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81.
82.
Caterina RINAUDO Daniela GASTALDI Orfeo ZERBINATI Elisa FORNERO Graziella BERTA 《《地质学报》英文版》2009,83(6):1224-1231
Abstract: Twenty-four soil samples were collected at three depths from an approximately 2.5 acre contaminated site in southern Piedmont (Italy) and then analyzed. The main soil parameters determined were: pH, Cation Exchange Capacity (CEC), particle size distribution, total organic carbon (TOC) content and retained metal concentration. The mineral phases were identified by X-Ray Powder Diffraction (XRPD). All of the samples contained Zn and Cu resulting from industrial contamination during the last century, and those obtained at depths of 20-40 cm consistently showed the highest levels. To determine which size fraction was most active in the retention process, the samples were separated into four fractions (≤2 mm, ≤63 μm, ≤30 μm and ≤2 μm) and the amount of pollutant measured in each. It was found that metal retention was the highest in the clayey fraction, whose clay minerals were identified by XRPD after K+ and Mg2+ saturation, glycerol treatment and heating to 550°C. The clayey fraction was also the richest in TOC, and a direct correlation between TOC amount and metal retention was observed. 相似文献
83.
Stéphane Erard Bruno Bézard Alain Doressoundiram Daniela Despan 《Planetary and Space Science》2011,59(15):1842-1852
Mercury has been observed in June 2006 with the SofI instrument at NTT. Resolved spectroscopy was performed in the range. The observations were acquired close to a favorable quadrature with maximum elongation, and span mostly the southern hemisphere in the 235–315°E longitude area.In contrast to recent observations from IRTF, the present study does not indicate any pyroxene absorption in the near-infrared range, neither in the region nor at . Detailed spectral analysis allows to derive an upper limit of 1.5% type-A pyroxene (hedenbergite) or 1.1% enstatite (assuming minimum lunar iron content) in the regions observed, at the 700 km scale. Assuming lunar-like maturity effects on band depth, this corresponds to an upper limit of 0.15 and 0.6 wt.% FeO content in silicates, an order of magnitude less than previous estimates. 相似文献
84.
J. Schwarz 《Marine Georesources & Geotechnology》2013,31(2):145-149
Tiomin Resources Inc. (“Tiomin”), the proponent of the Kwale Mineral Sands Project in Kenya, presents a response to the article authored by J. O. Z. Abuodha and P. O. Hayombe, entitled “Protracted Environmental Issues on a Proposed Titanium Minerals Development in Kenya's South Coast”, published in Volume 24, Number 2, April–June 2006. This article contains a series of inaccuracies, some grossly misleading and many statements relate to outdated information. Tiomin is greatly concerned at the publication of such a misleading report and is obliged to state the facts correctly. This response seeks to identify the misrepresentation of statements and/or facts in the article and present a correct and accurate perspective on the environmental issues of the project. 相似文献
85.
In this work, we perform an analysis of large dark dunes within Moreux Crater and Herschel Crater on Mars using High Resolution Imaging Science Experiment (HiRISE) and Context Camera (CTX) data sets. These data allow us to conduct a detailed analysis of dune morphology and slip faces, concluding that the studied dune fields are influenced by topographically‐controlled complex wind directions. Our morphological analysis reveals that inside Moreux Crater in particular, the topographic setting dominates the wind flow direction, leading to the development of a sand transport pathway encircling the central peak of the crater. The dune fields in Herschel Crater are also affected by winds controlled by variable topography as suggested by the presence of complex dunes and dune fields. Our analysis indicate that the studied dune systems is not the result of paleo‐wind regimes. Furthermore, we perform thermal inertia measurements using thermal emission spectrometer (TES) data, which indicate that the studied dune fields consist of medium sand 250–500 µm in diameter. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
86.
Tobias Dürig Fabio Dioguardi Ralf Büttner Pierfrancesco Dellino Daniela Mele Bernd Zimanowski 《Bulletin of Volcanology》2012,74(4):895-902
Brittle magmatic fragmentation plays a crucial role in explosive eruptions. It represents the starting point of hazardous
explosive events that can affect large areas surrounding erupting volcanoes. Knowing the initial energy released during this
fragmentation process is fundamental for the understanding of the subsequent dynamics of the eruptive gas-particle mixture
and consequently for the forecasting of the erupting column’s behavior. The specific kinetic energy (SKE) of the particles
quantifies the initial velocity shortly after the fragmentation and is therefore a necessary variable to model the gas-particle
conduit flow and eruptive column regime. In this paper, we present a new method for its determination based on fragmentation
experiments and identification of the timings of energy release. The results obtained on compositions representative for basaltic
and phonolitic melts show a direct dependence on magma material properties: poorly vesiculated basaltic melts from Stromboli
show the highest SKE values ranging from 7.3 to 11.8 kJ/kg, while experiments with highly vesiculated samples from Stromboli
and Vesuvius result in lower SKE values (3.1 to 3.8 kJ/kg). The described methodology presents a useful tool for quantitative
estimation of the kinetic energy release of magmatic fragmentation processes, which can contribute to the improvement of hazard
assessment. 相似文献
87.
88.
Daniela Suteu Doina Bilba Magdalena Aflori Florica Doroftei Gabriela Lisa Marinela Badeanu Teodor Malutan 《洁净——土壤、空气、水》2012,40(2):198-205
This study investigates structural and adsorption properties of the powdered waste shells of Rapana gastropod and their use as a new cheap adsorbent to remove reactive dye Brilliant Red HE‐3B from aqueous solutions under batch conditions. For the powder shells characterization, solubility tests in acidic solutions and X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDX), Fourier transform IR spectroscopy (FT‐IR) and thermogravimetric analyses were performed. The results revealed that the adsorbent surface is heterogeneous consisting mainly from calcium carbonate layers (either calcite or aragonite) and a small amount of organic macromolecules (proteins and polysaccharides). The dye adsorptive potential of gastropod shells powder was evaluated as function of initial solution pH (1–5), adsorbent dose (6–40 g L?1), dye concentration (50–300 mg L?1), temperature (5–60°C), and contact time (0–24 h). It was observed that the maximum values of dye percentage removal were obtained at the initial pH of solution 1.2, shells dose of 40 g L?1, dye initial concentration of 50–50 mg L?1 and higher temperatures; the equilibrium time decreases with increasing of dye concentration. It is proved that the waste seashell powder can be used as low cost bioinorganic adsorbent for dyes removal from textile wastewaters. 相似文献
89.
Assessing the results of scenarios of climate and land use changes on the hydrology of an Italian catchment: modelling study 总被引:1,自引:0,他引:1
Daniela R. D'Agostino Liuzzi Giuliana Trisorio Nicola Lamaddalena Ragab Ragab 《水文研究》2010,24(19):2693-2704
Hydrological models are recognized as valid scientific tools to study water quantity and quality and provide support for the integrated management and planning of water resources at different scales. In common with many catchments in the Mediterranean, the study catchment has many problems such as the increasing gap between water demand and supply, water quality deterioration, scarcity of available data, lack of measurements and specific information. The application of hydrological models to investigate hydrological processes in this type of catchments is of particular relevance for water planning strategies to address the possible impact of climate and land use changes on water resources. The distributed catchment scale model (DiCaSM) was selected to study the impact of climate and land use changes on the hydrological cycle and the water balance components in the Apulia region, southern Italy, specifically in the Candelaro catchment (1780 km2). The results obtained from this investigation proved the ability of DiCaSM to quantify the different components of the catchment water balance and to successfully simulate the stream flows. In addition, the model was run with the climate change scenarios for southern Italy, i.e. reduced winter rainfall by 5–10%, reduced summer rainfall by 15–20%, winter temperature rise by 1·25–1·5 °C and summer temperature rise by 1·5–1·75 °C. The results indicated that by 2050, groundwater recharge in the Candelaro catchment would decrease by 21–31% and stream flows by 16–23%. The model results also showed that the projected durum wheat yield up to 2050 is likely to decrease between 2·2% and 10·4% due to the future reduction in rainfall and increase in temperature. In the current study, the reliability of the DiCaSM was assessed when applied to the Candelaro catchment; those parameters that may cause uncertainty in model output were investigated using a generalized likelihood uncertainty estimation (GLUE) methodology. The results showed that DiCaSM provided a small level of uncertainty and subsequently, a higher confidence level. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
90.