全文获取类型
收费全文 | 161篇 |
免费 | 2篇 |
专业分类
安全科学 | 1篇 |
环保管理 | 9篇 |
综合类 | 73篇 |
基础理论 | 39篇 |
环境理论 | 1篇 |
污染及防治 | 30篇 |
评价与监测 | 5篇 |
社会与环境 | 5篇 |
出版年
2023年 | 2篇 |
2017年 | 4篇 |
2015年 | 4篇 |
2014年 | 2篇 |
2013年 | 2篇 |
2012年 | 6篇 |
2011年 | 7篇 |
2010年 | 4篇 |
2009年 | 5篇 |
2008年 | 12篇 |
2007年 | 5篇 |
2006年 | 5篇 |
2005年 | 3篇 |
2004年 | 2篇 |
2002年 | 4篇 |
2001年 | 5篇 |
1999年 | 5篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1990年 | 2篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1966年 | 3篇 |
1965年 | 2篇 |
1963年 | 2篇 |
1962年 | 3篇 |
1960年 | 2篇 |
1959年 | 2篇 |
1958年 | 4篇 |
1957年 | 3篇 |
1956年 | 1篇 |
1954年 | 5篇 |
1953年 | 1篇 |
1952年 | 1篇 |
1951年 | 2篇 |
1944年 | 1篇 |
1943年 | 1篇 |
1937年 | 1篇 |
1936年 | 2篇 |
1935年 | 2篇 |
1934年 | 2篇 |
1930年 | 1篇 |
1924年 | 1篇 |
1920年 | 2篇 |
1918年 | 1篇 |
1917年 | 1篇 |
1916年 | 2篇 |
1915年 | 3篇 |
排序方式: 共有163条查询结果,搜索用时 15 毫秒
21.
Rising crude oil prices favour the exploitation of hitherto unutilised energy carriers and the realisation of new technologies in all sectors where carbon is used. These changed economic constraints necessitate both savings in conventional petrochemistry and a change to oil-independent carbon sources in the chemical industry. While, in coal chemistry, the synthesis and process principles of petrochemistry — fragmentation of the raw material and subsequent buildup of molecular structures — can be maintained, the raw material structure largely remains unchanged in the chemistry of renewable raw materials. This lecture is to demonstrate the structural as well as the technological and energy criteria of the chemistry of alternative carbon sources, to forecast the chances of commercial realization and to discuss some promising fields of research and development. 相似文献
22.
23.
HCHs and DDTs in sediment-dwelling animals including mollusks and crabs from the Yangtze Estuary were determined by GC-ECD. Levels of t-HCH were in the range of 1.2-5.5 ng g(-1) and averaged 3.5 ng g(-1) in mollusks, while t-DDT concentrations ranged from 26.0 to 68.8 ng g(-1), with a mean of 34.5 ng g(-1). In crabs t-HCH concentrations varied from 2.0 to 25.7 ng g(-1) and averaged 13.8 ng g(-1), whereas the concentrations of t-DDT were in the range of 1.5-24.8 ng g(-1) with a mean value of 5.9 ng g(-1). The HCHs and DDTs levels depend on geographical position and sources, showing the high levels at fresh water area in the estuary, such as XP, CM and LHK sites, and lower at brackish water area, such as FX site, and little difference between species. Results also indicate there was no significant relationship between t-HCH (t-DDT) concentrations and lipid contents both in mollusks and crabs because of non-equilibrium state under a specific estuarine dynamics; smaller individuals accumulated more HCHs and DDTs than larger individuals of mollusks at LHK site, showing different uptake rate for these pesticides; moreover, HCHs and DDTs levels were lower in female crab bodies than male crab bodies suggesting that the release of spawning. BSAFs (Biota- Sediment Accumulation Factors) from sediment-dwelling animals for HCHs and DDTs show a significant "one high with two low" and "one low with two high" effect in the Yangtze Estuary. 相似文献
24.
Assessing the components of adaptive capacity to improve conservation and management efforts under global change
下载免费PDF全文
![点击此处可从《Conservation biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Adrienne B. Nicotra Erik A. Beever Amanda L. Robertson Gretchen E. Hofmann John O'Leary 《Conservation biology》2015,29(5):1268-1278
Natural‐resource managers and other conservation practitioners are under unprecedented pressure to categorize and quantify the vulnerability of natural systems based on assessment of the exposure, sensitivity, and adaptive capacity of species to climate change. Despite the urgent need for these assessments, neither the theoretical basis of adaptive capacity nor the practical issues underlying its quantification has been articulated in a manner that is directly applicable to natural‐resource management. Both are critical for researchers, managers, and other conservation practitioners to develop reliable strategies for assessing adaptive capacity. Drawing from principles of classical and contemporary research and examples from terrestrial, marine, plant, and animal systems, we examined broadly the theory behind the concept of adaptive capacity. We then considered how interdisciplinary, trait‐ and triage‐based approaches encompassing the oft‐overlooked interactions among components of adaptive capacity can be used to identify species and populations likely to have higher (or lower) adaptive capacity. We identified the challenges and value of such endeavors and argue for a concerted interdisciplinary research approach that combines ecology, ecological genetics, and eco‐physiology to reflect the interacting components of adaptive capacity. We aimed to provide a basis for constructive discussion between natural‐resource managers and researchers, discussions urgently needed to identify research directions that will deliver answers to real‐world questions facing resource managers, other conservation practitioners, and policy makers. Directing research to both seek general patterns and identify ways to facilitate adaptive capacity of key species and populations within species, will enable conservation ecologists and resource managers to maximize returns on research and management investment and arrive at novel and dynamic management and policy decisions. 相似文献
25.
Goal and Scope
Blast-furnace sludge is a waste originating from pig-iron production and contains contaminants such as lead, zinc, fluoride and cyanide assumably contaminating the groundwater by leaching.Methods
We investigated the chemical composition of 27 samples of landfilled blast-furnace sludge in pore waters which were obtained by the centrifugation of fresh material and elution with water according to DIN 38414 part 4 (S 4).Results
The pore waters as well as the eluates were neutral to alkaline (pH 7.3 to 10.7) and were dominated by alkali and alkaline-earth metals as well as sulphate and nitrate. The concentrations of all elements and compounds investigated were mostly clearly larger in the pore waters than in the eluates. The average concentrations of environmentally relevant constituents such as lead (0,18 mg?1), zinc (1,5 mg l?1), fluoride (10,6 mg l?1), and total cyanide (1.8 mg l?1) in the pore waters were distinctly larger than the inspection value of the German Federal soil Protection Ordinance for the pathway soil-groundwater. Lead, zinc, and total cyanide concentrations in the pore waters were largely underestimated by the eluates, as these concentrations were 70 to 90% lower in the eluates compared to the pore waters.Conclusion
In the case of landfilled blast-furnace sludge, eluates according to DIN 38414 part 4 (S 4) provide low concentrations which are unrealistic to forecast concentrations in the seepage water. 相似文献26.
András Bardossy Arne Färber Steffen Schönau Bernhard Westrich Thomas Jancke Gerhard Schmid Sven Wurms Karl Stahr Thomas Gaiser Harald Frauenknecht Thilo Streck Joachim Ingwersen Claudia Kreschnak Ulrich Kern Hilke Heppelmann Ekkehard Christoffels Ulrich Förstner Patrick Jacobs 《Environmental Sciences Europe》2006,18(1):67-69
27.
Arsenic resistant strains of bacteria and fungi were isolated from soil contaminated by chemical warfare agents. Until now, no metabolic products of microbial attack against the phenyl residues of the model substrate triphenylarsine (TP) were found if it was incubated together with these strains in liquid culture assays. However, one of the isolated fungi, Trichoderma harzianum As 11, was found to oxidize TP to triphenylarsineoxide (TPO). The yeast Trichosporon mucoides SBUG 801 and the white-rot fungus Phanerochaete chrysosporium were also able to oxidize the As(III) in TP. In addition, P. chrysosporium transformed phenylarsineoxide (PAO) to phenylarsonic acid (PAA) under O2-atmosphere. By means of a respirometer system, the oxidation of TP by T. harzianum As 11 was confirmed by a significantly higher consumption of oxygen in the presence of these compounds. HPLC analysis of the oxidation products TPO and PAA in the medium of the assays provided evidence for the transfer reaction of As(III) to As(V) in organic bonds. The oxidation products TPO and PAA are more hydrophilic than TP and PAO. Therefore, it was concluded that particular fungi contribute to the mobilization of arsenic in soil contaminated by chemical warfare agents. 相似文献
28.
29.
30.