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   1634篇
  免费   20篇
  国内免费   53篇
安全科学   79篇
废物处理   34篇
环保管理   247篇
综合类   990篇
基础理论   114篇
污染及防治   118篇
评价与监测   70篇
社会与环境   34篇
灾害及防治   21篇
  2024年   1篇
  2023年   7篇
  2022年   13篇
  2021年   23篇
  2020年   40篇
  2019年   15篇
  2018年   14篇
  2017年   24篇
  2016年   26篇
  2015年   39篇
  2014年   74篇
  2013年   72篇
  2012年   57篇
  2011年   83篇
  2010年   50篇
  2009年   76篇
  2008年   76篇
  2007年   76篇
  2006年   79篇
  2005年   71篇
  2004年   74篇
  2003年   85篇
  2002年   81篇
  2001年   68篇
  2000年   87篇
  1999年   68篇
  1998年   67篇
  1997年   67篇
  1996年   29篇
  1995年   33篇
  1994年   28篇
  1993年   25篇
  1992年   17篇
  1991年   11篇
  1990年   2篇
  1989年   3篇
  1988年   3篇
  1987年   4篇
  1986年   5篇
  1985年   5篇
  1984年   7篇
  1983年   4篇
  1982年   6篇
  1981年   1篇
  1980年   2篇
  1979年   5篇
  1978年   2篇
  1977年   1篇
  1975年   1篇
排序方式: 共有1707条查询结果,搜索用时 718 毫秒
801.
This article presents a case study of a successful effort to reach agreement on one of the most intractable environmental issues of our time: wolf management. This case is unusual in several ways. In this case, the members of the negotiating team were ordinary citizens rather than leaders of organized groups. This team was given an unusually high level of authority to write the plan as they saw fit; the agency pledged to implement “whatever they came up with.” The agency convened the process, but agency personnel were not members of the team and attended only when they were invited. The team members were able to reach agreement on this tough issue even though polar opposites were at the table—one who felt that wolves are a “spiritual essence” and another who felt that, as he put it, “wolves, coyotes, and cockroaches have a lot in common”. They produced a detailed plan that addressed all the issues in just 5 months. Another unusual aspect of this effort is that the final agreement does not list the team members. They explained that they wanted their plan to “stand alone” and be judged based on what it said, not on who was involved.However, just after their agreement was completed, a new, pro-wolf control government was elected that refused to endorse the plan. While the government gave various reasons for not ratifying the plan, more and more diverse interest groups came out in support for both the plan and the process that created it. Eventually, overwhelming public support forced the government to sign and implement the plan as written. This demonstrates that, while it is important for a team to seek the sanction of decision-makers, it is perhaps even more important for the general public to see the effort and the final agreement as fair. Strong support from a broad spectrum of the public can help win the necessary political support.In addition to discussing the unorthodox aspects of this consensus-building effort, this article also attempts to give the reader a front row seat to this process by using the informants' own words—words rich in detail, brimming with color and spoken straight from the heart. Certainly their experience dispels any notion that such efforts are simply a matter of following a recipe. During the process, members of the negotiating team experienced the entire gamut of emotions—anger, defeat, humor and, finally, a genuine sense of pride. As team member Patty Denison put it, “We showed that a random group of people could work together and do something truly monumental.”  相似文献   
802.
上海城市污泥成分特性及分析方法研究   总被引:1,自引:0,他引:1  
采用扫描电镜、X射线衍射仪、能量色散X荧光分析仪、原子吸收光谱等现代分析技术对上海市某污水处理厂的污泥中复杂的化合物的形貌及其中无机化合物的物种进行了综合分析,并对其中痕量重金属的分子存在状态进行分析和评价。  相似文献   
803.
Emissions of volatile organic compounds (VOCs) from the compost maturation building in a municipal solid waste treatment facility were inventoried by solid phase microextraction and gas chromatography–mass spectrometry. A large diversity of chemical classes and compounds were found. The highest concentrations were found for n-butanol, methyl ethyl ketone and limonene (ppmv level). Also, a range of compounds exceeded their odor threshold evidencing that treatment was needed. Performance of a chemical scrubber followed by two parallel biofilters packed with an advanced packing material and treating an average airflow of 99,300 m3 h?1 was assessed in the treatment of the VOCs inventoried. Performance of the odor abatement system was evaluated in terms of removal efficiency by comparing inlet and outlet abundances. Outlet concentrations of selected VOCs permitted to identify critical odorants emitted to the atmosphere. In particular, limonene was found as the most critical VOC in the present study. Only six compounds from the odorant group were removed with efficiencies higher than 90%. Low removal efficiencies were found for most of the compounds present in the emission showing a significant relation with their chemical properties (functionality and solubility) and operational parameters (temperature, pH and inlet concentration). Interestingly, benzaldehyde and benzyl alcohol were found to be produced in the treatment system.  相似文献   
804.
Animal movement patterns and use of space depend upon food and nonfood resources, as well as conspecific and heterospecific interactions, but models of habitat use often neglect to examine multiple factors and rarely include marsupials. We studied habitat use in an Australian population of koalas (Phascolarctos cinereus) over a 6-year period in order to determine how koalas navigate their environment and partition limited patchy food and nonfood resources. Tree selection among koalas appears to be mediated by folar chemistry, but nonfood tree selection exerts a major impact on home range use due to thermoregulatory constraints. Koalas moved on a daily basis, during both day and night, but daytime resting site was not necessarily in the same location as nighttime feeding site. Koalas had substantial home range overlap in the near absence of resource sharing with less than 1% of trees located in areas of overlap used by multiple koalas. We suggest that koala spatiotemporal distribution and habitat use are probably based upon a community structure of individuals, with a checkerboard model best describing overlap in home range area but not in resource use. Nonfood refugia and social networks should be incorporated into models of animal range and habitat use.  相似文献   
805.
介绍了白蚁对环境破坏程度,白蚁防治药物对环境污染和人体健康造成的严重后果;重点针对两种持久性有机污染物——氯丹和灭蚁灵的环境污染问题探讨其治理措施和处置方法。  相似文献   
806.
The global gaseous emissions produced by landfilling the Mechanically Sorted Organic Fraction (MSOF) with different weeks of Mechanical Biological Treatment (MBT) was evaluated for an existing waste management system. One MBT facility and a landfill with internal combustion engines fuelled by the landfill gas for electrical energy production operate in the waste management system considered. An experimental apparatus was used to simulate 0, 4, 8 and 16 weeks of aerobic stabilization and the consequent biogas potential (Nl/kg) of a large sample of MSOF withdrawn from the full-scale MBT. Stabilization achieved by the waste was evaluated by dynamic oxygen uptake and fermentation tests. Good correlation coefficients (R2), ranging from 0.7668 to 0.9772, were found between oxygen uptake, fermentation and anaerobic test values. On the basis of the results of several anaerobic tests, the methane production rate k (year?1) was evaluated. k ranged from 0.436 to 0.308 year?1 and the bio-methane potential from 37 to 12 N m3/tonne, respectively, for the MSOF with 0 and 16 weeks of treatment. Energy recovery from landfill gas ranged from about 11 to 90 kW h per tonne of disposed MSOF depending on the different scenario investigated. Life cycle analysis showed that the scenario with 0 weeks of pre-treatment has the highest weighted global impact even if opposite results were obtained with respect to the single impact criteria. MSOF pre-treatment periods longer than 4 weeks showed rather negligible variation in the global impact of system emissions.  相似文献   
807.
Beneficial utilization of residues from municipal solid waste incineration is an important objective for integrated waste management in many jurisdictions. When residues are to be used as an aggregate substitute in construction applications, the release of constituents of concern to soils and water through leaching is an important environmental consideration. In this paper, residue characteristics that control constituent leaching and testing approaches for evaluating leaching are discussed. Quality control and potential improvement in case of beneficial application are addressed.  相似文献   
808.
环境质量综合分析与创新思维   总被引:4,自引:3,他引:1  
阐述了创新思维的概念,提出环境质量综合分析应跳出思维定式,学会换位思考,提高成果的针对性;尝试逆向分析,提升信息的流畅性;学会流变思维,提高综合分析的科学性;运用“头脑风暴”,通过无序、有序的思维获取创意,为环境管理与综合决策提供技术支持和技术服务。  相似文献   
809.
蔡权 《环境技术》2005,23(2):27-28
概括总结了目前涂装(前处理)废水处理工艺,并对这些工艺进行了比较分析,并针对某厂家的涂装废水提出了可行可靠的处理工艺流程。最后提出几点建议来改善和优化涂装废水工艺。  相似文献   
810.
Ni-Si交联改性膨润土的制备与应用研究   总被引:1,自引:0,他引:1  
邵红  孙伶 《环境保护科学》2005,31(6):37-39,49
以钠基膨润土为原料,制备了镍硅交联改性膨润土,并应用于模拟废水、实验室废水,探讨了镍硅交联改性膨润土对废水中COD、Cr6+、色度、浊度的去除率的影响因素,分别对镍硅交联改性膨润土的镍硅比、废水处理的pH、改性膨润土的投加量、搅拌时间等条件进行了选择。结果令人满意。  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