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   29991篇
  免费   344篇
  国内免费   247篇
安全科学   1007篇
废物处理   1472篇
环保管理   4007篇
综合类   4497篇
基础理论   7831篇
环境理论   8篇
污染及防治   7383篇
评价与监测   2138篇
社会与环境   2057篇
灾害及防治   182篇
  2023年   133篇
  2022年   263篇
  2021年   320篇
  2020年   198篇
  2019年   244篇
  2018年   439篇
  2017年   469篇
  2016年   730篇
  2015年   540篇
  2014年   857篇
  2013年   2490篇
  2012年   1024篇
  2011年   1363篇
  2010年   1108篇
  2009年   1151篇
  2008年   1420篇
  2007年   1341篇
  2006年   1214篇
  2005年   1095篇
  2004年   1043篇
  2003年   997篇
  2002年   939篇
  2001年   1099篇
  2000年   776篇
  1999年   487篇
  1998年   373篇
  1997年   385篇
  1996年   401篇
  1995年   470篇
  1994年   399篇
  1993年   348篇
  1992年   379篇
  1991年   355篇
  1990年   328篇
  1989年   323篇
  1988年   297篇
  1987年   245篇
  1986年   250篇
  1985年   249篇
  1984年   272篇
  1983年   261篇
  1982年   269篇
  1981年   222篇
  1980年   166篇
  1979年   184篇
  1978年   164篇
  1977年   134篇
  1975年   138篇
  1973年   170篇
  1972年   144篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
881.
Environmental Science and Pollution Research - Landfilling is one of the most prevalent waste management strategies on a global scale. However, one major drawback of landfills is the production of...  相似文献   
882.
Environmental Science and Pollution Research - Harmful cyanobacterial blooms (HCB) have severe impacts on marine and freshwater systems worldwide. They cause oxygen depletion and produce potent...  相似文献   
883.
884.
Environmental Science and Pollution Research - COVID-19 was first discovered in Wuhan, China in December 2019. It is one of the worst pandemics in human history. Recent studies reported that...  相似文献   
885.
Environmental Science and Pollution Research - Water contamination is a common problem, especially considering dyes and drugs disposal. A possible and effective treatment method to remove these...  相似文献   
886.
Environmental Science and Pollution Research - Residential settings are of utmost importance for human exposure, as it is where people spend most of their time. Residential wood combustion is a...  相似文献   
887.
Food processing facilities often use antimicrobial quaternary ammonium compound (QAC) sanitizers to maintain cleanliness. These QACs can end up in wastewaters used as feedstock for anaerobic digestion. The aim of this study was to measure the effect of QAC contamination on biogas production and structure of microbial communities in thermophilic digester sludge. Methane production and biogas quality data were analyzed in batch anaerobic digesters containing QAC at 0, 15, 50, 100 and 150 mg/L. Increasing sanitizer concentration in the bioreactors negatively impacted methane production rate and biogas quality. Microbial community composition data was obtained through 16S rRNA gene sequencing from the QAC-contaminated sludges. Sequencing data showed no significant restructuring of the bacterial communities. However, significant restructuring was observed within the archaeal communities as QAC concentration increased. Further studies to confirm these effects on a larger scale and with a longer retention time are necessary.  相似文献   
888.
This study examined concentrations of 15 perfluoroalkyl acids (PFAAs) in tissues from male Mozambique tilapia (Oreochromis mossambicus) collected at Loskop Dam, Mpumalanga, South Africa in 2014 and 2016. Nine of the 15 PFAAs were detected frequently and were included in statistical analysis and included two of the most commonly known PFAAs, perfluorooctanesulfonic acid (PFOS) (median, 41.6 ng/g) and perfluorooctanoic acid (PFOA) (median, 0.0825 ng/g). Of the tissues measured, plasma (2016 and 2014 median, 22.2 ng/g) contained the highest PFAA burden followed by (in descending order): liver (median, 11.6 ng/g), kidney (median, 9.04 ng/g), spleen (median, 5.92 ng/g), adipose (median, 2.54 ng/g), and muscle (median, 1.11 ng/g). Loskop Dam tilapia have been affected by an inflammatory disease of the adipose tissue known as pansteatitis, so this study also aimed to investigate relationships between PFAA tissue concentrations and incidence of pansteatitis or fish health status. Results revealed that healthy tilapia exhibited an overall higher (p-value < 0.05) PFAA burden than pansteatitis-affected tilapia across all tissues. Further analysis showed that organs previously noted in the literature to contain the highest PFAA concentrations, such as kidney, liver, and plasma, were the organs driving the difference in PFAA burden between the two tilapia groups. Care must be taken in the interpretations we draw from not only the results of our study, but also other PFAA measurements made on populations (human and wildlife alike) under differing health status.  相似文献   
889.
Fever can reduce mortality in infected animals. Yet, despite its fitness-enhancing qualities, fever often varies among animals. We used several approaches to examine this variation in insects. Texas field crickets (Gryllus texensis) exhibited a modest fever (1 °C increase in preferred body temperature, T pref) after injection of prostaglandin, which putatively mediates fever in both vertebrates and invertebrates, but they did not exhibit fever during chronic exposure to heat-killed bacteria. Further, chronic food limitation and mating status did not affect T pref or the expression of behavioural fever, suggesting limited context dependency of fever in G. texensis. Our meta-analysis of behavioural fever studies indicated that behavioural fever occurs in many insects, but it is not ubiquitous. Thus, both empirical and meta-analytical results suggest that the fever response in insects ‘is widespread, although certainly not inevitable’ (Moore 2002). We highlight the need for future work focusing on standardizing an experimental protocol to measure behavioural fever, understanding the specific mechanism(s) underlying fever in insects, and examining whether ecological or physiological costs often outweigh the benefits of fever and can explain the sporadic nature of fever in insects.  相似文献   
890.
Salmon farming is a widespread activity around the world, also known to promote diverse environmental effects on aquatic ecosystems. However, information regarding the impact of salmon farming on bird assemblages is notably scarce. We hypothesize that salmon farming, by providing food subsidies and physical structures to birds, will change their local community structure. To test this hypothesis, we conducted a seasonal monitoring of bird richness, abundance, and composition at paired salmon pen and control plots in two marine and two lake sites in southern Chile, from fall 2002 to summer 2004. Overall, salmon farming had no significant effects on species richness, but bird abundance was significantly and noticeably higher in salmon pens than in controls. Such aggregation was mainly accounted for by the trophic guilds of omnivores, diving piscivores, carrion eaters, and perching piscivores, but not by invertebrate feeders, herbivores, and surface feeders. Species composition was also significantly and persistently different between salmon pens and controls within each lake or marine locality. The patterns described above remained consistent across environment types and seasons indicating that salmon farming is changing the community structure of birds in both lake and marine habitats by promoting functional and aggregation responses, particularly by favoring species with broader niches. Such local patterns may thus anticipate potential threats from the ongoing expansion of the salmon industry to neighboring areas in Chile, resulting in regional changes of bird communities, toward a less diverse one and dominated by opportunistic, common, and generalist species such as gulls, vultures, and cormorants.  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