全文获取类型
收费全文 | 178篇 |
免费 | 7篇 |
专业分类
测绘学 | 3篇 |
大气科学 | 39篇 |
地球物理 | 47篇 |
地质学 | 64篇 |
海洋学 | 6篇 |
天文学 | 16篇 |
自然地理 | 10篇 |
出版年
2022年 | 4篇 |
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 9篇 |
2017年 | 13篇 |
2016年 | 9篇 |
2015年 | 8篇 |
2014年 | 8篇 |
2013年 | 9篇 |
2012年 | 5篇 |
2011年 | 8篇 |
2010年 | 11篇 |
2009年 | 6篇 |
2008年 | 4篇 |
2007年 | 12篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2004年 | 4篇 |
2003年 | 7篇 |
2002年 | 10篇 |
2001年 | 7篇 |
2000年 | 5篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1989年 | 2篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1975年 | 1篇 |
排序方式: 共有185条查询结果,搜索用时 15 毫秒
71.
72.
Leonardo Cascini Gianfranco Fornaro Dario Peduto 《ISPRS Journal of Photogrammetry and Remote Sensing》2009,64(6):598-611
Landslide studies over large areas call for multidisciplinary analyses supported by accurate ground displacement measurements. At present, conventional techniques can be valuably complemented by innovative satellite techniques such as Differential SAR Interferometry (DInSAR), furnishing huge amounts of data at competitively affordable costs. This work investigates the remote sensed data potential in landslide studies starting from the awareness of the present constraints of the technique. To this end, with reference to a sample area–within the territory of the National Basin Authority of Liri-Garigliano and Volturno rivers (Central-Southern Italy)–for which detailed base and thematic maps are available, quantitative examples of DInSAR data coverage on both different land-uses and landslide-affected areas are shown. Then, an original tool for “a priori DInSAR landslide visibility zoning” is proposed to address the choice of the most suitable image datasets. Finally, referring to the visible zones, the outcomes of DInSAR data for checking/updating landslide inventory maps at 1:25,000 scale highlight appealing perspectives, also holding the promise of obtaining relevant information in the landslide hazard evaluation. 相似文献
73.
Sebastiano Foti Stefano Parolai Dario Albarello Matteo Picozzi 《Surveys in Geophysics》2011,32(6):777-825
Surface-wave dispersion analysis is widely used in geophysics to infer a shear wave velocity model of the subsoil for a wide
variety of applications. A shear-wave velocity model is obtained from the solution of an inverse problem based on the surface
wave dispersive propagation in vertically heterogeneous media. The analysis can be based either on active source measurements
or on seismic noise recordings. This paper discusses the most typical choices for collection and interpretation of experimental
data, providing a state of the art on the different steps involved in surface wave surveys. In particular, the different strategies
for processing experimental data and to solve the inverse problem are presented, along with their advantages and disadvantages.
Also, some issues related to the characteristics of passive surface wave data and their use in H/V spectral ratio technique
are discussed as additional information to be used independently or in conjunction with dispersion analysis. Finally, some
recommendations for the use of surface wave methods are presented, while also outlining future trends in the research of this
topic. 相似文献
74.
Rodolfo Puglia Dario Albarello Antonella Gorini Lucia Luzi Sandro Marcucci Francesca Pacor 《Bulletin of Earthquake Engineering》2011,9(6):1821-1838
This paper describes the analyses of the single-station ambient-vibration measurements performed on the Italian accelerometric
network to detect site resonance phenomena potentially affecting earthquake recordings. The use of low cost, high quality
microtremor measurement can be helpful to discriminate among soil classes, since several classification schemes based on resonance
frequencies were proposed in the last decades. Operatively, in the framework of the Italian Strong Motion Database project
(DPC-INGV 2007–2009 S4; ), soil resonance frequencies have been evaluated from more than 200 ambient vibration measurements in correspondence of accelerometric
stations included in ITACA (). The noise recordings have been analyzed using the same numerical protocol in order to standardize the results. Particular
attention has been paid to evaluate the quality of measurements and to develop an on-purpose mathematical tool to automatically
estimate the peaks in the horizontal-to-vertical spectral ratio (HVSR) curve. The reliability of the resonance frequencies
from HVSR has been tested by comparing estimates provided by independent methods (modeling or earthquake recordings). The
test confirmed the reliability of the microtremor HVSR for assessing the resonance frequencies of the examined sites. 相似文献
75.
AbstractDetrital zircon populations from Carboniferous to Permian sandstones from the Lozar Section of Spiti, northern India, were analyzed with the typology method in order to obtain complementary information on the source areas of the sediments. Zircon grains were subdivided into several groups and subgroups, according to degree of abrasion and morphological features.First appearance of detrital zircons with distinct typologic signature within successive stratigraphic intervals provided useful data about the tectono-magmatic evolution of the northern Indian margin during Late Paleozoic rifting of Gondwana and initial opening of Neotethys. The base of the studied sequence (Lower Carboniferous Thabo Fm.) is characterized by a largely cratonic provenance, seemingly from the Indian Shield to the South. In the Upper Carboniferous Chichong Fm., first occurrence of typical zircons from anatectic granites and increasing abundance of granitoid detritus suggest rapid uplift and unroofing of anatectic rocks of probable Cambro-Ordovician age. In the lowermost Permian (Asselian) glaciomarine Ganmachidam Diamictite, euhedral detrital zircons with peculiar features, associated with Cr-rich chromian spinels and mafic to felsic volcanic rock fragments, hint at emplacement of bimodal alkaline magmatic suites. The same sources, possibly including subvolcanic bodies, continued to be eroded until final break-up, documented by the Permian Kuling Group. 相似文献
76.
Here we outline some recent activities in the theory and phenomenology of Galactic cosmic rays, in the light of the great precision of direct cosmic ray measurements reached in the last decade. In the energy domain of interest, ranging from a few GeV/nucleon to tens of TeV/nucleon, data have revealed some novel features requiring an explanation. We shall emphasize the importance of a more refined modeling, of achieving a better assessment of theoretical uncertainties associated to the models, and of testing key predictions specific of different models against the rich datasets available nowadays. Despite the still shaky theoretical situation, several hints have accumulated suggesting the need to go beyond the approximation of a homogeneous and non-dynamical diffusion coefficient in the Galaxy. 相似文献
77.
78.
500-year temperature reconstruction in the Mediterranean Basin by means of documentary data and instrumental observations 总被引:3,自引:1,他引:2
Dario Camuffo C. Bertolin M. Barriendos F. Dominguez-Castro C. Cocheo S. Enzi M. Sghedoni A. della Valle E. Garnier M.-J. Alcoforado E. Xoplaki J. Luterbacher N. Diodato M. Maugeri M. F. Nunes R. Rodriguez 《Climatic change》2010,101(1-2):169-199
The paper reports the main results of the EU project Millennium in the Mediterranean area over the last 500 years. It analyses a long series of temperature from Portugal, Spain, France, Italy and Greece. The series are obtained by combining indices from documentary sources from AD 1500 to the onset of regular instrumental observations. There is an ongoing discussion regarding the proper way of combining documentary and instrumental data and how to translate accurately the conventional indices from ??3 to +?3 into modern units, i.e. degree Celsius. This paper produces for the first time a number of early instrumental observations, in some cases (i.e. Italy and France) covering 350 years, including thereby the earliest regular observations after the invention of the thermometer. These Mediterranean data show that anomalous temperatures usually had only a locally limited effect, while only few extreme events had a widespread impact over the whole region, such as the summer of 2003. During the period from 1850 to the present day, the Mediterranean temperature anomaly was close to the Northern Hemisphere in spring and summer, while it was warmer in autumn and winter. Compared with the long-term instrumental records (i.e. 1655 onwards), the recent warming has not exceeded the natural past variability characterized by heating–cooling cycles with no significant long-term trends. 相似文献
79.
Rüdiger Glaser Dirk Riemann Johannes Schönbein Mariano Barriendos Rudolf Brázdil Chiara Bertolin Dario Camuffo Mathias Deutsch Petr Dobrovolný Aryan van Engelen Silvia Enzi Monika Halíčková Sebastian J. Koenig Oldřich Kotyza Danuta Limanówka Jarmila Macková Mirca Sghedoni Brice Martin Iso Himmelsbach 《Climatic change》2010,101(1-2):235-256
The paper presents a qualitative and quantitative analysis of flood variability and forcing of major European rivers since AD 1500. We compile and investigate flood reconstructions which are based on documentary evidence for twelve Central European rivers and for eight Mediterranean rivers. Flood variability and underlying climatological causes are reconstructed by using hermeneutic approaches including critical source analysis and by applying a semi-quantitative classification scheme. The paper describes the driving climatic causes, seasonality and variability of observed flood events within the different river catchments covering the European mainland. Historical flood data are presented and recent research in the field of historical flood reconstructions is highlighted. Additionally, the character of the different flood series is discussed. A comparison of the historical flood seasonality in relation to modern distribution is given and aspects of the spatial coherence are presented. The comparative analysis points to the fact that the number of flood events is predominately triggered by regional climatic forcing, with at most only minor influence on neighbouring catchments. The only exceptions are extreme, supra-regional climatic events and conditions such as anomalous cold winters, similar to that of 1784, which affected large parts of Europe and triggered flood events in several catchments as a result of ice-break at the beginning of the annual thaw. Four periods of increased occurrence of flooding, mostly affecting Central European Rivers, have been identified; 1540–1600, 1640–1700, 1730–1790, 1790–1840. The reconstruction, compilation and analysis of European-wide flood data over the last five centuries reveal the complexity of the underlying climatological causes and the high variability of flood events in temporal and spatial dimension. 相似文献
80.