全文获取类型
收费全文 | 117篇 |
免费 | 10篇 |
国内免费 | 3篇 |
专业分类
测绘学 | 1篇 |
大气科学 | 12篇 |
地球物理 | 39篇 |
地质学 | 56篇 |
海洋学 | 8篇 |
天文学 | 3篇 |
自然地理 | 11篇 |
出版年
2022年 | 1篇 |
2021年 | 11篇 |
2020年 | 5篇 |
2019年 | 5篇 |
2018年 | 7篇 |
2017年 | 8篇 |
2016年 | 7篇 |
2015年 | 7篇 |
2014年 | 7篇 |
2013年 | 8篇 |
2012年 | 7篇 |
2011年 | 14篇 |
2010年 | 1篇 |
2009年 | 8篇 |
2008年 | 7篇 |
2007年 | 6篇 |
2006年 | 2篇 |
2005年 | 3篇 |
2003年 | 3篇 |
2002年 | 2篇 |
1999年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1988年 | 2篇 |
排序方式: 共有130条查询结果,搜索用时 15 毫秒
81.
Sergio Caetano-Filho Pierre Sansjofre Magali Ader Gustavo M.Paula-Santos Cristian Guacaneme Marly Babinski Carolina Bedoya-Rueda Matheus Kuchenbecker Humberto L.S.Reis Ricardo I.F.Trindade 《地学前缘(英文版)》2021,12(1):203-218
Carbon isotope compositions of both sedimentary carbonate and organic matter can be used as key proxies of the global carbon cycle and of its evolution through ... 相似文献
82.
A high-resolution 43-year atmospheric hindcast for South America generated with the MPI regional model 总被引:1,自引:1,他引:0
Gabriel Silvestri Carolina Vera Daniela Jacob Susanne Pfeifer Claas Teichmann 《Climate Dynamics》2009,32(5):693-709
An evaluation of the present-day climate in South America simulated by the MPI atmospheric limited area model, REMO, is made.
The model dataset was generated by dynamical downscaling from the ECMWF-ERA40 reanalysis and compared to in-situ observations.
The model is able to reproduce the low-level summer monsoon circulation but it has some deficiencies in representing the South
American Low-Level Jet structure. At upper levels, summer circulation features like the Bolivian High and the associated subtropical
jet are well simulated by the model. Sea-level pressure fields are in general well represented by REMO. The model exhibits
reasonable skill in representing the general features of the mean seasonal cycle of precipitation. Nevertheless, there is
a systematic overestimation of precipitation in both tropical and subtropical regions. Differences between observed and modeled
temperature are smaller than 1.5°C over most of the continent, excepting during spring when those differences are quite large.
Results also show that the dynamical downscaling performed using REMO introduces some enhancement of the global reanalysis
especially in temperature at the tropical regions during the warm season and in precipitation in both the subtropics and extratropics.
It is then concluded that REMO can be a useful tool for regional downscaling of global simulations of present and future climates. 相似文献
83.
84.
Velichka Kontozova-Deutsch Carolina Cardell Maja Urosevic Encarnación Ruiz-Agudo Felix Deutsch René Van Grieken 《Environmental Earth Sciences》2011,63(7-8):1433-1445
Indoor and outdoor concentrations of atmospheric gaseous pollutants as well as composition, size, and morphology of particulate matter have been investigated at the monastery of San Jerónimo in Granada (Southern Spain). Complementary micro- and nano-analytical techniques were applied; elemental and mineralogical composition and morphological characteristics of particulate matter were investigated combining electron probe microanalysis at the single particle level, and bulk aerosol samples were analyzed using energy-dispersive X-ray fluorescence, X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray analyzer and transmission electron microscopy (TEM). Microclimatic conditions at the monastery were monitored, and gas concentrations were assessed by means of diffusion tubes subsequently analyzed with ion chromatography. Results revealed high abundances of soil dust particles (aluminosilicates, calcite, dolomite, quartz), salt aerosols (chlorides, sulfates and ammonium-rich salts), and NO2 and SO2 both outdoors and indoors. Amorphous black carbon particles had surprisingly high abundances for Granada, a non-industrialized city. The composition of indoor particles corresponds to severe weathering affecting the construction materials and artworks inside the church; moreover their composition promotes a feedback process that intensifies the deterioration. Chemical reactions between chloride-rich salts and pigments from paintings were confirmed by TEM analyses. Indoors, blackening of surface decorative materials is fostered by particle re-suspension due to cleaning habits in the monastery (i.e. dusting). This is the first air quality study performed in a monument in the city of Granada with the aim of developing a strategy for preventive conservation. 相似文献
85.
Carolina Bernal Frédéric Christophoul José Darrozes Jean-Claude Soula Patrice Baby José Burgos 《International Journal of Earth Sciences》2011,100(7):1759-1782
The geomorphological study by means of remote sensing imagery of the Rio Pastaza Megafan (Ecuador and northern Peru) reveals
the traces of numerous avulsions. One hundred and eight avulsion sites have been defined. The location of these sites, the
available radiocarbon ages as well as historical maps of the seventeenth century, enable us to propose an evolution history
of the migration and avulsions of the Rio Pastaza since the Last Glacial Maximum. The first avulsions of the Río Pastaza occurred
after the LGM in a zone close to and roughly parallel to the sudandean front, where the developed avulsion gave a distributive
pattern to the ancient stream of the Río Pastaza in an area located between the modern Río Morona and Pastaza, where they
caused the Rio Pastaza to develop a fan-like distributary pattern. This is interpreted as a response to thrust-related forelimb
tilt, progressively shifting eastward the Rio Pastaza and the apex of the megafan. This sequence of events ended with the
Great Diversion of the Rio Pastaza towards the modern Rios Corrientes and Tigre. Avulsions occurred in the Tigre-Corrientes
Area between 9200 and 8,500 years Cal BP. Afterwards, the Río Pastaza was diverted to its present-day north–south course.
This last significant avulsion occurred before AD 1691. In the area located between the modern Río Morona and Pastaza, avulsion
frequency—probably overestimated—ranges between 100 and 200 years. In the Ríos Tigre and Corrientes area, avulsion frequency—probably
underestimated—ranges from 300 to 400 years. Regional tectonics is likely to have triggered most of the avulsions in the Morona
Pastaza area but its influence is restricted to this area. The factors controlling the avulsions in the Tigre-Corrientes area
are less clear because the frequently described “hydrologic”-driven avulsion as observed in areas characterized by contrasted
hydrologic cycles are inconsistent with the characteristics of the hydrologic cycles of the Rio Pastaza. 相似文献
86.
Antonio Maldonado Julio L. Betancourt Claudio Latorre Carolina Villagran 《第四纪科学杂志》2005,20(5):493-507
Precipitation in northern Chile is controlled by two great wind belts—the southern westerlies over the southern Atacama and points south (> 24° S) and the tropical easterlies over the northern and central Atacama Desert (16–24° S). At the intersection of these summer and winter rainfall regimes, respectively, is a Mars‐like landscape consisting of expansive surfaces devoid of vegetation (i.e. absolute desert) except in canyons that originate high enough to experience runoff once every few years. Pollen assemblages from 39 fossil rodent middens in one of these canyons, Quebrada del Chaco (25° 30′ S), were used to infer the history of vegetation and precipitation at three elevations (2670–2800 m; 3100–3200 m; 3450–3500 m) over the past 50 000 years. When compared to modern conditions and fossil records to the north and south, the pollen evidence indicates more winter precipitation at > 52, 40–33, 24–17 k cal. yr BP, more precipitation in both seasons at 17–14 k cal. yr BP, and more summer precipitation from 14–11 k cal. yr BP. Younger middens are scarce at Quebrada del Chaco, and the few Holocene samples indicate hyperarid conditions comparable to today. The only exception is a pollen assemblage that indicates a brief but significant interlude of increased winter precipitation in the last millennium. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
87.
88.
Carolina Perpiña Castillo Carlo Lavalle Claudia Baranzelli Sarah Mubareka 《International journal of geographical information science》2013,27(10):1807-1825
This paper presents a modelling approach for the spatial allocation of second-generation feedstock (lignocellulosic crops) under a reference policy scenario in European Union of 28 Member State (EU-28). The land-use modelling platform (LUMP) was used in order to simulate the land-use changes from 2010 to 2050. Within the LUMP, the land demand for these lignocellulosic energy crops was derived from the Common Agricultural Policy Regionalised Impact analysis model. Suitability maps were generated for two main energy crop groups: herbaceous and woody lignocellulosic crops, using multicriteria analysis techniques. Biophysical factors (climate, soil properties and topographical aspects), natural and artificial constraints and location-specific land categories were defined as relevant components within the platform. A sensitivity analysis determined the most influential factors to be temperature, precipitation, length of growing period and number of frost-free days. The results of the modelling exercise in the LUMP reflect the significant renewable energy contribution from energy crops in EU-28, which was estimated to be between 2.3 EJ/year (in 2020) and 6.3 EJ/year (in 2050), accounting for 2.3% and 9.6% of total energy consumption in the EU-28. The results of the allocation were aggregated at regional level to analyse trends. Regions with considerably high demand were identified in Germany, the United Kingdom and Poland. 相似文献
89.
Juan C. Colombo Carlos N. Skorupka Claudio Bilos Leandro Tatone Natalia Cappelletti M. Carolina Migoya 《水文科学杂志》2013,58(6):1155-1163
AbstractWater quality of the Uruguay River was evaluated with multi-parametric (temperature, turbidity, conductivity, pH, dissolved oxygen) and sediment trap data (particle flux, total organic carbon and nitrogen contents) and correlated to precipitation, river discharge and El Niño Southern Oscillation (ENSO) indices for the period 2006–2011. Hydro-meteorological parameters averaged 24–85% variability with coincident precipitation (200–400 mm month-1), discharge (7000–28 000 m3 s-1) and turbidity peaks (50–80 NTU) in the austral spring, and absolute maxima during the El Niño 2009 episode. Spectral analysis of discharge and sea-surface temperature anomaly (SSTA) showed consistent variance maxima at approx. 3 and 1.5 years. Deseasonalized discharge was significantly correlated to SSTA. During river floods, pH decreased (from 7.5 to 6.6) and particle dynamics peaked (turbidity: 15–80 NTU; vertical fluxes: 20–200 g m-2 d-1; total solid load: <1000 to 100 000 t d-1),whereas TOC remained stable (3.2 ± 0.8%) and C/N ratios increased (10–12) due to the higher contribution of terrestrial detritus. 相似文献
90.
Natural dams are caused by the blockage of streams as a result of the sudden arrival of detritus material during a glacial surge advance or fast slope collapse threatening downstream populations. Nevertheless, origin, morphological characteristics and stability of dammed lakes are frequently ignored. Six impounded palaeo-lakes were geomorphologically studied in the Benjamin Matienzo gully (32°14′ S–70°02′ W), denominated, from north to south: Goyete, Negro, Casa de Piedra, Lagunita, Susanita and Matienzo. We determined the origin, morphometric parameters, stability index and rate of streamflow rupture for these dammed ancient lakes in order to shed light on the potential outburst flood hazard in this Andean mountain region. According to our findings, we concluded that palaeo-lakes would have had a short life as they turned out to be unstable, except for the Goyete Lake, matching with the lack of fine lacustrine sediments in all river blockages. We also estimated the maximum peak discharge of a probable outburst flow generated during a drastic collapse of these dams. Obtained values range between 22 and 151 m3/s being notably higher than the average annual streamflow of Las Cuevas River (6.6 m3/s), but similar to the instantaneous streamflow of this river (157 m3/s, 2-year recurrence time). 相似文献