全文获取类型
收费全文 | 131篇 |
免费 | 8篇 |
专业分类
大气科学 | 3篇 |
地球物理 | 51篇 |
地质学 | 42篇 |
海洋学 | 16篇 |
天文学 | 14篇 |
自然地理 | 13篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 5篇 |
2016年 | 7篇 |
2015年 | 4篇 |
2014年 | 7篇 |
2013年 | 10篇 |
2012年 | 8篇 |
2011年 | 11篇 |
2010年 | 10篇 |
2009年 | 5篇 |
2008年 | 13篇 |
2007年 | 2篇 |
2006年 | 5篇 |
2005年 | 3篇 |
2004年 | 14篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1986年 | 1篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有139条查询结果,搜索用时 15 毫秒
61.
Alexander I. Gorshkov Giuliano F. Panza Alexander A. Soloviev Abdelkrim Aoudia Antonella Peresan 《地学学报》2009,21(4):257-264
We introduce a new method based on the analysis of the topographical alignments and used to delineate the structural boundaries of the nodes, which permits the definition of relatively narrow earthquake-prone areas by the pattern recognition approach. The structurally bounded nodes capable of earthquakes with M ≥ 6.0, identified with pattern recognition, in fact, cover a significantly smaller area of the study region as compared with that defined by Gorshkov et al. (2004) who used conventional circles. The proposed method thus improves the precision in the location of potential large earthquakes. 相似文献
62.
63.
Estelle Leroux Marina Rabineau Daniel Aslanian Didier Granjeon Laurence Droz Christian Gorini 《地学学报》2014,26(3):230-238
Determining the relative importance of factors interacting to control stratigraphic organization is a key issue in sedimentology. The Pliocene‐Quaternary chronostratigraphy on the Gulf of Lions platform is still poorly constrained, giving rise to different interpretations of the evolution of its subsidence through time. This paper examines the Pliocene‐Quaternary sedimentary filling of the Gulf of Lion's shelf with Dionisos, a numerical stratigraphic model. Our results show that a constant subsidence rate accurately reproduces the observed geometries, whereas a varying subsidence rate reproduces them only if the acceleration of subsidence is limited. At this time‐scale, a third‐order eustatic curve is also reappraised: a higher resolution curve (built using δ18O measurements) gives a more realistic restitution of our stratigraphic markers. Finally, the constant subsidence rate and sediment fluxes implied in these modellings are discussed relative to climate and local factors of sedimentation. 相似文献
64.
A general coastal retreat affects almost all the beaches of the Apulia region (southern Italy). In particular, the coastal strip of the Gulf of Manfredonia shows an evident retreat due to human activity. To control coastal erosion, several defence interventions have been realised: breakwaters, shore parallel defences, and, above all, several types of groynes (rectilinear, hook-shaped, T-shaped) were built along the shoreline in accordance with local request. Nowadays, there are about 300 coastal defences built up to protect against human activities. A laser scanner survey of these defences, using a Leica Geosystems HDS3000, was carried out between April 2006 and September 2008 to collect data about the beach profiles and changes occurring in the defence framework. The survey work consists of 3D rendering of defences in order to make comparisons between scans of different periods. Overlap between the points cloud of the whole coastline showed that defences preserved their own profile when no human interventions took place. Moreover, throughout the length of the investigated area, not a single trend occurred in the beach profile: according to the defence framework, some stretches of coast display advancing trend, while others are stable or retreating. Therefore, this preliminary study indicated that the changes that occurred in the beach profiles and defence structures are mainly due to human interventions. 相似文献
65.
Cecilia T. Satta Sílvia Anglès Esther Garcés Nicola Sechi Silvia Pulina Bachisio Mario Padedda Daniela Stacca Antonella Lugliè 《Estuaries and Coasts》2014,37(3):646-663
The present study identified and quantified dinoflagellate cysts in surface sediments from three Mediterranean lagoons. Sediment samples were recovered from 11 stations in May 2009 at Cabras Lagoon, eight stations in May 2010 at Corru S'Ittiri Lagoon, and five stations in May 2011 at Santa Giusta Lagoon. Fifty-three dinoflagellate cyst morphotypes were identified. Sixteen species are first reports for the lagoons, and two for the Mediterranean Sea. Moreover, a new Scrippsiella species was discovered in Cabras. Seven harmful algal species were identified, primarily belonging to the potentially toxic genus Alexandrium. Total cyst abundance, number of morphotypes, and assemblages varied among lagoons, and each lagoon showed a distinct morphotype composition. A degree of heterogeneity was also detected within lagoon. Cabras and Santa Giusta cyst assemblages were characterised by morphotypes belonging to the autotrophic genus Scrippsiella, whereas Corru S'Ittiri assemblages showed dominance of heterotrophic morphotypes, including Protoperidinium cf tricingulatum. Differentiation among lagoons was also evident according to environmental conditions. Salinity proved to be a fundamental variable in determining total cyst abundance, morphotype number, and composition. This study was among the first to examine dinoflagellate cyst composition in coastal lagoons, especially from the Mediterranean region, and contributed data that increased our knowledge of cyst-producing dinoflagellates in these environments. 相似文献
66.
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
67.
Antonella Diana 《Singapore journal of tropical geography》2013,34(1):25-39
This paper discusses the governing of subjects and objects' mobility in the context of trans‐border rice and corn trade on the China‐Laos frontier. It traces the attempts by a group of ethnic Tai Lue traders from China to assert themselves as ‘flexible subjects’ and economically triumphant actors on the Upper Mekong market in the era of economic regionalization. It illustrates how, between 2005 and mid‐2006, the traders' economic success relied on a variety of ‘border strategies’. ‘Border strategies’ include a gender‐balanced organization of trade, the instrumental deployment of trans‐border ethnicity, the appropriation of a Han style of business, the opportunistic reliance on the Chinese administration's ‘regime of graduated mobility’, and the enactment of a ‘war‐machine’ against Lao state agents. Yet, in late 2006, a new wave of state authoritarianism, enmeshed in corporate accumulation processes, inhibited the traders' success. The paper suggests that, unlike what some defenders of globalization and transnational theories maintain, in the age of economic regionalization, the alleged flexibility and increased mobility of subjects and objects across the borders of the Greater Mekong Subregion remain conditional on an unpredictable mechanism of loosening and tightening. This is part of a long‐applied governing pattern of ‘experimentation under hierarchy’ on the Sino‐Lao frontier. 相似文献
68.
The Italian strong motion network 总被引:2,自引:2,他引:0
Antonella Gorini Mario Nicoletti Paolo Marsan Riccardo Bianconi Rita De Nardis Luisa Filippi Sandro Marcucci Franco Palma Elisa Zambonelli 《Bulletin of Earthquake Engineering》2010,8(5):1075-1090
The Italian Strong Motion Network is a permanent monitoring system run by the Italian national emergency management department
(Dipartimento della Protezione Civile, DPC). The network is known as RAN (Rete Accelerometrica Nazionale). An extensive project
for updating and improving the technology of RAN instruments as well as the number of recording points was performed in the
last 10 years. A wide site selection survey was carried out from eastern Sicily along the Italian peninsula, covering high
seismic risk areas. The recording station density and the choice of high-quality digital strong motion instruments ensure
reliability of the RAN network in the long-term. At the end of 2008, the free field sites selection and instruments installation,
planned in the project, were quite completed. In planning and drawing the new RAN, special attention has been devoted to the
robustness of the transmission systems, and to the distribution of new stations in order to ensure plenty of data during a
seismic emergency. We spent special care both in the estimation of the RAN site responses and in the diffusion of the strong
motion data. In order to better identify damaged earthquake areas, improved ground motion parameters need to be set. Such
parameters will also assist future progress for engineering seismic design techniques as well as disaster mitigation. 相似文献
69.
Simona Scollo Antonella Boselli Mauro Coltelli Giuseppe Leto Gianluca Pisani Nicola Spinelli Xuan Wang 《Bulletin of Volcanology》2012,74(10):2383-2395
In this paper, we use data obtained from LiDAR measurements during an ash emission event on 15 November 2010 at Mt. Etna, in Italy, in order to evaluate the spatial distribution of volcanic ash in the atmosphere. A scanning LiDAR system, located at 7?km distance from the summit craters, was directed toward the volcanic vents and moved in azimuth and elevation to analyse different volcanic plume sections. During the measurements, ash emission from the North East Crater and high degassing from the Bocca Nuova Crater were clearly visible. From our analysis we were able to: (1) evaluate the region affected by the volcanic plume presence; (2) distinguish volcanic plumes containing spherical aerosols from those having non-spherical ones; and (3) estimate the frequency of volcanic ash emissions. Moreover, the spatial distribution of ash mass concentration was evaluated with an uncertainty of about 50?%. We found that, even during ash emission episodes characterised by low intensity like the 15 November 2010 event, the region in proximity of the summit craters should be avoided by air traffic operations, the ash concentration being greater than 4?×?10?3?g/m3. The use of a scanning permanent LiDAR station may usefully monitor the volcanic activity and help to drastically reduce the risks to aviation operations during the frequent Etna eruptions. 相似文献
70.
Cuoco Emilio Minissale Angelo Di Leo Antonella “Magda” Tamburrino Stella Iorio Marina Tedesco Dario 《International Journal of Earth Sciences》2017,106(7):2429-2444
International Journal of Earth Sciences - The geochemistry of natural thermal fluids discharging in the Mondragone Plain has been investigated. Thermal spring emergences are located along the... 相似文献