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   2060篇
  免费   224篇
  国内免费   224篇
测绘学   59篇
大气科学   268篇
地球物理   492篇
地质学   758篇
海洋学   324篇
天文学   4篇
综合类   88篇
自然地理   515篇
  2024年   14篇
  2023年   28篇
  2022年   68篇
  2021年   93篇
  2020年   80篇
  2019年   73篇
  2018年   44篇
  2017年   117篇
  2016年   90篇
  2015年   98篇
  2014年   111篇
  2013年   130篇
  2012年   64篇
  2011年   118篇
  2010年   84篇
  2009年   144篇
  2008年   144篇
  2007年   116篇
  2006年   127篇
  2005年   98篇
  2004年   85篇
  2003年   66篇
  2002年   71篇
  2001年   54篇
  2000年   59篇
  1999年   65篇
  1998年   49篇
  1997年   33篇
  1996年   38篇
  1995年   38篇
  1994年   17篇
  1993年   22篇
  1992年   15篇
  1991年   13篇
  1990年   7篇
  1989年   11篇
  1988年   4篇
  1987年   5篇
  1986年   2篇
  1985年   4篇
  1984年   2篇
  1983年   3篇
  1982年   2篇
  1980年   1篇
  1976年   1篇
排序方式: 共有2508条查询结果,搜索用时 656 毫秒
991.
ABSTRACT. Large amounts of synthetic pesticides are used in Guatemala to increase the production of nontraditional crops. Almolonga, a township in the western highlands, produces vegetables for markets in Mexico and Central America. Almolongueños make intensive use of limited cultivable land and abundant water resources, as well as sizable amounts of synthetic pesticides. Among Almolongueños, congenital malformations, cancer, anemia, and respiratory infections await substantiated links to exposure to pesticides. The prevalence of infectious and parasitic diseases and nutritional deficiencies—the dominant health concerns—may be heightened by excessive use of pesticides. Public-health initiatives involve the rational use of pesticides or their elimination.  相似文献   
992.
This paper investigates the environmental perceptions of three disparate culture groups: Vermonters, non-Native Quebecers, and Native Cree of northern Quebec. All three groups were affiliated with the James Bay hydroelectric project. The hydroelectric project, per se, was not the focus of this research endeavor. Instead, this study merely took advantage of the environmental awareness promulgated by the project. The concept of “wilderness” was qualitatively employed to probe environmental perceptions cross-culturally. Pressing each group to define, locate, and assess the value of wilderness provided insight into each culture's framework regarding land use and exposed the mental scaffolding that undergirds their environmental conceptualizations.  相似文献   
993.
国际贸易中环境措施的公平性分析   总被引:6,自引:0,他引:6  
国际贸易被人们视为经济增长的发动机,在全球经济一体化的大潮中,它与环境保护的关系日益受到人们重视,各国纷纷制定出一些有利于环境保护的国际贸易条例和法规。尽管各国制定政策、条例和法规的目的之一在于解决环境经济的外部性,但是由于国际贸易中的环境外部性问题有全球性的和地区性的,且各国政策、条例和法规不一,目前国际上流行的五类贸易中的环境措施在解决环境外部性问题时具有局限性和非公平性,本文探讨之,旨在指导我国制定有效的、积极的环境政策、条例和法规,以适应国际贸易的大趋势。  相似文献   
994.
Marine ecosystems provide a wide range of goods and services that directly and indirectly benefit economies and support human health and wellbeing. However, these ecosystems are vulnerable to anthropogenic influences such as climate change, pollution and habitat destruction. The European Union (EU) recognises the role of the blue economy in providing jobs and contributing to economic growth, with the EU Integrated Maritime Policy being a cross-sectoral framework within which maritime activities are managed and coordinated. Sustainability is a central tenet, ensuring that sectors such as aquaculture and offshore wind energy, which are earmarked for growth, must develop in ways that do not negatively impact the health of the marine environment. However, there is currently little consideration of how these activities might impact public health. The current research used survey data from 14 European countries to explore public perceptions of these issues, broadly focusing on 10 maritime activities, with a specific focus on five activities related to the EU’s 2012 Blue Growth Strategy. The respondents appreciated the interconnections between these maritime activities, environmental protection and public health, as well as the potential trade-offs. Preferences for policy intervention to protect public health from different activities were predicted by both marine contact (marine sector employment, recreational activities) and socio-demographic (political attitudes, gender, age) variables, potentially aiding future engagement and communication initiatives. Substantive differences observed across countries in terms of policy preferences for different activities, however, warn against generalising for the European population as a whole.  相似文献   
995.
Small-scale fisheries are becoming a global social and environmental concern. The contribution of marine small-scale fisheries to global food security and coastal livelihoods, coupled with the significant challenges they face, has attracted increasing attention and aid from environmental organizations, philanthropies, and multilateral agencies over recent decades. Our study attends to the understudied role of the World Bank, the largest individual funder shaping present and future sustainability of coastal marine regions, as a key actor shaping global environmental governance paradigms. We asked how funding to the sector has changed over the last 50 years and why, outlining distinct patterns in the flow of small-scale fisheries aid and the underlying intervention models. We contextualize our quantitative analysis of aid patterns over time with qualitative interview data with bank staff, identifying underlying paradigm shifts driven by internal and external factors. More than $2.48 billion was allocated by the World Bank to marine fisheries over the last 50 years, approximately 47% (~$1.17 billion) of which was targeted to marine small-scale fisheries. Three distinct funding periods are identified: rising support to SSF from the 1970s to mid-1980s; a sharp decline in funding in the mid-to-late 1980s and low levels of funding throughout the 1990s; and a steady return to funding SSF in the mid-2000s up to the present. Over time, Bank-funded interventions shifted from pure economic development in the earlier era, to an emphasis on governance and multi-dimensional environmental goals in the recent period. To understand why, we used key-informant interviews to unpack major internal drivers: internal staff changes and presence of key individuals, the decentralization and recentralization of decision-making, and the organization’s shifting emphasis from traditional economic growth to multi-dimensional objectives of poverty reduction, among others. External drivers behind funding and paradigm shifts included pressure from the environmental movement, the rise of sustainable development discourses, key global environmental summits in the 1990s, and rising levels of interest in the fisheries sector by the governments of both donor and recipient countries. Processes of ‘paradigm shifts’ were not swift or singular, rather they were affected by multiple, convergent factors over time. Our findings contribute to the literature on multi-lateral institutions as key actors in environmental governance shaping global development thinking, illustrating the arc of the last half-century of fisheries aid at the Bank while highlighting present dilemmas and future challenges that actors interested in working towards sustainable marine small-scale fisheries face.  相似文献   
996.
The concept of industrial system transition introduced in the IPCC special report on Global Warming of 1.5 °C remains poorly conceptualized. In this paper, we deepen the conceptualization of the industrial system transition to decarbonization, dematerialization, and sustainable industrial production. Aided by fuzzy cognitive maps that use perception-based data from stakeholders to model complex and difficult-to-model systems, we chart the pathways for industrial system transition. The industrial system transition entails interactions between dematerialization and decarbonization goals while enabling governance and systemic corporate strategies. The respondents of the fuzzy cognitive maps-based surveys comprised practitioners from companies, authors, and the policymaking community. Fuzzy cognitive map-based simulations reveal that resorting to technical measures of dematerialization and decarbonization is insufficient to accomplish industrial system transition. The efficient industrial system transition to dematerialization and decarbonization requires the combined measures of (i) dematerialization and decarbonization, (ii) governance, policies, and regulations (effective governance including transnational governance, technology push, market-pull, technology transfer and financial flows, carbon price and carbon market; and (iii) enabling corporate strategies (regenerative and conscious capitalism, a new conception of transparency, and collaborative and constructive lobbying). Large companies are mostly transnational entities, necessitating the adoption of effective transnational governance strategies for achieving the objectives of dematerialization and decarbonization. Several transnational governance networks have partnered under the public–private co-governance mechanism in the decarbonization space dominated by mainly larger players. The advent of polycentric governance provides new opportunities for trans-local governance where large numbers of small and medium enterprises can participate in the advancement of at least decarbonization objectives; however, such networks require support from national governments. Besides implications for governance, policy and regulations, the findings of this research could also have implications for corporate behavior in terms of promoting conscious and transparent organizational culture.  相似文献   
997.
Payments for ecosystem services (PES) are increasingly promoted as nature-based solutions to climate, environmental, and business challenges. While participation in PES schemes is mandated in countries such as China, Costa Rica, and Vietnam, it remains unclear how PES schemes emerge in countries devoid of national mandates. This article investigates how actors have attempted institutional change to enable PES, by reinterpreting or adapting national laws, policies, and plans. We present an analytical framework theorising how geographical variations in (1) institutional frameworks, and (2) actor capabilities, dictate which institutions actors attempt to change. We then apply this framework to multi-scalar actors and institutions in Thailand and the Philippines. Our empirics reveal the types of institutional work that actors perform such as advocacy, education, mimicry, and networking, and demonstrate how this creates legal and discursive support, and improves stakeholder awareness and acceptance of PES as an environmental management strategy. Eight formal institutions are shown to have undergone change to enable PES across these countries, including those related to indigenous people, energy production, protected areas, pollution control, carbon offsetting, and decentralised governance. We show institutional change to be a geographical and contextual process that requires actors to match the right types of institutional work, with the right mechanism of institutional change, and a suitable target institution if they are to be successful in effecting change. Yet, we also report failed attempts, and explain how informal cultural norms act as challenges to formal institutional change. Through our comparative analysis of multiple institutions, actors, and national settings, we identify trends and make recommendations with global relevance to PES scholars and practitioners, and that can aid other initiatives that seek to address climate change and promote environmental sustainability.  相似文献   
998.
Environmental governance research has discovered much about what drives collective action to address human-environment issues, including factors such as risk perceptions and self-efficacy. Yet the design of many studies limits our ability to draw conclusions about collective action under conditions of environmental change, especially across spatial or temporal scales. In this study, we integrate social and biophysical data—assessing data over time and examining the influence of space—to analyze efforts by community members to manage rapid environmental change in the form of an invasive plant (Mikania micrantha) in community forests in Chitwan, Nepal. Invasive species are an increasingly complex ethical, cultural, and ecological issue that is becoming more pressing with global environmental and social changes. We combine household surveys, ecological surveys, and spatial data in Bayesian hierarchical linear models to explore changes in the drivers of collective action since initial household surveys in 2014. We find that risk perceptions, reliance on forest resources, perceptions of forest safety, and M. micrantha abundance were the most influential factors in our models. Additionally, our findings suggest that the influence of M. micrantha abundance on collective action varies across spatial scales, indicating important interactions between social and biophysical drivers of collective action. Ultimately, our results highlight the importance of considering social and biophysical factors across space and time to inform the design of institutions that will be effective in addressing collection action problems tied to environmental change.  相似文献   
999.
Cobalt is an important critical material and a constituent of a broad range of products such as batteries, electronics, superalloys, and hard metals. Effective recycling of cobalt is considered one of the most pivotal processes in alleviating its criticality. In this paper, using the dynamic modelling of material, energy, and water flows in cobalt supply chain, we show that by 2050 around 25% of the total demand for cobalt could be supplied by recycling. Our results indicate that, compared to the primary production of cobalt, its recycling might lead to a reduction of energy consumption by 46% associated with the global cobalt supply chain and the corresponding fall in the use of water by 40%. In addition, recycling of cobalt is estimated to mitigate around 59% of the total emissions of greenhouse gases and 98% of the total emissions of sulfur oxides. Finally, we present the regionally distributed projections of cobalt-related energy and water use from 2020 to 2050.  相似文献   
1000.
Extensive ecosystem degradation and increasing urbanization are altering human relationships with nature. To explore these trends, we created a transdisciplinary, narrative-led podcast series produced by the BBC, called Forest 404. The series explored the implications of a world without nature. An online experimental component mobilized audience participation (n = 7,596) to assess responses to natural soundscapes with and without abiotic, biotic, and poetic elements across five biomes. Conditions featuring the sounds of wildlife, such as bird song, were perceived to be more psychologically restorative than those without. Participants’ personal lived experiences were strongly related to these outcomes; those who had memories triggered by the sounds were more likely to find them psychologically restorative and exhibited a greater motivation to preserve them. Moreover, the effects of both soundscape composition and memories on preservation behavior were partially mediated by restorative potential; respondents were more likely to want to protect the sounds they heard if they thought they might offer therapeutic outcomes. Our findings highlight the value of art-science collaborations and demonstrate how maintaining contact with the natural world can promote wellbeing and foster behaviors that protect planetary health.  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