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   10210篇
  免费   934篇
  国内免费   1120篇
安全科学   1236篇
废物处理   153篇
环保管理   2476篇
综合类   5520篇
基础理论   938篇
环境理论   47篇
污染及防治   397篇
评价与监测   682篇
社会与环境   760篇
灾害及防治   55篇
  2024年   46篇
  2023年   122篇
  2022年   165篇
  2021年   255篇
  2020年   273篇
  2019年   284篇
  2018年   270篇
  2017年   507篇
  2016年   515篇
  2015年   543篇
  2014年   485篇
  2013年   740篇
  2012年   750篇
  2011年   724篇
  2010年   606篇
  2009年   561篇
  2008年   388篇
  2007年   643篇
  2006年   637篇
  2005年   583篇
  2004年   508篇
  2003年   474篇
  2002年   362篇
  2001年   349篇
  2000年   344篇
  1999年   233篇
  1998年   175篇
  1997年   148篇
  1996年   106篇
  1995年   125篇
  1994年   69篇
  1993年   68篇
  1992年   42篇
  1991年   26篇
  1990年   22篇
  1989年   17篇
  1988年   10篇
  1986年   9篇
  1984年   5篇
  1982年   5篇
  1981年   6篇
  1980年   6篇
  1979年   10篇
  1978年   4篇
  1977年   7篇
  1976年   5篇
  1975年   6篇
  1974年   4篇
  1973年   5篇
  1972年   5篇
排序方式: 共有10000条查询结果,搜索用时 390 毫秒
361.
清洁生产纳入环境影响评价的意义   总被引:2,自引:0,他引:2  
当前的环境影响评价在某种程度上更侧重于环境的末端治理,无法将污染控制与生产过程控制密切结合,资源和能源不能在生产过程中得到充分利用.而清洁生产在这方面却有着独特的特点和优势.根据清洁生产与环境影响评价的内在联系,尽快地将清洁生产纳入环境影响评价是具有重要意义的,清洁生产应该成为环境影响评价报告撰写中的重要内容.  相似文献   
362.
ABSTRACT: Water quality indicators of two agriculturally impacted karst areas in southeastern West Virginia were studied to determine the water quality effects of grazing agriculture and water quality trends following initiation of water quality improvement programs. Both areas are tributaries of the Greenbrier River and received funding for best management practices under the President's Initiative for Water Quality and then under the Environmental Quality Incentives Program (EQIP). After 11 years of study there was little evidence to suggest that water quality improved in one area. Three and a half years of study in the other area showed little evidence of consistent water quality improvement under EQIP. Lack of consistent water quality improvement at the catchment scale does not imply that the voluntary programs were failures. Increased livestock numbers as a result of successful changes in forage management practices may have overridden water quality improvements achieved through best management practices. Practices that target well defined contributing areas significantly impacting aquifer water quality might be one way to improve water quality at catchment scales in karst basins. For example, a significant decrease in fecal coliform concentrations was observed in subterranean drainage from one targeted sinkhole after dairy cattle were permanently excluded from the sinkhole.  相似文献   
363.
Like many federal statutes, the U.S. Endangered Species Act (ESA) contains vague or ambiguous language. The meaning imparted to the ESA's unclear language can profoundly impact the fates of endangered and threatened species. Hence, conservation scientists should contribute to the interpretation of the ESA when vague or ambiguous language contains scientific words or refers to scientific concepts. Scientists need to know at least these 2 facts about statutory interpretation: statutory interpretation is subjective and the potential influence of normative values results in different expectations for the parties involved. With the possible exception of judges, all conventional participants in statutory interpretation are serving their own interests, advocating for their preferred policies, or biased. Hence, scientists can play a unique role by informing the interpretative process with objective, policy‐neutral information. Conversely, scientists may act as advocates for their preferred interpretation of unclear statutory language. The different roles scientists might play in statutory interpretation raise the issues of advocacy and competency. Advocating for a preferred statutory interpretation is legitimate political behavior by scientists, but statutory interpretation can be strongly influenced by normative values. Therefore, scientists must be careful not to commit stealth policy advocacy. Most conservation scientists lack demonstrable competence in statutory interpretation and therefore should consult or collaborate with lawyers when interpreting statutes. Professional scientific societies are widely perceived by the public as unbiased sources of objective information. Therefore, professional scientific societies should remain policy neutral and present all interpretations of unclear statutory language; explain the semantics and science both supporting and contradicting each interpretation; and describe the potential consequences of implementing each interpretation. A review of scientists’ interpretations of the phrase “significant portion of its range” in the ESA is used to critique the role of scientists and professional societies in statutory interpretation.  相似文献   
364.
Asymmetric regulation of a global pollutant between countries can alter the competitiveness of industries and lead to emissions leakage, which hampers countries’ welfare. In order to limit leakage, governments consider supporting domestic trade-exposed firms by subsidizing their investments in abatement technology. The suppliers of such technologies tend to be less than perfectly competitive, particularly when both emissions regulations and advanced technologies are new. In this context of twin market failures, we consider the relative effects and desirability of subsidies for abatement technology. We find a more robust recommendation for upstream subsidies than for downstream subsidies. Downstream subsidies tend to increase global abatement technology prices, reduce pollution abatement abroad and increase emission leakage. On the contrary, upstream subsidies reduce abatement technology prices, and hence also emissions leakage.  相似文献   
365.
Local rural and indigenous communities have assumed increasing responsibility for conservation within and between areas buffering the impacts of agricultural or resource‐extraction zones and protected areas. Empowering local communities as central partners in conservation and climate‐change mitigation has allowed many people to gain access to land and citizenship rights but has provided limited improvements in access to social services and economic opportunities even as expectation about their role as environmental stewards grows. These expectations, however, are inconsistent with reality. We conducted multiple field studies in Brazil since the mid‐1980s to illustrate the discrepancies between conservation programs and local conditions and expectations. We suggest that public policies and conservation programs should not delegate responsibility for managing protected areas to local and indigenous communities without considering local needs and expectations and locals’ attitudes toward conservation. In other words, behavior that maintains or improves the environment should not be treated as traditional based on the expectations of outsiders. Framing local populations as traditional environmentalists creates contradictions and frustrations for local populations and for conservation professionals and policy makers.  相似文献   
366.
ABSTRACT

Sketch-map-facilitated interviews were conducted in 23 villages in two adjacent regions in the southern Yucatan Peninsula of Mexico – the Maya (and increasingly Mennonite) forest-agriculture mosaic of the Chenes, and the late-20th-century-settlement forest frontier of Calakmul – to determine the frequency and typology of local-scale reserves, including the external (e.g. Payments for Environmental Services programs) and internal sources of their generation. 9% of the study communities are found to satisfy the author’s criteria for deliberate, autochthonous reserves. The static polygon reserve and static map are found to have limited value for understanding the evolving cultural ecologies of these regions. Alternative approaches are discussed, particularly those employed by geographers.  相似文献   
367.
The sharing of environmental cost by residents in various residential areas in the developing world is perceived to be unfair. This study therefore assessed residents’ experiences of environmental justice in Ile-Ife, Nigeria. Three residential areas were identified in the study area and samples were selected using systematic sampling. Using availability and condition of urban infrastructure, severity of environmental problems and residents’ involvement in environmental issues, the study examined environmental justice in the study area. The study established a variation in environmental issues across identified residential areas. The severity of environmental problem measured through an index tagged Severity of Environmental Problem (SEPI) revealed that environmental problems was most severe in the core (SEPI = 4.00), followed by the peripheral area (SEPI = 3.71) and least in the transition area (SEPI = 3.56). On the condition of available environmental infrastructure, the study revealed that the conditions of infrastructure were most improved in the peripheral area (ICI = 3.07), followed by the core (ICI = 2.67) and the least in the transition area (ICI = 2.42). The study concluded that residents’ experiences of environmental justice differ significantly across the different residential zones as reflected by residents’ socio-economic characteristics. Furthermore, it established that age, gender, educational status, and number of years spent in the area can be used to explain the differences in residents’ experience of environmental justice in the study area. To enhance the liveability, the study recommends adequate provision of environmental amenities needed by each category of people in the city.  相似文献   
368.
海岛是海洋生态系统的重要组成部分,保护海岛生态环境是推进海洋生态文明建设、保护海洋生态环境的重要方面。海岛居民是保护海岛生态环境的主体之一,研究海岛居民环境友好行为的影响因素,引导和鼓励海岛居民主动采取环境友好行为是改善海岛生态环境的有效途径。本研究在梳理国内外相关文献的基础上,对海岛居民环境友好行为的概念、类型及影响因素进行理论分析,建立包含生态管理行为、消费行为、说服行为、公民行为四个环境友好行为变量,环境态度、环境保护知识、环境经历、社会政策、行为约束五个影响因素变量在内的理论模型。结合海岛生态环境和海岛居民的特点,设计海岛居民版环境友好行为测量量表,并在长岛县进行问卷调查,运用描述性统计分析、结构方程模型分析探究海岛居民环境友好行为的影响因素及影响因素间的内在关系。研究发现:①海岛居民环境友好行为总体水平差异较大,难度较低的环境友好行为实施较好,而难度较高的实施较差;影响因素变量中,环境态度积极,环境经历丰富,环境保护知识掌握较好,相关社会政策较为不利,行为约束偏中性。②环境态度、环境经历、社会政策对海岛居民环境友好行为具有显著正向影响。③环境保护知识对环境态度具有显著正向影响,但对海岛居民环境友好行为无显著影响,存在“知易行难”现象。行为约束对海岛居民环境友好行为无显著影响。④环境经历不仅直接影响海岛居民环境友好行为,而且通过环境态度对海岛居民环境友好行为施加间接影响。基于研究结论,提出了改善海岛居民环境友好行为的对策建议。  相似文献   
369.
Conservation policy sits at the nexus of natural science and politics. On the one hand, conservation scientists strive to maintain scientific credibility by emphasizing that their research findings are the result of disinterested observations of reality. On the other hand, conservation scientists are committed to conservation even if they do not advocate a particular policy. The professional conservation literature offers guidance on negotiating the relationship between scientific objectivity and political advocacy without damaging conservation science's credibility. The value of this guidance, however, may be restricted by limited recognition of credibility's multidimensionality and emergent nature: it emerges through perceptions of expertise, goodwill, and trustworthiness. We used content analysis of the literature to determine how credibility is framed in conservation science as it relates to apparent contradictions between science and advocacy. Credibility typically was framed as a static entity lacking dimensionality. Authors identified expertise or trustworthiness as important, but rarely mentioned goodwill. They usually did not identify expertise, goodwill, or trustworthiness as dimensions of credibility or recognize interactions among these 3 dimensions of credibility. This oversimplification may limit the ability of conservation scientists to contribute to biodiversity conservation. Accounting for the emergent quality and multidimensionality of credibility should enable conservation scientists to advance biodiversity conservation more effectively.  相似文献   
370.
Solar energy conversion into electricity by photovoltaic modules is now a mature technology. We discuss the need for materials and device developments using conventional silicon and other materials, pointing to the need to use scalable materials and to reduce the energy payback time. Storage of solar energy can be achieved using the energy of light to produce a fuel. We discuss how this can be achieved in a direct process mimicking the photosynthetic processes, using synthetic organic, inorganic, or hybrid materials for light collection and catalysis. We also briefly discuss challenges and needs for large-scale implementation of direct solar fuel technologies.  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