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   11325篇
  免费   19篇
  国内免费   24篇
安全科学   51篇
废物处理   829篇
环保管理   1451篇
综合类   1314篇
基础理论   3409篇
环境理论   1篇
污染及防治   2216篇
评价与监测   1094篇
社会与环境   989篇
灾害及防治   14篇
  2023年   18篇
  2022年   13篇
  2021年   30篇
  2020年   21篇
  2019年   27篇
  2018年   1503篇
  2017年   1401篇
  2016年   1239篇
  2015年   187篇
  2014年   93篇
  2013年   94篇
  2012年   538篇
  2011年   1425篇
  2010年   784篇
  2009年   690篇
  2008年   954篇
  2007年   1311篇
  2006年   83篇
  2005年   72篇
  2004年   115篇
  2003年   105篇
  2002年   165篇
  2001年   83篇
  2000年   40篇
  1999年   21篇
  1998年   28篇
  1997年   25篇
  1996年   21篇
  1995年   31篇
  1994年   19篇
  1993年   6篇
  1992年   14篇
  1991年   26篇
  1990年   11篇
  1989年   19篇
  1988年   8篇
  1987年   4篇
  1985年   5篇
  1984年   16篇
  1983年   11篇
  1982年   12篇
  1981年   11篇
  1979年   9篇
  1970年   6篇
  1969年   4篇
  1965年   4篇
  1962年   3篇
  1960年   4篇
  1959年   3篇
  1954年   3篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
103.
This paper presentse-SEREM (Smart Emission ReductionEstimation Manual), a cost-free, easilyaccessed and updated, web-based manual forestimating emission reductions from Joint Implementation (JI) andClean Development Mechanism (CDM) projects. e-SEREM's main functions arethe selection of a benchmark for a specificproject type in the power or heat sectorand the calculation of the annual andcumulative emission reductions accrued bythis project for its crediting lifetime.e-SEREM was developed in order to test itsapplicability and practicality in assistingproject developers and evaluators toelaborate baselines easily and calculatethe emission credits earned by candidate JIor CDM projects hosted in several countries.  相似文献   
104.
Independent teams undertook environmental monitoring of particular concentrations of major construction projects forming part of Hong Kong’s U.S. $20 billion airport infrastructure programme located in dense urban areas. The team combination of environmental specialists with experienced civil engineers enabled pragmatic mitigation measures to be developed and accepted by the construction personnel with the result that potentially significant adverse impacts were averted. The authors discuss the mechanism and success of this innovative approach.  相似文献   
105.
106.
107.
108.
109.
荷兰的生物质能政策   总被引:7,自引:0,他引:7  
本文是根据荷兰经济事务部能源局局长Okko van Aardenne博士在2000年11月30日中荷垃圾填埋气研讨会上发言稿和会议资料翻译,整理的。文内小标题为译者所加。作者简明扼要地介绍了荷兰可再生能源尤其是生物质能源的利用情况,研发方向和政府的鼓励政策。  相似文献   
110.
Hydrogen storage and transportation or distribution is closely linked together. Hydrogen can be distributed continuously in pipelines or batch wise by ships, trucks, railway or airplanes. All batch transportation requires a storage system but also pipelines can be used as pressure storage system. Hydrogen exhibits the highest heating value per weight of all chemical fuels. Furthermore, hydrogen is regenerative and environment friendly. There are two reasons why hydrogen is not the major fuel of toady’s energy consumption: First of all, hydrogen is just an energy carrier. And, although it is the most abundant element in the universe, it has to be produced, since on earth it only occurs in the form of water. This implies that we have to pay for this energy, which results in a difficult economic task, because since the industrialization we are used to consuming energy for free. The second difficulty with hydrogen as an energy carrier is the low critical temperature of 33 K, i.e. hydrogen is a gas at room temperature. For mobile and in many cases also for stationary applications the volumetric and gravimetric density of hydrogen in a storage system is crucial. Hydrogen can be stored by six different methods and phenomena: high pressure gas cylinders (up to 800 bar), liquid hydrogen in cryogenic tanks (at 21 K), adsorbed hydrogen on materials with a large specific surface area (at T < 100 K), absorbed on interstitial sites in a host metal (at ambient pressure and temperature), chemically bond in covalent and ionic compounds (at ambient pressure), oxidation of reactive metals e.g. Li, Na, Mg, Al, Zn with water. These metals easily react with water to the corresponding hydroxide and liberate the hydrogen from the water. Finally, the metal hydroxides can be thermally reduced to the metals in a solar furnace.  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