全文获取类型
收费全文 | 14313篇 |
免费 | 100篇 |
国内免费 | 154篇 |
专业分类
安全科学 | 346篇 |
废物处理 | 591篇 |
环保管理 | 1556篇 |
综合类 | 3238篇 |
基础理论 | 3336篇 |
环境理论 | 6篇 |
污染及防治 | 3566篇 |
评价与监测 | 1100篇 |
社会与环境 | 758篇 |
灾害及防治 | 70篇 |
出版年
2022年 | 126篇 |
2021年 | 105篇 |
2019年 | 100篇 |
2018年 | 193篇 |
2017年 | 202篇 |
2016年 | 299篇 |
2015年 | 226篇 |
2014年 | 399篇 |
2013年 | 1021篇 |
2012年 | 447篇 |
2011年 | 583篇 |
2010年 | 467篇 |
2009年 | 522篇 |
2008年 | 562篇 |
2007年 | 576篇 |
2006年 | 536篇 |
2005年 | 492篇 |
2004年 | 450篇 |
2003年 | 454篇 |
2002年 | 430篇 |
2001年 | 595篇 |
2000年 | 372篇 |
1999年 | 260篇 |
1998年 | 147篇 |
1997年 | 164篇 |
1996年 | 171篇 |
1995年 | 188篇 |
1994年 | 179篇 |
1993年 | 131篇 |
1992年 | 164篇 |
1991年 | 172篇 |
1990年 | 168篇 |
1989年 | 141篇 |
1988年 | 156篇 |
1987年 | 96篇 |
1986年 | 128篇 |
1985年 | 127篇 |
1984年 | 122篇 |
1983年 | 114篇 |
1982年 | 120篇 |
1981年 | 120篇 |
1980年 | 87篇 |
1979年 | 99篇 |
1978年 | 101篇 |
1976年 | 92篇 |
1974年 | 104篇 |
1972年 | 87篇 |
1971年 | 85篇 |
1967年 | 100篇 |
1964年 | 92篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
921.
Kelly K. Moran Julie D. Jastrow 《Environmental pollution (Barking, Essex : 1987)》2010,158(4):1088-1094
The potential for storing additional C in U.S. Corn Belt soils - to offset rising atmospheric [CO2] - is large. Long-term cultivation has depleted substantial soil organic matter (SOM) stocks that once existed in the region's native ecosystems. In central Illinois, free-air CO2 enrichment technology was used to investigate the effects of elevated [CO2] on SOM pools in a conservation tilled corn-soybean rotation. After 5 and 6 y of CO2 enrichment, we investigated the distribution of C and N among soil fractions with varying ability to protect SOM from rapid decomposition. None of the isolated C or N pools, or bulk-soil C or N, was affected by CO2 treatment. However, the site has lost soil C and N, largely from unprotected pools, regardless of CO2 treatment since the experiment began. These findings suggest management practices have affected soil C and N stocks and dynamics more than the increased inputs from CO2-stimulated photosynthesis. 相似文献
922.
Pesticide transport models commonly assume first-order pesticide degradation kinetics for describing reactive transport in soil. This assumption was assessed in mini-column studies with associated batch degradation tests. Soil mini-columns were irrigated with atrazine in two intermittent steps of about 30 days separated by 161 days application of artificial rain water. Atrazine concentration in the effluent peaked to that of the influent concentration after initial break-through but sharply decreased while influx was sustained, suggesting a degradation lag phase. The same pattern was displayed in the second step but peak height and percentage of atrazine recovered in the effluent were lower. A Monod model with biomass decay was successfully calibrated to this data. The model was successfully evaluated against batch degradation data and mini-column experiments at lower flow rate. The study suggested that first-order degradation models may underestimate risk of pesticide leaching if the pesticide degradation potential needs amplification during degradation. 相似文献
923.
Frederik De Laender K. Soetaert 《Environmental pollution (Barking, Essex : 1987)》2010,158(5):1775-1782
The majority of ecotoxicological enclosure experiments monitor species abundances at different chemical concentrations. Here, we present a new modelling approach that estimates changes in food web flows from such data and show that population- and food web level effects are revealed that are not apparent from abundance data alone. For the case of cypermethrin in freshwater enclosures, photosynthesis and excretion (d−1) of phytoplankton at 3.643 μg L−1 cypermethrin were 30% lower and 100% higher than in the control, respectively. The ingestion rate of mesozooplankton (d−1) was 6 times higher in the treated enclosures than in the control as food concentration increased with insecticide exposure. With increasing cypermethrin concentrations, nanoflagellates progressively relied on phytoplankton as their main food source, which rendered the food web less stable. We conclude that this tool has excellent potential to analyse the wealth of enclosure data as it only needs species abundance and general constraints. 相似文献
924.
Ben K. Greenfield Andrew Jahn 《Environmental pollution (Barking, Essex : 1987)》2010,158(8):2716-2724
In the San Francisco Estuary, management actions including tidal marsh restoration could change fish mercury (Hg) concentrations. From 2005 to 2007, small forage fish were collected and analyzed to identify spatial and interannual variation in biotic methylmercury (MeHg) exposure. The average whole body total Hg concentration was 0.052 μg g−1 (wet-weight) for 457 composite samples representing 13 fish species. MeHg constituted 94% of total Hg. At a given length, Hg concentrations were higher in nearshore mudflat and wetland species (Clevelandia ios, Menidia audens, and Ilypnus gilberti), compared to species that move offshore (e.g., Atherinops affinis and Lepidogobius lepidus). Gut content analysis indicated similar diets between Atherinops affinis and Menidia audens, when sampled at the same locations. Hg concentrations were higher in sites closest to the Guadalupe River, which drains a watershed impacted by historic Hg mining. Results demonstrate that despite differences among years and fish species, nearshore forage fish exhibit consistent Hg spatial gradients. 相似文献
925.
926.
A. Zierhut K. Leopold L. Harwardt M. Schuster 《Umweltwissenschaften und Schadstoff-Forschung》2010,22(1):72-77
Routinef?hige, kostengünstige analytische Messverfahren sind die Grundlage für ein fl?chendeckendes Umweltmonitoring von Schadstoffen
und somit für die Sicherung unserer Gesundheit und natürlichen Lebensgrundlagen. Hierbei kann die Analytik zur nachhaltigen
Nutzung und zur Schonung unserer Umweltressourcen beitragen, indem auf den Einsatz umweltgef?hrdender Reagenzien verzichtet
wird. 相似文献
927.
K. Hund-Rinke K. Schlich A. Wenzel 《Umweltwissenschaften und Schadstoff-Forschung》2010,22(5):517-528
Abstract
Purpose Little is known about the ecotoxicity of nanomaterials and there are no specific guidelines for sample preparation and testing.
We set out to establish whether the method used to prepare TiO2 dispersions had a significant impact on aquatic ecotoxicity. We also followed the formation of agglomerates during the incubation
period. 相似文献
928.
C. Munschy K. Héas-Moisan G. Pacepavicius 《Environmental pollution (Barking, Essex : 1987)》2010,158(12):3527-3533
The uptake, elimination and transformation of six PBDE congeners (BDE-28, -47, -99, -100, -153, -209) were studied in juvenile common sole (Solea solea L.) exposed to spiked contaminated food over a three-month period, and then depurated over a five-month period. Methoxylated (MeO-) and hydroxylated (OH-) PBDEs were determined in fish plasma exposed to PBDEs and compared to those obtained in control fish. While all MeO- and some OH- congeners identified in fish plasma were found to originate from non-metabolic sources, several OH- congeners, i.e., OH-tetraBDEs and OH-pentaBDEs, were found to originate from fish metabolism. Among these, 4′-OH-BDE-49 was identified as a BDE-47 metabolite. Congener 4′-OH-BDE-101, identified here for the first time, may be the result of BDE-99 metabolic transformation. Our results unequivocally showed that PBDEs are metabolised in juvenile sole via the formation of OH- metabolites. However, this was not a major biotransformation route compared to biotransformation through debromination. 相似文献
929.
Implications of high altitude desert dust transport from Western Sahara to Nile Delta during biomass burning season 总被引:1,自引:0,他引:1
Anup K. Prasad Hesham El-Askary Menas Kafatos 《Environmental pollution (Barking, Essex : 1987)》2010,158(11):3385-3391
The air over major cities and rural regions of the Nile Delta is highly polluted during autumn which is the biomass burning season, locally known as black cloud. Previous studies have attributed the increased pollution levels during the black cloud season to the biomass or open burning of agricultural waste, vehicular, industrial emissions, and secondary aerosols. However, new multi-sensor observations (column and vertical profiles) from satellites, dust transport models and associated meteorology present a different picture of the autumn pollution. Here we show, for the first time, the evidence of long range transport of dust at high altitude (2.5-6 km) from Western Sahara and its deposition over the Nile Delta region unlike current Models. The desert dust is found to be a major contributor to the local air quality which was previously considered to be due to pollution from biomass burning enhanced by the dominant northerly winds coming from Europe. 相似文献
930.
Virender K. Sharma Nigel J. D. Graham Xiang-Zhong Li Bao-Ling Yuan 《Environmental science and pollution research international》2010,17(2):453-461