全文获取类型
收费全文 | 276篇 |
免费 | 10篇 |
国内免费 | 1篇 |
专业分类
测绘学 | 8篇 |
大气科学 | 26篇 |
地球物理 | 85篇 |
地质学 | 83篇 |
海洋学 | 36篇 |
天文学 | 27篇 |
综合类 | 2篇 |
自然地理 | 20篇 |
出版年
2024年 | 1篇 |
2023年 | 6篇 |
2022年 | 4篇 |
2021年 | 7篇 |
2020年 | 13篇 |
2019年 | 10篇 |
2018年 | 11篇 |
2017年 | 10篇 |
2016年 | 18篇 |
2015年 | 15篇 |
2014年 | 15篇 |
2013年 | 15篇 |
2012年 | 16篇 |
2011年 | 20篇 |
2010年 | 16篇 |
2009年 | 23篇 |
2008年 | 18篇 |
2007年 | 10篇 |
2006年 | 7篇 |
2005年 | 9篇 |
2004年 | 6篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 5篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 4篇 |
排序方式: 共有287条查询结果,搜索用时 78 毫秒
191.
A computationally efficient method for delineating irregularly shaped spatial clusters 总被引:1,自引:0,他引:1
Juan C. Duque Jared Aldstadt Ermilson Velasquez Jose L. Franco Alejandro Betancourt 《Journal of Geographical Systems》2011,13(4):355-372
In this paper, we present an efficiency improvement for the algorithm called AMOEBA, A Multidirectional Optimum Ecotope-Based Algorithm, devised by Aldstadt and Getis (Geogr Anal 38(4):327?C343, 2006). AMOEBA embeds a local spatial autocorrelation statistic in an iterative procedure in order to identify spatial clusters (ecotopes) of related spatial units. We provide an analysis of the computational complexity of the original AMOEBA and develop an alternative formulation that reduces computational time without losing optimality. Empirical evidence is provided using georeferenced socio-demographic data in Accra, Ghana. 相似文献
192.
Oldřich Praus Jana Pěčová Václav Červ Svetlana Kováčiková Josef Pek Jakub Velímský 《Studia Geophysica et Geodaetica》2011,55(2):241-264
We present results of a classical global induction analysis of the geomagnetic variation data in the range of daily Sq variations,
as well as for long period variations within the period range of about 8 to 400 days. The Sq data from 88 to 94 world observatories
are processed in two ways, first by constructing and analyzing average monthly daily variations for the whole months of the
International Quiet Sun Year (IQSY) 1995, and second by analyzing the individual, especially quiet Q* daily records from the
same year. The electrical images of the Sq response functions obtained via the Schmucker’s ρ* — z* procedure show a good fit
with results of other induction studies, though especially our global impedance phases show a larger scatter than two other
published data sets used for comparison. 相似文献
193.
Sensitivity analysis of main variables present in flash flood processes. Application in two Spanish catchments: Arás and Aguilón 总被引:1,自引:0,他引:1
Jesús Mateo Lázaro José Ángel Sánchez Navarro Alejandro García Gil Vanesa Edo Romero 《Environmental Earth Sciences》2014,71(6):2925-2939
The program Simulation of Hydrological Extreme Events provides a set of functionalities that combined together allows constructing, manipulating, analyzing and comparing the hydrological processes involved in flash flood generation. The program makes use of existing databases of interest in hydrology and available in Spain, such as digital terrain models, coverage of rainfall or curve number. Two pilot watersheds from Spain were selected, Arás and Aguilón, where flash flood episodes have taken place. A sensitivity analysis of the flash flood episodes in response to changes in the main hydrological processes involved has been made, such as spatial and temporal distribution of rainfall, soil moisture status and water flow through channel network. In this work, we found that the antecedent moisture condition is the most influential factor in the magnitude of flash floods produced by the same amount of rain. The temporal distribution of the storm represents the second characteristic in order of relevance. In addition, terrain morphology (specially the slope) is found to be decisive in the results differences obtained. 相似文献
194.
Potential for added value in temperature simulated by high-resolution nested RCMs in present climate and in the climate change signal 总被引:3,自引:2,他引:1
Regional Climate Models (RCMs) have been developed in the last two decades in order to produce high-resolution climate information by downscaling Atmosphere-Ocean General Circulation Models (AOGCMs) simulations or analyses of observed data. A crucial evaluation of RCMs worth is given by the assessment of the value added compared to the driving data. This evaluation is usually very complex due to the manifold circumstances that can preclude a fair assessment. In order to circumvent these issues, here we limit ourselves to estimating the potential of RCMs to add value over coarse-resolution data. We do this by quantifying the importance of fine-scale RCM-resolved features in the near-surface temperature, but disregarding their skill. The Reynolds decomposition technique is used to separate the variance of the time-varying RCM-simulated temperature field according to the contribution of large and small spatial scales and of stationary and transient processes. The temperature variance is then approximated by the contribution of four terms, two of them associated with coarse-scales (e.g., corresponding to the scales that can be simulated by AOGCMs) and two of them describing the original contribution of RCM simulations. Results show that the potential added value (PAV) emerges almost exclusively in regions characterised by important surface forcings either due to the presence of fine-scale topography or land-water contrasts. Moreover, some of the processes leading to small-scale variability appear to be related with relatively simple mechanisms such as the distinct physical properties of the Earth surface and the general variation of temperature with altitude in the Earth atmosphere. Finally, the article includes some results of the application of the PAV framework to the future temperature change signal due to anthropogenic greenhouse gasses. Here, contrary to previous studies centred on precipitation, findings suggest for surface temperature a relatively low potential of RCMs to add value over coarser resolution models, with the greatest potential located in coastline regions due to the differential warming occurring in land and water surfaces. 相似文献
195.
196.
197.
D’Altri Antonio Maria Cannizzaro Francesco Petracca Massimo Talledo Diego Alejandro 《Bulletin of Earthquake Engineering》2022,20(4):1999-2043
Bulletin of Earthquake Engineering - In this paper, a simple and practitioners-friendly calibration strategy to consistently link target panel-scale mechanical properties (that can be found in... 相似文献
198.
Escudero Christian R. Ramirez Gaytan Alejandro Zamora Camacho Araceli Preciado Adolfo Flores Karen L. Gomez Hernandez Adan 《Natural Hazards》2022,110(1):247-267
Natural Hazards - We performed a seismic vulnerability assessment that involves geotechnical and building structure analysis for Puerto Vallarta, Mexico, a city located along the pacific coast.... 相似文献
199.
200.
Juan Pablo de Rosas Alexander Dario Esquivel Diego Martinez Heimann Agustin E. Negri Flavia Lohaiza Diego Leonardo Valladares Alejandro I. Zavala Hugo Huck Jimena Juri Ayub 《Environmental Earth Sciences》2018,77(16):587
This work presents the results of a soil erosion study using the 7Be technique. This technique estimates the water erosion/deposition from the comparison between 7Be soil content of a reference site and an eroded or sedimented site. The soil samples were collected from an agricultural area of the semiarid region of Argentina near San Luis City, which has a marked rainfall season. The area has been used for crop cultivation, being subjected to plowing practices. The 7Be in the Reference Site was in the first centimeter of soil, showing the typical exponential decreasing of 7Be soil content with depth, with the 7Be inventories value being 340?±?50 Bq m?2 for the dry season and 571?±?48 Bq m?2 for the rainy season. The 7Be technique was applied to a potential eroded site subjected to traditional tillage practices (plowing). A net soil erosion value of 13.5 t ha?1 (1.35 kg m?2) was obtained. From the assumptions of the applied technique, we can draw the inference that this erosion was caused by rains produced in the month prior to the date of soil sampling. 相似文献