全文获取类型
收费全文 | 66篇 |
免费 | 1篇 |
专业分类
测绘学 | 3篇 |
大气科学 | 3篇 |
地球物理 | 19篇 |
地质学 | 27篇 |
海洋学 | 7篇 |
天文学 | 6篇 |
自然地理 | 2篇 |
出版年
2021年 | 4篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 3篇 |
2012年 | 2篇 |
2011年 | 5篇 |
2010年 | 6篇 |
2009年 | 1篇 |
2008年 | 3篇 |
2007年 | 3篇 |
2006年 | 10篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2002年 | 3篇 |
1998年 | 2篇 |
1990年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有67条查询结果,搜索用时 46 毫秒
61.
The academic conference, a site of possible changes in professional knowledge and hierarchy, is an area of academic life rarely studied. Through three main concerns this article illuminates this point for the first time with respect to the status of women and gender research at the last thirty‐two annual meetings of the Israeli Geographical Society. First, although men still present the majority of the conference papers, women have increased their share and now constitute one‐third of all active participants. Second, women's appearance as chairs of sessions and keynote speakers is significantly lower in proportion to their overall participation in the conference, and they are consistently more involved in its less prestigious aspects. Third, the production of geographic knowledge as reflected in conference papers is gendered, but its pattern differs from that in academia in general. The findings reveal a new facet of the gendered construction of academic life in general, and of Israeli geography in particular, and offer new avenues to revealing the impact of social exclusion on academia. 相似文献
62.
63.
Ever since the 1999 Kocaeli earthquake, in which the Kandilli Observatory and Earthquake Research Institute (KOERI) was not able to correctly reflect the magnitude size in its preliminary report because of the saturation effect, a rapid and accurate determination of the earthquake becomes a very important issue. Therefore, in the framework of this study, an automatic determination of the moment magnitude was performed by using the displacement spectra of selected earthquakes in the Marmara Region. For this purpose, 39 three-component broadband stations from KOERI seismic network which recorded 174 earthquakes with magnitudes 2.5?≤?M?≤?5.0 in between 2006–2009 were used. Due to the importance of quality factor in determination of the moment magnitude with spectral analysis method, the quality factor was calculated for the whole region in the beginning. Source spectrum which was obtained by converting the velocity records to displacement spectra and moment magnitudes of earthquakes were determined by fitting this spectrum to classical Brune model. For this aim, an automatic procedure was utilized which based on minimizing the differences between observed and synthetic source spectra identified by the S waves. Besides moment magnitude and location parameters, some source parameters such as seismic moment, spectral level, corner frequency and stress drop were also calculated. Application of the method proves that determining the seismic moment from the source spectra is applicable not only for earthquakes with small magnitude but also moderate earthquakes as well. 相似文献
64.
Irina Olenina Norbert Wasmund Iveta Jurgensone Janina Kownacka Diana Vaiciūt? 《Marine pollution bulletin》2010,60(10):1691-1700
There is an increasing understanding and requirement to take into account the effects of invasive alien species (IAS) in environmental quality assessments. While IAS are listed amongst the most important factors threatening marine biodiversity, information on their impacts remains unquantified, especially for phytoplankton species. This study attempts to assess the impacts of invasive alien phytoplankton in the Baltic Sea during 1980-2008. A bioinvasion impact assessment method (BPL - biopollution level index) was applied to phytoplankton monitoring data collected from eleven sub-regions of the Baltic Sea. BPL takes into account abundance and distribution range of an alien species and the magnitude of the impact on native communities, habitats and ecosystem functioning. Of the 12 alien/cryptogenic phytoplankton species recorded in the Baltic Sea only one (the dinoflagellate Prorocentrum minimum) was categorized as an IAS, causing a recognizable environmental effect. 相似文献
65.
The origin of the stratiform tin deposits in the schist belt of the Stara Kamienica Chain, southwestern Poland, is re-examined based upon new data which has become available. It is the author's opinion that no genetic implications should be attached to the stratiform character of the deposits. Hydrothermal metasomatism associated with acid intrusives of the Variscan Karkonosze massif introduced mineralizing fluids along tectonic lineaments. 相似文献
66.
Barış Önol Deniz Bozkurt Ufuk Utku Turuncoglu Omer Lutfi Sen H. Nuzhet Dalfes 《Climate Dynamics》2014,42(7-8):1949-1965
In this study, human-induced climate change over the Eastern Mediterranean–Black Sea region has been analyzed for the twenty-first century by performing regional climate model simulations forced with large-scale fields from three different global circulation models (GCMs). Climate projections have been produced with Special Report on Emissions Scenarios A2, A1FI and B1 scenarios, which provide greater diversity in climate information for future period. The gradual increases for temperature are widely apparent during the twenty-first century for each scenario simulation, but ECHAM5-driven simulation generally has a weaker signal for all seasons compared to CCSM3 simulations except for the Fertile Crescent. The contrast in future temperature change between the winter and summer seasons is very strong for CCSM3-A2-driven and HadCM3-A2-driven simulations over Carpathians and Balkans, 4–5 °C. In addition, winter runoff over mountainous region of Turkey, which feeds many river systems including the Euphrates and Tigris, increases in second half of the century since the snowmelt process accelerates where the elevation is higher than 1,500 m. Moreover, analysis of daily temperature outputs reveals that the gradual decrease in daily minimum temperature variability for January during the twenty-first century is apparent over Carpathians and Balkans. Analysis of daily precipitation extremes shows that positive trend is clear during the last two decades of the twenty-first century over Carpathians for both CCSM3-driven and ECHAM5-driven simulations. Multiple-GCM driven regional climate simulations contribute to the quantification of the range of climate change over a region by performing detailed comparisons between the simulations. 相似文献
67.
Pedro Jiménez-Guerrero Juan J. Gómez-Navarro Rocío Baró Raquel Lorente Nuno Ratola Juan P. Montávez 《Climatic change》2013,121(4):661-671
Climate change alone influences future levels of tropospheric ozone and their precursors through modifications of gas-phase chemistry, transport, removal, and natural emissions. The goal of this study is to determine at what extent the modes of variability of gas-phase pollutants respond to different climate change scenarios over Europe. The methodology includes the use of the regional modeling system MM5 (regional climate model version)-CHIMERE for a target domain covering Europe. Two full-transient simulations covering from 1991–2050 under the SRES A2 and B2 scenarios driven by ECHO-G global circulation model have been compared. The results indicate that the spatial patterns of variability for tropospheric ozone are similar for both scenarios, but the magnitude of the change signal significantly differs for A2 and B2. The 1991–2050 simulations share common characteristics for their chemical behavior. As observed from the NO2 and α-pinene modes of variability, our simulations suggest that the enhanced ozone chemical activity is driven by a number of parameters, such as the warming-induced increase in biogenic emissions and, to a lesser extent, by the variation in nitrogen dioxide levels. For gas-phase pollutants, the general increasing trend for ozone found under A2 and B2 forcing is due to a multiplicity of climate factors, such as increased temperature, decreased wet removal associated with an overall decrease of precipitation in southern Europe, increased photolysis of primary and secondary pollutants as a consequence of lower cloudiness and increased biogenic emissions fueled by higher temperatures. 相似文献