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   810篇
  免费   6篇
  国内免费   4篇
安全科学   11篇
废物处理   31篇
环保管理   60篇
综合类   183篇
基础理论   167篇
污染及防治   254篇
评价与监测   62篇
社会与环境   47篇
灾害及防治   5篇
  2023年   10篇
  2022年   32篇
  2021年   19篇
  2020年   9篇
  2019年   14篇
  2018年   29篇
  2017年   32篇
  2016年   49篇
  2015年   18篇
  2014年   49篇
  2013年   59篇
  2012年   37篇
  2011年   67篇
  2010年   34篇
  2009年   31篇
  2008年   44篇
  2007年   43篇
  2006年   39篇
  2005年   28篇
  2004年   31篇
  2003年   18篇
  2002年   19篇
  2001年   12篇
  2000年   5篇
  1999年   5篇
  1998年   3篇
  1997年   4篇
  1996年   3篇
  1995年   3篇
  1994年   4篇
  1993年   3篇
  1992年   3篇
  1991年   2篇
  1990年   3篇
  1989年   3篇
  1988年   3篇
  1983年   2篇
  1979年   2篇
  1966年   2篇
  1965年   3篇
  1964年   5篇
  1963年   4篇
  1962年   2篇
  1961年   4篇
  1960年   5篇
  1959年   2篇
  1958年   2篇
  1957年   5篇
  1942年   2篇
  1941年   2篇
排序方式: 共有820条查询结果,搜索用时 15 毫秒
761.
An analytical framework is developed in this paper in order to explore the diversity of eco-innovations according to several key dimensions (design, user, product service and governance). The framework is used to analyse a set of case studies of eco-innnovation processes. The diversity of the analysed eco-innovations appears to be considerable; each of them involves different kinds of combinations of elements pertaining to those dimensions. Albeit the design dimension is decisive to determine the environmental impacts of the innovation, all dimensions can play a significant role in the management of eco-innovation. Our findings suggest that the capacity of eco-innovations to provide new business opportunities and contribute to the transformation towards a sustainable society depends on the interplay of those dimensions and the engagement of key stakeholders in the innovation process.  相似文献   
762.
In order to distinguish between ‘local’ and ‘background’ sources of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in coastal British Columbia (Canada) air, we collected samples from two sites: a remote site on western Vancouver Island, and a near-urban site in the Strait of Georgia. Seasonally-integrated samples of vapor, particulate, and rain were collected continuously during 365 days for analysis of 275 PCB and PBDE congeners. While deposition of the legacy PCBs was similar at both sampling sites, deposition of PBDEs at the remote site amounted to 42% (10.4 mg/ha/year) of that at the near-urban site. Additional research into atmospheric circulation in the NE Pacific Ocean will provide more insight into the transport and fate of priority pollutants in this region, but trans-Pacific delivery of PBDEs to the west coast of North America may underlie in part our observations. For example, approximately 40% of >12,000 ten-day back trajectories calculated for the remote site originated over Asia, compared to only 2% over North America.  相似文献   
763.
764.
765.
In the years 2004 and 2005, we collected samples of phytoplankton, zooplankton, and macroinvertebrates in an artificial small pond in Budapest (Hungary). We set up a simulation model predicting the abundances of the cyclopoids, Eudiaptomus zachariasi, and Ischnura pumilio by considering only temperature and the abundance of population of the previous day. Phytoplankton abundance was simulated by considering not only temperature but the abundances of the three mentioned groups. When we ran the model with the data series of internationally accepted climate change scenarios, the different outcomes were discussed. Comparative assessment of the alternative climate change scenarios was also carried out with statistical methods.  相似文献   
766.
The development and implementation of new procedures and operational changes in the production processes constitutes a powerful tool for the practical application of Cleaner Production in industries. In this work an operational change (new procedure) was developed for the elaboration of a type of beer which uses sugar as malt adjunct. The change consists in processing separately the three main components of the beer wort: malt extract, sugar and water, and use them properly in a different sequence than that used up to date in the traditional process. The new procedure was successfully assayed on industrial scale in Tínima brewery, located in Camagüey, Cuba, obtaining a good quality beer, technological and economical advantages with benefits for the environment, registering significant savings in energy (49%), sugar (4%), water (7%) and caustic soda (3%) consumption; and diminishing the surplus hot water (74%), waste generation (11%) and greenhouse gases emission (21%). Beer production capacity is increased also almost three times. With the application of the new technology to the Cuban beer type of 8 °P, it was achieved a total saving of US$ 481.83/1000 hL of beer produced.  相似文献   
767.
768.
769.
Knowing the depth zone of neutral buoyancy of divers is important because buoyancy can determine how animals manage their energy budget. In this study, we estimate the depth zone of neutral buoyancy of free-ranging cormorants for the first time, using time-depth recorders. We discovered that vertical ascent rates of 12 Crozet and 15 Kerguelen diving blue-eyed shags (respectively Phalacrocorax melanogenis and P. verrucosus) slowed down considerably at the 50–60 m depth zone. We suggest this was due to birds trying to reach the surface from that point upwards using reduced locomotor activity because the force of buoyancy becomes greater than the force of gravity at that depth. The results show a shift of this depth zone in relation to maximum targeted dive depth, suggesting cormorants may control buoyancy through respiratory air volume adjustment. Interestingly, 60 m is close to the maximum depth zone reached by these two species during dives lasting 4 min, their estimated behavioural aerobic dive limit. This suggests that the decision to swim deeper has a direct consequence on the energy budget, with time spent recovering at the surface (time thus lost to foraging) strongly increasing relative to the preceding time of submergence. Resources found in deeper waters must be of sufficient quantity or quality to justify crossing the frontier of physical neutral buoyancy.  相似文献   
770.
Behavioral Ecology and Sociobiology - Cooperation plays a crucial role in primate social life. However, the evolution of large-scale human cooperation from the cognitive fundamentals found in other...  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