全文获取类型
收费全文 | 110篇 |
免费 | 8篇 |
国内免费 | 4篇 |
专业分类
测绘学 | 8篇 |
大气科学 | 5篇 |
地球物理 | 19篇 |
地质学 | 73篇 |
海洋学 | 1篇 |
天文学 | 4篇 |
综合类 | 9篇 |
自然地理 | 3篇 |
出版年
2023年 | 1篇 |
2022年 | 8篇 |
2021年 | 7篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 17篇 |
2017年 | 15篇 |
2016年 | 16篇 |
2015年 | 2篇 |
2014年 | 10篇 |
2013年 | 10篇 |
2012年 | 6篇 |
2011年 | 2篇 |
2010年 | 3篇 |
2009年 | 5篇 |
2008年 | 1篇 |
2007年 | 2篇 |
2006年 | 3篇 |
2005年 | 1篇 |
2004年 | 2篇 |
2003年 | 1篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有122条查询结果,搜索用时 0 毫秒
121.
Guiyao Zhou Yanyou Wu Deke Xing Mingming Zhang Rui Yu Weiyi Qiao Qaiser Javed 《中国地球化学学报》2016,35(1):64-71
This study aims to investigate the effects of region and three regional dominated mangrove species (Avicennia marina, Aegiceras corniculatum and Kandelia candel) on the distribution of inorganic nitrogen and phosphorus. Measurement of the inorganic nitrogen and phosphorus and enzymatic activities was carried out in soils covered by three mangrove species in the Quanzhou Bay estuarine wetlands, a typical coastal wetland in China. Species with a higher biomass in upstream and midstream absorb more nitrogen from soils, and the retention of the available phosphorus in the soils of different regions causes the regional variation of phosphorus. In areas dominated by A. marina, nitrate nitrogen is lower while available phosphorus is higher. Meanwhile, nitrate nitrogen and available phosphorus are higher in the soils covered by K. candel. Moreover, all three species affect the elemental and enzymic stoichiometry. The mangrove species influences the diversity of the elemental and enzymic stoichiometric relationship through differential microenvironments, which induce the biodiversity of wetland ecosystems. Thus, this study may facilitate a better understanding of the transformation ability of mangroves to nitrogen and phosphorus and will therefore be beneficial for providing a basis for the ecological restoration of estuarine wetlands. 相似文献
122.
Gui-sheng Hu Ning-sheng Chen Javed Iqbal Tanoli Mei Liu Rong-Kun Liu Kun-Ting Chen 《山地科学学报》2017,14(9):1712-1727
The upper Yangtze River region is one of the most frequent debris flow areas in China. The study area contains a cascade of six large hydropower stations located along the river with total capacity of more than 70 million kilowatts. The purpose of the study was to determine potential and dynamic differences in debris flow susceptibility and intensity with regard to seasonal monsoon events. We analyzed this region’s debris flow history by examining the effective peak acceleration of antecedent earthquakes, the impacts of antecedent droughts, the combined effects of earthquakes and droughts, with regard to topography, precipitation, and loose solid material conditions. Based on these factors, we developed a debris flow susceptibility map. Results indicate that the entire debris flow susceptibility area is 167,500 km2, of which 26,800 km2 falls within the high susceptibility area, with 60,900 km2 in medium and 79,800 km2 are in low susceptibility areas. Three of the six large hydropower stations are located within the areas with high risk of debris flows. The synthetic zonation map of debris flow susceptibility for the study area corresponds with both the investigation data and actual distribution of debris flows. The results of debris flow susceptibility provide base-line data for mitigating, assessing, controlling and monitoring of debris flows hazards. 相似文献