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1.
The Rharb basin is located in northwestern Morocco. It is a part of one of the most important hydrogeological basins of Morocco, and extends over some 4000 km2. The nature of its Plio-Quaternary sedimentary fill and its structural and palaeoenvironmental contexts are reflected by great variations in aerial and temporal facies distribution. This distribution, in turn, is a direct cause of the observed complexity in the geometry of potentially water-bearing beds. In the present work, we present an image of potential new hydrogeological reservoirs and define new structures that partially explain their architecture. To cite this article: M. Kili et al., C. R. Geoscience 338 (2006).  相似文献   
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The fracturing analysis in the Permian basins of Jebilet and Rehamna (Hercynian Morocco) and the underlying terranes allowed us to suggest a model for their opening. Three tectonic episodes are distinguished: a transtensional episode NNE–SSW-trending (Permian I), occurring during the opening along sinistral wrench faults N70–110-trending, associated with synsedimentary normal faults; a transpressive episode ESE–WNW-trending (Permian II), initiating the closure, the normal faults playing back reverse faults and the N70 trending faults dextral wrench faults; a compressional episode NNW–SSE (post-Permian, ante-Triassic), accentuating the closure and the deformation and putting an end to the Tardi-Hercynian compressive movements. To cite this article: A. Saidi et al., C. R. Geoscience 334 (2002) 221–226.  相似文献   
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To evaluate the risk of contaminant transport by mobile colloids, it is necessary to understand how colloids and associated pollutants behave during their migration through uncontaminated soil or groundwater. In this study, we investigated the influence of aggregation induced by Ca2+ and trace metals (Pb2+, Cu2+) concentrations on the transport of humic-coated kaolinite colloids through a natural quartz sand at pH=4. Adsorbed divalent cations reduce the colloids surface charge and thereby induce aggregation and deposition in porous media. To cite this article: R. Ait Akbour et al., C. R. Geoscience 334 (2002) 981–985.  相似文献   
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Weak dust acoustic (DA) solitary waves are investigated in a mixed nonthermal high energy-tail electron distribution, focusing on the influence of an interplay between nonthermality and superthermality on the DA soliton energy. It is shown that in a pure superthermal plasma (α=0), electron thermalization (κ→∞) leads to an increase of the energy carried by the soliton. Addition of minute quantities of nonthermal electrons drastically modifies the κ-dependence of the soliton energy E κ,α . The latter first decreases, then exhibits a local minimum before leveling at a constant value. The energy exchange between the non-Maxwellian electrons and the localized solitary structure depends drastically on the interplay between superthermality and nonthermality.  相似文献   
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The lower Mesozoic of the Traras mount starts with the so-called Red Series, which lays uncomformably on the folded and granitized Paleozoic basement. This series is overlain by Middle Liassic limestones. On the basis of its lower and upper limits and the lack of dating evidence, former authors attribute a Permian to lower Liassic (Sinemurian) age for this series. Palynological results allow to range it in the upper Triassic probably Norian-Rhetian. The Red Series is studied from five sections that depict important thickness and facies variations from southwest to the northeast, inferring the irregularities of the Hercynian erosional surface. In the Central Traras, this series shows over 130-m-thick micaceous sandy conglomeratic units, deposited within alluvial fans, where the bedrock source corresponds to granite of Nedroma or its equivalent. In the southern and eastern Traras, where the series’ thickness respectively does not exceed 30 m and averages 40–80 m, besides alluvial deposits issued from hercynian basement erosion, it exhibits volcanic evidences interbedded by lacustrine deposits. Vertical and spatial distribution depicts synsedimentary infilling of narrow elongated rift basins, typically half-grabens, bounded on one side by a normal fault or a series of normal faults trending NNE-SSW to NW-SE, inherited from the hercynian event. The study of tectonostratigraphic units permitted to put forward geodynamics of the infilling basins.  相似文献   
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The Agadir-Essaouira area in the occidental High Atlas Mountains of Morocco is characterized by a semi-arid climate. The scarcity and quality of water resources, exacerbated by long drought periods, constitute a major problem for a sustainable development of this region. Groundwater resources of carbonate units within Jurassic and Cretaceous aquifers are requested for drinking and irrigation purposes. In this study, we collected 84 samples from wells, boreholes, springs, and rivers. Hydrochemical and isotopic data were used to examine the mineralization and origin of water, which control groundwater quality. The chemical composition of water seems to be controlled by water-rock interactions, such as dissolution of carbonates (calcite and dolomite), weathering of gypsum, as well as ion exchange processes, which explain the observed variability. Stable isotopes results show that groundwater from the mainly marly Cretaceous aquifer are submitted to an evaporation effect, while samples from the chiefly calcareous Jurassic aquifer indicate a meteoric origin, due to a rapid infiltration of recharge runoff through the karstic outcrops. The low values of δ18O and δ2H suggest a local recharge from areas with elevations ranging from 400 to 1200 m for the Cretaceous aquifer and from 800 to 1500 m for the Jurassic units.  相似文献   
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Arid to semi-arid regions are characterized by low levels of surface water and low annual precipitation (generally <350 mm/year). In such areas, groundwater must be used to meet all the needs of the population for water. As a consequence, careful management is required to ensure the sustainability of this scarce resource in response to the demands of urban centers, industry, agriculture, and tourism. The concept of the aquifer recharge rate is particularly useful in the quantification of these groundwater resources and can be used to form the basis of a decision support system. This study determined the potential recharge rate in the Haouz aquifer using a multi-criteria analysis that included both the major and minor factors influencing the rate of infiltration of water into the aquifer. The analysis was based on the use of a geographical information system supported by remote sensing techniques to develop thematic data layers. These layers were then used to describe the spatial variation of the factors influencing the recharge rate of the aquifer and were subsequently integrated and analyzed to derive the spatial distribution of the potential recharge. This approach was used to classify the Haouz Plain (Morocco) into three different zones with respect to the recharge rate, with recharge rates ranging from 3.5 to 18.2 %.  相似文献   
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Weak ion-acoustic (IA) solitary wave propagation is investigated in the presence of electron trapping and background nonextensivity. A physically meaningful distribution is outlined and a Schamel-like equation is derived. The role a background electron nonextensivity may play on the energy carried by the IA soliton is then examined. It is found that nonextensivity may cause a soliton energy depletion. An increase of the amount of electron trapping leads to a net shift towards higher values of the soliton energy.  相似文献   
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