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   8783篇
  免费   684篇
  国内免费   1526篇
安全科学   1672篇
废物处理   73篇
环保管理   1468篇
综合类   4475篇
基础理论   1058篇
环境理论   19篇
污染及防治   492篇
评价与监测   872篇
社会与环境   328篇
灾害及防治   536篇
  2024年   45篇
  2023年   191篇
  2022年   314篇
  2021年   389篇
  2020年   468篇
  2019年   373篇
  2018年   300篇
  2017年   393篇
  2016年   449篇
  2015年   442篇
  2014年   488篇
  2013年   639篇
  2012年   584篇
  2011年   768篇
  2010年   446篇
  2009年   576篇
  2008年   426篇
  2007年   482篇
  2006年   490篇
  2005年   286篇
  2004年   237篇
  2003年   281篇
  2002年   261篇
  2001年   222篇
  2000年   252篇
  1999年   216篇
  1998年   177篇
  1997年   173篇
  1996年   112篇
  1995年   78篇
  1994年   94篇
  1993年   87篇
  1992年   58篇
  1991年   37篇
  1990年   17篇
  1989年   21篇
  1988年   15篇
  1987年   8篇
  1986年   17篇
  1985年   15篇
  1984年   17篇
  1983年   5篇
  1982年   9篇
  1981年   8篇
  1980年   4篇
  1978年   12篇
  1977年   7篇
  1971年   1篇
  1970年   1篇
  1969年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
The Biopotentiality Index is a landscape ecology indicator, which can be used to estimate the latent energy of a given land and to assess the environmental impacts due to the loss of naturalness on a landscape scale. This indicator has been applied to estimate the effectiveness of the measures put in place to provide an environmental compensation for the revamping of a composting plant. These compensation measures are represented by a green belt with a minimum width of 25 m all around the plant, representing both a windbreak and a buffer zone, and by two wide wooded zones acting as core natural areas.This case-study shows that the compensation index could be used as a key tool in order to negotiate the acceptance of waste treatment plant with the population.  相似文献   
952.

The mutagenicity of chlornitrofen (CNP)-containing solutions has been reported to increase during anaerobic biodegradation. In the present study, the fate of this increased mutagenicity under subsequent aerobic and anaerobic incubation conditions was investigated using two Salmonella tester strains, YG1024 (a frameshift-detecting strain) and YG1029 (a base-pair-substitution-detecting strain). Mutagenicity for both YG1024 and YG1029 strains increased during nine-day anaerobic biodegradation. During subsequent anaerobic incubation, the increased mutagenicity decreased gradually for YG1029 but did not change significantly for YG1024. By contrast, the increased mutagenicity decreased rapidly after the conversion to aerobic incubation for both YG1024 and YG1029 strains. The rapid decrease in mutagenicity during aerobic incubation was due to decreases, not only in an identified mutagenic metabolite (CNP-amino) but also in unidentified mutagenic metabolites.  相似文献   
953.
Disaster risk management, particularly management of climate-related risks, has become central to the international policy agenda. Reducing hazard-related loss and damage relies heavily on scientific inputs. Science, in turn, relies on data—in this case 1) risk-related data on hazards, exposure and vulnerability, and 2) data on associated loss and damage outcomes. The latter, data on losses and damage, are also post-2015 international policy outcome indicators at the highest level, required for countries’ monitoring of progress in reducing disaster risk, adapting to climate change, and achieving sustainable development. Although the quantity and accessibility of loss and damage data are improving, a number of issues continue to constrain their potential. These include needs for more consistent cataloguing of hazards and extreme events, more systematic and accurate documentation of per-event losses and damage, more precise cross-referencing of hazard events with associated loss and damage, and improved standardization and interoperability among databases. We identify measures for improvement in this regard, both for research purposes and for post-2015 international policy implementation.  相似文献   
954.
Climate governance in Small Island developing States (SIDS) is a pressing priority to preserve livelihoods, biodiversity and ecosystems for the next generations. Understanding the dynamics of climate change policy integration is becoming more crucial as we try to measure the success of environmental governance efforts and chart new goals for sustainable development. At the international level, climate change policy has evolved from single issue to integrated approaches towards achieving sustainable development. New actors, new mechanisms and institutions of governance with greater fragmentation in governance across sectors and levels (Biermann and Pattberg, 2008) make integration of policy in the area of climate change governance even more of a challenge today. What is the Caribbean reality regarding policy coherence in climate change governance? Are the same climate change policy coherence frameworks useful or indeed applicable for environmental governance in developing states more generally and for SIDS in particular? What are the best triggers to achieve successful climate change policy integration in environmental governance—especially as the complex interconnectivity of new actors, institutions and mechanisms make the process of integration even more challenging? What facilitates and what hampers climate policy integration in the regional Caribbean context? This article reviews the debates around policy coherence for climate change governance, creates a framework to test or measure policy coherence and examines how relevant this has been to regional climate change governance processes in Commonwealth Caribbean States. The study found that though at the regional level, there is substantial recognition of the importance of and mechanics involved in climate policy coherence, this has not translated to policy coherence at the regional and national levels. There is a large degree of fragmentation in the application of climate policy in each Caribbean Island with no mechanism to breach the gap. Silos in public environmental governance architectures, unwillingness to share data, insufficient political will; unsustainable project-based funding and lack of accountability among actors are the main challenges to climate policy coherence. The findings fill a gap in the literature on the elements of climate policy coherence from a SIDS perspective.  相似文献   
955.
Early research showed that citizens’ environmental concern in the United States was linked to three individual-level factors: socio-demographic variables, political orientations, and personal beliefs or worldviews about human-nature relations. Given many changes in the American society over the last several decades, one important, yet unanswered question is whether these factors still drive public environmental concern in the United States today, and if so, to what extent. This study, drawing from extant theoretical and empirical studies, aims to reinvestigate the determinants of citizens’ environmental concern by employing three national public surveys conducted in 2004, 2007, and 2013. Our data analyses confirm and expand the findings of previous research on the significance and importance of political ideology, fundamental beliefs about human-nature relations, and certain socioeconomic factors such as gender and race in explaining citizens’ environmental concern. More specifically, political liberals, people with higher New Ecological Paradigm values, females, and Non-Whites tend to be more concerned about environmental problems than their counterparts are. Our data analyses also reveal some interesting findings when compared to many previous studies: first, our data indicate a positive relationship between age and environmental concern, suggesting that older people in the United States are more concerned about the environment than younger adults; second, unlike most past research showing a positive Education-Environmental Concern relationship, our study suggests that education level seems to have little effect in explaining citizens’ environmental concern measured in this study. Key implications for environmental policymaking and recommendations for future research are discussed in the conclusion.  相似文献   
956.
可持续发展实验区灾害风险定量估算方法研究   总被引:13,自引:0,他引:13  
作者将探索性数据分析方法引入区域灾害风险的定量估算,系统地建立了区域灾害风险的定量估算方法。计算实例表明,文中给出的方法可便捷地用于可持续发展实验区灾害风险评估。  相似文献   
957.
通过对铁岭市的餐饮业进行了环境污染现状分析,并提出了相应的综合应对措施。  相似文献   
958.
Ecosystem functions can be understood as the quantified amount of an ecosystem’s role in a natural process, while ecosystem services are the requantification of the ecosystem functions by factoring in environmental conditions and human needs based on social perspectives. In this study, differences between ecosystem functions and services were presented in terms of air purification of a forest ecosystem. Forest volume growth was employed to quantify the pollutant absorption capacity of a forest and was indicated by the natural functions (NF) for air purification by a forest ecosystem. Forest ecosystem services can be requantified from the forest functions by adding the air pollutant and population densities. Air pollutant density was applied to the assessment of the environmental services (ES) of forest ecosystems. Furthermore, the environmental social services (ESS) of forest ecosystems were assessed by including population density considerations. We simulated differences in NF, ES, and ESS in relation to pollutant and population density; while NF was spatially quantified without a close relationship to air pollutant and population density, ES and ESS reacted to environmental and social condition more sensitively. These results imply that the ecosystem services of forest resources for air purification are high where the pollutant and population densities are high, while the ecosystem functions of forest resources for air purification depend solely on forest conditions and not on the density changes of air pollutants and population. This study suggests that the differences in NF, ES, and ESS are important factors to be understood and considered in the decision-making process for ecosystem services. When considering human needs and surrounding environmental conditions, the results suggest that decision makers should utilize the ES and ESS concepts, which reflect both population and pollutant density along with additional human-related factors.  相似文献   
959.
960.
Studies based on information acquired by participative geographic approaches have sought to cope with emergency situations and disasters such as floods. However, the impact of these approaches to flood risk governance systems in order to understand these types of events as a complete risk cycle is still not clear. This paper focuses on analysing the governance possibilities of using participative geographic information like volunteered and public participatory geographic information for flood risk reduction in the case of Santiago de Chile, a city which regularly experiences urban floods during rainy seasons. Based on in-depth interviews and document analysis, our study indicates that a relevant part of the current information used for flood risk reduction efforts is provided to local and regional authorities by the affected population. Though, local actors are not recognized by central agencies as valid agents for the production of official information. Moreover, there are neither instances of communication or deliberation with the community, which reduces the capacity of local actors to discuss possible solutions. Participative geographic instruments are seen as potential mechanisms to strengthen work relations among local actors and authorities, by enhancing new logics for producing and sharing information. The impacts for the current risk governance system though can be diverse depending on the participants' level of commitment of participants and the political relations between actors and agencies. Considered as merely data acquisition and analysis mechanisms, participative instruments reproduce the existing hierarchical top-down structures. Furthermore, local-based approaches can enhance local work, support local diagnostics and increase the decision capacity of citizens.  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