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排序方式: 共有610条查询结果,搜索用时 31 毫秒
161.
Ivan Kimák Karel Kudela P. V. Vakulov Reviewer S. Fischer 《Studia Geophysica et Geodaetica》1982,26(2):207-211
Summary Data obtained from apparatus detecting energetic particles on low altitude polar orbiting satellite Intercosmos-13 show enhancement of quiasitrapped proton flux (Ep=1–11 MeV) near L=4 in comparison with both and lower L. This phenomenon persists during intervals with low level of geomagnetic activity. Possibility of influence of false pulses on the result is discussed. 相似文献
162.
Jaroslava Bošková František Jiříček Reviewer S. Fischer 《Studia Geophysica et Geodaetica》1982,26(3):295-299
Summary In the set of VLF data from the Interkosmos-14 satellite (launched on 11 December 1975 with apogee height of 1707 km, perigee 345 km and inclination 74°) as received in direct telemetry transmissions at the Observatory Panská Ves (Czechoslovakia), ion cyclotron whistlers were found at unusually high geomagnetic latitudes. These whistlers indicate a marked decrease of proton density in the close vicinity of the satellite with increasing geomagnetic latitude. It appeared, moreover, that proton whistlers at higher geomagnetic latitudes even sensitively reflected the rapid changes of plasma parameters within the region of the mid-latitude trough of light ions. 相似文献
163.
Priv.-Doz. Dr. med. H. Rüden Prof. Dr. med. E. Thofern Dr. med. P. Fischer Dr. Ing. U. Mihm 《Pure and Applied Geophysics》1978,116(2-3):335-350
For a period of approximately six months the concentrations of airborne microorganisms were determined by the uptake of their day-characteristic at local places differing by the extent of air pollution. By simultaneously recording the meteorological parameters as temperature, relative humidity, direction and velocity of wind and intensity of solar radiation, it was intended to find out the relationship between these factors and the viability of airborne microorganisms. The present data show an oscillation of the concentration counts over a wide range and seem not yet to depend on the local situation of air pollution.In a further series of experiments the atmospheric aerosol <10 m was collected on air-filters. The decreased substances were extracted from the filter material by aqueous and organic solutants and tested for their antimicrobial activities. In this context the seasonal dependence of the microbicidal activity of organic compounds of aerosol is discussed. 相似文献
164.
165.
166.
Irene Fischer 《Journal of Geodesy》1954,28(4):343-353
The deflection of the vertical at 23 stations was determined by gravimetrical methods and compared to the difference of astronomic
observations and geodetic values of the European adjustment.
The results show a fair agreement between the two independent sets of values, indicating that doubts about the relative reliability
of submarine gravity observations are not justified. A systematic discrepancy in the meridian components of the deflection
may reflect on theHayford ellipsoid as used in the European adjustment.
Zusammenfassung Auf 23 Stationen wurde die Lotabweichung gravimetrisch bestimmt und den astro-geod?tischen Werten der europ?ischen Ausgleichung gegenübergestellt. Die beiden Ergebnisse stimmen sehr gut überein. Damit werden die Bedenken hinf?llig, die sich gegen den Wert von Messungen in Unterseebooten richteten. Systematische Abweichungen in den meridionalen Komponenten beruhen m?glicherweise auf der art der Anwendung des Hayfordschen Ellipsoids in der Ausgleichung des Zentraleurop?ischen Netzes.
Resumen La desviación de la vertical en 23 estaciones ha sido determinada por el método gravimétrico y compara con los resultados astrogeodéticos de la compensación europea. Existe muy buen acuerdo entre los dos conjuntos de datos, que demuestra que las dudas emitidas en cuanto al valor de las observaciones en submarino son injustificadas. Una discordancia sistemática en las componentes meridianas podria ser debida al empleo del elipsoide deHayford en la compensación de la red europea.
Résumé La déviation de la verticale en 23 stations a été déterminée par la méthode gravimétrique et comparée aux résultats astrogéodésiques de la compensation européenne. Il y a très bon accord entre les 2 ensembles de données, ce qui montre que les doutes émis quant à la valeur des observations en sous-marins sont injustifiés. Une discordance systématique dans les composantes méridiennes pourrait être due à la fa?on dont on a employé l'ellipso?de deHayford dans la compensation du réseau central européen.
Sommario E'stata determinata col metodo gravimetrico la deviazione della verticale in 23 stazioni e comparata ai risultati astro-geodetici della compensazione europea. Vi é molto buon accordo tra i due insiemi di dati, ciò che dimostra che i dubbi emessi circa il valore delle osservazioni in sottomarino sono ingiustificati. Una discordanza sistematica tra le componenti maridiane potrebbe essere dovuta all'impiego nella compensazione della rete central europea dell'ellisoide diHayford.相似文献
167.
Dr. R. Fischer 《Mineralogy and Petrology》1972,17(3):196-207
Zusammenfassung Die Kristallstruktur von Molybdomenit, PbSeO3, wurde mit Hilfe von Einkristallmethoden bestimmt und nach der Methode der kleinsten Quadrate verfeinert. Die Gitterparameter, der Elementarzelle (Raumgruppe P21/m–C
2h
2
) betragen:a
0=6,91,b
0=5,48,c
0=4,51 Å, =112° 50;Z=2. Mit allen beob. Reflexen wurde einR-Wert von 0,079, unter Einschluß derHamilton-Reflexe einR-Wert von 0,092 erhalten. Die Selenatome sitzen an der Spitze einer trigonalen Pyramide, deren Basis aus drei Sauerstoffatomen besteht. Die vier nächsten Sauerstoffnachbarn des Bleis liegen zwar auf einer Seite, doch sind die weiteren fünf Sauerstoffabstände nicht viel länger. Die Baueinheiten sind zu einem dreidimensionalen Gerüst verknüpft.
Mit 2 Abbildungen 相似文献
The crystal structure of molybdomenite, PbSeO3
Summary The crystal structure of molybdomenite, PbSeO3, has been determined by single crystal X-ray methods and refined by the full-matrix least-squares technique. Molybdomenite crystallizes in the monoclinic space group P 21/m–C 2h 2 ,a 0=6.91,b 0=5.48,c 0=4.51, =112° 50;Z=2. With all abserved reflections aR=0.092. The SeO3 2–-ion has a pyramidal shape with the selenium at the vertex and three oxygen atoms at the base. Lead has the nearest four oxygen neighbours lying all to one side, but ht edistances to the next five oxygens lying to the other side are not much longer. These units are linked together to a three-dimensional structure.
Mit 2 Abbildungen 相似文献
168.
Phytoplankton community composition and size distribution in the Langat River estuary,Malaysia 总被引:1,自引:0,他引:1
Majbritt?Fischer?Lassen Mette?Elisabeth?Bramm Katherine?RichardsonEmail author Fatimah?Yusoff Muhamed?Shariff 《Estuaries and Coasts》2004,27(4):716-727
Phytoplankton patchiness, as expressed by community composition and size distribution, during the rainy season in the Langat River estuary (Malaysia) is described. Four sites in the estuary were sampled on two different occasions. The sampling area covered a stretch of the river from upstream to downstream of aquaculture activities (shrimp farms). Water samples from a shrimp farm outlet were also analyzed for nutrient and phytoplankton content. Differences in community structure between stations were found by means of multivariate procedures. Genera composition and total biomass were related to environmental factors, revealing salinity, light, and nutrients as important explaining factors. Elevated phytoplankton biomass and total phosphorus concentration, as well as lower inorganic nitrogen: phosphorus ratios, were found downstream of the shrimp farming activities. The size distribution spectrum of the phytoplankton population downstream of the shrimp farms was significantly different from that at the other stations but not different than that found in the sampled effluent from the shrimp farms, where phytoplankton biomass was also high. Twenty-two of the 24 recorded genera from the shrimp farm outlet were also found downstream of the farming activities. A number of different environmental factors potentially alter conditions for phytoplankton in the lower reaches of the estuary as compared to the upper regions. A cause and effect relationship explaining the differences noted between the upper and lower reaches of the estuary cannot be established. This study suggests that nutrient enrichment from the shrimp farming activities is of a magnitude that may contribute to the phytoplankton community changes observed in the lower reaches of the estuary. 相似文献
169.
Relative sea level at Vancouver, British Columbia rose from below the present datum about 30,000 cal yr B.P. to at least 18 m above sea level 28,000 cal yr B.P. In contrast, eustatic sea level in this interval was at least 85 m lower than at present. The difference in the local and eustatic sea-level positions is attributed to glacio-isostatic depression of the crust in the expanding forefield of the Cordilleran ice sheet during the initial phase of the Fraser Glaciation. Our findings suggest that about 1 km of ice was present in the northern Strait of Georgia 28,000 cal yr B.P., early during the Fraser Glaciation. 相似文献
170.
Weak tidal correlation of NW-Bohemia/Vogtland earthquake swarms 总被引:3,自引:0,他引:3
We analyze the possible effect of solid Earth tidal stresses upon a vertical strike-slip fault in NW-Bohemia/Vogtland, central Europe, typical by occurrence of swarm earthquakes. The horizontal components of solid Earth tidal stresses were found strongly to prevail and to reach the level of 2 kPa. We examined tidal triggering as influence of tidal stresses to launching the swarm activity in relative absence of other stress disturbances. The onset times of 46 swarms of mostly ML < 3 earthquakes that occurred in the period 1991–2005 displayed an increased occurrence near the fortnightly maximum of tidal extensive normal stress. The statistical test however did not prove a statistically significant correlation indicating a triggering effect of fault extension due to tidal loading. We also examined tidal effects to the already running seismic activity of the prominent 2000 swarm by comparing the tidal stress distribution in the investigated period with the distribution of tidal stresses in the occurrence times of each earthquake. The results show that these distributions are almost similar, which indicates that individual earthquakes occur independent of tidal stresses. The unclear tidal correlation of the swarm seismicity may be interpreted by small amplitudes and rates of tidal stress changes compared to the amplitudes and rates of coseismic stress perturbations and of pressure bursts of deep generated fluids. 相似文献