全文获取类型
收费全文 | 289篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
安全科学 | 3篇 |
废物处理 | 7篇 |
环保管理 | 13篇 |
综合类 | 196篇 |
基础理论 | 25篇 |
污染及防治 | 32篇 |
评价与监测 | 3篇 |
社会与环境 | 12篇 |
出版年
2022年 | 5篇 |
2018年 | 9篇 |
2015年 | 4篇 |
2013年 | 6篇 |
2012年 | 4篇 |
2010年 | 5篇 |
2009年 | 6篇 |
2008年 | 4篇 |
2007年 | 5篇 |
2006年 | 6篇 |
2005年 | 4篇 |
2002年 | 4篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 7篇 |
1998年 | 6篇 |
1994年 | 3篇 |
1992年 | 5篇 |
1985年 | 3篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1967年 | 3篇 |
1966年 | 3篇 |
1963年 | 6篇 |
1962年 | 8篇 |
1961年 | 4篇 |
1960年 | 6篇 |
1959年 | 3篇 |
1958年 | 9篇 |
1957年 | 12篇 |
1956年 | 13篇 |
1955年 | 17篇 |
1954年 | 6篇 |
1953年 | 6篇 |
1952年 | 4篇 |
1950年 | 5篇 |
1942年 | 2篇 |
1941年 | 2篇 |
1939年 | 4篇 |
1938年 | 4篇 |
1937年 | 3篇 |
1935年 | 5篇 |
1933年 | 2篇 |
1931年 | 3篇 |
1930年 | 5篇 |
1929年 | 3篇 |
1924年 | 2篇 |
1922年 | 2篇 |
1920年 | 2篇 |
1913年 | 3篇 |
排序方式: 共有291条查询结果,搜索用时 605 毫秒
131.
Metal distribution and stability in constructed wetland sediment 总被引:2,自引:0,他引:2
Knox AS Paller MH Nelson EA Specht WL Halverson NV Gladden JB 《Journal of environmental quality》2006,35(5):1948-1959
The A-01 wetland treatment system (WTS) is a surface flow wetland planted with giant bulrush [Schoenoplectus californicus (C.A. Mey.) Palla] that is designed to remove Cu and other metals from the A-01 National Pollution Discharge Elimination System (NPDES) effluent at the Savannah River Site near Aiken, SC. Copper, Zn, and Pb concentrations in water were usually reduced 60 to 80% by passage through the treatment system. The Cu concentrations in the wetland sediments increased from about 4 to 205 and 796 mg kg(-1), respectively, in the organic and floc sediment layers in cell 4A over a 5-yr period. Metal concentrations were higher in the two top layers of sediment (i.e., the floc and organic layers) than in the deeper inorganic layers. Sequential extraction was used to evaluate remobilization and retention of Cu, Pb, Zn, Mn, and Fe in the wetland sediment. Metal remobilization was determined by the potentially mobile fraction (PMF) and metal retention by the recalcitrant factor (RF). The PMF values were high in the floc layer but comparatively low in the organic and inorganic layers. High RF values for Cu, Zn, and Pb in the organic and inorganic layers indicated that these metals were strongly bound in the sediment. The RF values for Mn were lower than for the other elements especially in the floc layer, indicating low retention or binding capacity. Retention of contaminants was also evaluated by distribution coefficient (Kd) values. Distribution coefficient (Kd) values were lower for Cu and Zn than for Pb, indicating a smaller exchangeable fraction for Pb. 相似文献
132.
Manfred Niecke Andreas Krüger Peter Hauff Hermann Ellenberg Ralph Labes Susanne Niecke 《Environmental Sciences Europe》1998,10(1):3-14
With the aid of the Hamburg proton micro-probe, we examined the concentration of mercury in sea eagle feathers collected over the course of several decades in the Mecklenburg-Vorpommern area. Based on the sites where these feathers were collected and the data of these findings, it is possible to get a differential picture of mercury contamination related both temporally and regionally to the mercurial pollution of seed mordants used agriculturally. We compared the concentrations found with a basic “geogenic” contamination which was also to be seen in the feather samples from the last century as detected in museum animal specimens. 相似文献
133.
To find out more on the structure of humic substances (HS), isolated dissolved organic carbon (DOC) samples from a brown water lake and a wastewater effluent were fractionated and subjected to alkaline hydrolysis. UV/Vis and fluorescence spectroscopy, as well as size-exclusion chromatography with on-line detection of UV absorption, fluorescence and DOC concentration were used to investigate the structural changes caused by the hydrolysis reaction. Following hydrolysis, the fluorescence intensity increased considerably despite a decrease in the UV absorption. The UV absorption and the DOC data from the SEC experiments revealed a strong shift to smaller molecular sizes after hydrolysis. The spectra of the hydrolysed samples, as well as the size-exclusion chromatograms, were compared to spectra of hydroxybenzoic acids and hydroxycinnamic acids. From this comparison, it can be concluded that the hydrolysis products have a structure similar to these organic acids. 相似文献
134.
Hermann Dinges G. Hettner H. Lehmann E. Preuss G. Vieth 《Die Naturwissenschaften》1962,49(22):527-528
135.
136.
Preindustrial man influenced and changed the earth's ecosystems decisively. The disappearance of large animals from all continents (Eurasia, e.g., mammoth; America, e.g., the giant sloths and the giant armadillo) after the Pleistocene was most probably due to a large extent to the early hunters and collectors. Corn-growing and breeding of domestic animals led to the disappearance of their wild forms (e.g., the wild form of today's old world camel is unknown) and the cultivation of huge monocultures. The increasing need for wood resulted in the disappearance of forests almost all over Europe. Specific needs, such as pig-raising or bee-keeping, supported the formation of particular landscapes, e.g., sparsely wooded forests and extensive heathlands. All these factors resulted in extreme soil erosion and the disappearance of nutritionally important minerals from the soil, which was thus severely depleted. 相似文献
137.
138.
139.
Hermann Remmert 《Die Naturwissenschaften》1982,69(11):524-527
Africa has lost only very few big mammals at the end of the pleistocene. Evidence is put forward that the reason for the present richness of the African mammal fauna is a very early coevolution between evolving man and the megafauna of this area. Areas without such an early coevolution suffered severe losses (up to 100%) of their native megafauna, when early hunters invaded them. 相似文献
140.