全文获取类型
收费全文 | 201篇 |
免费 | 3篇 |
专业分类
测绘学 | 6篇 |
大气科学 | 7篇 |
地球物理 | 70篇 |
地质学 | 53篇 |
海洋学 | 18篇 |
天文学 | 44篇 |
综合类 | 1篇 |
自然地理 | 5篇 |
出版年
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 5篇 |
2019年 | 2篇 |
2018年 | 8篇 |
2017年 | 7篇 |
2016年 | 14篇 |
2015年 | 3篇 |
2014年 | 14篇 |
2013年 | 11篇 |
2012年 | 9篇 |
2011年 | 15篇 |
2010年 | 13篇 |
2009年 | 17篇 |
2008年 | 14篇 |
2007年 | 14篇 |
2006年 | 7篇 |
2005年 | 6篇 |
2004年 | 8篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2001年 | 1篇 |
2000年 | 5篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1983年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有204条查询结果,搜索用时 15 毫秒
131.
132.
Correlating Alpine glaciation with Adriatic sea‐level changes through lake and alluvial stratigraphy
Giovanni Monegato Roberta Pini Cesare Ravazzi Paula J. Reimer Lucia Wick 《第四纪科学杂志》2011,26(8):791-804
We compare lake and alluvial stratigraphy along a frame connecting the southern Alpine foothills and the Adriatic Sea, with the aim of matching the effects of Alpine glaciation and sea‐level changes on sedimentation during the last glacial cycle. The palynostratigraphy of Lake Fimon provided proxies for regional vegetation and climate change and was coupled with sediment petrography, loss on ignition and magnetic susceptibility, disentangling alluvial phases from fluvioglacial activity related to culminations of the southeastern Alpine glaciers. The Fimon area was not reached by alluvial fans during the penultimate glacial maximum, nor by the sea transgression during the last interglacial, but a closed lake soon developed at the Eemian onset due to enhanced rainfall. Sea‐level fall at glacial inception triggered the entrenchment of the drainage network in the plain reaching the outer Fimon Basin. Slow aggradation, but no sign of fluvioglacial activity, lasted to 38.2 ± 1.45 cal. ka BP, when a major forest withdrawal took place, coeval to the spread of alluvial fans. By 27.5 ± 0.5 cal. ka BP the Fimon Basin was dammed by the Brenta outwash system. The main step of of forest recovery commenced at around (15.8) cal. ka BP, when apex trenching of the outwash fans was triggered by the glacier's decay. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
133.
Felix Borleanu Mihaela Popa Mircea Radulian Johannes Schweitzer 《Journal of Seismology》2011,15(3):431-442
The BURAR seismic array, located in Northern Romania (Bucovina region), is designed to monitor events located in an area poorly
covered by other existing seismic stations. In order to use the BURAR array for single-station locations, it is crucial to
calibrate the azimuth and slowness parameters, which are currently used in array techniques to locate earthquakes, blasts
or nuclear explosions. The goal of this study is to apply “f–k” and plane wave fit techniques in order to constrain the slowness
and azimuth parameters at BURAR for teleseismic, regional and local events. The analysis was carried out using P and S waves
recorded for events occurred between 2004 and 2008 within a radius of 50° around BURAR. The azimuth values obtained applying
both methods strongly deviated from the theoretical values for regions like Central Turkey, Bulgaria, Dodecanese Islands and
other parts of Greece, while the ray parameter deviations with respect to a 1-D IASP91 reference model are less significant.
For the local events, the anomalies are smaller, except the particular case of Vrancea intermediate-depth earthquakes for
which strong azimuth deviations (33.5°), both positive and negative, are observed. We investigate how these systematic deviations
in azimuth are explained by the structure lateral heterogeneities which characterize the study region. 相似文献
134.
Domenico Cicchella Lucia Giaccio Annamaria Lima Stefano Albanese Antonio Cosenza Diego Civitillo Benedetto De Vivo 《Environmental Earth Sciences》2014,71(12):5129-5143
The Sarno River basin area is one of the most polluted in Europe and it is due to the waste products of the tomato industry, the leather tanneries and the pharmaceutical industry. This area also has been densely populated and urbanized since the Middle Bronze Age, as testified by the presence of numerous archeological sites, including the ancient Pompeii town, and environmental degradation that characterizes the area is absolutely unacceptable. This paper represents a detailed study to assess the potentially harmful element content of topsoils. In total, 283 soil samples were collected and analyzed, after an aqua regia extraction, by a combination of inductively coupled plasma atomic emission and inductively coupled plasma mass spectrometry for 53 elements. Univariate and multivariate analyses were carried out to show the single-element geochemical distribution and the distribution of factor scores of the elemental associations resulting from R-mode factor analysis. Maps showing elements and the association factor score distributions have been obtained using GeoDAS and ArcGIS software. The assessment of the soil contamination was also carried out using the contamination factor and degree of contamination. The results obtained indicate that soil pollution has different anthropogenic sources. Specifically, Cr pollution derives from tanneries discharging wastewaters in the main water bodies of the basin while Cu contamination seems to depend on widespread agricultural practices. Tin, Pb, Hg, Zn, Cd, Sb anomalies are found mainly in urban and industrial areas, sometimes close to roads with high traffic levels while there is a substantial coincidence with background values for other elements (Co, Ni, Se, Tl and V). 相似文献
135.
Stanislav S. Shabala Jamie N. McCallum Lucia Plank Johannes Böhm 《Journal of Geodesy》2015,89(9):873-886
136.
Lucia Angiolini Andrea Zanchi Stefano Zanchetta Alda Nicora Giovanni Vezzoli 《地学学报》2013,25(5):352-360
Based on its Permian‐Triassic stratigraphic and biotic evolution, we correlate the SE Pamir to the Karakoram terrane, and we consider them equivalent, along with the Central Pamir, to the Qiantang Terrane of Tibet, all of Palaeozoic Gondwanan ancestry. We prove the occurrence of a marked Cimmerian unconformity, documented by lowermost Jurassic deposits suturing intensively faulted and folded Permian and Triassic units, which suggests that the South Pamir collided around the T‐J boundary with the Central Pamir along the Rushan‐Pshart suture. Collision of the Karakoram to the South Pamir happened slightly later along the Wakhan‐Tirich Boundary Zone. Progressive time shifting of deformation can be related to the complex setting of the Cimmerian belt, which was subdivided into minor blocks by incipient oceanic basins, providing strong crustal mobility. 相似文献
137.
138.
AbstractThe upper Lower Carboniferous to lowermost Permian terrigenous succession of the Spiti Valley can be subdivided into five formations (Thabo Formation, Fenestella Shale, Kabjima Quartzarenite, Chichong Formation and Ganmachidam Diamictite), here described in detail and subdivided into members or lithozones.The Po Group, overlying the platform carbonates and gypsum deposits of the Lipak Formation, records an increase of subarkosic to quartzarenitic terrigenous detritus derived from uplift and erosion of continental blocks in the south during the initial stage of Neo-Tethyan rifting. Increasing mineralogic stability through the Thabo Formation broadly coincides with a climate change from tropical arid to temperate humid conditions during the Visean-Serpukhovian. The Fenestella Shale, containing rich brachiopod associations of Bashkirian age, documents a stage of widespread subsidence and transgression, followed by the regressive Kabjima Quartzarenite, which records recycling of quartzose sedimentary sequences in the south.The Chichong Formation marks another transgressive event, associated with a significant increase of granitoid detritus, partly from nearby Lesser to High Himalayan source areas. Chaetetid, cephalopod and brachiopod faunas hint at a Moscovian age for the “Chaetetid beds”, at the top of which varve-like lamination and scattered pebbles suggest glacially influenced deposition. The overlying glacio-fluvial (?) cobble conglomerates (“Pebbly beds”) reflect onset of rapid tectonic uplift.Abundant detritus from sedimentary rocks characterizes the overlying Ganmachidam Diamictite, deposited in glacio-marine environments; cold-water marine faunas of Asselian age occur in its middle part. Erosion of progressively older pre-rift sedimentary successions is ascribed to basin inversion, associated with unroofing of anatectic granitoids of the Lesser and High Himalayas. Basaltic to rhyolitic volcanic detritus documents alkalic magmatism at the climax of continental rifting. 相似文献
139.
Giancarlo Biotto Lucia Gobbo Elisa Furlan Sonia Valenti Roberto Rosselli 《International journal of geographical information science》2013,27(10):1233-1244
This work deals with the identification of potentially contaminated areas using remote sensing, geographic information systems (GIS) and multi‐criteria spatial analysis. The identification of unknown illegal landfills is a crucial environmental problem in all developed and developing countries, where a large number of illegal waste deposits exist as a result of fast, and relatively unregulated, industrial growth over the past century. The criteria used to perform the spatial analysis are here selected by considering the characteristics which are ‘desirable’ for an illegal waste disposal site, chiefly related to the existence of roads for easy access and to a low population density which facilitates unnoticed dumping of illegal waste materials. A large dataset describing known legal and illegal landfills and the context of their location (population, road network, etc.) was used to perform a spatial statistical analysis to select factors and criteria allowing for the identification of the known waste deposits. The final result is a map describing the likelihood of an illegal waste deposit to be located at any arbitrary location. Such a probability map is then used together with remote sensing techniques to narrow down the set of possibly contaminated sites (Silvestri and Omri, 2008), which are candidates for further analyses and field investigations. The importance of the integration of GIS and remote sensing is highlighted and represents a key instrument for environmental management and for the spatially‐distributed characterization of possible uncontrolled landfill sites. 相似文献
140.
Lucia Maria Seebach Peter Strobl Jesus San Miguel-Ayanz Annemarie Bastrup-Birk 《International journal of geographical information science》2013,27(11):1865-1884
Detailed and harmonized information on spatial forest distribution is an essential input for forest-related environmental assessments, in particular, for biomass and growing stock modeling. In the last years, several mapping approaches have been developed in order to provide such information for Europe in a harmonized way. Each of these maps exhibits particular properties and varies in accuracy. Yet, they are often used in parallel for different modeling purposes. A detailed spatial comparison seemed necessary in order to provide information on the advantages and limitations of each of these forest cover maps in order to facilitate their selection for modeling purposes. This article confronts the high-resolution forest cover map recently developed by the Joint Research Centre for the year 2000 (FMAP2000) with previously existing maps for the same time period: the CORINE Land Cover 2000 (CLC2000) and the Calibrated European Forest Map 1996 (CEFM1996). The spatial comparison of these three maps was carried out based on forest proportion maps of 1 km derived from the original maps. To characterize differences according to biogeographic regions, two criteria were used: detail of thematic content within each map and local spatial agreement. Concerning thematic content, CLC2000 displayed a surfeit of non-forested areas at the cost of low forest proportions, while FMAP2000 showed a more balanced distribution likely to preserve more detail in forest spatial pattern. Good spatial agreement was found for CLC2000 and FMAP2000 within about 70% of the study area, while only 50% agreement was found when compared with CEFM1996. The largest spatial differences between all maps were found in the Alpine and Mediterranean regions. Reasons for these might be different input data and classification techniques and, in particular, the calibration of CEFM1996 to reported national statistics. 相似文献