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   1067篇
  免费   40篇
  国内免费   8篇
安全科学   53篇
废物处理   132篇
环保管理   173篇
综合类   191篇
基础理论   225篇
环境理论   5篇
污染及防治   224篇
评价与监测   42篇
社会与环境   57篇
灾害及防治   13篇
  2023年   7篇
  2022年   14篇
  2021年   29篇
  2020年   16篇
  2019年   21篇
  2018年   34篇
  2017年   35篇
  2016年   52篇
  2015年   39篇
  2014年   28篇
  2013年   95篇
  2012年   45篇
  2011年   63篇
  2010年   55篇
  2009年   50篇
  2008年   54篇
  2007年   56篇
  2006年   57篇
  2005年   37篇
  2004年   26篇
  2003年   24篇
  2002年   29篇
  2001年   14篇
  2000年   10篇
  1999年   12篇
  1998年   11篇
  1997年   13篇
  1996年   9篇
  1995年   9篇
  1994年   6篇
  1993年   9篇
  1992年   9篇
  1991年   14篇
  1990年   8篇
  1989年   6篇
  1986年   6篇
  1985年   4篇
  1981年   7篇
  1980年   4篇
  1978年   4篇
  1966年   3篇
  1964年   3篇
  1962年   4篇
  1961年   5篇
  1959年   4篇
  1958年   5篇
  1957年   5篇
  1955年   6篇
  1924年   3篇
  1916年   3篇
排序方式: 共有1115条查询结果,搜索用时 31 毫秒
91.
92.
ABSTRACT: To comprehend the distributions of salinity, temperature, and suspended sediment in the Danshuei River estuary in Taiwan, monthly field surveys were conducted in 2003. These included several high and low slackwater surveys and intensive surveys. The results show that the Danshuei River estuary is predominately a partially mixed estuary. The highest concentration of suspended sediment is typically observed at the Chung‐Hsin Bridge, the most upstream sampling station. The suspended sediment concentration exhibits a general decreasing trend in the downstream direction. It may be concluded that the sediments mostly come from the upstream reach. A locally high concentration of suspended sediment is found at the Kuan‐Du station because of the local deep channel bathymetry and two‐layered estuarine circulation. A vertical two‐dimensional hydrodynamic and sediment transport model is applied to investigate the tidally averaged salinity distribution, residual circulation, and suspended sediment concentration. The modeling results reveal that, under the Q75 flow condition (i.e., low flow), a turbidity maximum occurs at the Kuan‐Du station due to the strong estuarine circulation. The model simulation with a much higher river flow condition results in a weaker residual circulation and weaker turbidity maximum.  相似文献   
93.
This study examined the influence of organizational justice perceptions on employee work outcome relationships as moderated by individual differences that are influenced by societal culture. Power distance, but not country or individualism, moderated the relationships between perceived justice and satisfaction, performance, and absenteeism. The effects of perceived justice on these outcomes were stronger among individuals scoring lower on power distance index, and most of these study participants were in the U.S. (versus Hong Kong) sample. Limitations of the study and the implications of the findings for managing cross‐culturally are discussed. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
94.
95.
96.
97.
98.
Animal-sediment relations and community analysis of a Florida estuary   总被引:3,自引:0,他引:3  
Five species assemblages of the intertidal infauna of Old Tampa Bay, Florida, USA are identified. Two assemblages are judged to constitute distinct communities, while a third is shown to be an interdigitation of the two communities. Dominance by on species is the prevalent pattern within the assemblages. Numbers of deposit feeders are found to be inversely correlated to that of filter feeders, and both trophic types are found to be correlated to the sediment parameters of median grain size, sorting and skewness. Three transects with three stations each were established along the south side of Courtney Campbell Causeway in Tampa Bay, Florida. A faunal sample (0.4 m2), a sediment sample, and a water sample were taken at each station in September, December, and March of 1968/1969. Sediment samples were wet-seived. Animal samples were reduced to numbers of organisms and biomass per species. Trellis diagrams and correlation tests were generated. Support is shown for the trophic group-amensalims hypothesis, however, the silt-clay fraction is apparently of lesser importance to deposit feeders in Florida sediments than in Buzzards Bay sediments. An attempt is made to relate an analysis of the optimal grain size for filter feeders to the trophic group-amensalism hypothesis. A view of communities as abstractions from continua is more realistic than communities as discrete units.  相似文献   
99.
Hazardous waste site investigations were carried out at the Marine Corps Air Station (MCAS) in Yuma, Arizona and at Hanscom Air Force Base (HAFB) in Bedford, Massachusetts. The purpose of the first was to determine the location and extent of metals contamination throughout the base. The objective of the second was to evaluate the risk of metals contamination to groundwater from soil at three locations within the airfield. Dynamic workplans were developed and an adaptive sampling and analysis plan carried out with the data produced in the field used to support the goals of each project. An inductively coupled plasma/optical emission spectrometer (ICP/OES) was modified for field operation. A more efficient microwave digestion method and pressurized Teflon filtration system were developed for the HAFB project. Results were comparable to standard Environmental Protection Agency (EPA) methods, which must rely on two digestion procedures to recover EPA-targeted metals within the prescribed recovery range. The MCAS investigation, conducted over a five-month period, advanced the Navy's efforts from 30 months behind schedule to 18 months ahead of schedule, while the data generated at HAFB showed no risk to groundwater from metals.  相似文献   
100.
ABSTRACT

Ecological democracy confronts a challenge of not only reconciling democracy and ecology, but doing so where human activities and their environmental consequences are increasingly global. Deliberative scholars dealing with these issues emphasise reflexive governance, involving the contestation of discourses, as part of the solution, mostly aimed at high-level institutions and intergovernmental cooperation. However, even at this level democracy demands responsiveness to the citizen. To this end, the paper explores citizen-level deliberation to inform possibilities for ecological democracy writ large, via a growing literature on deliberative governance and polycentrism. Different system levels are connected via ecologically reflexive capacity and the discursive conditions under which it is enhanced, including in small-scale minipublics. This understanding informs mechanisms for ‘scaling up’ deliberative quality to the wider public sphere via regulating the manipulation of public discourse. Minipublic deliberation, properly harnessed, can serve to decontaminate public debate of anti-reflexive strategic arguments and reshape public discourse. Such anti-reflexive strategies seek to shape the public will, specifically by de-emphasising ecology via intuitive arguments that short-cut public reasoning. Acting as discursive regulatory trustees, minipublics can improve reflexivity in the wider system via a nested polycentric approach that discursively connects citizens’ deliberation to the global system both horizontally and vertically.  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