全文获取类型
收费全文 | 284篇 |
免费 | 0篇 |
专业分类
安全科学 | 2篇 |
废物处理 | 6篇 |
环保管理 | 8篇 |
综合类 | 125篇 |
基础理论 | 50篇 |
污染及防治 | 68篇 |
评价与监测 | 11篇 |
社会与环境 | 12篇 |
灾害及防治 | 2篇 |
出版年
2021年 | 3篇 |
2018年 | 9篇 |
2017年 | 4篇 |
2015年 | 7篇 |
2014年 | 13篇 |
2013年 | 7篇 |
2012年 | 7篇 |
2011年 | 5篇 |
2010年 | 12篇 |
2009年 | 11篇 |
2008年 | 8篇 |
2007年 | 9篇 |
2006年 | 9篇 |
2005年 | 8篇 |
2004年 | 7篇 |
2003年 | 8篇 |
2002年 | 8篇 |
1998年 | 7篇 |
1996年 | 7篇 |
1995年 | 3篇 |
1993年 | 4篇 |
1979年 | 2篇 |
1971年 | 2篇 |
1969年 | 2篇 |
1966年 | 3篇 |
1965年 | 5篇 |
1964年 | 2篇 |
1963年 | 7篇 |
1962年 | 4篇 |
1961年 | 3篇 |
1960年 | 2篇 |
1959年 | 5篇 |
1958年 | 5篇 |
1957年 | 3篇 |
1956年 | 10篇 |
1955年 | 7篇 |
1954年 | 3篇 |
1953年 | 3篇 |
1952年 | 2篇 |
1950年 | 2篇 |
1949年 | 2篇 |
1947年 | 2篇 |
1942年 | 2篇 |
1940年 | 2篇 |
1939年 | 4篇 |
1934年 | 3篇 |
1933年 | 2篇 |
1929年 | 2篇 |
1925年 | 2篇 |
1918年 | 2篇 |
排序方式: 共有284条查询结果,搜索用时 15 毫秒
1.
Only three decades ago it was thought inconceivable that organic compounds could transport electric charges like metals do. However, recently organic molecules exhibiting high conductivities have been synthesized. Some examples of organic conductors are presented together with the present status of this research which is both interesting to chemists and physicists. Some applications of organic conductors are discussed. 相似文献
2.
3.
4.
5.
6.
7.
Impact of Land Use on Soluble Organic Nitrogen in Soil 总被引:5,自引:0,他引:5
Victoria B. Willett James J. Green Andrew J. Macdonald John A. Baddeley Georg Cadisch Steven M. J. Francis Keith W. T. Goulding Gary Saunders Elizabeth A. Stockdale Christine A. Watson David L. Jones 《Water, Air, & Soil Pollution: Focus》2004,4(6):53-60
Although it has been hypothesized that soluble organic nitrogen (SON) plays a central role in regulating productivity in some terrestrial ecosystems, the factors controlling the size of the SON pool in soil remain poorly understood. Therefore our principal aim in this work was to assess the impact of seven different land use systems (rough and managed grassland, deciduous and coniferous woodland, heathland, wetland and tilled land) on the size of the SON and inorganic N (NO
3
–
, NH
4
+
) pools in the surface soil layer (0–15 cm). After extraction with deionised water, we found that in most cases the size of the water extractable organic N (WEON) pool was similar in size to the inorganic N pool. In contrast, the KCl extractable organic N (KClEON) pool constituted the dominant form of soluble N in soils under all land uses, perhaps indicating that significant amounts were held on the soil exchange phase. In contrast to inorganic N, which varied significantly with land use, the size of the KClEON and WEON pool was similar for all land uses with the exception of KClEON in tilled land, where significantly lower amounts were observed. We conclude that SON constitutes an important soil N pool in a broad range of land uses, and that its role in microbial N assimilation, plant nutrition and ecosystem responses to atmospheric N deposition warrants further attention.
SAFRD, University of Newcastle, Newcastle-upon-Tyne, NE1 7RU, U.K. 相似文献
8.
Estelle Lefrançois Laure Apothéloz-Perret-Gentil Philippe Blancher Samuel Botreau Cécile Chardon Laura Crepin Tristan Cordier Arielle Cordonier Isabelle Domaizon Benoit J. D. Ferrari Julie Guéguen Jean-Christophe Hustache Louis Jacas Stephan Jacquet Sonia Lacroix Anne-Laurence Mazenq Alina Pawlowska Pascal Perney Jan Pawlowski Frédéric Rimet Jean-François Rubin Dominique Trevisan Régis Vivien Agnès Bouchez 《Environmental science and pollution research international》2018,25(34):33858-33866
The effectiveness of environmental protection measures is based on the early identification and diagnosis of anthropogenic pressures. Similarly, restoration actions require precise monitoring of changes in the ecological quality of ecosystems, in order to highlight their effectiveness. Monitoring the ecological quality relies on bioindicators, which are organisms revealing the pressures exerted on the environment through the composition of their communities. Their implementation, based on the morphological identification of species, is expensive because it requires time and experts in taxonomy. Recent genomic tools should provide access to reliable and high-throughput environmental monitoring by directly inferring the composition of bioindicators’ communities from their DNA (metabarcoding). The French-Swiss program SYNAQUA (INTERREG France-Switzerland 2017–2019) proposes to use and validate the tools of environmental genomic for biomonitoring and aims ultimately at their implementation in the regulatory bio-surveillance. SYNAQUA will test the metabarcoding approach focusing on two bioindicators, diatoms, and aquatic oligochaetes, which are used in freshwater biomonitoring in France and Switzerland. To go towards the renewal of current biomonitoring practices, SYNAQUA will (1) bring together different actors: scientists, environmental managers, consulting firms, and biotechnological companies, (2) apply this approach on a large scale to demonstrate its relevance, (3) propose robust and reliable tools, and (4) raise public awareness and train the various actors likely to use these new tools. Biomonitoring approaches based on such environmental genomic tools should address the European need for reliable, higher-throughput monitoring to improve the protection of aquatic environments under multiple pressures, guide their restoration, and follow their evolution. 相似文献
9.
Janina Seemann Cindy T. González Rodrigo Carballo-Bolaños Kathryn Berry Georg A. Heiss Ulrich Struck Reinhold R. Leinfelder 《Environmental monitoring and assessment》2014,186(3):1747-1763
Environmental and biological reef monitoring was conducted in Almirante Bay (Bahía Almirante) in Bocas del Toro, Panama, to assess impacts from anthropogenic developments. An integrated monitoring investigated how seasonal temperature stress, turbidity, eutrophication and physical impacts threatened reef health and biodiversity throughout the region. Environmental parameters such as total suspended solids [TSS], carbon isotopes (δ13C), C/N ratios, chlorophyll a, irradiance, secchi depth, size fractions of the sediments and isotope composition of dissolved inorganic carbon [DIC] of the water were measured throughout the years 2010 and 2011 and were analysed in order to identify different impact sources. Compared to data from Collin et al. (Smithsonian Contributions to the Marine Sciences 38:324–334, 2009) chlorophyll a has doubled at sites close to the city and the port Almirante (from 0.46–0.49 to 0.78–0.97 μg l?1) and suspension load increased, visible by a decrease in secchi depth values. Visibility decreased from 9-13 m down to 4 m at the bay inlet Boca del Drago, which is strongly exposed to river run off and dredging for the shipping traffic. Eutrophication and turbidity levels seemed to be the determining factor for the loss of hard coral diversity, most significant at chlorophyll a levels higher than 0.5 μg l?1 and TSS levels higher than 4.7 mg l?1. Hard coral cover within the bay has also declined, at some sites down to <10 % with extremely low diversities (7 hard coral species). The hard coral species Porites furcata dominated the reefs in highly impacted areas and showed a strong recovery after bleaching and a higher tolerance to turbidity and eutrophication compared to other hard coral species in the bay. Serious overfishing was detected in the region by a lack of adult and carnivorous fish species, such as grunts, snappers and groupers. Study sites less impacted by anthropogenic activities and/or those with local protection showed a higher hard coral cover and fish abundance; however, an overall loss of hard coral diversity was observed. 相似文献
10.
Boy Jens Strey Simone Schönenberg Regine Strey Robert Weber-Santos Oscarlina Nendel Claas Klingler Michael Schumann Charlotte Hartberger Korbinian Guggenberger Georg 《Regional Environmental Change》2018,18(1):63-75
Regional Environmental Change - Soil carbon stocks of 29 plots along a transect through tropical Brazil showed only minor soil carbon losses after land use shift, although replacement of... 相似文献