全文获取类型
收费全文 | 545篇 |
免费 | 3篇 |
国内免费 | 5篇 |
专业分类
安全科学 | 1篇 |
废物处理 | 9篇 |
环保管理 | 25篇 |
综合类 | 299篇 |
基础理论 | 87篇 |
污染及防治 | 98篇 |
评价与监测 | 21篇 |
社会与环境 | 12篇 |
灾害及防治 | 1篇 |
出版年
2018年 | 5篇 |
2017年 | 8篇 |
2016年 | 11篇 |
2015年 | 8篇 |
2013年 | 17篇 |
2012年 | 8篇 |
2011年 | 21篇 |
2010年 | 13篇 |
2009年 | 15篇 |
2008年 | 20篇 |
2007年 | 18篇 |
2006年 | 6篇 |
2005年 | 13篇 |
2004年 | 14篇 |
2003年 | 15篇 |
2002年 | 13篇 |
2001年 | 7篇 |
1999年 | 12篇 |
1998年 | 14篇 |
1997年 | 7篇 |
1996年 | 6篇 |
1995年 | 7篇 |
1994年 | 7篇 |
1993年 | 5篇 |
1975年 | 5篇 |
1973年 | 6篇 |
1972年 | 5篇 |
1970年 | 8篇 |
1967年 | 8篇 |
1966年 | 4篇 |
1965年 | 11篇 |
1964年 | 4篇 |
1963年 | 13篇 |
1962年 | 10篇 |
1961年 | 9篇 |
1960年 | 10篇 |
1959年 | 13篇 |
1958年 | 9篇 |
1957年 | 7篇 |
1956年 | 9篇 |
1955年 | 7篇 |
1954年 | 5篇 |
1953年 | 6篇 |
1952年 | 5篇 |
1951年 | 4篇 |
1938年 | 4篇 |
1930年 | 4篇 |
1926年 | 6篇 |
1914年 | 6篇 |
1913年 | 10篇 |
排序方式: 共有553条查询结果,搜索用时 15 毫秒
211.
Vanessa S. Mascorro Nicholas C. Coops Werner A. Kurz Marcela Olguín 《Regional Environmental Change》2016,16(1):213-228
Detailed observations of natural and anthropogenic disturbance events that impact forest structure and the distribution of carbon are essential to estimate changes in terrestrial carbon pools and the associated emissions and removals of greenhouse gasses. Recent advances in remote sensing approaches have resulted in annual and decadal estimates of land-cover change derived from observations using broad-scale moderate resolution imaging spectroradiometer (MODIS) 250 m–1 km imagery. These land-use change estimates, however, are often not attributed directly to a cause or activity and are not well validated, especially in tropical areas. Knowledge of the type of disturbance that caused the observed land-cover changes is important, however, for the quantification of the associated impacts on ecosystem carbon stocks and fluxes. In this paper, we provide estimates of the amount of forest land-cover change in a Mexican forested region and propose an approach for attributing the cause of the observed changes to the underlying disturbance driver. To do so, we collate geospatial and remote sensing data from a variety of sources to summarize statistics about the major disturbances within the Yucatan Peninsula, an “early action” region for the reduction of emissions from deforestation and degradation, from 2005 to 2010. We combine the datasets to develop rules to estimate the likely disturbances that caused the observed land-cover changes based on their spatially explicit location. Finally, we compare our observed disturbance rates to those detected using classified land-cover data derived from MODIS. 相似文献
212.
Bioventing is a relatively new technology that uses forced air movement to deliver supplemental oxygen to contaminated soils to stimulate the biodegradation of contaminants by indigenous microorganisms. A bioventing pilot test was initiated at Offutt Air Force Base, Nebraska, in August 1992, at a site contaminated with jet fuel. Air was injected into the subsurface over a period of 15 months, and tests were conducted at 6 months, and again at 15 months, to determine the effectiveness of the system. This article describes the bioventing process and its application at this test site. The results of the pilot test are discussed to illustrate the extent of the remediation accomplished through bioventing. 相似文献
213.
214.
Werner E. G. Müller 《Die Naturwissenschaften》1995,82(7):321-329
Dedicated to Prof. Dr. H. Risler and Prof. Dr. Dr. h. c. R. K Zahn 相似文献
215.
216.
Biological diversity--or biodiversity--is the term given to the variety of life on Earth and the natural patterns it forms. The biodiversity we see today is the fruit of billions of years of evolution, shaped by natural processes and, increasingly, by the influence of humans. It forms the web of life of which we are an integral part and upon which we so fully depend. The research on molecular biodiversity tries to lay the scientific foundation of a rational conservation policy that has its roots in various disciplines including systematics/taxonomy (species richness), present day ecology (diversity of ecological systems), and functional genetics (genetic diversity). The results of ongoing genome analyses (genome projects and expressed sequence tag projects) and the achievements of molecular evolution may allow us not only to quantitate the diversity of the present biota but also to extrapolate to their diversification in the future. A link between biodiversity and genomics/molecular evolution will create a platform which we hope may facilitate a sustainable management of organismic life and ensure its exploitation for human benefit. In the present review we outline possible strategies, using the Porifera (sponges) as a prominent example. On the basis of solid taxonomy and ecological data, the high value of this phylum for human application becomes obvious, especially with regard to the field of chemical ecology and the desire to find novel potential drugs for clinical use. In addition, the benefit of trying to make sense of molecular biodiversity using sponges as an example can be seen in the fact that the study of these animals, which are "living fossils", gives us a good insight into the history of our planet, especially with respect to the evolution of Metazoa. 相似文献
217.
Werner Kroebel 《Die Naturwissenschaften》1962,49(16):361-363
218.
219.
220.