全文获取类型
收费全文 | 146篇 |
免费 | 6篇 |
国内免费 | 2篇 |
专业分类
测绘学 | 4篇 |
大气科学 | 3篇 |
地球物理 | 22篇 |
地质学 | 73篇 |
海洋学 | 15篇 |
天文学 | 29篇 |
综合类 | 1篇 |
自然地理 | 7篇 |
出版年
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 5篇 |
2018年 | 7篇 |
2017年 | 6篇 |
2016年 | 7篇 |
2015年 | 10篇 |
2014年 | 4篇 |
2013年 | 10篇 |
2012年 | 5篇 |
2011年 | 10篇 |
2010年 | 3篇 |
2009年 | 9篇 |
2008年 | 7篇 |
2007年 | 6篇 |
2006年 | 5篇 |
2005年 | 6篇 |
2004年 | 4篇 |
2003年 | 8篇 |
2002年 | 6篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有154条查询结果,搜索用时 35 毫秒
1.
Journal of Oceanology and Limnology - The hydrological models and simplified methods of Saint-venant equations are used extensively in hydrological modeling, in particular for the simulation of the... 相似文献
2.
The present study reports on population structure analysis of the marbled crabPachygrapsus marmoratus (Fabricius, 1787) from the Tunisian coast, an appropriate location to study biogeographical process... 相似文献
3.
Pennsylvanian carbonate platforms adjacent to deltaic systems in an active marine foreland basin (Escalada Fm., Cantabrian Zone,NW Spain) 下载免费PDF全文
Juan Ramón Bahamonde Oscar Merino‐Tomé Giovanna Della Porta Elisa Villa 《Basin Research》2015,27(2):208-229
The Pennsylvanian marine foreland basin of the Cantabrian Zone (NW Spain) is characterized by the unique development of kilometre‐size and hundred‐metre‐thick carbonate platforms adjacent to deltaic systems. During Moscovian time, progradational clastic wedges fed by the orogen comprised proximal alluvial conglomerates and coal‐bearing deltaic sequences to distal shelfal marine deposits associated with carbonate platforms (Escalada Fm.) and distal clay‐rich submarine slopes. A first phase of carbonate platform development (Escalada I, upper Kashirian‐lower Podolskian) reached a thickness of 400 m, nearly 50 km in width and developed a distal high‐relief margin facing a starved basin, nearly 1000‐m deep. Carbonate slope clinoforms dipped up to 30° and consisted of in situ microbial boundstone, pinching out downslope into calciturbidites, argillaceous spiculites and breccias. The second carbonate platform (Escalada II, upper Podolskian‐lower Myachkovian) developed beyond the previous platform margin, following the basinward progradation of siliciclastic deposits. Both carbonate platforms include: (1) a lower part composed of siliciclastic‐carbonate cyclothems characterized by coated‐grain and ooid grainstones; and (2) a carbonate‐dominated upper part, composed of tabular and mound‐shaped wackestone and algal‐microbial boundstone strata alternating at the decametre scale with skeletal and coated‐grain grainstone beds. Carbonate platforms initiated in distal sectors of the foreland marine shelf during transgressions, when terrigenous sediments were stored in the proximal part, and developed further during highstands of 3rd‐order sequences in a high‐subsidence context. During the falling stage and lowstand systems tracts, deltaic systems prograded across the shelf burying the carbonate platforms. Key factors involved in the development of these unique carbonate platforms in an active foreland basin are: (1) the large size of the marine shelf (approaching 200 km in width); (2) the subsidence distribution pattern across the marine shelf, decreasing from proximal shoreline to distal sectors; (3) Pennsylvanian glacio‐eustacy affecting carbonate lithofacies architecture; and (4) the environmental conditions optimal for fostering microbial and algal carbonate factories. 相似文献
4.
Galimberti Matteo Marinoni Nicoletta Della Porta Giovanna Marchi Maurizio Dapiaggi Monica 《Mineralogy and Petrology》2017,111(5):793-806
Mineralogy and Petrology - Limestone represents the main raw material for ordinary Portland cement clinker production. In this study eight natural limestones from different geological environments... 相似文献
5.
6.
Tommaso Maccacaro Roberto Della Ceca Valentina Braito Alessandro Caccianiga Paola Severgnini Anna Wolter 《Astrophysics and Space Science》2004,294(1-2):89-94
We present here some initial results from the ongoing XMM-Newton bright serendipitous survey. The survey is aimed at selecting
and spectroscopically identifying a large and statistically representative sample of bright (f
x ≳ 7× 10−14 c.g.s) serendipitous X-ray sources in the 0.5–4.5 keV energy band (BSS) and a complementary (smaller) sample in the 4.5–7.5
keV energy band (HBSS).
The work is partly based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributors directly founded by ESA member states and the USA(NASA) and on
observations collected at TNG. The TNG telescope is operated on the island of La Palma by the Centro Galileo Galilei of the
INAF in the Spanish Observatorio del Roque de Los Muchachos of the Instituto de Astrofísica de Canarias.
On behalf of the XMM-Newton Survey Science Center. 相似文献
7.
Castagnoli G. Cini Bonino G. Della Monica P. Taricco C. Bernasconi S.M. 《Solar physics》1999,188(1):191-202
In this paper we present the 18O profile of Globigerinoides ruber measured in the GT90/3 shallow water Ionian sea core, dated with high precision. The 18O profile covers the period 1200–1900 AD, with a resolution of 3.87 years. This long record of 700 years of 18O allows us to identify the imprint of the solar cycle in a climatic record. In fact, the spectral analysis of the time series performed with different methods shows a dominant periodicity of about 11 years with an amplitude of 0.07. The signal is in opposition to the sunspot number cycle. This component is identified at a high significance level by Monte Carlo Singular Spectrum Analysis (MC-SSA). 相似文献
8.
Gabriella Della Penna 《Celestial Mechanics and Dynamical Astronomy》1999,75(2):103-124
A model for planetary precession is investigated using analytical and numerical techniques. A Hamiltonian function governing
the model is derived in terms of action-angle Andoyer-Déprit variables under the assumption of equatorial symmetry. As a first
approximation a simplified Hamiltonian with zero-eccentricity is considered and stability estimates are derived using KAM
theory. A validation of the analytical results is performed computing Poincaré surfaces of section for the circular and elliptical
model. We also investigate the role of the eccentricity and its connection with the appearance of resonances. Special attention
is devoted to the particular case of the Earth–Moon system.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
9.
S. Benetti E. Cappellaro I. J. Danziger M. Turatto F. Patat & M. Della Valle 《Monthly notices of the Royal Astronomical Society》1998,294(3):448-456
Extensive photometric and spectroscopic observations of SN 1994aj until 540 d after maximum light have been obtained. The photometry around maximum suggests that the SN belongs to the Type II Linear class, with a peak absolute magnitude of M V ∼−17.8 (assuming H 0 =75 km s−1 Mpc−1 ). The spectra of SN 1994aj were unusual, with the presence of a narrow line with a P Cygni profile on top of the broad Balmer line emission. This narrow feature is attributed to the presence of a dense superwind surrounding the SN. At 100–120 d after maximum light the SN ejecta start to interact with this circumstellar material. The SN luminosity decline rates slowed down [γ R =0.46 mag (100 d)−1 ], becoming less steep than the average late luminosity decline of normal SN II [∼1 mag (100 d)−1 ]. This dense ( ˙M / u W ∼1015 g cm−1 ) wind was confined to a short distance from the progenitor ( R out =∼5×1016 cm), and results from a very strong mass-loss episode ( ˙M =10−3 M⊙ yr−1 ), which terminated shortly before explosion (∼5–10 yr). 相似文献
10.
Roberto Danovaro Mauro Fabiano Giancarlo Albertelli Norberto Della Croce 《Marine Ecology》1995,16(2):103-116
Abstract. Quantitative information on the vertical distribution of meiofaunal abundances and biomass were obtained from samples collected at 3 bathyal stations in the Eastern Mediterranean Sea located at the same depth but characterized by different food supply. Vertical distribution patterns of nieiofauna were investigated in relation to the biochemical composition of the sediment organic matter (proteins, carbohydrates, and lipids) and compared to benthic bacterial standing stocks. No significant relationship between bacteria and meiofauna was found, whereas a significant relationship between protein and lipid concentrations and total meiofauna density was observed. These data suggest that labile organic matter. considered as material readily aVdihbk to benthic consumers, may be an important factor regulating meiofaunal abundance and vertical distribution in deep-sea sediments. 相似文献