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51.
Izvestiya, Atmospheric and Oceanic Physics - The main characteristics (coherences, phase velocities, propagation directions, characteristic periods, and amplitudes) of wave disturbances in the...  相似文献   
52.
Methods of celestial mechanics are used to refine a mathematical model for irregularity in the axial rotation of the Earth proposed earlier. This refinement applies corrections (residuals) introduced by perturbations of zonal tides. We examine intraday and near-diurnal variations in the Earth’s axial rotation, and a celestial-mechanical model explaining the origin of the intraday and near-diurnal oscillations in the rotational angular velocity is constructed. The correspondence between the variations of the intrayear rotational irregularity and the overall angular momentum of the atmosphere is analyzed.  相似文献   
53.
Using the phenomenon of the partial reflection of acoustic waves from anisotropic wind-velocity and temperature inhomogeneities in the lower troposphere is justified in determining the structure of these inhomogeneities. The data (obtained with the method of bistatic acoustic sounding) on signals reflected from stratified inhomogeneities in the lower 600-m layer of the troposphere are given. A detonation-type pulsed acoustic source was used. The methods of isolating a small (in amplitude) reflected signal against the background of noise and determining the reflecting-layer height and the partial-reflection coefficient from the measured parameters (time delay and amplitude) of a reflected signal are presented. The method of estimating the vertical gradients of the effective sound speed and the squared acoustic refractive index from the partial-reflection coefficient previously calculated is described on the basis of an Epstein transition-layer model. The indicated parameters are experimentally estimated for concrete cases of recording reflected signals. A comparison of our estimates with independent analogous data simultaneously obtained for the same parameters with monitoring instruments (a sodar and a temperature profiler) has yielded satisfactory results.  相似文献   
54.
Izvestiya, Atmospheric and Oceanic Physics - Conditions for the occurrence of the “voice of the sea” within the infrasonic range are studied and its parameters are determined from...  相似文献   
55.
Doklady Earth Sciences - The results of study of the Hovsgol earthquake with M w = 4.9, which occurred on December 5, 2014, in the northern part of Hovsgol Lake in Mongolia, are presented. An...  相似文献   
56.
57.
Zusammenfassung Die Schalen limnischer Gastropoden und Pelecypoden aus verschiedenen mitteleuropäischen Seen zeigen neben der zu erwartenden, von marinen Mollusken grundsätzlich abweichenden Isotopenzusammensetzung beim18O, ortsspezifische Unterschiede, die auf unterschiedlich isotopisch zusammengesetzte Wässer in den einzelnen Seen zurückzuführen sind.So spiegeln die Mollusken des Bodensees die isotopische Zusammensetzung des schmelzwasserführenden Alpenrheins wider und sind entsprechend arm an18O, während beim sehr flachen Neusiedler See durch starke Evaporation das18O/16O-Verhältnis in Richtung des schwereren Isotops verschoben ist.
Isotope geochemistry of mollusc shells from central European lakes
Summary Carbonate shells of limnic gastropods and pelecypods from various lakes of central Europe have an isotopic composition which is principally asimilar—as to be expected—to the composition of marine molluscs.Differences in the18O concentration can be related to the specific isotopic composition of the water in which the molluscs live. The low18O concentration of-for example-Lake Constance molluscs reflects the isotopic composition of the Rhine Rive, which carries abundant melting water from the Alps with a correspondingly low18O concentration. In the Neusiedler See, strong evaporation leads to an enrichment in the heavy isotope18O in the water of the very shallow lake and consequently in the mollusc shells.


Mit 2 Abbildungen  相似文献   
58.
On their way from the Rhine estuary into the North Sea and Dutch Wadden Sea, Rhine sediments “lose” large portions of their original heavy metal concentrations. Until now these losses were explained by a mobilization process, solubilization — the decomposition products of organic matter form soluble organometallic complexes with the metals of the sediment. Our investigations of the sediments of the Elbe clearly indicate that a mixing process, whereby highly polluted Elbe sediments mix with relatively non-polluted North Sea sediments, rather than solubilization, is the cause of the dilution of heavy metals in the sediments of the Elbe estuary. Because of the similarity of the Elbe data with those from the Rhine River, we propose that a mixing process is also effective in the Rhine estuary and adjacent North Sea areas. The mechanism by which heavy metals are “diluted” is important to the marine ecosystem. In the mixing process proposed in this paper, the heavy metals fixed to the suspected material are trapped in bottom sediments of the marine environment, whereas solubilization would increase the concentration of heavy metals in the sea water and thus they would be more available for uptake by aquatic organisms.  相似文献   
59.
Zusammenfassung Aus randlichen Teilbecken des Tuz Gölü (Salzsee), Türkei, werden bis zu 40 cm große, über dem Wasserspiegel des Salzbeckens liegende Salzschirme beschrieben, deren einzelne Anwachsstreifen verschiedenen Wasserständen bei der Evaporation des Beckens entsprechen. Die Schirmform kann durch bevorzugtes Horizontal-Wachstum der NaCl-Kristalle in der obersten Wasserschicht bei gleichzeitig sinkendem Wasserspiegel gedeutet werden. Ansatzpunkte für die Schirmbildung sind im Sediment steckende NaCl-inkrustierte Pflanzenstengel, die in das Becken eingeschwemmt wurden.
Occurrence and origin of Salt-umbrellas in the Tuz Gölü (Salt-Lake), Turkey
Salt umbrellas with a maximum diameter of 40 cm are a special form of NaCl growth. They occur above the water surface of evaporating Tuz Gölü (Salt Lake) in Central Anatolia, Turkey. The different growth rims of the umbrella correspond to the different water levels during evaporation of the basin.The umbrella-like shape is best to be explained by the fact that within the uppermost water layer (highest NaCl-concentration) NaCl-crystals grow preferentially in horizontal direction while the water level is steadily sinking.Small plant-stems having been brought into the basin and incrusted by NaCl act as crystallization centers for the formation of the umbrellas.


Herrn R. H. Okan, Direktor der Salzwerke von Yavsan Tuzlasi, sowie Herrn Georg Irion, Heidelberg, danke ich herzlich für die wertvolle Mithilfe bei der Probenahme.  相似文献   
60.
Algal and mollusk carbonates in Lake Constance sediments proved Sr/Ca-ratios unusually high for fresh water environments. In most cases the observed Sr/Ca-ratios for mollusk shells fall into the range of marine mollusks. These high ratios can be attributed to a high Sr/Ca-ratio (6 ± 0.5) in Lake Constance water. In the Alpenrhein River, the main influent of Lake Constance, Sr/Ca-ratios were found to vary between 4.7 (at high water discharge) and 10.7 (at low water level). High Sr/Ca-ratios correspond to high sulfate contents. From all tributaries of the Alpenrhein, the Ill River revealed to have the highest Sr-contents and Sr/Ca-ratios. A detailed study of its drainage area led to the detection of exceptionally high Sr-contents (up to 11.6 mg/l) and Sr/Ca-ratios (up to 116.5) in springs of the Triassic Ladinian stage of the Austroalpine nappe zone (Ostalpine Deckenzone). The fact that high Sr-concentrations occur together with high sulfate contents leads to the assumption that celestite is leached within Ladinian rocks. This assumption is confirmed by the evidence that celestite deposits have been reported from the same stratigraphic section (Wettersteinkalk) from other localities in the Northern Calcareous Alps.
Zusammenfassung In Bodensee-Sedimenten auftretende biogene Carbonate zeigen ein für Süßwasserbildungen ungewöhnlich hohes Sr/Ca-Verhältnis; die meisten bei Mollusken gefundenen Werte fallen in den marinen Bildungsbereich. Diese hohen Sr/Ca-Verhältnisse können durch das hohe Sr/Ca-Verhältnis des Bodenseewassers (6 ± 0,5) gedeutet werden, das seinerseits vom noch höheren Sr/Ca-Verhältnis des wichtigsten Zuflusses, des Alpenrheins (4,7 bei Hochwasser, 10,7 bei Niedrigwasser) geprägt wird. Hohe Sr/Ca-Verhältnisse fallen mit hohen Sulfatgehalten zusammen. Von allen Nebenflüssen des Alpenrheins zeigt die Ill die höchsten Sr-Gehalte und Sr/Ca-Verhältnisse. Eine Untersuchung des Einzugsgebietes der Ill führte zur Auffindung von Bächen und Quellen mit ungewöhnlich hohen Sr-Gehalten (bis 11,6 mg/l) und Sr/Ca-Verhältnissen (bis 116,5), die im Ladin der Alpinen Trias der Ostalpinen Deckenzone entspringen. Da hohe Konzentrationen mit hohen Sulfatgehalten zusammenfallen, kann angenommen werden, daß Coelestin aus Gesteinen des Ladins ausgelaugt wird und die hohen Sr/Ca-Verhältnisse der Wässer bedingt. Diese Annahme wird durch die Tatsache erhärtet, daß Coelestin im gleichen stratigraphischen Horizont (Wettersteinkalk) an mehreren anderen Stellen der Nördlichen Kalkalpen beobachtet wurde.
  相似文献   
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