全文获取类型
收费全文 | 612篇 |
免费 | 19篇 |
国内免费 | 5篇 |
专业分类
安全科学 | 14篇 |
废物处理 | 33篇 |
环保管理 | 98篇 |
综合类 | 70篇 |
基础理论 | 188篇 |
污染及防治 | 161篇 |
评价与监测 | 46篇 |
社会与环境 | 22篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 6篇 |
2022年 | 6篇 |
2021年 | 7篇 |
2020年 | 7篇 |
2019年 | 8篇 |
2018年 | 14篇 |
2017年 | 26篇 |
2016年 | 25篇 |
2015年 | 17篇 |
2014年 | 14篇 |
2013年 | 66篇 |
2012年 | 15篇 |
2011年 | 24篇 |
2010年 | 16篇 |
2009年 | 25篇 |
2008年 | 34篇 |
2007年 | 36篇 |
2006年 | 18篇 |
2005年 | 22篇 |
2004年 | 22篇 |
2003年 | 15篇 |
2002年 | 15篇 |
2001年 | 19篇 |
2000年 | 11篇 |
1999年 | 8篇 |
1998年 | 6篇 |
1997年 | 8篇 |
1996年 | 11篇 |
1995年 | 10篇 |
1994年 | 12篇 |
1993年 | 8篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1988年 | 10篇 |
1987年 | 7篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 8篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1973年 | 3篇 |
1972年 | 5篇 |
1969年 | 4篇 |
排序方式: 共有636条查询结果,搜索用时 15 毫秒
631.
Phytoremediation depends on the ability of plants to tolerate and assimilate contaminants. This research characterized the interaction between several ornamental plant species and the fungicidal active ingredient, metalaxyl [N-(2,6-dimethylphenyl)-N-(methoxyacetyl)alanine methyl ester]. Species evaluated included sweetflag (Acorus gramineus Sol. ex Aiton), canna (Canna hybrida L. 'Yellow King Humbert'), parrotfeather [Myriophyllum aquaticum (Vell.) Verdc.], and pickerelweed (Pontederia cordata L.). Metalaxyl tolerance levels for each species were determined by exposing plants for 7 d to solutions containing 0, 5, 10, 25, 50, 75, or 100 mg metalaxyl L-1 aqueous nutrient media. Response endpoints included fresh mass production after 7 d exposure and 7 d post-exposure and quantum efficiency using dark-adapted (Fv/Fm) and light-adapted (fluorescence yields) plants. Metalaxyl uptake and distribution within the plant was determined by growing plants in aqueous nutrient media containing 1.18 x 10(6) Bq L-1 [14C]metalaxyl (0.909 mg L-1) for 1, 3, 5, or 7 d. Plant tissues were combusted and analyzed by liquid scintillation counting. Metalaxyl had no effects on the endpoints measured, except for fresh mass production of sweetflag at the 75 and 100 mg L-1 treatment levels. However, leaf necrosis was apparent in most species after 5 d exposure to concentrations greater than 25 mg L-1. Metalaxyl removal from the spiked nutrient media ranged from 15 to 60% during the 7-d exposure period. The majority of metalaxyl removed from the solution was detected within individual plants. In nearly all cases, activity from the radiolabeled pesticide accumulated in the leaves. Uptake of metalaxyl was correlated with water uptake throughout the 7 d. These results suggest that all species examined may be good candidates for incorporation into a phytoremediation scheme for metalaxyl. 相似文献
632.
Francis Hassard Jasmine H. Sharp Helen Taft Lewis LeVay John P. Harris James E. McDonald Karen Tuson James Wilson David L. Jones Shelagh K. Malham 《Food and environmental virology》2017,9(2):123-141
We review the risk of norovirus (NoV) infection to the human population from consumption of contaminated shellfish. From a UK perspective, risk is apportioned for different vectors of NoV infection within the population. NoV spreads mainly by person-to-person contact or via unsanitary food handling. NoV also enters the coastal zone via wastewater discharges resulting in contamination of shellfish waters. Typically, NoV persists in the marine environment for several days, with its presence strongly linked to human population density, wastewater discharge rate, and efficacy of wastewater treatment. Shellfish bioaccumulate NoV and current post-harvest depuration is inefficient in its removal. While NoV can be inactivated by cooking (e.g. mussels), consumption of contaminated raw shellfish (e.g. oysters) represents a risk to human health. Consumption of contaminated food accounts for 3–11% of NoV cases in the UK (~74,000 cases/year), of which 16% are attributable to oyster consumption (11,800 cases/year). However, environmental and human factors influencing NoV infectivity remain poorly understood. Lack of standard methods for accurate quantification of infective and non-infective (damaged) NoV particles represent a major barrier, hampering identification of an appropriate lower NoV contamination limit for shellfish. Future management strategies may include shellfish quality assessment (at point of harvest or at point of supply) or harvesting controls. However, poor understanding of NoV inactivation in shellfish and the environment currently limits accurate apportionment and risk assessment for NoV and hence the identification of appropriate shellfish or environmental quality standards. 相似文献
633.
Ingestion of antioxidants has been argued to scavenge circulating reactive molecules (e.g., free radicals), play a part in
mate choice (by mediating access to this important resource), and perhaps increase life span. However, recent work has come
to question these relationships. We have shown elsewhere in the polychromatic lizard, Ctenophorus pictus, that diet supplementation of carotenoids as antioxidants does not depress circulating natural reactive oxygen species (ROS)
levels and leads to no corresponding improvement of color traits. However, a much stronger test would be to experimentally
manipulate the ROS levels themselves and assess carotenoid-induced ROS depression. Here, we achieve this by using carbonyl
cyanide 3-chlorophenylhydrazone, which elevates superoxide (SO) formation approximately threefold at 10 μM in this model system.
We then look for depressing effects on ROS of the carotenoids in order to assess whether ‘super-production’ of SO makes carotenoid
effects on elevated ROS levels detectable. The rationale for this treatment was that if not even such elevated levels of SO
are reduced by carotenoid supplementation, the putative link carotenoids, ROS depression, and mate quality (in terms of antioxidant
capacity) is highly questionable. We conclude that there is no significant effect of carotenoids on mean SO levels even at
the induced ROS levels. However, our results showed a significant interaction effect between carotenoid treatment and male
color, with red males having higher ROS levels than yellow males. We suggest that this may be because different pigments are
differently involved in the generation of the integumental colors in the two morphs with concomitant effects on ROS depletion
depending on carotenoid uptake or allocation to coloration and antioxidation. 相似文献
634.
Schlindweinn Elizabeth Bianchini Chacon Wilson Daniel Caicedo Koop Betina Luiza de Matos Fonseca Jéssica Monteiro Alcilene Rodrigues Valencia Germán Ayala 《Journal of Polymers and the Environment》2022,30(9):3547-3565
Journal of Polymers and the Environment - Anthocyanins (ACNs) are natural pigments broadly used in the food industry due to their color, antioxidant, and antimicrobial properties, however, these... 相似文献
635.
John R. Post Hillary G. M. Ward Kyle L. Wilson George L. Sterling Ariane Cantin Eric B. Taylor 《Conservation biology》2022,36(3):e13783
Use of extensive but low-resolution abundance data is common in the assessment of species at-risk status based on quantitative decline criteria under International Union for Conservation of Nature (IUCN) and national endangered species legislation. Such data can be problematic for 3 reasons. First, statistical power to reject the null hypothesis of no change is often low because of small sample size and high sampling uncertainty leading to a high frequency of type II errors. Second, range-wide assessments composed of multiple site-specific observations do not effectively weight site-specific trends into global trends. Third, uncertainty in site-specific temporal trends and relative abundance are not propagated at the appropriate spatial scale. A common result is the propensity to underestimate the magnitude of declines and therefore fail to identify the appropriate at-risk status for a species. We used 3 statistical approaches, from simple to more complex, to estimate temporal decline rates for a designatable unit (DU) of rainbow trout in the Athabasca River watershed in western Canada. This DU is considered a native species for purposes of listing because of its genetic composition characterized as >0.95 indigenous origin in the face of continuing introgressive hybridization with introduced populations in the watershed. Analysis of abundance trends from 57 time series with a fixed-effects model identified 33 sites with negative trends, but only 2 were statistically significant. By contrast, a hierarchical linear mixed model weighted by site-specific abundance provided a DU-wide decline estimate of 16.4% per year and a 3-generation decline of 93.2%. A hierarchical Bayesian mixed model yielded a similar 3-generation decline trend of 91.3% and the posterior distribution showed that the estimate had a >99% probability of exceeding thresholds for an endangered listing. We conclude that the Bayesian approach was the most useful because it provided a probabilistic statement of threshold exceedance in support of an at-risk status recommendation. 相似文献
636.
Lichtfouse Eric Morin-Crini Nadia Bradu Corina Boussouga Youssef-Amine Aliaskari Mehran Schfer Andrea Iris Das Soumya Wilson Lee D. Ike Michihiko Inoue Daisuke Kuroda Masashi Don Sbastien Fievet Patrick Crini Grgorio 《Environmental Chemistry Letters》2022,20(3):2019-2041
Environmental Chemistry Letters - Worldwide contamination of waters by metals, metalloids, and organometallic pollutants is a major health issue. In particular, the occurrence of the selenium... 相似文献