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   23986篇
  免费   534篇
  国内免费   5766篇
安全科学   917篇
废物处理   1667篇
环保管理   2354篇
综合类   9032篇
基础理论   5544篇
环境理论   2篇
污染及防治   7279篇
评价与监测   1500篇
社会与环境   1375篇
灾害及防治   616篇
  2024年   3篇
  2023年   224篇
  2022年   681篇
  2021年   545篇
  2020年   408篇
  2019年   431篇
  2018年   1905篇
  2017年   1924篇
  2016年   1924篇
  2015年   1123篇
  2014年   1173篇
  2013年   1621篇
  2012年   1703篇
  2011年   2643篇
  2010年   1619篇
  2009年   1538篇
  2008年   1879篇
  2007年   2123篇
  2006年   826篇
  2005年   621篇
  2004年   452篇
  2003年   610篇
  2002年   579篇
  2001年   420篇
  2000年   442篇
  1999年   475篇
  1998年   431篇
  1997年   351篇
  1996年   333篇
  1995年   284篇
  1994年   235篇
  1993年   188篇
  1992年   151篇
  1991年   88篇
  1990年   69篇
  1989年   54篇
  1988年   47篇
  1987年   30篇
  1986年   25篇
  1985年   13篇
  1984年   26篇
  1983年   26篇
  1982年   11篇
  1981年   12篇
  1979年   2篇
  1978年   3篇
  1976年   2篇
  1975年   4篇
  1974年   2篇
  1935年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Empirical studies investigating the natural resource curse theory mostly employ cross-country and panel regression techniques subject to endogeneity bias. Also, most of these studies employ GDP in its aggregate or per-capita terms as the outcome variable in their analyses. However, the use of GDP measures of income for resource curse investigations may not portray the true incomes of resource-intensive economies. Standard national accounts treat natural resource rents as a positive contribution to income without adjusting for the value of depleted natural resource stock. This treatment often leads to a positive bias in the national income computations of resource-rich economies. Unlike previous studies, we test the robustness of the curse in the predominantly used measures of national income, GDP, by investigating the theme in genuine income measures of economic output as well. Also, the paper deviates from most empirical studies in the literature by using the Arellano–Bond difference GMM method in investigating the oil curse in OECD and Non-OECD oil-exporting economies. Additionally, we employ two alternative measures of resource intensity in our explorations; the share of oil rents in GDP and per-capita oil reserves. Our results provide evidence of the curse in Non-OECD countries employing aggregate and per-capita measures of genuine income.  相似文献   
102.
In recent decades, there has been a growing concern about measuring and evaluating the results of intensive production practices, such as the mode of integration practiced on a large scale by agro-industries. The present study discusses the application and the results of a Sustainability Indicators System in the context of the swine industry in the Brazilian State of Santa Catarina. These indicators, focused on the level of sustainability maturity, can be used as a way to diagnose and compare the efficiency of the industry from a broader perspective. The research findings indicate that most of the pig farms that have been studied can be classified as “in search of sustainability or sustainable.” Nevertheless, there are differences among the dimensions and between the most ranked farms and the others which must be considered for a better design and application of public policies and company strategies toward an effective and balanced social, economic and environmental sustainability.  相似文献   
103.
Due to the high rates of energy consumption and its impact on environment over the last decades, policy decision-makers are increasingly recognising the need to take actions that allow to address problems associated with the deployment of non-renewable resources and climate changes. One field of action has been the promotion of measures that contribute to improve energy efficiency of countries. The purpose of this study is to identify the main factors explaining changes in energy efficiency applying the multiplicative Log Mean Divisia Index decomposition method for a set of countries (Portugal, UK, Brazil and China) with different socio-economic background and energy mix. The results show that overall energy efficiency trends display different patterns between countries and the same happens within each country from a sectoral perspective. Major drivers of improvements of overall energy efficiency were the intensity effect and the affluence effect, whereas the driver that hampered those improvements was the energy consumption per capita. Some policy implications derived from the results achieved are: policy decision-makers should support measures that promote the adoption of energy-saving technologies resulting from new technological developments; policy measures should be directed to raise awareness of end-users regarding energy efficiency and energy conservation efforts; policy measures promoting economic growth through the development (or expansion) of sectors of activity that consume less energy can also be implemented; finally, policy instruments may also be used to reduce the costs of implementing energy efficiency and energy-saving measures to households and firms.  相似文献   
104.
Despite the often mentioned environmental benefits associated with transition from fossil fuels to renewable energy sources, their use for electricity production has non-negligible negative environmental impacts. The most commonly mentioned in surveys concern different types of landscape impacts, impacts on the fauna and flora, and noise. These impacts differ by size and location of plants, and by source of energy, rendering the policy decision complex. In addition, there are other welfare issues to take into consideration, as positive and negative environmental impacts are not evenly distributed among population groups. This paper proposes to compare the welfare impacts of renewable energy sources controlling for the type of renewable as well as the specific environmental impact by source. To this end, two discrete-choice experiments are designed and applied to a national sample of the Portuguese population. In one case, only individual negative impacts of renewables are used, and in another case, the negative impacts interact with a specific source. Results show the robustness of discrete-choice experiments as a method to estimate the welfare change induced by the impacts of renewable energy sources. Overall, respondents are willing to pay to reduce the environmental impacts, thus making compensation for local impacts feasible. Moreover, the estimations reveal that respondents are significantly sensitive to the detrimental environmental effects of specific renewable energy sources, being willing to pay more to use these sources of energy relative to others.  相似文献   
105.
In this work, we apply the Modern Portfolio Theory and the Capital Assets Pricing Model financial tools to a portfolio of CO2-emitting generation technologies under diverse scenarios. We will calculate the efficient—in the sense of having the minimum risk for a given level of emissions—portfolios frontier. The Capital Market Line (CML) is the place where all the possible combinations of a specific efficient portfolio and a pollution-free portfolio—made up with nuclear and renewable generation technologies—lie. In Finance, that specific efficient portfolio is called the market portfolio but we will see that in our case it lacks an evident meaning. Therefore, we will explain which should be the reference portfolio for power generation planning analysis. Anyway, the fact is that those combinations are less pollutant than the portfolios in the efficient frontier. Thus, a policy-maker can analyse which is their effect on emissions reduction. We will start analysing the efficient pollutant generation portfolios. Then, we will introduce the CML-analogous lines (CML-A) to allow the possibility of reducing emissions by combining an efficient portfolio with a non-pollutant portfolio—this non-pollutant portfolio is free of both emissions and risk. Results support the necessity of considering the carbon capture and storage technology to achieve a less risky generation mix, with less emissions and allowing a higher diversification due to the presence of cleaner fossil fuel technologies. All of that leads to better levels of energy security.  相似文献   
106.
How can we restore the ecological balance of our planet? The present article is aimed at contributing a structural framework for such a restoration. In the quest for ecological recovery, cybernetic–systemic approaches are in demand. They specialize in coping with complexity and offer new, transdisciplinary and non-reductionist ways of system design for renewing sustainability. This contribution uses a proven model from organizational cybernetics—the viable system model—as a frame for sustainable development. The model specifies how the viability of any human or social system can be achieved by means of clearly defined organizational structures. In accord with the logic of recursive organization inherent in the model, a proposal for a structural design aimed at enabling ecological recovery is formulated. That design includes all organizational levels of recursion, from individual to world. The implications of such a novel approach are far-reaching, and the impact powerful.  相似文献   
107.
Although studies on environmental conflicts have engaged with the subject of violence, a multidimensional approach has been lacking. Using data from 95 environmental conflicts in Central America, we show how different forms of violence appear and overlap. We focus on direct, structural, cultural, slow, and ecological forms of violence. Results suggest that the common understanding of violence in environmental conflicts as a direct event in time and space is only the tip of the iceberg and that violence can reach not only environmental defenders, but also communities, nature, and the sustainability of their relations.  相似文献   
108.
Although knowledge integration and co-production are integral to transdisciplinary approaches to foster sustainable change in social–ecological systems, this type of research is usually not evaluated based on assessments of the learning process. While participants are meant to be central in such approaches, too often, their perspectives are not central to the evaluation. Moreover, there is limited empirical information about how new knowledge is transformed into action. We respond to these knowledge gaps by analyzing (A) farmers’ perspectives on the collaborative learning process and (B) how farmers’ new knowledge can serve as the basis for changed actions. Theoretically, we are guided by second-order cybernetics and have integrated the Control Loop Model with Learning Loops to extend Kirkpatrick (Evaluating training programs: the four levels, 2nd edn. Berrett-Koehler Publisher, San Francisco, 1998) four-level evaluation scheme. We apply this to evaluate a 2-year collaborative learning process with two smallholder dairy farmer groups in Nakuru County, Kenya that aimed to co-develop local sustainable pathways to reduce milk losses. Results showed that farmers learned by (1) implementing corrective actions based on known cause–effect relations (single-loop learning); (2) discovering new cause–effect relations and testing their effect (double-loop learning); and (3) further questioning and changing their aims (triple-loop learning). Highlighting the importance of knowledge integration and co-production, this collaboration between farmers, researchers, and field assistants improved the farmers’ ability to respond, adapt, and intentionally transform their farming system in relation with complex sustainability challenges. Results demonstrate that the potential of our evaluation scheme to better reflect learning and empowerment experienced by actors involved in transdisciplinary research for sustainability.  相似文献   
109.
Conservation discourses tend to portray invasive species as biological entities temporally connected to colonial timelines, using terms such as “alien”, “colonizing”, “colonial”, and “native”. This focus on a colonial timeline emerges from scientific publications within conservation biology and invasion ecology and is enacted through invasive species management by state and NGO actors. Colonialism is influential for indigenous nations in myriad ways, but in what ways do indigenous understandings of invasive species engage with colonialism? We conducted ethnographic research with indigenous Anishnaabe communities to learn about the ways Anishnaabe people conceptualize invasive species as a phenomenon in the world and were gifted with three primary insights. First, Anishnaabe regard plants, like all beings, as persons that assemble into nations more so than “species”. The arrival of new plant nations is viewed by some Anishnaabe as a natural form of migration. The second insight highlights the importance of actively discovering the purpose of new species, sometimes with the assistance of animal teachers. Lastly, while Anishnaabe describe invasive species as phenomenologically entangled with colonialism, the multiple ways Anishnaabe people think about invasive species provide alternatives to native–non-native binaries that dominate much of the scientific discourse.  相似文献   
110.
Sustainability challenges rarely align with the conventional boundaries of our disciplines, institutions and means of communication. To address these challenges amid real-world complexity, we need to think holistically and collaborate across disciplines. In this paper, we synthesise three themes: (1) more integrated conceptual frameworks; (2) digital visual communication which provides fluid expression of complex ideas and perceptions; and (3) online networks which can empower sustainability initiatives and communicate them across social and institutional barriers at a global scale. Each of these tools can help to overcome persistent barriers to sustainability. When used together, they provide a strategic basis for the design of digital collaboration platforms for addressing sustainability challenges. Using design thinking, we developed a Synergy Map which identifies relationships among a number of barriers to sustainability and conceptual and digital tools which help to address them. The Map identifies the potential for synthesising these tools into effective digital artefacts. We provide several examples and identify characteristics of particular value for overcoming barriers to sustainability. Combining new theoretical developments in sustainability sciences with recent advances in communication and networking technologies offers substantial potential for advancing sustainability on multiple fronts.  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