospheric surface layer at the high-level Mondy station (East Sayan), those in the Listvyanka settlement south of Lake Baikal, in the city of Irkutsk, and at the Primorskaya station near the city of Ussuriysk (Primorskii krai). We use measurement data on the concentrations of the following ions: HCO 3 ? , SO 4 2? , NO 3 ? , Cl?, H+, Na+, K+, Mg2+, Ca2+ in the soluble fraction of aerosols and gases HNO3, HCl, NH3, and SO2 in air samples over a 10-year period conducted in the mode of online monitoring. We found the lognormal form of distributions of concentrations of each of the abovementioned components according to the number of samples. A versatile scheme of the distribution of mean geometric concentrations of atmospheric components was proposed for all four groups. 相似文献
934.
935.
E. F. Mikhailov V. V. Merkulov S. S. Vlasenko T. I. Ryshkevich U. J. Pöschl 《Izvestiya Atmospheric and Oceanic Physics》2011,47(6):747-759
We describe a new differential analyzer implementing a technique for studying the hygroscopic properties of filter-precipitated aerosol particles based on a katharometric measurement of the amount of water vapor absorbed by an aerosol sample. The instrument has been tested on particles of sodium chloride and ammonium sulphate. A comparison of our data with the results of analogous measurements described in literature shows that the suggested technique has several important advantages, i.e., (1) higher sensitivity, which allows the measurement of particles of no more than 0.1 mg in mass; (2) a wide range of relative humidity variations (up to 99% at an accuracy of 0.06% RH at the upper-range value); (3) the absence of intermediate measurement steps connected with the need to account for water absorption by elements of a measurement system; and (4) the absence of restrictions to the size and shape of particles studied. In addition, the measurement technique rules out the possibility of errors caused by the kinetic effects of mass transport in the aerosol-water vapor system. 相似文献
936.
937.
A. V. Eliseev 《Izvestiya Atmospheric and Oceanic Physics》2011,47(2):131-153
ensemble simulations with the A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences (IAP RAS) climate
model (CM) for the 21st century are analyzed taking into account anthropogenic forcings in accordance with the Special Report
on Emission Scenarios (SRES) A2, A1B, and B1, whereas agricultural land areas were assumed to change in accordance with the
Land Use Harmonization project scenarios. Different realizations within these ensemble experiments were constructed by varying
two governing parameters of the terrestrial carbon cycle. The ensemble simulations were analyzed with the use of Bayesian
statistics, which makes it possible to suppress the influence of unrealistic members of these experiments on their results.
It is established that, for global values of the main characteristics of the terrestrial carbon cycle, the SRES scenarios
used do not differ statistically from each other, so within the framework of the model, the primary productivity of terrestrial
vegetation will increase in the 21st century from 74 ± 1 to 102 ± 13 PgC yr−1 and the carbon storage in terrestrial vegetation will increase from 511 ± 8 to 611 ± 8 PgC (here and below, we indicate the
mean ± standard deviations). The mutual compensation of changes in the soil carbon stock in different regions will make global
changes in the soil carbon storage in the 21st century statistically insignificant. The global CO2 uptake by terrestrial ecosystems will increase in the first half of the 21st century, whereupon it will decrease. The uncertainty
interval of this variable in the middle (end) of the 21st century will be from 1.3 to 3.4 PgC yr−1 (from 0.3 to 3.1 PgC yr−1). In most regions, an increase in the net productivity of terrestrial vegetation (especially outside the tropics), the accumulation
of carbon in this vegetation, and changes in the amount of soil carbon stock (with the total carbon accumulation in soils
of the tropics and subtropics and the regions of both accumulation and loss of soil carbon at higher latitudes) will be robust
within the ensemble in the 21st century, as will the CO2 uptake from the atmosphere only by terrestrial ecosystems located at extratropical latitudes of Eurasia, first and foremost
by the Siberian taiga. However, substantial differences in anthropogenic emissions between the SRES scenarios in the 21st
century lead to statistically significant differences between these scenarios in the carbon dioxide uptake by the ocean, the
carbon dioxide content in the atmosphere, and changes in the surface air temperature. In particular, according to the SRES
A2 (A1B, B1) scenario, in 2071–2100 the carbon flux from the atmosphere to the ocean will be 10.6 ± 0.6 PgC yr−1 (8.3 ± 0.5, 5.6 ± 0.3 PgC yr−1), and the carbon dioxide concentration in the atmosphere will reach 773 ± 28 ppmv (662 ± 24, 534 ± 16 ppmv) by 2100. The
annual mean warming in 2071–2100 relatively to 1961–1990 will be 3.19 ± 0.09 K (2.52 ± 0.08, 1.84 ± 0.06 K). 相似文献
938.
We considered the problem dealing with the far field of internal gravity waves generated by the source oscillating in the
vertical. It is shown that, at a fixed observation point, we first record the arrival of the main wave front of a separate
mode followed by the arrival of two fronts of an additional field of this wave mode, which is caused by the oscillations of
the source, the asymptotics near the additional wave front being expressed via Airy function. 相似文献
939.
The composition of suprabenthic crustacean assemblages, their diversity, production (P) and production/biomass (P/B) ratios, were analyzed at species level along two transects situated to the north (N) and south (S) of Mallorca (Balearic Islands, western Mediterranean) at depths between 134 m and 760 m, based on a ca. bi-monthly sampling performed between August 2003 and June 2004. Differences with depth and season in assemblage composition and diversity were analyzed as a function of the contrasting environmental features (e.g. water mass dynamics) of the two areas. We identified 187 species (18 decapods, 5 euphausiids, 16 mysids, 76 gammaridean amphipods, 13 hyperiids, 1 caprellid, 21 isopods and 37 cumaceans). Substantial mesoscale variability in the deep-sea suprabenthic assemblages coupled with diversity trends between the N and S transects were found. Seasonality was the most important gradient influencing the dynamics of suprabenthos over the upper (350 m) and middle (650–750 m) slope in the N area. Conversely, the S area appeared to be more stable temporally with depth as the main gradient inducing assemblage differences. Different depth-related patterns were observed both for diversity and P/B. To the north diversity was very low at the shelf-break, increasing on the upper-slope (H′ > 3.00) and then decreasing again on the middle-slope. To the south diversity increased smoothly downward, reaching the highest values on the middle-slope. Regarding productivity, P/B was highest at intermediate depths to the north (over ca. 450–500 m), while to the south highest P/Bs were found deeper (over ca. 600–650 m). The higher P/B at intermediate depths found along N are likely due to higher % of organic matter (OM) in sediments, a product of oceanographic frontal systems. In particular, P/B was higher along N among omnivores and detritus feeders (e.g. Andaniexis mimonectes, Lepechinella manco and combined cumaceans), coupled to enriched OM in sediments, while along S mesoplanktonic carnivores (Rhachotropis spp.) had higher P/Bs. We conclude that on the north slope the influence of frontal systems and more active flow dynamics of different water masses (WIW and LIW) increases natural disturbance in the area, increasing productivity and diversity of suprabenthic peracarids in the Benthic Boundary Layer. Also, species showed a displacement of their average distributions (their Centres of Gravity, CoG) to shallower depths along N, which is another indicator of more favorable habitat conditions for suprabenthos in the 400–500 m range at N. 相似文献
940.
On the basis of the results of regional reanalysis of the atmospheric circulation presented with a resolution of 9 km, the
process of formation of breezes is studied for the case of weak synoptic background activity in the rectilinear part of the
west coast of the Black Sea for the period 01–04.07.2007. It is shown that the gravitational currents, breeze fronts, and
intense internal waves are formed under these conditions in the troposphere during the daytime. The Hovm?ller diagrams of
the wind velocity and the maps of the vertical sections of potential temperature, vertical velocity of the air masses, and
other parameters are presented. On the basis of these diagrams and maps, we obtain quantitative estimates of the wind velocity
in the breeze and of the velocity of propagation of the breeze front and compare these estimates with the available literature
data. 相似文献