全文获取类型
收费全文 | 1295篇 |
免费 | 43篇 |
国内免费 | 14篇 |
专业分类
测绘学 | 29篇 |
大气科学 | 95篇 |
地球物理 | 323篇 |
地质学 | 569篇 |
海洋学 | 106篇 |
天文学 | 133篇 |
综合类 | 5篇 |
自然地理 | 92篇 |
出版年
2021年 | 9篇 |
2020年 | 8篇 |
2019年 | 8篇 |
2018年 | 26篇 |
2017年 | 28篇 |
2016年 | 45篇 |
2015年 | 29篇 |
2014年 | 33篇 |
2013年 | 76篇 |
2012年 | 47篇 |
2011年 | 70篇 |
2010年 | 74篇 |
2009年 | 77篇 |
2008年 | 60篇 |
2007年 | 62篇 |
2006年 | 56篇 |
2005年 | 81篇 |
2004年 | 60篇 |
2003年 | 42篇 |
2002年 | 43篇 |
2001年 | 35篇 |
2000年 | 21篇 |
1999年 | 28篇 |
1998年 | 22篇 |
1997年 | 10篇 |
1996年 | 20篇 |
1995年 | 15篇 |
1994年 | 16篇 |
1993年 | 9篇 |
1992年 | 18篇 |
1991年 | 11篇 |
1990年 | 15篇 |
1989年 | 9篇 |
1988年 | 10篇 |
1987年 | 10篇 |
1986年 | 16篇 |
1985年 | 16篇 |
1984年 | 15篇 |
1983年 | 10篇 |
1982年 | 10篇 |
1981年 | 15篇 |
1980年 | 8篇 |
1979年 | 11篇 |
1978年 | 8篇 |
1977年 | 10篇 |
1976年 | 11篇 |
1975年 | 4篇 |
1974年 | 13篇 |
1973年 | 4篇 |
1953年 | 2篇 |
排序方式: 共有1352条查询结果,搜索用时 15 毫秒
901.
Christian Montenat Michel Monbaron Ronan Allain Najat Aquesbi Jean Dejax Jean Hernandez Dale Russell et Philippe Taquet 《Eclogae Geologicae Helvetiae》2005,98(2):261-270
Resume. Le gisement de dinosauriens du Jurassique inférieur de Toundoute, à sauropode primitif (Tazoudasaurus naimi), est examiné sous ses aspects stratigraphiques, sédimentologiques et paléoenvironnementaux. Les couches continentales détritiques
à dinosaures, succédant en continuité à des niveaux marins carbonatés trés peu épais du Lias inférieur (Hettangien-Sinémurien
probables), sont rapportées au Lias moyen-supérieur. Les dép?ts continentaux contiennent une part importante de produits volcanoclastiques
différents des basaltes triasiques. Les centres d’émission, non connus, étaient sans doute proches. La sédimentation continentale,
de type chenaux fluviatiles – plaine d’inondation, refléte un climat chaud à périodes alternativement humides et séches, ces
derniéres étant fortement marquées. Les deux niveaux à ossements correspondent à des coulées boueuses ayant charrié des ossements
et portions de carcasses (os en connexion) sur de courtes distances. Ce mode de transport a préservé les ossements de l’érosion
et favorisé un enfouissement rapide permettant leur conservation.
Manuscrit re?u le 16 juillet 2004 Révision acceptée le 17 mars 2005 相似文献
902.
In Lorraine, flooding of the iron mines leads to a degradation of groundwater quality. Based on a global approach, a numerical simulator has been built that can reproduce and predict the evolution of water quality at the overflow point of the mining basin. In order to specify the spatial distribution of these pollutant concentrations, a new model has been developed. The basin is represented as a network of homogeneous reservoirs. Although encouraging, the results show the need to specify the spatial organisation of water flow in order to reproduce the pollutant concentrations in the different monitored wells. To cite this article: P. Collon et al., C. R. Geoscience 337 (2005). 相似文献
903.
Michel Villeneuve Jean-Jacques Cornée Agus Harsolumakso Rossana Martini et Louisette Zaninetti 《Eclogae Geologicae Helvetiae》2005,98(2):297-310
Resume. De nombreuses échelles stratigraphiques de l’?le de Timor ont vu le jour car les corrélations stratigraphiques étaient rendues
difficiles par la complexité tectonique de l’?le et par la variété des faciès. Dès les premiers travaux, plusieurs séries
ont été distinguées, regroupées en trois unités litho-structurales principales: unité allochtone, sub-autochtone et autochtone.
Les données stratigraphiques et géodynamiques récentes montrent que l’?le de Timor est en fait constituée par six unités litho-structurales,
chacune témoignant d’un épisode majeur de l’histoire géologique de l’Ile. Cette histoire consiste d’abord à la séparation,
au Jurassique, d’un bloc issu du continent de Gondwana (unité para-allochtone) qui est entré en collision avec l’arc volcanique
asiatique à l’Oligo-Miocène (unités allochtone et sub-allochtone). Cet ensemble a ensuite été séparé de l’Asie lors de l’ouverture
de la mer de Banda sud, au Miocène supérieur (unité sub-autochtone) pour finalement entrer en collision avec la marge nord
australienne au cours du Pliocène moyen (plateforme australienne et groupe de Kolbano). Timor est depuis incorporée à la marge
nord australienne (unité autochtone).
Ce travail présente les différentes échelles stratigraphiques de chaque nouvelle unité, des propositions de corrélations et
une comparaison avec les ?les voisines de Sumba et de Sulawesi pour aboutir à une proposition d’évolution géodynamique.
Manuscrit re?u le 13 février 2004 Révision acceptée le 14 février 2005 相似文献
904.
Frédéric Gazeau Jean-Pierre Gattuso Jack J. Middelburg Natacha Brion Laure-Sophie Schiettecatte Michel Frankignoulle Alberto Vieira Borges 《Estuaries and Coasts》2005,28(6):868-883
Planktonic gross primary production (GPP), community respiration (CR), and nitrification (NIT) were measured monthly in the
Scheldt estuary by the oxygen incubation method in 2003. No significant evolution of planktonic GPP was observed since the
1990s with high rates in the freshwater area (salinity 0; 97±65 mmol C m−2 d−1) decreasing seaward (22–37 mmol C m−2 d−1). A significant decrease of NIT was observed with regard to previous investigations although this process still represents
up to 20% of total organic matter production in the inner estuary. Planktonic CR was highest in the inner estuary and seemed
to be mainly controlled by external organic matter inputs. Planktonic net community production was negative most of the time
in the estuary with values ranging from −300 to 165 mmol C m−2 d−1. Whole estuary net ecosystem production (NEP) was investigated on an annual scale using the results mentioned above and published
benthic metabolic rates. A NEP of −39±8 mmol C m−2 d−1 was estimated, which confirms the strong heterotrophic status of this highly nutrified estuary. NEP rates were computed from
June to December 2003 to compare with results derived from the Land-Ocean Interaction in the Coastal Zone budgeting procedure
applied to dissolved inorganic phosphorus and carbon (DIP and DIC). DIP budgets failed to provide realistic estimates in the
inner estuary where abiotic processes account for more than 50% of the nonconservative DIP flux. DIC budgets predicted a much
lower NEP than in situ incubations (−109±31 versus −42±9 mmol C m−2 d−1) although, as each approach is associated with several critical assumptions, the source of this discrepancy remains unclear. 相似文献
905.
Perrine Paquereau Jean-Claude Thouret Gerhard Wörner Michel Fornari Orlando Macedo Pierrick Roperch 《Comptes Rendus Geoscience》2005,337(5):477-486
Four ignimbritic units have filled the Arequipa Basin and outcrop around the Chachani Volcano. (1) The oldest Río Chili ignimbrite is 13.33 Ma old; (2) the most widespread La Joya ignimbrite is 4.9 Ma old; (3) the Arequipa Airport ignimbrite (1.65 Ma) flowed from an area buried beneath Chachani; (4) the Yura Tuffs, 1.02 Ma old, are restricted to the west of Chachani. All are calc-alkaline rhyolites with plagioclase, biotite, quartz, sanidine, and opaques, but the Río Chili and La Joya ignimbrites also contain amphibole. Trace elements of the older ignimbrites reflect stronger crustal influence. To cite this article: P. Paquereau et al., C. R. Geoscience 337 (2005). 相似文献
906.
Jean-Len Léticée Auran Randrianasolo Jean-Jacques Cornée Philippe Münch Jean-Frédéric Lebrun Jean-Paul Saint-Martin Michel Villeneuve 《Comptes Rendus Geoscience》2005,337(6):617-624
A major emersion surface (S1) reveals at least a 60-m relative sea-level fall within the ‘Calcaires supérieurs’ of Grande-Terre (Lesser Antilles fore-arc), an Upper Pliocene–Lower Pleistocene reefal unit. We thus divide the ‘Calcaires supérieurs’ into 2 units. S1, together with the transgresssive calcarenitic and the Acropora-rich reefal units on top of it, corresponding to the record of a complete eustatic cycle by the carbonate platform of this active margin. A comparison with the carbonate platform of the Bahama Bank stable margin, allows us to relate S1 to the major emersive event of 1.66 Ma and to infer that its origin is glacio-eustatic. To cite this article: J.-L. Léticée et al., C. R. Geoscience 337 (2005). 相似文献
907.
Late Cenozoic geodynamic evolution of eastern Indonesia 总被引:2,自引:0,他引:2
Florent Hinschberger Jacques-Andr Malod Jean-Pierre Rhault Michel Villeneuve Jean-Yves Royer Safri Burhanuddin 《Tectonophysics》2005,404(1-2):91-118
This paper presents an internally and globally consistent model of plate evolution in eastern Indonesia from Middle Miocene to Present time. It is centered on the Banda Sea region located in the triple junction area between the Pacific–Philippine, Australia and South–East Asia plates. The geological and geophysical data available from Indonesia were until recently insufficient to define a unique plate tectonic model. In this paper, the new data taken into account clearly restrict the possible interpretations. Owing to a great number of geological, geophysical and geochemical studies, the major plate boundaries (the Sunda–Banda subduction zone to the south, the Tarera–Aiduna Fault zone and the Seram Thrust to the east, and the Sorong Fault zone and Molucca Sea collision zone to the north) are now clearly identified. The age of the major tectonic structures is also better known. Geodetic measurements well constrain the Present time plate kinematics. We also consider the deformation history within eastern Indonesia, where numerous short-lived microplates and their related microcontinents successively accreted to the Asiatic margin. Moreover, magnetic anomalies identification of the North and South Banda Sea basins allows a precise kinematic reconstruction of the back-arc opening. We used the Plates software to test the coherency of our model, presented as a series of 4 plate reconstruction maps from 13 Ma to the present. Finally, the origin of oceanic domains restored by our reconstruction is discussed. 相似文献
908.
Jean-Claude Tanguy Michel Condomines Maxime Le Goff Vito Chillemi Santo La Delfa Giuseppe Patanè 《Bulletin of Volcanology》2007,70(1):55-83
A careful re-examination of the well-known written documents pertaining to the 2,750-year-long historical period of Mount
Etna was carried out and their interpretation checked through the high-accuracy archeomagnetic method (>1,200 large samples),
combined with the 226Ra-230Th radiochronology. The magnetic dating is based upon secular variation of the direction of the geomagnetic field (DGF) and
estimated to reach a precision of ±40 years for the last 1,200 years, and ±100 to 200 years up to circa 150 B.C. Although
less precise, the 226Ra-230Th method provides a unique tool for distinguishing between historic and prehistoric lavas, which in some cases might have
similar DGFs. We show that despite the abundance of details on ancient historical eruptions, the primary sources of information
are often too imprecise to identify their lava flows and eruptive systems. Most of the ages of these lavas, which are today
accepted on the geological maps and catalogues, were attributed in the 1800s on the basis of their morphology and without
any stratigraphical control. In fact, we found that 80% of the “historically dated” flows and cones prior to the 1700s are
usually several hundreds of years older than recorded, the discrepancies sometimes exceeding a millennium. This is proper
the case for volcanics presumed of the “1651 east” (actually ∼1020), “1595” (actually two distinct flows, respectively, ∼1200
and ∼1060), “1566” (∼1180), “1536” (two branches dated ∼1250 and ∼950), “1444” (a branch dated ∼1270), “1408” (lower branches
dated ∼450 and ∼350), “1381” (∼1160), “1329” (∼1030), “1284” (∼1450 and ∼700), “1169 or 812” (∼1000) eruptions. Conversely,
well-preserved cones and flows that are undated on the maps were produced by recent eruptions that went unnoticed in historical
accounts, especially during the Middle Ages. For the few eruptions that are recorded between A.D. 252 and 750 B.C., none of
their presumed lava flows shows a DGF in agreement with that existing at their respective dates of occurrence, most of these
flows being in fact prehistoric. The cinder cones of Monpeloso (presumed “A.D. 252”) and Mt. Gorna (“394 B.C.”), although
roughly consistent magnetically and radiochronologically with their respective epochs, remain of unspecified age because of
a lack of precision of the DGF reference curve at the time. It is concluded that at the time scale of the last millennia,
Mount Etna does not provide evidence of a steady-state behavior. Periods of voluminous eruptions lasting 50 to 150 years (e.g.,
A.D. 300–450, 950–1060, 1607–1669) are followed by centuries of less productive activity, although at any time a violent outburst
may occur. Such a revised history should be taken into account for eruptive models, magma output, internal plumbing of the
volcano, petrological evolution, volcano mapping and civil protection. 相似文献
909.
An inter-comparison of regional climate models for Europe: model performance in present-day climate 总被引:3,自引:0,他引:3
Daniela Jacob Lars Bärring Ole Bøssing Christensen Jens Hesselbjerg Christensen Manuel de Castro Michel Déqué Filippo Giorgi Stefan Hagemann Martin Hirschi Richard Jones Erik Kjellström Geert Lenderink Burkhardt Rockel Enrique Sánchez Christoph Schär Sonia I. Seneviratne Samuel Somot Aad van Ulden Bart van den Hurk 《Climatic change》2007,81(1):31-52
The analysis of possible regional climate changes over Europe as simulated by 10 regional climate models within the context of PRUDENCE requires a careful investigation of possible systematic biases in the models. The purpose of this paper is to identify how the main model systematic biases vary across the different models. Two fundamental aspects of model validation are addressed here: the ability to simulate (1) the long-term (30 or 40 years) mean climate and (2) the inter-annual variability. The analysis concentrates on near-surface air temperature and precipitation over land and focuses mainly on winter and summer. In general, there is a warm bias with respect to the CRU data set in these extreme seasons and a tendency to cold biases in the transition seasons. In winter the typical spread (standard deviation) between the models is 1 K. During summer there is generally a better agreement between observed and simulated values of inter-annual variability although there is a relatively clear signal that the modeled temperature variability is larger than suggested by observations, while precipitation variability is closer to observations. The areas with warm (cold) bias in winter generally exhibit wet (dry) biases, whereas the relationship is the reverse during summer (though much less clear, coupling warm (cold) biases with dry (wet) ones). When comparing the RCMs with their driving GCM, they generally reproduce the large-scale circulation of the GCM though in some cases there are substantial differences between regional biases in surface temperature and precipitation. 相似文献
910.
Michel Valladon 《Geostandards and Geoanalytical Research》2007,31(4):395-409
A total of twenty-five bibliographic reviews were published between 1979 and 2004 in Geostandards Newsletter, subsequently renamed Geostandards and Geoanalytical Research, which list more than 5500 papers. These cited references contain information about geochemical reference materials, analytical methods or address general issues concerning the use of reference materials (protocols for sampling, certification, or new analytical techniques). In support of emerging fields of interest in geoanalysis, frequently associated with environmental research, and reflecting the increased breadth in the topics addressed by the Journal, new reference headings were added over time, while retaining the original style and format of the review. Reference management software was used to extract information from these publications related to methods, reference materials and analytes. Major developments during these 25 years, reflecting both advances in laboratory hardware as well as shifts in research interests, can readily be seen in both the types of reference materials being studied and in nature of the new analytical protocols that were developed. These two topics were the core foci of the twenty-five reviews, though much more information might also be extracted from this extensive resource. 相似文献