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   595篇
  免费   16篇
  国内免费   10篇
安全科学   16篇
废物处理   38篇
环保管理   114篇
综合类   103篇
基础理论   167篇
环境理论   4篇
污染及防治   99篇
评价与监测   51篇
社会与环境   26篇
灾害及防治   3篇
  2023年   5篇
  2022年   6篇
  2021年   12篇
  2020年   11篇
  2019年   12篇
  2018年   14篇
  2017年   22篇
  2016年   31篇
  2015年   25篇
  2014年   25篇
  2013年   54篇
  2012年   41篇
  2011年   40篇
  2010年   27篇
  2009年   36篇
  2008年   27篇
  2007年   22篇
  2006年   29篇
  2005年   18篇
  2004年   14篇
  2003年   15篇
  2002年   15篇
  2001年   10篇
  2000年   8篇
  1999年   11篇
  1998年   7篇
  1997年   9篇
  1996年   4篇
  1995年   9篇
  1994年   2篇
  1993年   6篇
  1992年   4篇
  1991年   6篇
  1990年   2篇
  1989年   2篇
  1988年   2篇
  1986年   6篇
  1985年   2篇
  1982年   5篇
  1981年   4篇
  1980年   3篇
  1979年   2篇
  1978年   3篇
  1974年   3篇
  1965年   1篇
  1961年   1篇
  1960年   1篇
  1956年   1篇
  1933年   1篇
  1931年   1篇
排序方式: 共有621条查询结果,搜索用时 125 毫秒
501.
Recent calls for knowledge-based journalism advocate a new level of formal knowledge in news reporting to meet the professional challenges caused by rapid change in the news industry. Scientifically knowledgeable journalism has the potential to redefine the existing science–media relationship. However, the audience for such journalism is unclear, nor is it known how this new journalism would function within rapidly changing newsroom practices. Implementing knowledge-based journalism requires theory-based propositions to show the actual benefits of improved scientific understanding for news consumers and an understanding, from research into professional cultures, of why new practices in journalism are adopted or abandoned. This paper develops that theoretical basis by examining knowledge-based journalism’s potential and some of the intellectual and institutional barriers to it.  相似文献   
502.
In the face of the current global ecological crisis and the threats it poses to human survival and security, the fundamental solution is to resolve the deep contradiction between conservation and economic development. We considered the 3 key and basic questions of why to protect, how much to protect, and where to protect natural areas. Human survival depends on functioning ecosystems and the ecosystem services they provide. In this regard, conserving core biodiversity conservation priority areas (BCPAs) can provide maximum conservation benefit. The goals of protected area (PA) systems globally and nationally must be clearly defined so as to sustain the survival and development of people and to coordinate and balance other objectives with this goal at the center. There is an urgent need to study, calculate, and define the extent of the natural world to ensure the well-being of people. We call this area over which natural areas of land and sea extend across the world or a country nature proportion (N%). Especially, a minimum area that ensures human survival should be protected, and we suggest that this area should cover core BCPAs so that it can achieve the maximum conservation benefit. These recommendations could be applied at global or national levels. The Chinese government proposes “developing a protected-area system composed mainly of national parks,” and it has unified the administration of PAs into a central management authority. At this key time in the reform of the PA system, should this proposal be adopted, conservation will garner the greatest social consensus and support, and planning at the national level for BCPA coverage will be improved. We believe these recommendations are critical for China and other countries and extremely important for the world because they will pave the way toward a balance between nature conservation and human development as the projected human population reaches 10 billion by 2050.  相似文献   
503.
Environmental Economics and Policy Studies - The primary objective of this research is to estimate the willingness to pay in Ghana for reliable piped water services. Three competing economic...  相似文献   
504.
Evidence of declines in insect populations has recently received considerable scientific and societal attention. However, the lack of long-term insect monitoring makes it difficult to assess whether declines are geographically widespread. By contrast, bird populations are well monitored and often used as indicators of environmental change. We compared the population trends of European insectivorous birds with those of other birds to assess whether patterns in bird population trends were consistent with declines of insects. We further examined whether declines were evident for insectivores with different habitats, foraging strata, and other ecological preferences. Bird population trends were estimated for Europe (1990–2015) and Denmark (1990–2016). On average, insectivores declined over the study period (13% across Europe and 28% in Denmark), whereas omnivores had stable populations. Seedeaters also declined (28% across Europe; 34% in Denmark), but this assessment was based on fewer species than for other groups. The effects of insectivory were stronger for farmland species (especially grassland species), for ground feeders, and for cold-adapted species. Insectivory was associated with long-distance migration, which was also linked to population declines. However, many insectivores had stable populations, especially habitat generalists. Our findings suggest that the decline of insectivores is primarily associated with agricultural intensification and loss of grassland habitat. The loss of both seed and insect specialists indicates an overall trend toward bird communities dominated by diet generalists.  相似文献   
505.
As goose populations increase in abundance, their influence on ecological processes is increasing. We review the evidence for key ecological functions of wild goose populations in Eurasia and North America, including aquatic invertebrate and plant propagule transport, nutrient deposition in terrestrial and aquatic ecosystems, the influence of goose populations on vegetation biomass, carbon storage and methane emission, species diversity and disease transmission. To estimate the implications of their growing abundance for humans, we explore how these functions contribute to the provision of ecosystem services and disservices. We assess the weight, extent and trends among such impacts, as well as the balance of their value to society. We examine key unresolved issues to enable a more balanced assessment of the economic costs or benefits of migratory geese along their flyways, including the spatial and temporal variation in services and their contrasting value to different user groups. Many ecological functions of geese are concluded to provide neither services nor disservices and, ecosystem disservices currently appear to outweigh services, although this varies between regions. We consider an improved quantification of ecosystem services and disservices, and how these vary along population flyways with respect to variation in valuing certain cultural services, and under different management scenarios aimed at reducing their disservices, essential for a more balanced management of goose populations.  相似文献   
506.
ABSTRACT

The European Union (EU) has had a profound effect upon its members’ environmental policy. Even in the United Kingdom (UK), the EU’s most recalcitrant member state (historically labeled the ‘Dirty man of Europe’), environmental policy has been Europeanised. As the UK moves to the EU’s exit door it is timely to assess the utility of Europeanisation for understanding policy dynamics in the UK. Drawing upon interviews and extensive engagement with stakeholders, this article analyses the potential impact of Brexit upon environmental policy and politics. The analytical toolkit offered by de-Europeanisation is developed to identify the factors that drive and inhibit de-Europeanisation processes, thereby providing insights that may be applicable in other settings. Disengagement and policy stagnation are presented as more likely environmental outcomes of Brexit, with capacity emerging as a central explanatory variable.  相似文献   
507.
508.
509.
510.
Controlling the spread of invasive species, pests, and pathogens is often logistically limited to interventions that target specific locations at specific periods. However, in complex, highly connected systems, such as marine environments connected by ocean currents, populations spread dynamically in both space and time via transient connectivity links. This results in nondeterministic future distributions of species in which local populations emerge dynamically and concurrently over a large area. The challenge, therefore, is to choose intervention locations that will maximize the effectiveness of the control efforts. We propose a novel method to manage dynamic species invasions and outbreaks that identifies the intervention locations most likely to curtail population expansion by selectively targeting local populations most likely to expand their future range. Critically, at any point during the development of the invasion or outbreak, the method identifies the local intervention that maximizes the long‐term benefit across the ecosystem by restricting species’ potential to spread. In so doing, the method adaptively selects the intervention targets under dynamically changing circumstances. To illustrate the effectiveness of the method we applied it to controlling the spread of crown‐of‐thorns starfish (Acanthaster sp.) outbreaks across Australia's Great Barrier Reef. Application of our method resulted in an 18‐fold relative improvement in management outcomes compared with a random targeting of reefs in putative starfish control scenarios. Although we focused on applying the method to reducing the spread of an unwanted species, it can also be used to facilitate the spread of desirable species through connectivity networks. For example, the method could be used to select those fragments of habitat most likely to rebuild a population if they were sufficiently well protected.  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