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   1082篇
  免费   16篇
  国内免费   21篇
安全科学   34篇
废物处理   39篇
环保管理   238篇
综合类   131篇
基础理论   208篇
环境理论   2篇
污染及防治   364篇
评价与监测   66篇
社会与环境   33篇
灾害及防治   4篇
  2023年   8篇
  2022年   14篇
  2021年   20篇
  2020年   5篇
  2019年   15篇
  2018年   20篇
  2017年   27篇
  2016年   28篇
  2015年   20篇
  2014年   31篇
  2013年   177篇
  2012年   45篇
  2011年   45篇
  2010年   48篇
  2009年   59篇
  2008年   46篇
  2007年   56篇
  2006年   69篇
  2005年   38篇
  2004年   31篇
  2003年   32篇
  2002年   35篇
  2001年   6篇
  2000年   15篇
  1999年   8篇
  1998年   4篇
  1997年   16篇
  1996年   6篇
  1995年   13篇
  1994年   14篇
  1993年   11篇
  1992年   11篇
  1991年   8篇
  1990年   10篇
  1989年   6篇
  1988年   4篇
  1987年   7篇
  1986年   7篇
  1985年   4篇
  1984年   5篇
  1983年   10篇
  1982年   10篇
  1981年   14篇
  1980年   4篇
  1979年   4篇
  1978年   5篇
  1977年   7篇
  1976年   5篇
  1972年   7篇
  1967年   4篇
排序方式: 共有1119条查询结果,搜索用时 866 毫秒
661.
Environmental Chemistry Letters - Heavy metals and dyes are major pollutants that pose potential threat to the health of humans and ecosystems. Various technologies are available to remediate such...  相似文献   
662.
Environmental Fluid Mechanics - We report novel results of a numerical experiment designed for examining the basin-scale hydrodynamics that control the mass, momentum, and energy distribution in a...  相似文献   
663.
Environment, Development and Sustainability - Environmental sustainability has received much attention in recent times by world leaders. This is largely due to the rate at which the natural...  相似文献   
664.
Regional Environmental Change - For Inuit and Naskapi living in the eastern Canadian Subarctic, local meteorological and environmental conditions (e.g., snow and ice cover extent, thickness, and...  相似文献   
665.
This paper explains the perceived implementation behaviour of counties in the United States with respect to the National Incident Management System (NIMS). The system represents a massive and historic policy mandate designed to restructure, standardise and thereby unify the efforts of a wide variety of emergency management entities. Specifically, this study examined variables identified in the NIMS and policy literature that might influence the behavioural intentions and actual behaviour of counties. It found that three key factors limit or promote how counties intend to implement NIMS and how they actually implement the system: policy characteristics related to NIMS, implementer views and a measure of local capacity. One additional variable—inter‐organisational characteristics—was found to influence only actual behaviour. This study's findings suggest that the purpose underlying NIMS may not be fulfilled and confirm what disaster research has long suggested: the potential for standardisation in emergency management is limited.  相似文献   
666.
The effect of different Lystek biosolids doses on the anaerobic digestability of thickened waste activated sludge (TWAS) was evaluated in a lab- and full-scale anaerobic digester. The overall findings of this study emphasize the beneficial impact of Lystek addition to the lab- and full-scale anaerobic digesters in terms of enhanced biogas production and increased volatile suspended solids reduction (VSSR) efficiency. Lystek added at 4% by volume to TWAS increased the methane yield from 0.22 to 0.26 L CH4/g VSSadded at an solids retention time (SRT) of 10 days, and from 0.27 to 0.29 L CH4/g VSSadded at an SRT of 15 days. Furthermore, the VSSRs of 37% and 47% were observed for the TWAS, and the TWAS with 4% Lystek, while at an SRT of 15 days, the observed VSSR were 49% and 58%, respectively. The lab-scale study showed that the influence of Lystek addition on methane yield and solids destruction efficiencies was more pronounced at the shorter SRT, 20% enhancement (SRT of 10 d) vs. 9% enhancement (SRT of 15 d) for methane yield, and 27% (SRT of 10 d) vs. 22% (SRT of 15 d) for VSS destruction efficiency improvement. Furthermore, addition of 4% of Lystek to the feed of the full-scale anaerobic digester at St. Marys wastewater treatment plant (WWTP) resulted in a 50% increase in the average specific methanogenic activity and 23% increase in methane yield of the biochemical methane potential tests after eight months. The results showed that Lystek degradation kinetics were 40% faster than the TWAS, as reflected by first order kinetic coefficients of 0.053 d?1 and 0.073 d?1 for TWAS and Lystek at an SRT of 10 days.  相似文献   
667.
Studies that incorporate information from habitat-specific ecological interactions (e.g., epibiotic associations) can reveal valuable insights into the cryptic habitat-use patterns and behavior of marine vertebrates. Sea turtles, like other large, highly mobile marine vertebrates, are inherently difficult to study, and such information can inform the implementation of conservation measures. The presence of epipelagic epibionts, such as the flotsam crab Planes major, on sea turtles strongly suggests that neritic turtles have recently occupied epipelagic habitats (upper 200 m in areas with >200 m depth) and that epipelagic turtles spend time at or near the surface. We quantified the effects of turtle species, turtle size, and habitat (neritic or epipelagic) on the frequency of epibiosis (F 0) by P. major on sea turtles in the Pacific Ocean. In neritic habitats, we found that loggerhead (F 0 = 27.6 %) and olive ridley turtles (F 0 = 26.2 %) host crabs frequently across a wide range of body sizes, and green turtles almost never host crabs (F 0 = 0.7 %). These results suggest that loggerheads and olive ridleys display variable/flexible epipelagic-neritic transitions, while green turtles tend to transition unidirectionally at small body sizes. In epipelagic habitats, we found that loggerheads host crabs (F 0 = 92.9 %) more frequently than olive ridleys (F 0 = 50 %) and green turtles (F 0 = 38.5 %). These results suggest that epipelagic loggerheads tend to spend more time at or near the surface than epipelagic olive ridleys and green turtles. Results of this study reveal new insights into habitat-use patterns and behavior of sea turtles and display how epibiont data can supplement data from more advanced technologies to gain a better understanding of the ecology of marine vertebrates during cryptic life stages.  相似文献   
668.
669.
670.
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