全文获取类型
收费全文 | 131篇 |
免费 | 11篇 |
国内免费 | 1篇 |
专业分类
测绘学 | 2篇 |
大气科学 | 19篇 |
地球物理 | 41篇 |
地质学 | 53篇 |
海洋学 | 13篇 |
天文学 | 8篇 |
综合类 | 1篇 |
自然地理 | 6篇 |
出版年
2022年 | 2篇 |
2021年 | 1篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 7篇 |
2017年 | 7篇 |
2016年 | 19篇 |
2015年 | 11篇 |
2014年 | 8篇 |
2013年 | 9篇 |
2012年 | 13篇 |
2011年 | 11篇 |
2010年 | 6篇 |
2009年 | 5篇 |
2008年 | 12篇 |
2007年 | 4篇 |
2006年 | 5篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 1篇 |
2002年 | 2篇 |
2001年 | 2篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1973年 | 1篇 |
排序方式: 共有143条查询结果,搜索用时 15 毫秒
131.
Osmar O. Möller Patrice Castaing Elisa Helena Leão Fernandes Pascal Lazure 《Estuaries and Coasts》2007,30(2):311-320
The Patos Lagoon is a choked, microtidal coastal laggon situated in southern Brazil between 30°S and 32°S. The response of
the lagoon to tidal oscillations is studied through data analysis and numerical modeling experiments. Two types of high frequency
oscillations are observed in the tidal frequency band: mixed tides, predominantly diurnal; and forced oscillations having
a period of 24 h occurring in the inner lagoon. In the southern portion of the lagoon, tides are selectively filtered by the
entrance channel. The main diurnal constituent O1 is linearly attenuated as it progresses landwards. In the inner parts of the lagoon, 24-h oscillations are mainly forced
by the combined effect of diurnal tides and sea breeze action. They are tied with a natural period of oscillation of 24 h.
Results also indicate that these are not inertial frequency oscillations, despite the lagoon being placed in a critical 30°S
area. The interaction between astronomical tides and meteorological effects produces a complicated picture for tidal forecasting
derived from data collected inside the lagoon. 相似文献
132.
133.
The focal mechanism solutions of 83 European earthquakes withM>6, selected from a total of 140, have been used to derive the directions of the principal axes of stress along the plate boundary between Eurasia and Africa from the Azores islands to the Caucasus mountains. Along most of the region, the horizontalP-axes are at an angle of 45° to 90° with the trend of the plate boundary. HorizontalT-axes are concentrated in central Italy and northern Greece in association with normal faulting. Large strike-slip motion of right-lateral character takes place at the center of the Azores-Gibraltar fault and the North Anatolian fault. From Gibraltar to the Caucasus the boundary is complicated by the presence of secondary blocks and zones of extended deformations with earthquakes spread over wide areas. Intermediate and deep earthquakes are present at four areas with arc-like structure, namely, Gibraltar, Sicily-Calabria, Hellenic arc and Carpathians. 相似文献
134.
Volcanic evolution of the island of Tenerife (Canary Islands) in the light of new K-Ar data 总被引:2,自引:0,他引:2
Eumenio Ancochea JosMaría Fuster Elisa Ibarrola Antonio Cendrero Juan Coello Francisco Hernan Jean M. Cantagrel Colette Jamond 《Journal of Volcanology and Geothermal Research》1990,44(3-4)
New age determinations from Tenerife, together with those previously published (93 in all), provide a fairly comprehensive picture of the volcanic evolution of the island. The oldest volcanic series, with ages starting in the late Miocene, are formed mainly by basalts with some trachytes and phonolites which appear in Anaga, Teno and Roque del Conde massifs. In Anaga (NE), three volcanic cycles occurred: one older than 6.5 Ma, a second one between 6.5 and 4.5 Ma, with a possible gap between 5.4 and 4.8 Ma, and a late cycle around 3.6 Ma. In Teno (NW), after some undated units, the activity took place between 6.7 and 4.5 Ma, with two main series separated by a possible pause between 6.2 and 5.6 Ma. In the zone of Roque del Conde (S), the ages are scattered between 11.6 and 3.5 Ma. Between 3.3 and 1.9 Ma, the whole island underwent a period of volcanic quiescence and erosion.The large Cañadas volcano, made up of basalts, trachytes and phonolites, was built essentially between 1.9 and 0.2 Ma. To the NE of this central volcano, linking it with Anaga, is a chain of basaltic emission centers, with a peak of activity around 0.8 Ma. The Cañadas Caldera had several collapse phases, associated with large ignimbrite emissions. There were, at least, an older phase more than 1 Ma old, on the western part of the volcano, and a younger one, less than 0.6 Ma old, in the eastern side. The two large “valleys” of Guimar and la Orotava were formed by large landslides less than 0.8 Ma ago, and probably before 0.6 Ma ago. The present Cañadas caldera was formed by another landslide, less than 0.2 Ma ago. This caldera was later filled by the huge Teide volcano, which has been active even in historic times. During the same period a series of small volcanoes erupted at scattered locations throughout the island.The average eruptive rate in Tenerife was 0.3 km3/ka, with relatively small variations for the different eruptive periods. This island and La Gomera represent a model of growth by discontinuous pulses of volcanic activity, separated by gaps often coinciding with episodes of destruction of the edifices and sometimes extended for several million years. The neighbouring Gran Canaria, on the other hand, had an initial, rapid “shield-building phase” during which more than 90% of the island was built, and a series of smaller pulses at a much later period.A comparison between these three central islands indicates that the previously postulated westward displacement in time of a gap in the volcanic activity is valid only as a first approximation. Several gaps are present on each island, overlapping in time and not clearly supporting either of the models proposed to explain the evolution of the Canaries. 相似文献
135.
Daniele Nizzoli Giuseppe Castaldelli Marco Bartoli David Thomas Welsh Patricia Arriaga Gomez Anna Elisa Fano Pierluigi Viaroli 《Marine Ecology》2002,23(S1):297-306
Abstract. Dark respiration rates, dissolved inorganic nitrogen (DIN) fluxes and nitrification rates were measured at two sites in the microtidal Sacca di Goro lagoon in September 2000. DIN fluxes correlated with the biomass of the dominant macrofauna species (the amphipod Corophium spp. at station Giralda and the polychaete Neanthes spp. at station Faro). Respiration (> 6 mmol O2 m−2 h−1 ) and ammonium fluxes (> 80μmol N m−2 h−1 ) were higher at station Giralda despite the lower organic matter content (4.5 %) and lower macrofauna biomass (4 g AFDW m−2 ). At both sites ammonium fluxes were significantly correlated with the biomass of the benthic infauna, but Corophium stimulated ammonium NH4 + fluxes 3-fold compared to Neanthes. The amphipod also enhanced nitrification rates (> 300 μmol N m−2 h−1 ) due to the high density of its burrows, the higher NH4 + regeneration rates and the enhanced oxygen supply to the bacteria. 相似文献
136.
Ihsane Bensaid Taj-Eddine Cherkaoui Fida Medina Bento Caldeira Elisa Buforn Anas Emran Youssef Hahou 《Journal of Seismology》2012,16(1):35-53
The Tafilalt region, located at the eastern end of the Anti-Atlas chain in Morocco, was shaken on 23 and 30 October 1992 by
two moderate earthquakes of magnitude mb ∼ 5 and intensity ∼ VI MSK64, which caused two deaths and great damage in the area between Erfoud and Rissani. The review
of data available on the seismic crisis allowed us to improve the knowledge on the macroseismic, instrumental and source parameters
of the earthquakes. The main results of the present study are: (1) location of the epicentres with the help of data from a
close portable network allowed us to propose new epicentral coordinates at 31.361° N, 4.182° W (23 October) and 31.286° N,
4.347° W (30 October); both events have focal depths of 2 km; (2) the shock of 30 October was followed by a series of 305
aftershocks, most of which were located west of Rissani; the 61 best-constrained events had focal depths of 5 to 19 km and
magnitudes 0.7 to 3; (3) the largest damage was located in an area between the two epicentres within the Tafilalt valley and
was probably amplified by site effects due to the proximity of the water table within the Quaternary sediments; (4) focal
mechanisms of the main events correspond to strike-slip faulting with fault planes oriented N–S (left lateral) and E–W (right
lateral); the only mechanism available for the aftershocks also corresponds to strike-slip faulting; (5) spectral analysis
shows that the scalar seismic moment (Mo) of the first event is slightly larger than the second; the corresponding values of Mw are 5.1 and 5.0, respectively; (6) the dimensions of the faults for a circular fault model are 7.7 ± 1.4 and 7.4 ± 1.2 km,
respectively; the average displacement is 4 cm for the first event and 3.7 cm for the second; the stress drop is 0.4 and 0.3 MPa,
respectively, in agreement with standard values; (7) the Coulomb Stress test performed for both earthquakes suggests a relationship
between both events only when the used location is at the limit of the horizontal uncertainty; (8) finally, the occurrence
of these shocks suggests that the Anti-Atlas is undergoing tectonic deformation in addition to thermal uplift as suggested
by recent publications. 相似文献
137.
Elisa Zuccolo Tony Gibbs Carlo G. Lai Joan L. Latchman Walter Salazar Luigi Di Sarno Anthony Farrell Lloyd Lynch Addison Workman 《Bulletin of Earthquake Engineering》2016,14(9):2579-2605
A feasibility study of an earthquake early warning (EEW) system was conducted for the Eastern Caribbean region using scenario earthquakes, corresponding to the maximum credible earthquakes and to the earthquakes associated with a return period of 475 years. Broadband synthetic seismograms were produced at selected critical facilities, where there is potential interest in the installation of an EEW system. The expected damage was derived from the synthetic seismograms and compared with the lead-time determined for both a regional and on-site EEW configuration. Next, the Virtual Seismologist EEW algorithm, as included in SeisComP3, was tested. Additional broadband synthetic seismograms were produced for the stations in the Eastern Caribbean seismic networks in order to simulate the real time behaviour of the seismic networks during the occurrence of the synthetic earthquakes and to assess the predictive capacity of the selected ground motion prediction equation. Expected peak ground parameters and lead-times at the critical facilities constitute the major outcome of the study. 相似文献
138.
Lyuba Moroz Giuseppe Baratta Larissa Starukhina Maria Antonietta Barucci Elisa Distefano 《Icarus》2004,170(1):214-228
Most ion irradiation experiments relevant to primitive outer Solar System objects have been performed on ice and silicate targets. Here we present the first ion irradiation experiments performed on natural complex hydrocarbons (asphaltite and kerite). These materials are very dark in the visible and have red-sloped spectra in the visible and near-infrared. They may be comparable in composition and structure to refractory organic solids on the surfaces of primitive outer Solar System objects. We irradiated the samples with 15-400 keV H+, N+, Ar++, and He+ ions and measured their reflectance spectra in the range of 0.3-2.5 μm before ion implantation and after each irradiation step. The results show that irradiation-induced carbonization gradually neutralizes the spectral slopes of these red organic solids. This implies a similar space weathering trend for the surfaces of airless bodies optically dominated by spectrally red organic components. The reduction of spectral slope was observed in all experiments. Irradiation with 30 keV protons, which transfers energy to the target mostly via electronic (inelastic) collisions, showed lower efficiency than the heavier ions. We found that spectral alteration in our experiments increased with increasing contribution of nuclear versus electronic energy loss. This implies that nuclear (elastic) energy deposition plays an important role in changing the optical properties of irradiated refractory complex hydrocarbon materials. Finally, our results indicated that temperature variations from 40 K to room temperature did not influence the spectral properties of these complex hydrocarbon solids. 相似文献
139.
Elisa Sacchi Jean-Luc Michelot Helmut Pitsch Philippe Lalieux Jean-François Aranyossy 《Hydrogeology Journal》2001,9(1):17-33
This paper summarises the results of a comprehensive critical review, initiated by the OECD/NEA "Clay Club," of the extraction
techniques available to obtain water and solutes from argillaceous rocks. The paper focuses on the mechanisms involved in
the extraction processes, the consequences on the isotopic and chemical composition of the extracted pore water and the attempts
made to reconstruct its original composition. Finally, it provides some examples of reliable techniques and information, as
a function of the purpose of the geochemical study.
Electronic Publication 相似文献
140.
Elisa Sainz de Murieta Pedro P. Cunha Alejandro Cearreta Andrew S. Murray Jan-Pieter Buylaert 《第四纪科学杂志》2021,36(4):570-585
A detailed study is presented of a 15.3-m-thick Pleistocene coastal terrace located on the Cantabrian coast (northern Spain). Stratigraphic, sedimentological, topographic and micropalaeontological information is combined with a chronology based on luminescence dating to characterize the deposits. The sedimentary succession records: (i) a basal transgressive system, consisting of a wave-cut surface covered by a lower layer of beach gravels and upper beach pebbly sands; and (ii) a thicker upper highstand system (aggrading), comprising medium to very fine aeolian sands interbedded with thin palustrine muds. Luminescence dating involved a detailed sampling strategy (36 samples and two modern analogues) and the use of both quartz optically stimulated luminescence (OSL) and feldspar post-infrared infrared stimulated luminescence single aliquot regeneration protocols; feldspar results were used to confirm the completeness of bleaching of the quartz OSL signal. The quartz OSL luminescence age–depth relationship shows significant dispersion, but nevertheless two rapid phases of deposition can be clearly identified: one at ~130 ka [Marine Oxygen Isotope Stage (MIS) 5] and one at ~100 ka (MIS 5c). The top of the succession is dated to ~70 ka. The MIS 5e marine maximum flooding surface is identified at an elevation of 6.85 m above mean seal level. This elevation provides evidence of a regional sea-level highstand for this sector of the Cantabrian coast. 相似文献