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81.
Andrés García García Carolina Perpiñá Carlos de Alfonso Vicente Hernández 《Earth Science Informatics》2013,6(4):199-207
This paper presents the integration of desktop grid infrastructure with GIS technologies, by proposing a parallel resolution method in a generic distributed environment. A case study focused on a discrete facility location problem, in the biomass area, exemplifies the high amount of computing resources (CPU, memory, HDD) required to solve the spatial problem. A comprehensive analysis is undertaken in order to analyse the behaviour of the grid-enabled GIS system. This analysis, consisting of a set of the experiments on the case study, concludes that the desktop grid infrastructure is able to use a commercial GIS system to solve the spatial problem achieving high speedup and computational resource utilization. Particularly, the results of the experiments showed an increase in speedup of fourteen times using sixteen computers and a computational efficiency greater than 87 % compared with the sequential procedure. 相似文献
82.
A model describing macroalgal early life stages and adult dynamics was used to quantify the effects of non-adult forms on the productivity of adult macroalgae in a eutrophic estuary. Predictions indicate that during years with mild winters and low rainfall, spring blooms will occur at the expense of the growth and reproduction of overwintering adults and without the contribution of the spore bank. In these circumstances, there is a positive correlation between the intensity of the blooms and the biomass of overwintering adults until a maximum threshold value. On the contrary, in years with high rainfall and low or inexistent biomass of overwintering adults, the onset of adult’s growth depends on the biomass of viable dormant spores, the growing season occurs later and adult productivity is very limited. Long-term predictions for climate change scenarios suggest that, in general, global warming will have adverse affects on Ulva intestinalis productivity, with the adults being more affected than the early life stages. 相似文献
83.
Overview of integrative tools and methods in assessing ecological integrity in estuarine and coastal systems worldwide 总被引:8,自引:1,他引:8
Borja A Bricker SB Dauer DM Demetriades NT Ferreira JG Forbes AT Hutchings P Jia X Kenchington R Carlos Marques J Zhu C 《Marine pollution bulletin》2008,56(9):1519-1537
In recent years, several sets of legislation worldwide (Oceans Act in USA, Australia or Canada; Water Framework Directive or Marine Strategy in Europe, National Water Act in South Africa, etc.) have been developed in order to address ecological quality or integrity, within estuarine and coastal systems. Most such legislation seeks to define quality in an integrative way, by using several biological elements, together with physico-chemical and pollution elements. Such an approach allows assessment of ecological status at the ecosystem level ('ecosystem approach' or 'holistic approach' methodologies), rather than at species level (e.g. mussel biomonitoring or Mussel Watch) or just at chemical level (i.e. quality objectives) alone. Increasing attention has been paid to the development of tools for different physico-chemical or biological (phytoplankton, zooplankton, benthos, algae, phanerogams, fishes) elements of the ecosystems. However, few methodologies integrate all the elements into a single evaluation of a water body. The need for such integrative tools to assess ecosystem quality is very important, both from a scientific and stakeholder point of view. Politicians and managers need information from simple and pragmatic, but scientifically sound methodologies, in order to show to society the evolution of a zone (estuary, coastal area, etc.), taking into account human pressures or recovery processes. These approaches include: (i) multidisciplinarity, inherent in the teams involved in their implementation; (ii) integration of biotic and abiotic factors; (iii) accurate and validated methods in determining ecological integrity; and (iv) adequate indicators to follow the evolution of the monitored ecosystems. While some countries increasingly use the establishment of marine parks to conserve marine biodiversity and ecological integrity, there is awareness (e.g. in Australia) that conservation and management of marine ecosystems cannot be restricted to Marine Protected Areas but must include areas outside such reserves. This contribution reviews the current situation of integrative ecological assessment worldwide, by presenting several examples from each of the continents: Africa, Asia, Australia, Europe and North America. 相似文献
84.
Carlos Schubert 《International Journal of Earth Sciences》1981,70(2):542-551
Three major fault systems have been recognized in Venezuela: the Oca, Boconó, and El Pilar fault zones. The Boconó-El Pilar system is an active, Late Pleistocene-Holocene fault system, which extends for over 1300 km between the Venezuela-Colombia border, through the Venezuelan Andes and along the northern Venezuelan coast, to the east of Trinidad. Recent tectonic evidence suggests that until the Late Tertiary or Early Quaternary, the Caribbean Plate-South America Plate boundary included the El Pilar and Oca fault systems. Since then, it has included the Boconó fault system. Right-lateral offset along these fault systems is not sufficient to derive the Caribbean Plate from Pacific crust; alternatively, the Caribbean Plate may have been a part of the South America Plate until comparatively recent geologic-time.
Dedicated to the memory of John D. Weaver. 相似文献
Zusammenfassung Drei wichtige Bruchsysteme sind in Venezuela festgestellt worden: die Oca, Boconé und El Pilar Bruchzonen. Das Boconó-El-Pilar-System ist ein aktives, Spätpleistozänes-Holozänes System, daß sich über mehr als 1300 km erstreckt, von der venezolanischkolumbianischen Grenze, durch die venezolanischen Anden und längs der nördlichen venezolanischen Küste, bis östlich von Trinidad. Rezente tektonische Daten lassen andeuten, daß bis zum Spättertiär oder Frühquartär, die Grenze zwischen der Karibischen Platte und der Südamerika-Platte die El Pilar- und Oca-Bruchsysteme einschloß. Später hat sie das Boconó-Bruchsystem eingeschlossen. Rechtsinnige Blattverschiebung an diesen Bruchsystemen ist nicht groß genug, um die Karibische Platte als ein Stück pazifischer Kruste zu betrachten; oder aber, die Karibische Platte war mit der Südamerika-Platte vereinigt bis zu einem relativ jungen geologischen Alter.
Resumen Se han establecido tres sistemas mayores de fallamiento en Venezuela: las zonas de falla de Oca, Boconó y El Pilar. El sistema de Boconó-El Pilar es un sistema de falla activo pleistoceno-holoceno, el cual se extiende por más de 1300 km entre la frontera colombo-venezolana, a traves de los Andes venezolanos y a lo largo de la costa norte de Venezuela, hasta más al este de Trinidad. Evidencias tectónicas recientes sugieren que hasta el Terciario Tardio o Cuatemario Temprano, el límite entre las Plaças del Caribe y de América del Sur incluía los sistemas de falla de Oca y El Pilar. Desde entonces incluye al sistema de falla de Boconó. El desplazamiento de rumbo hacia la derecha a lo largo de estos sistemas de fallamiento no es suficiente para derivar la Plaça del Caribe de la corteza pacifica; alternativamente, la Placa del Caribe puede haber sido parte de la Placa de América del Sur hasta una época geológica relativamente reciente.
: , ' El Pilar. - / , 1300 - , . , 1 Pilar. '. , , , , , .
Dedicated to the memory of John D. Weaver. 相似文献
85.
Arias-Molinares Daniela García-Palomares Juan Carlos Romanillos Gustavo Gutiérrez Javier 《Journal of Geographical Systems》2023,25(3):403-427
Journal of Geographical Systems - In the past ten years, cities have experienced a burst of micromobility services as they offer a flexible transport option that allows users to cover short trips... 相似文献
86.
José María González-Jiménez Carlos Villaseca William L. Griffin Suzanne Y. O’Reilly Elena Belousova Eumenio Ancochea Norman J. Pearson 《Contributions to Mineralogy and Petrology》2014,168(2):1-24
Spinel lherzolite and wehrlite xenoliths from the Cenozoic Calatrava volcanic field carry the geochemical imprint of metasomatic agents that have affected the subcontinental lithospheric mantle beneath Central Iberia. Some xenoliths (mainly wehrlites) were enriched in REE, Sr, P, and CO2 by silicic-carbonate-rich metasomatic melts/fluids, while others record the effects of subduction-related hydrous silicate fluids that have precipitated amphibole and induced high Ti/Eu in primary clinopyroxene. The petrographic observations and geochemical data suggest that interstitial glass in the xenoliths represent the quenched products of Si-rich melts that infiltrated the mantle peridotite shortly before the entrainment of the xenoliths in the host magmas that erupted ca 2 million years ago. During their infiltration, the metasomatic melts reacted with peridotite, resulting in silica enrichment, while remobilizing grains of iron-rich monosulfide solid solution (Fe-rich Mss) initially enclosed in, or intergranular to, primary olivine and pyroxenes. In situ laser ablation inductively coupled plasma-mass spectrometry analysis of single sulfide grains reveals that the Fe-rich Mss in glass shows platinum-group element (PGE) patterns and 187Os/188Os compositions identical to the Fe-rich Mss occurring as inclusions in, or at grain boundaries of primary silicates. Moreover, independent of its microstructural position, Fe-rich Mss exhibits PGE and 187Os/188Os signatures typical of Mss either residual after partial melting or crystallized directly from sulfide melts. Our findings reveal that young metasomatic melt(s)/fluid(s) may carry remobilized sulfides with PGE and Os-isotopic signatures identical to those of texturally older sulfides in the peridotite xenolith. These sulfides thus still provide useful information about the timing and nature of older magmatic events in the subcontinental mantle. 相似文献
87.
Juan Carlos Carracedo Francisco Pérez Torrado Alejandro Rodríguez González Vicente Soler José Luis Fernández Turiel Valentin R. Troll Sebastian Wiesmaier 《Geology Today》2012,28(2):53-58
Forty years after the Teneguía Volcano (La Palma, 1971), a submarine eruption took place off the town of La Restinga, south of El Hierro, the smallest and youngest island of the Canarian Archipelago. Precursors allowed an early detection of the event and its approximate location, suggesting it was submarine. Uncertainties derived from insufficient scientific information available to the authorities during the eruption, leading to disproportionate civil protection measures, which had an impact on the island's economy—based primarily on tourism—while residents experienced extra fear and distress. 相似文献
88.
João Magalhães Neto Heliana Teixeira Joana Patrício Alexandra Baeta Helena Veríssimo Rute Pinto João Carlos Marques 《Estuaries and Coasts》2010,33(6):1327-1339
Anthropogenic activities are a disturbance factor of coastal systems and can be widely recognized as a major threat to the
health of coastal systems. However, natural events cannot be disregarded from management issues because of their significant
influence on the communities living in these areas. Based on long-term subtidal data from the Mondego Estuary (Portugal),
the effects of natural events (e.g., floods and droughts) on macrobenthic communities were compared with the anthropogenic
events. Sampling stations were grouped into characteristic zones (mouth, north arm, south arm) so the community dynamics of
each of these estuarine areas could be followed over time. Environmental assessment was performed for stations using the Benthic
Assessment Tool (BAT), and compared with the existing pressures. Human impacts persist over a number of years and gradually
reduce ecosystem health, as discussed in the European Water Framework Directive. Paradoxically, natural events cause stronger
impacts but are of a shorter duration, which allows for a faster recovery of macrobenthic communities. The study showed that
caution should be taken when developing and implementing water policies so as not to disregard the importance of the different
events (natural and human-caused) on the ecosystem health (e.g., community degradation and water quality and ecological quality
status assessment). 相似文献
89.
The kinematic evolution of the Barinas–Apure Basin and the southern Mérida Andes from Lower Miocene to the Present is numerically modelled using flexural isostatic theory and geophysical and geological data. Two published regional transects are used to build up a reference section, which is then used to constrain important parameters (e.g. shortenings and sedimentary thicknesses) for the flexural modelling. To control the location of the main fault system in the flexural model earthquake information is also used. The estimated flexural elastic thickness of the South American lithosphere beneath the Barinas–Apure Basin and the Mérida Andes Range is 25 km. The value for the final total shortening is 60 km. The flexural isostatic model shows that the Andean uplift has caused the South American lithosphere subsidence and the development of the Barinas–Apure Basin.In addition, gravity modelling was used to understand deep crustal features that could not be predicted by flexural theory. Consequently, the best-fit flexural model is used to build a gravity model across the Mérida Andes and the Barinas–Apure Basin preserving the best-controlled structural features from the flexural modelling (e.g. basin wavelength and depth) and slightly changing the main bodies density values and deep crustal structures. The final gravity model is intended to be representative of the major features affecting the gravity field in the study area. The predicted morphology in the lower crustal level of the final gravity model favours the hypothesis of a present delamination or megathrust of the Maracaibo crust over the South American Shield. This process would use the Conrad discontinuity as a main detachment surface within an incipient NW dipping continental subduction. 相似文献
90.
Matúš Hyžný Carlos S. Melo Ricardo S. Ramalho Ricardo Cordeiro Patrícia Madeira Lara Baptista A. Cristina Rebelo Cynthia Gómez Alfred Uchman Markes E. Johnson Björn Berning Sérgio P. Ávila 《第四纪科学杂志》2021,36(1):91-109
The presence of decapod crustaceans in the Pliocene and Pleistocene (MIS 5e) fossil record of Santa Maria Island (Azores Archipelago) is herein reviewed. Our study raises the number of fossil decapods from this island from one species to 10 taxa (three for the Pliocene and seven for the Last Interglacial). Four of these 10 taxa are reported for the first time in the fossil record, worldwide. A new species of a mud shrimp is also described (Upogebia azorensis n. sp.). Our study suggests that the Plio–Pleistocene decapod assemblages of the Azores did not differ significantly from modern ones, being dominated by species that are today widespread across the Webbnesia ecoregion, the Mediterranean Sea, and the eastern Atlantic shores, including the Azores. As far as can be judged from the limited fossil record, apparently no tropical crab species with a Cabo Verdean/Senegalese provenance reached the Azores during windows of opportunity associated with Glacial Termination 2 or with the initial setting of the Last Interglacial period. This contribution increases the total number of marine taxa reported for the Pliocene and Pleistocene outcrops of Santa Maria Island to 218 and 155, respectively, highlighting the scientific relevance of its palaeontological heritage. 相似文献