首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   825篇
  免费   11篇
  国内免费   9篇
安全科学   15篇
废物处理   66篇
环保管理   67篇
综合类   90篇
基础理论   159篇
环境理论   1篇
污染及防治   289篇
评价与监测   96篇
社会与环境   58篇
灾害及防治   4篇
  2023年   16篇
  2022年   63篇
  2021年   71篇
  2020年   31篇
  2019年   27篇
  2018年   51篇
  2017年   43篇
  2016年   52篇
  2015年   32篇
  2014年   56篇
  2013年   69篇
  2012年   47篇
  2011年   43篇
  2010年   32篇
  2009年   31篇
  2008年   31篇
  2007年   29篇
  2006年   20篇
  2005年   25篇
  2004年   14篇
  2003年   7篇
  2002年   16篇
  2001年   12篇
  2000年   3篇
  1999年   2篇
  1998年   2篇
  1997年   2篇
  1996年   3篇
  1995年   1篇
  1994年   2篇
  1991年   1篇
  1989年   1篇
  1985年   1篇
  1984年   2篇
  1982年   1篇
  1981年   1篇
  1979年   1篇
  1978年   2篇
  1973年   1篇
  1969年   1篇
排序方式: 共有845条查询结果,搜索用时 93 毫秒
511.
Seed dispersal is a crucial component of plant population dynamics. Human landscape modifications, such as habitat destruction and fragmentation, can alter the abundance of fruiting plants and animal dispersers, foraging rates, vector movement, and the composition of the disperser community, all of which can singly or in concert affect seed dispersal. Here, we quantify and tease apart the effects of landscape configuration, namely, fragmentation of primary forest and the composition of the surrounding forest matrix, on individual components of seed dispersal of Heliconia acuminata, an Amazonian understory herb. First we identified the effects of landscape configuration on the abundance of fruiting plants and six bird disperser species. Although highly variable in space and time, densities of fruiting plants were similar in continuous forest and fragments. However, the two largest-bodied avian dispersers were less common or absent in small fragments. Second, we determined whether fragmentation affected foraging rates. Fruit removal rates were similar and very high across the landscape, suggesting that Heliconia fruits are a key resource for small frugivores in this landscape. Third, we used radiotelemetry and statistical models to quantify how landscape configuration influences vector movement patterns. Bird dispersers flew farther and faster, and perched longer in primary relative to secondary forests. One species also altered its movement direction in response to habitat boundaries between primary and secondary forests. Finally, we parameterized a simulation model linking data on fruit density and disperser abundance and behavior with empirical estimates of seed retention times to generate seed dispersal patterns in two hypothetical landscapes. Despite clear changes in bird movement in response to landscape configuration, our simulations demonstrate that these differences had negligible effects on dispersal distances. However, small fragments had reduced densities of Turdus albicollis, the largest-bodied disperser and the only one to both regurgitate and defecate seeds. This change in Turdus abundance acted together with lower numbers of fruiting plants in small fragments to decrease the probability of long-distance dispersal events from small patches. These findings emphasize the importance of foraging style for seed dispersal and highlight the primacy of habitat size relative to spatial configuration in preserving biotic interactions.  相似文献   
512.
Food and Environmental Virology - Oysters are filter-feeders and retain sewage-derived pathogens in their organs or tissues. Since most enteric viruses involved in outbreaks cannot grow in cell...  相似文献   
513.
Journal of Material Cycles and Waste Management - In this article, we present the results of the composite development obtained from polyurethane (PU), polyvinyl chloride (PVC), and aluminum...  相似文献   
514.
Journal of Material Cycles and Waste Management - This work presents a survey on the management of the home medical care waste (HMCW) from the municipality of Caruaru, an important medical and...  相似文献   
515.
Journal of Material Cycles and Waste Management - A crushed concrete aggregate, processed from construction and demolition waste and a siderurgical aggregate, processed from electric arc furnace...  相似文献   
516.
Journal of Polymers and the Environment - The purpose of this study was to investigate the phosphorus (P) adsorption mechanism, kinetic, isothermal and thermodynamic parameters using alginate-like...  相似文献   
517.
During the Amazonian flood season in 2012, the Negro River reached its highest level in 110 years, submerging residential and commercial areas which appeared associated with an elevation in the observed gastroenteritis cases in the city of Manaus. The aim of this study was to evaluate the microbiological water quality of the Negro River basin during this extreme flood to investigate this apparent association between the illness cases and the population exposed to the contaminated waters. Forty water samples were collected and analysed for classic and emerging enteric viruses. Human adenoviruses, group A rotaviruses and genogroup II noroviruses were detected in 100, 77.5 and 27.5% of the samples, respectively, in concentrations of 103–106 GC/L. All samples were compliant with local bacteriological standards. HAdV2 and 41 and RVA G2, P[6], and P[8] were characterised. Astroviruses, sapoviruses, genogroup IV noroviruses, klasseviruses, bocaviruses and aichiviruses were not detected. Statistical analyses showed correlations between river stage level and reported gastroenteritis cases and, also, significant differences between virus concentrations during this extreme event when compared with normal dry seasons and previous flood seasons of the Negro River. These findings suggest an association between the extreme flood experienced and gastrointestinal cases in the affected areas providing circumstantial evidence of causality between the elevations in enteric viruses in surface waters and reported illness.  相似文献   
518.
Plastics are dominant pollutants in freshwater ecosystems worldwide. Scientific studies that investigated the interaction between plastics and freshwater biodiversity are incipient, especially if compared to the marine realm. In this review, we provide a brief overview of plastic pollution in freshwater ecosystems around the world. We found evidence of plastic ingestion by 206 freshwater species, from invertebrates to mammals, in natural or semi-natural ecosystems. In addition, we reported other consequences of synthetic polymers in freshwater ecosystems—including, for instance, the entanglement of animals of different groups (e.g., birds). The problem of plastic pollution is complex and will need coordinated actions, such as recycling programs, correct disposal, stringent legislation, regular inspection, replacement of synthetic polymers with other materials, and ecological restoration. Current information indicates that the situation in freshwater ecosystems may be as detrimental as the pollution found in the ocean, although highly underappreciated.Supplementary InformationThe online version of this article (10.1007/s13280-020-01496-5) contains supplementary material, which is available to authorized users.  相似文献   
519.
Environmental Science and Pollution Research - Selenium (Se) presents a dual role to human body, harmful or beneficial, depending on its concentration. The exposure to this element has been...  相似文献   
520.
Environmental Science and Pollution Research - The relationship between green innovation and environmental regulations has received increasing attention from researchers, gaining prominence both in...  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号