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91.
Abstract— We present a new weathering index (wi) for the metallic‐Fe‐Ni‐poor chondrite groups (CK and R) based mainly on transmitted light observations of the modal abundance of crystalline material that is stained brown in thin sections: wi‐0, <5 vol%; wi‐1, 5–25 vol%; wi‐2, 25–50 vol%; wi‐3, 50–75 vol%; wi‐4, 75–95 vol%; wi‐5, >95 vol%; wi‐6, significant replacement of mafic silicates by phyllosilicates. Brown staining reflects mobilization of oxidized iron derived mainly from terrestrial weathering of Ni‐bearing sulfide. With increasing degrees of terrestrial weathering of CK and R chondrites, the sulfide modal abundance decreases, and S, Se, and Ni become increasingly depleted. In addition, bulk Cl increases in Antarctic CK chondrites, probably due to contamination from airborne sea mist.  相似文献   
92.
A list of reports of Lunar Transient Phenomena (LTP) which have been observed in 1972 and 1973 by an international group of amateur astronomers is given. From 907 monitoring observations (1972: 526, 1973: 381) 92 LTP (74 reliable, 18 possible individual sightings) have been reported (1972: 52, 1973: 40) including parallel observations of the same event. The LTP were brightenings, shadings, flashes, colours, moving clouds and brightness diminutions of stars before occultations. 45 LTP events may be expected to be real in a catalogue of criteria for the reliability of observations. Sixteen events have been reported by several independent observers. A short examination of the temporal distributions of monitoring observations and recorded LTP is given.  相似文献   
93.
The line blocking is tabulated for 10 Å ( < 6300 Å) or 20 Å ( > 6300 Å) wide intervals. It follows from the spectral averages and the local continuum derived by Neckel and Labs from high-resolution Fourier transform spectra, which had been obtained by J. Brault at Kitt Peak. The internal accuracy (the scatter) is in the order of 0.1%. Significant systematic errors arising from local distortions of the adopted continuum level can be excluded. Larger errors are to be expected only near the Balmer limit, where the localization of the continuum is very ambiguous.  相似文献   
94.
Moving object databases are designed to store and process spatial and temporal object data. An especially useful moving object type is a moving region, which consists of one or more moving polygons suitable for modeling the spread of forest fires, the movement of clouds, spread of diseases and many other real-world phenomena. Previous implementations usually allow a changing shape of the region during the movement; however, the necessary restrictions on this model result in an inaccurate interpolation of rotating objects. In this paper, we present an alternative approach for moving and rotating regions of fixed shape, called Fixed Moving Regions, which provide a significantly better model for a wide range of applications like modeling the movement of oil tankers, icebergs and other rigid structures. Furthermore, we describe and implement several useful operations on this new object type to enable a database system to solve many real-world problems, as for example collision tests, projections and intersections, much more accurate than with other models. Based on this research, we also implemented a library for easy integration into moving objects database systems, as for example the DBMS Secondo (1) (2) developed at the FernUniversität in Hagen.  相似文献   
95.
Elemental and isotopic ratio analyses of U ore concentrate samples, from the 3 operating U mining facilities in Australia, were carried out to determine if significant variations exist between their products, thereby allowing the U ore concentrate’s origin to be identified. Elemental analyses were conducted using inductively coupled plasma mass spectrometry (ICP-MS) and X-ray fluorescence spectrometry (XRF). Lead isotope ratios were measured using ICP-MS and U isotope analyses were conducted using thermal ionisation mass spectrometry (TIMS). Minute quantities of sample, such as that obtained from a swipe, were also examined for elemental concentrations using secondary ion mass spectrometry (SIMS). The results of multivariate statistical analysis show clear patterns in the trace elemental composition of the processed U ores, indicating that it is possible to use this feature as a unique identifier of an Australian U ore concentrate’s source. Secondary ion mass spectrometry analyses also allow individual particles to be differentiated using this ‘fingerprinting’ technique. Isotope ratios determined using TIMS reveal that there is a significant difference in the n(234U)/n(238U) isotope ratio between the U ore concentrate from each mine.  相似文献   
96.
97.
Zusammenfassung Nach einer Theorie von Press und Ewing entsteht die seismische Bodenunruhe dadurch, daß atmosphärische Energie von der Meeresoberfläche in einer Kompressionswelle durch das Wasser auf den Ozeanboden übertragen und im Untergrunde in einer elastischen Welle den Kontinenten zugeleitet wird. Es wird der Effekt der von Press und Ewing vernachlässigten Reibung des Wassers am Meeresboden abgeschätzt. Das wesentlichste Ergebnis der Theorie von Press und Ewing, die quantitativ richtige Erklärung der in der seismischen Bodenunruhe zu beobachtenden Perioden durch den Effekt der Dispersion, bleibt auch bei Berücksichtigung der Reibung näherungsweise erhalten. Der Effekt der Dispersion bei den Wellen, die nach der Wiechertschen Brandungshypothese entstehen würden, wird auch abgeschätzt. Er führt zu einer Periode von 11,9 sec, ein Wert, der etwas zu hoch ist. Die Rechnungsgrundlagen sind aber sehr unsicher.
On the theory of microseisms
Summary According to a theory advanced by Press and Ewing atmospheric energy is transmitted to the sea-bottom by compression waves and forwarded to the continents by elastic oscillations of the sub-soil. In the paper that follows an estimate is made of the effect of friction (of the water on the sea-bottom), an effect which has been neglected by Press and Ewing. The outstanding result of their theory, the explanation of the periods observed in microseisms as an effect of dispersion (which is quantitatively correct), is found to remain approximately valid if friction is taken into account. In addition the effect of dispersion is estimated for waves corresponding to Wiechert's surf hypothesis, and a period of 11,9 sec is found, which is somewhat too high. The bases of calculation are, however, by no means reliable.


Herrn Prof. Dr. F. Errulat, seinem verehrten Lehrer, zum 60. Geburtstage gewidmet vom Verfasser.  相似文献   
98.
Zusammenfassung Der zeitliche Gang der atmosph?tischen St?rungen ist zwei Einflüssen unterworfen: 1) Der zeitlichen und r?umlichen Verteilung der St?rquellen, 2) Den jeweiligen Ausbreitungsbedingungen des zu empfangenden Frequenzbandes. Die bei 5,5 MHz durchgeführten Messungen des atmosph?rischen St?rpegels zeigen den erwarteten Zusammenhang zwischen dem t?glichen Gang und dem Sonnenstand entsprechend den normalen Ausbreitungsbedingungen im 50 m Band. W?hrend M?gel-Dellinger Effekte nicht festgestellt werden konnten, ist die Nordlichtst?rung als Folge einer Korpuskularstrahlung der Sonne klar zu erkennen.
Summary The temporal variation of atmospherics is subjected to two facts: 1) The temporal and local distribution of sources of atmospherics, 2) The present conditions of propagation with regard to the just received short-wave band. Measurements of atmospherics in 50 m-band proved the connection between atmospherics and solar-radiation corresponding to the normal conditions of short-wave propagation, showing a minimum at day and a maximum at night. Whilst the Dellinger-effect did not happen, atmospherics disappeard on account of aurora borealis and strong disturbance of the earth's magnetic field, in consequence of corpusculare-radiation of the sun. Monthly distribution of atmospherics in 50 m-band for 2 years measurements are given.
  相似文献   
99.
The transportation of rich mineral resources from the Arctic by means of large ice-going bulk and oil carrier, is expected to be a suitable and economical technique. The construction of such large vessels requires the knowledge of various glaciological parameters of the sea ice and their dependence on Arctic environmental conditions. Of particular interest on the small scale are the strength, elasticity, and metal to ice friction characteristics, on a larger geophysical scale relevant parameters are the ice stress, pressure, and movement rates and the relation of these parameters to the temperature and salinity of the ice and to the wind field and the ocean current. Furthermore electrical and electromagnetical properties of the ice are relevant to the navigation in ice covered waters by the aid of remote sensing techniques.The German shipyard A.G. Weser in Bremen initiated in 1972 an expedition to the Canadian Arctic to study all relevant physical properties at one location and at the same time to comprehend the whole glaciological regime. The expedition was a cooperative effort between Brook University, St. Catherines (Canada) and the University of Münster (W. Germany). The field measurements were carried out in May and June 1972 on the sea ice between Pond Inlet (Northern Baffin Island) and Bylot Island, N.W.T. This article sumarizes the essential results and presents a synthesis of all the results.  相似文献   
100.
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