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101.
John J. Flynn Reynaldo Charrier Darin A. Croft Phillip B. Gans Trystan M. Herriott Jill A. Wertheim Andr R. Wyss 《Journal of South American Earth Sciences》2008,26(4):412-423
Recent work in the central Andean Main Range of Chile near Laguna del Laja (37.5°S, 71°W) has produced the first mammal fossils for the region. Fossils, locally abundant and well preserved, occur patchily across a wide area southeast of the lake. Mammalian remains are derived from generally strongly folded (kilometer-scale) exposures of the locally 1.8 km thick, early to middle Miocene Cura-Mallín Formation; two identifiable specimens have been recovered from the overlying Trapa Trapa Formation as well. Both formations consist primarily of well-stratified (1–5 m thick layers) volcaniclastic and volcanic strata, deposited predominantly in fluviatile systems. The Cura-Mallín Formation is possibly the southern continuation of (or lateral equivalent to) the richly fossiliferous Abanico Formation mapped between 32°S and 36°S. Intensive sampling in a series of localities east and south of Laguna del Laja has yielded diverse faunas, in addition to radioisotopically dateable horizons. The new fossil mammal faunas represent as many as six South American Land Mammal “Ages” (SALMAs). Fossils, together with preliminary 40Ar/39Ar radioisotopic dates, ranging from 9 to 20 Ma across the exposed thickness of the Cura-Mallín Formation and into the overlying Trapa Trapa Formation, provide a robust geochronological framework for middle Cenozoic strata in the Laguna del Laja region. The sequence of directly superposed mammalian assemblages at Laguna del Laja is one of the longest in all of South America, rivaled only by the classic Gran Barranca section of Patagonian Argentina. These data illuminate the geological history of the area and its record of mammalian evolution. The potential to isotopically date these diverse faunas with high precision (error ± 0.5 Ma) presents a rare opportunity to calibrate related portions of the SALMA sequence. 相似文献
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This paper describes analyses involving patterned string bags collected in the upper Sepik in Papua New Guinea. The Mantel test and correspondence analysis were used to explore whether variability in craft repertoires exhibits any covariance with the region's complex linguistic picture, and if so, whether this relationship is more significant than any spatial autocorrelation the data may exhibit. Bag construction techniques exhibited strong spatial autocorrelation, while for colour patterns the effect was weaker. An effect for language remained for both dependents after statistical control, but colour pattern characteristics had a slightly stronger association with language overall. The weaker spatial autocorrelation for colour pattern variability is argued to be due to higher rates of dissemination facilitated by the visibility of the patterns and their compatibility with a broad range of construction techniques. The effect for language, on the other hand, is argued to have resulted from of a higher rate of inter-settlement migration along a particular stretch of the Sepik where people speak the same language. 相似文献
104.
Jill S.M. Coleman 《The Professional geographer》2013,65(2):190-206
Although much research has been done linking meteorological variables individually with various aspects of human health, few studies have considered the collective impact of weather. This study examines the relationship among ten synoptic-scale weather patterns and daily cause-specific human mortality rates for metropolitan areas in the central United States during the 1978 to 1998 autumn and spring seasons. The results show that distinctive changes in mortality rates are often associated with one or two of the more moderate synoptic types, displaying notable spatial and temporal variability. The occurrence of the Eastern Zonal (EZ) pattern during spring and the East Coast Trough (ECT) pattern during autumn seems to invoke the most significant increased mortality response across all causes of death and metropolitan statistical areas. For the EZ and ECT types, the largest adverse response occurs for locations influenced by cold, anticyclonic situations and atmospheric stability. 相似文献
105.
This paper addresses alternative procedures to the ESO supplied pipeline procedures for the reduction of UVES spectra of two quasar spectra to determine the value of the fundamental constant at early times in the universe. The procedures utilize intermediate product images and spectra produced by the pipeline with alternative wavelength calibration and spectrum addition methods. Spectroscopic studies that require extreme wavelength precision need customized wavelength calibration procedures beyond that usually supplied by the standard data reduction pipelines. An example of such studies is the measurement of the values of the fundamental constants at early times in the universe. This article describes a wavelength calibration procedure for the UV–visual Echelle spectrometer on the very large telescope, however, it can be extended to other spectrometers as well. The procedure described here provides relative wavelength precision of better than for the long-slit Thorium–Argon calibration lamp exposures. The gain in precision over the pipeline wavelength calibration is almost entirely due to a more exclusive selection of Th/Ar calibration lines. 相似文献
106.
107.
Matthew T. Bizjack Susan M. Kidwell Ronald G. Velarde Jill Leonard-Pingel Adam Tomašových 《Marine pollution bulletin》2017,114(1):448-465
Molluscan shell debris is an under-exploited means of detecting, sourcing, and age-dating dredged sediments in open-shelf settings. Backscatter features on the Southern California shelf are suggestive of dredged sediment hauled from San Diego Bay but deposited significantly inshore of the EPA-designated ocean disposal site. We find that 36% of all identifiable bivalve shells > 2 mm (44% of shells > 4 mm) in sediment samples from this 'short dump' area are from species known to live exclusively in the Bay; such shells are absent at reference sites of comparable water depth, indicating that their presence in the short-dump area signals non-compliant disposal rather than natural offshore transport or sea level rise. These sediments lack the shells of species that invaded California bays in the 1970s, suggesting that disposal preceded federal regulations. This inexpensive, low-tech method, with its protocol for rejecting alternative hypotheses, will be easy to adapt in other settings. 相似文献
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109.
A high-resolution, regional coupled atmosphere–ocean model is used to investigate strong air–sea interactions during a rapidly developing extratropical cyclone (ETC) off the east coast of the USA. In this two-way coupled system, surface momentum and heat fluxes derived from the Weather Research and Forecasting model and sea surface temperature (SST) from the Regional Ocean Modeling System are exchanged via the Model Coupling Toolkit. Comparisons are made between the modeled and observed wind velocity, sea level pressure, 10 m air temperature, and sea surface temperature time series, as well as a comparison between the model and one glider transect. Vertical profiles of modeled air temperature and winds in the marine atmospheric boundary layer and temperature variations in the upper ocean during a 3-day storm period are examined at various cross-shelf transects along the eastern seaboard. It is found that the air–sea interactions near the Gulf Stream are important for generating and sustaining the ETC. In particular, locally enhanced winds over a warm sea (relative to the land temperature) induce large surface heat fluxes which cool the upper ocean by up to 2 °C, mainly during the cold air outbreak period after the storm passage. Detailed heat budget analyses show the ocean-to-atmosphere heat flux dominates the upper ocean heat content variations. Results clearly show that dynamic air–sea interactions affecting momentum and buoyancy flux exchanges in ETCs need to be resolved accurately in a coupled atmosphere–ocean modeling framework. 相似文献
110.
Jill Wakefield 《Marine pollution bulletin》2010,60(3):323-333
The European Union’s Integrated Maritime Policy is intended in part to co-ordinate sectoral policies, to achieve joined-up thinking and action and overcome the inconsistency between policy approaches that has led to the degradation of European seas. An integrated governance would be relatively straight-forward if the different interests and actors were operating on the basis of shared values, but they are not. While the fisheries sector, whether large or small-scale, is driven by a commercial imperative which tends towards the greatest extraction of the resource possible, environmentalists would champion the removal of all human impacts, other than redress activity, as the optimum state for the ecosystem. However, the greatest impediment to an integrated approach is the failure to subject the EU’s Common Fisheries Policy to the objectives of the Integrated Maritime Policy. Instead, all decisions concerning fisheries will continue to be made in accordance with the Fisheries Regulation which demands exploitation of the fragile resource. Attention needs to be given to how EU fisheries policy is to acquire values beyond that of commercial extraction for immediate economic benefit so that it may cohere with objectives of the Integrated Maritime Policy and aid the regeneration of the seas. 相似文献