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111.
Application and validation of bivariate GIS-based landslide susceptibility assessment for the Vitravo river catchment (Calabria,south Italy) 总被引:3,自引:1,他引:2
Massimo Conforti Gaetano Robustelli Francesco Muto Salvatore Critelli 《Natural Hazards》2012,61(1):127-141
The Calabria (Southern Italy) region is characterized by many geological hazards among which landslides, due to the geological,
geomorphological, and climatic characteristics, constitute one of the major cause of significant and widespread damage. The
present work aims to exploit a bivariate statistics-based approach for drafting a landslide susceptibility map in a specific
scenario of the region (the Vitravo River catchment) to provide a useful and easy tool for future land planning. Landslides
have been detected through air-photo interpretation and field surveys, by identifying both the landslide detachment zones
(LDZ) and landslide bodies; a geospatial database of predisposing factors has been constructed using the ESRI ArcView 3.2
GIS. The landslide susceptibility has been assessed by computing the weighting values (Wi) for each class of the predisposing factors (lithology, proximity to fault and drainage line, land use, slope angle, aspect,
plan curvature), thus evaluating the distribution of the landslide detachment zones within each class. The extracted predisposing
factors maps have then been re-classified on the basis of the calculated weighting values (Wi) and by means of overlay processes. Finally, the landslide susceptibility map has been considered by five classes. It has
been determined that a high percentage (61%) of the study area is characterized by a high to very high degree of susceptibility;
clay and marly lithologies, and slope exceeding 20° in inclination would be much prone to landsliding. Furthermore, in order
to ascertain the proposed landslide susceptibility estimate, a validation procedure has been carried out, by splitting the
landslide detachment zones into two groups: a training and a validation set. By means of the training set, the susceptibility
map has first been produced; then, it has been compared with the validation set. As a result, a great majority of LDZ-validation
set (85%) would be located in highly and very highly susceptible areas. The predictive power of the model is considered reliable,
since more than 50% of the LDZ fall into 20% of the most susceptible areas. The reliability of the susceptibility map is also
suggested by computing the SCAI index, true positive and false positive rates; nevertheless, the most susceptible areas are
overestimated. As a whole, the results indicate that landslide susceptibility assessment based on a bivariate statistics-based
method in a GIS environment may be useful for land planning policy, especially when considering its cost/benefit ratio and
the need of using an easy tool. 相似文献
112.
Fatemeh Jalayer Raffaele De Risi Francesco De Paola Maurizio Giugni Gaetano Manfredi Paolo Gasparini Maria Elena Topa Nebyou Yonas Kumelachew Yeshitela Alemu Nebebe Gina Cavan Sarah Lindley Andreas Printz Florian Renner 《Natural Hazards》2014,73(2):975-1001
Identifying urban flooding risk hotspots is one of the first steps in an integrated methodology for urban flood risk assessment and mitigation. This work employs three GIS-based frameworks for identifying urban flooding risk hotspots for residential buildings and urban corridors. This is done by overlaying a map of potentially flood-prone areas [estimated through the topographic wetness index (TWI)], a map of residential areas and urban corridors [extracted from a city-wide assessment of urban morphology types (UMT)], and a geo-spatial census dataset. A maximum likelihood method (MLE) is employed for estimating the threshold used for identifying the flood-prone areas (the TWI threshold) based on the inundation profiles calculated for various return periods within a given spatial window. Furthermore, Bayesian parameter estimation is employed in order to estimate the TWI threshold based on inundation profiles calculated for more than one spatial window. For different statistics of the TWI threshold (e.g. MLE estimate, 16th percentile, 50th percentile), the map of the potentially flood-prone areas is overlaid with the map of urban morphology units, identified as residential and urban corridors, in order to delineate the urban hotspots for both UMT. Moreover, information related to population density is integrated by overlaying geo-spatial census datasets in order to estimate the number of people affected by flooding. Differences in exposure characteristics have been assessed for a range of different residential types. As a demonstration, urban flooding risk hotspots are delineated for different percentiles of the TWI value for the city of Addis Ababa, Ethiopia. 相似文献
113.
Carbon capture and sequestration versus carbon capture utilisation and storage for enhanced oil recovery 总被引:1,自引:1,他引:0
There are 74 integrated carbon capture projects worldwide currently listed by the Global CCS Institute, including the few already running and those still at the identification, evaluation, definition or execution stage for operation by 2018. Significant funding programmes have recently been launched by the European Commission (NER300 in November 2011) and by the UK Department of Energy and Climate Change (CCS Commercialisation Programme in April 2012) for commercial demonstration projects leading to innovation across the CCS/CCUS technology chain to reduce energy system costs. In their calls for proposals, these programmes were open to both CCS and CCUS projects. However, there are significant technical and commercial differences between projects for enhanced oil recovery and those for permanent storage of carbon dioxide in saline aquifers or in depleted hydrocarbon reservoirs, the same way that there exist more complexities and limitations for offshore implementation. Such differences are accompanied by different levels of field verification of the various storage and utilisation concepts, with permanent sequestration having only a more recent history and smaller-scale implementation. In this scenario, the need for appropriate due diligence workflows and screening criteria to assess the technical viability and the deliverability of different CCS/CCUS projects remains crucial, vis-à-vis the high component costs, efficiency penalties, reservoir uncertainties and the many challenges related to full chain integration (from carbon dioxide capture to underground sequestration). Based on information in the public domain, this paper reviews the current status of offshore CCS/CCUS implementation worldwide and discusses screening criteria for use by governments, operators and investors alike. 相似文献
114.
Gaetano Zimbardo 《Planetary and Space Science》2011,59(7):468-1498
We propose a new model for explaining the observations of preferential heating of heavy ions in the polar solar corona. We consider that a large number of small scale shock waves can be present in the solar corona, as suggested by recent observations of polar coronal jets by the Hinode and STEREO spacecraft. The heavy ion energization mechanism is, essentially, the ion reflection off supercritical quasi-perpendicular collisionless shocks in the corona and the subsequent acceleration by the motional electric field E=−(1/c)V ×B. The acceleration due to E is perpendicular to the magnetic field, giving rise to large temperature anisotropy with T⊥?T∥, which can excite ion cyclotron waves. Also, heating is more than mass proportional with respect to protons, because the heavy ion orbit is mostly upstream of the quasi-perpendicular shock foot. The observed temperature ratios between O5+ ions and protons in the polar corona, and between α particles and protons in the solar wind are easily recovered. We also discuss the mechanism of heavy ion reflection, which is based on ion gyration in the magnetic overshoot of the shock. 相似文献
115.
Marcelo Enrique Conti Mabel Tudino Jorge Stripeikis Gaetano Cecchetti 《Journal of Atmospheric Chemistry》2004,49(1-3):83-94
The lichen Evernia prunastri has been employed for biomonitoring the atmospheric deposition of heavy metals at urban, rural and industrial sites in Central Italy. Lichen samples have been collected in a control site 1500 m a. s. l. (Parco Nazionale dAbruzzo, Central Italy) and subsequently transplanted at urban site (Cassino city center), at rural location 7 km away from Cassino (S. Elia Fiumerapido) and at industrial location (Piedimonte S. Germano) surrounding an automobile factory. Once defined the surface of impact relevant to this work, the lichen samples were transplanted at the four cardinal points of each site. Studies of bioaccumulation of Pb, Cd, Cr, Cu and Zn in lichen samples were performed five times at regular intervals between November 2000–December 2001. Microwave digestion of the samples and graphite furnace atomic absorption spectrometry were employed for the heavy metal determinations. Suitable certified reference materials (CRM) were used for validation of the analytical methodology. Results showed the ability of Evernia prunastri to accumulate the heavy metals under study. As expected, the area chosen as control site showed significantly (Friedman test, cluster analysis) lower impact in comparison to the other sites and the rural site showed smaller impact than the urban and the industrial sites. 相似文献