全文获取类型
收费全文 | 4171篇 |
免费 | 36篇 |
国内免费 | 16篇 |
专业分类
安全科学 | 45篇 |
废物处理 | 272篇 |
环保管理 | 285篇 |
综合类 | 661篇 |
基础理论 | 862篇 |
环境理论 | 4篇 |
污染及防治 | 1459篇 |
评价与监测 | 378篇 |
社会与环境 | 248篇 |
灾害及防治 | 9篇 |
出版年
2024年 | 11篇 |
2023年 | 62篇 |
2022年 | 130篇 |
2021年 | 136篇 |
2020年 | 46篇 |
2019年 | 53篇 |
2018年 | 150篇 |
2017年 | 110篇 |
2016年 | 206篇 |
2015年 | 115篇 |
2014年 | 234篇 |
2013年 | 395篇 |
2012年 | 254篇 |
2011年 | 249篇 |
2010年 | 195篇 |
2009年 | 142篇 |
2008年 | 235篇 |
2007年 | 239篇 |
2006年 | 217篇 |
2005年 | 146篇 |
2004年 | 127篇 |
2003年 | 111篇 |
2002年 | 100篇 |
2001年 | 60篇 |
2000年 | 45篇 |
1999年 | 38篇 |
1998年 | 15篇 |
1997年 | 14篇 |
1996年 | 8篇 |
1995年 | 24篇 |
1994年 | 16篇 |
1993年 | 13篇 |
1992年 | 8篇 |
1991年 | 8篇 |
1990年 | 11篇 |
1989年 | 9篇 |
1967年 | 7篇 |
1966年 | 11篇 |
1965年 | 15篇 |
1964年 | 28篇 |
1963年 | 12篇 |
1962年 | 17篇 |
1961年 | 11篇 |
1960年 | 9篇 |
1959年 | 26篇 |
1958年 | 25篇 |
1957年 | 17篇 |
1956年 | 13篇 |
1955年 | 18篇 |
1954年 | 7篇 |
排序方式: 共有4223条查询结果,搜索用时 15 毫秒
291.
Landslides are a natural hazard that presents a major threat to human life and infrastructure. Although they are a very common phenomenon in Colombia, there is a lack of analysis that entails national and comprehensive spatial, temporal, and socioeconomic evaluations of such events based on historical records. This study provides a detailed assessment of the spatial and temporal patterns and the socioeconomic impacts associated with landslides that occurred in the country between 1900 and 2018. Two national landslide databases were consulted and this information was complemented by local and regional landslide catalogues. A total of 30,730 landslides were recorded in the 118-year period. Rainfall is the most common trigger of landslides, responsible for 92 per cent of those registered, but most fatalities (68 per cent) are due to landslides caused by volcanic activity and earthquakes. An ‘fN curve’ revealed a very high frequency of small and moderate fatal landslides in the time frame. 相似文献
292.
293.
294.
295.
296.
297.
298.
299.
Prof. J. M. Gutiérrez-Vázquez 《The Environmentalist》1983,3(3):209-211
Summary This paper looks at the problems of science and technology education in Mexico, and proposes ways in which the quality of education at every level can be improved. It advocates an interdisciplinary approach, and from that approach to science education, the development of environmental education.Prof. Gutiérrez-Vázquez received his training in microbiology and biochemistry in the National Polytechnic Institute in his native Mexico City, receiving his degree in 1954. He went from instructor to assistant professor (1950–1960), becoming a full professor, deputy dean and then dean of the Faculty of Biology in the same Institute (1961–1969); he published two books and some 20 papers dealing with the physiology of tubercle bacillus and other mycobacteria, as well as with other topics on microbiology. More recently (1970 to date), he became a full professor in the Center for Advanced Studies of the same Institute, where he has been head of the Department of Educational Research (1972–1981) and carried out research and development projects on science education for children and adolescents. During this period he has published some 20 more books and 30 odd papers, and written more than 80 science programmes for commercial television. 相似文献
300.