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   2130篇
  免费   188篇
  国内免费   57篇
安全科学   127篇
废物处理   27篇
环保管理   936篇
综合类   540篇
基础理论   293篇
环境理论   44篇
污染及防治   50篇
评价与监测   48篇
社会与环境   232篇
灾害及防治   78篇
  2024年   8篇
  2023年   38篇
  2022年   25篇
  2021年   59篇
  2020年   70篇
  2019年   103篇
  2018年   79篇
  2017年   159篇
  2016年   126篇
  2015年   94篇
  2014年   81篇
  2013年   128篇
  2012年   113篇
  2011年   132篇
  2010年   73篇
  2009年   117篇
  2008年   87篇
  2007年   82篇
  2006年   85篇
  2005年   82篇
  2004年   58篇
  2003年   51篇
  2002年   70篇
  2001年   61篇
  2000年   56篇
  1999年   46篇
  1998年   31篇
  1997年   27篇
  1996年   26篇
  1995年   33篇
  1994年   18篇
  1993年   19篇
  1992年   13篇
  1991年   8篇
  1990年   14篇
  1989年   10篇
  1988年   7篇
  1987年   7篇
  1986年   9篇
  1985年   18篇
  1984年   8篇
  1983年   9篇
  1982年   6篇
  1981年   5篇
  1979年   4篇
  1978年   4篇
  1977年   5篇
  1973年   2篇
  1972年   2篇
  1971年   3篇
排序方式: 共有2375条查询结果,搜索用时 46 毫秒
871.
ABSTRACT: There is increasing interest in using watershed councils to provide information to public natural resource managers, particularly in the western states. Watershed councils are composed of interested governmental and nongovernmental stakeholders that form to collaboratively manage water and other natural resources at the scale of a watershed. This research is the first step in a multi-step policy analysis designed to answer the question of whether watershed councils are an improvement over traditional methods of public involvement in natural resource management. This paper outlines why watershed councils form and discusses their structure and operation. There is considerable variability in terms of watershed councils' goals, their effectiveness, stakeholder composition, their involvement in the “real” decision-making process, types of participation that are allowed, leadership, financing, decision-making procedures, efficiency, and temporal scale. These structural components are presented as a framework that can be used by researchers to develop criteria to evaluate watershed councils.  相似文献   
872.
随着我国铜冶炼(原生铜和再生铜)行业对含铜二次资源需求量的增加,集废旧资源回收、拆解和分选、二次资源出售、铜再生利用于一体的产业链逐渐发展壮大起来。然而高能耗、高污染、低质量、低产出的特点在再生铜行业依然存在,环境监管政策和标准也不健全不完善。随着人们对美丽生态环境诉求的增加,必须加强有色金属行业的环境管理。本文对再生铜行业发展和环境管理做了一些思考,特别是对再生铜行业环境管理存在的问题进行了分析,并针对问题提出了几点政策性建议,以期为我国再生铜产业的环境友好发展和环境监管提供借鉴。  相似文献   
873.
Mass media worldwide has contributed to increasing awareness of the illegal wildlife trade and its significant impact on wildlife conservation. We used mass media coverage as a proxy for macro-level public opinion to analyze the media framing of elephant ivory in 6394 Chinese newspaper articles published from 2000 to 2021 and thus determine the effects of wildlife policies on public opinion. We focused on 2 events: the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) approval of China as a trading partner in the purchase and import of ivory stockpiles from Africa in July 2008 and the Chinese government's announcement of a domestic ivory ban in December 2016. Using latent Dirichlet allocation topic modeling, we identified 8 topics about elephant ivory and grouped them into 3 frames: ivory arts and culture, ivory crimes, and elephant conservation. Over the last 2 decades, topics related to ivory crimes remained the most prevalent in news articles. Topics about ivory arts and culture showed a significant shift in media salience before and after the 2 events (from 0.44 to 0.19 and from 0.08 to 0.15, respectively, p < 0.05), whereas the other 2 frames did not change significantly. Contrary to popular belief, our results indicated that Chinese macro-level public opinion on ivory had become more negative following the CITES approval of ivory importation and less negative after the ivory ban announcement, at least for certain periods. The relationship between mass media, public opinion, and wildlife trade policies is complex and requires further examination of the sociopolitical dynamics that influence media narratives. Our results showed the value of topic modeling in monitoring and assessing media representations of wildlife issues in the era of big data. Conservationists should remain vigilant of mass media coverage and collaborate with media practitioners to produce comprehensive narratives on wildlife issues if resources permit.  相似文献   
874.
The Common Agricultural Policy (CAP) is the European Union's main instrument for agricultural planning, with a new reform approved for 2023–2027. The CAP intends to align with the European Green Deal (EGD), a set of policy initiatives underpinning sustainable development and climate neutrality in the European Union (EU), but several flaws cast doubts about the compatibility of the objectives of these 2 policies. We reviewed recent literature on the potential of CAP environmental objectives for integration with the EGD: protection of biodiversity, climate change mitigation and adaptation, and sustainable management of natural resources. The CAP lacks appropriate planning measures, furthering instead risks to biodiversity and ecosystem services driven by landscape and biotic homogenization. Funding allocation mechanisms are not tailored to mitigate agricultural emissions, decreasing the efficiency of climate mitigation actions. The legislation subsidies farmers making extensive use of synthetic inputs without adequately supporting organic production, hindering the transition toward sustainable practices. We recommend proper control mechanisms be introduced in CAP Strategic Plans from each member state to ensure the EU is set on a sustainable production and consumption path. These include proportional assignment of funds to each CAP objective, quantitative targets to set goals and evidence-based interventions, and relevant indicators to facilitate effective monitoring of environmental performance. Both the CAP and the EGD should maintain ambitious environmental commitments in the face of crisis to avoid further degradation of the natural resources on which production systems stand.  相似文献   
875.
Antarctic specially protected areas (ASPAs) are a key regulatory mechanism for protecting Antarctic environmental values. Previous evaluations of the effectiveness of the ASPA system focused on its representativeness and design characteristics, presenting a compelling rationale for its systematic revision. Upgrading the system could increase the representation of values within ASPAs, but representation alone does not guarantee the avoided loss or improvement of those values. Identifying factors that influence the effectiveness of ASPAs would inform the design and management of an ASPA system with the greatest capacity to deliver its intended conservation outcomes. To facilitate evaluations of ASPA effectiveness, we devised a research and policy agenda that includes articulating a theory of change for what outcomes ASPAs generate and how; building evaluation principles into ASPA design and designation processes; employing complementary approaches to evaluate multiple dimensions of effectiveness; and extending evaluation findings to identify and exploit drivers of positive conservation impact. Implementing these approaches will enhance the efficacy of ASPAs as a management tool, potentially leading to improved outcomes for Antarctic natural values in an era of rapid global change. Evaluación del impacto de conservación de las áreas protegidas de la Antártida  相似文献   
876.
谢花林  程玲娟 《自然资源学报》2017,32(12):2012-2022
近年来,国家大力提倡耕地休养生息,推行土地休耕制度,以提高地力,保障农业可持续发展。由于水资源短缺已经成为制约我国华北地区经济社会发展的重要因素。华北地下水漏斗区作为土地休耕的三个试点之一,主要目标是退耕高耗水的冬小麦,实现“一季休耕、一季雨养”,以减少地下水用量,修复地下水环境。农户作为农村最主要的生产与经营主体,如何给予农户合理的补偿,使其有效地实施冬小麦休耕政策成为缓解华北地区水资源短缺的关键因素。论文运用问卷调查法、机会成本法与Logistic模型对意愿与补偿标准进行分析,探讨了河北衡水地下水漏斗区农户冬小麦休耕意愿的主要影响因素及其生态补偿标准的合理性,以便为我国科学合理地制定地下水漏斗区耕地轮作休耕政策提供理论依据。研究结果表明:1)农户的文化程度、家庭农业劳动力总数、抚养比、农户对地下水漏斗区冬小麦休耕态度、农户对政府实行政策的信任度与农户休耕意愿呈显著的正向影响;2)务农工日、耕地质量、人均耕地面积与农户休耕意愿呈显著的负向影响;3)只考虑冬小麦对地下水影响,不考虑农产品市场价格变化的影响,建议河北衡水地区休耕农户补偿标准为518元/亩(7 770元/hm2)。最后论文提出了因地制宜地制定地下水漏斗区冬小麦休耕的补偿政策,发展绿色产业,转移剩余劳动力,并做好休耕政策宣传力度等政策建议。  相似文献   
877.
针对维修机构中由于维修资源的有限性造成的排队现象进行研究,建立了一种有限服务者多种类顾客的维修排队模型,研究了一种求解维修机构中每种故障件数量的方法。通过此方法,可以计算任意时刻排队系统中每种故障件的数量,然后根据维修机构中故障件的种类和数量,判断是否应该在该时刻将某种装备进行停机维修,以最大程度地降低停机损失,最后通过与仿真结果比较,验证了模型与方法的可行性和准确性。  相似文献   
878.
企业实施清洁生产政策激励机制研究   总被引:6,自引:0,他引:6  
我国清洁生产的实践表明;现行条件下,由于企业内外部存在一系列实施清洁生产的障碍约束,要使作为清洁生产主体的企业完全自发地采取自觉主动的清洁生产行为是极其困难的,营造有利于调动企业实施清洁生产的外部政策激励机制则是促进我国清洁生产向纵深发展的关键。  相似文献   
879.
This paper examines local sustainability concepts in Connemara, a predominantly rural region in the West of Ireland (in this paper, the term “Ireland” refers to the Republic of Ireland), to show how they are (re-)constituted through people's interactions with social and biophysical environments. We argue that these interactions produce diverse forms of lay environmental knowledge and expertise that encompass cognitive and emotional aspects, a fact that is frequently ignored in environmental policy-making which prioritises rational arguments over reactions rooted in people's sense of place and community. Local people's responses to this dominance of “official” rational-technical sustainability concepts are central to recent cases of environmental controversy and lack of compliance to environmental policies that have characterised the study area but that show many parallels to conflicts and disputes elsewhere. Drawing on rich qualitative evidence from interviews and ethnographic fieldwork, this paper demonstrates how communities' responses to environmental policies depend on how well (or poorly) sustainability concepts underpinning these policies match local people's social-ecological practices and related place-specific views of what should be sustained.  相似文献   
880.
Yasuo Takao 《Local Environment》2016,21(9):1100-1117
The aim of the present article is to examine the importance of public participation in the production and use of environmental science, with special reference to “expert citizens” who can facilitate and mediate between expert knowledge and lay people. The study of expert citizens is largely unexplored in Japan's environmental policy. As uncertainty, inherent in the complexity of environmental science, increases, there are calls for refashioning expert knowledge into a more citizen–expert interactive governance. In the USA, the way that lay people can participate in scientific knowledge application and policy-making is organised through grassroots and national environmental organisations, such as the National Resources Defense Council. In Japan, such professional associations that build networks of interaction with scientific experts, policy-makers, interest groups and the media, have yet to emerge on a wider scale. Nonetheless, voluntary citizens individually or collectively have developed their expertise over many years and have begun to play an intermediary role at the local level. This article will analyse the potential roles of expert citizens by conducting the case studies of two Japanese localities, Shiki and Joyo cities.  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