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   566篇
  免费   9篇
  国内免费   9篇
安全科学   2篇
废物处理   1篇
环保管理   240篇
综合类   97篇
基础理论   123篇
污染及防治   91篇
评价与监测   16篇
社会与环境   13篇
灾害及防治   1篇
  2023年   4篇
  2022年   14篇
  2021年   28篇
  2020年   1篇
  2019年   5篇
  2018年   4篇
  2017年   16篇
  2016年   31篇
  2015年   25篇
  2014年   15篇
  2013年   28篇
  2012年   13篇
  2011年   44篇
  2010年   16篇
  2009年   51篇
  2008年   34篇
  2007年   41篇
  2006年   19篇
  2005年   12篇
  2004年   14篇
  2003年   18篇
  2002年   13篇
  2001年   12篇
  2000年   22篇
  1999年   10篇
  1998年   5篇
  1997年   8篇
  1996年   22篇
  1995年   11篇
  1994年   4篇
  1993年   4篇
  1992年   7篇
  1991年   1篇
  1990年   2篇
  1989年   2篇
  1988年   4篇
  1987年   2篇
  1986年   5篇
  1985年   3篇
  1984年   3篇
  1983年   3篇
  1982年   1篇
  1981年   2篇
  1979年   3篇
  1978年   1篇
  1977年   1篇
排序方式: 共有584条查询结果,搜索用时 421 毫秒
101.
通过环境因子、生物多样性指示物种筛选和情景分析,建立经济、社会、环境各要素间的相关关系模型。该模型体现了各要素间的相互影响,通过指示生物的风险阀值分析,对经济发展、结构调整、环境影响和环境投资进行综合分析,提出决策意见。这体现了可持续发展的原则,在我国有较大的发展应用前景。   相似文献   
102.
103.
Regional ecosystem monitoring is a central form of knowledge sharing and collaboration amongst scientists and decision makers on environmental health, land use change, and science-policy development. Despite the proliferation of such research networks on long-term monitoring on many continents, little has been achieved in Africa. This study aims to assess and examine the spatiotemporal trend and categorical patterns in ecosystem monitoring-related research in Africa for the benefits of conserving biodiversity and sustaining natural resource sectors for well-being and livelihood security, environmental planning, and ecological stewardship. A systematic review was conducted using bibliometric tools. Based on a set of search terms and peer-reviewed publications retrieved from various ecosystem monitoring networks and journal databases, further analysis was conducted using social network approaches, mapping tools, and content analysis. About 1442 scientific publications on ecosystem monitoring and related research were documented from 1987 to 2014 mostly published in English. The number of publication increased progressively since 1992 after the Convention on Biodiversity was signed and this trend peaked till 2008. South African Journal of Science was the most leading journal and Nature the most cited. Internationally coauthored and collaborative articles represented majority of the findings with the United Kingdom at the central position in the research network due to colonial relationships. Regional collaboration amongst countries is limited owing to language barriers and other institutional constraints such as funding and short-term projects. These findings have implication for prioritizing national and regional policies toward biodiversity science and its contribution to human well-being, food security, and global change responses.  相似文献   
104.
Environmental damage is often an unseen byproduct of other activities. Disclosing environmental impact privately to consumers can reduce the costs and/or increase the moral benefits of conservation behaviors, while publicly disclosing such information can provide an additional motivation for conservation - cultivating a green reputation. In a unique field experiment in the residence halls at the University of California – Los Angeles, we test the efficacy of detailed private and public information on electricity conservation. Private information was given through real-time appliance level feedback and social norms over usage, and public information was given through a publicly visible conservation rating. Our analysis is based on 7,120 daily observations about energy use from heating and cooling, lights and plug load for 66 rooms collected over an academic year. Our results suggest that while private information alone was ineffective, public information combined with private information motivated a 20 percent reduction in electricity consumption achieved through lower use of heating and cooling. Public information was particularly effective for above median energy users.  相似文献   
105.
Human activities are expected to result in a diversity of directional or stochastic constraints that affect species either directly or by indirectly impacting their resources. However, there is no theoretical framework to predict the complex and various effects of these constraints on ecological communities. We developed a dynamic model that mimics the use of different resource types by a community of competing species. We investigated the effects of different environmental constraints (affecting either directly the growth rate of species or having indirect effects on their resources) on several biodiversity indicators. Our results indicate that (i) in realistic community models (assuming uneven resource requirements among species) the effects of perturbations are strongly buffered compared to neutral models; (ii) the species richness of communities can be maximized for intermediate levels of direct constraints (unimodal response), even in the absence of trade-off between competitive ability and tolerance to constraints; (iii) no such unimodal response occurs with indirect constraints; (iv) an increase in the environmental (e.g., climatic) variance may have different effects on community biomass and species richness.  相似文献   
106.
The direct equivalence between ecology and thermodynamics has not been attained despite accepted thermodynamic features of the ecosystem. This article explores the homeomorphism between ecology and statistical mechanics by analysis of ruderal vegetation. In conventional thermostatistical algorithm, the pro-kinetic effect of temperature on molecules was replaced by the anti-kinetic effect of species diversity on biological individuals. The existence of an ecological equivalent of the thermodynamic Boltzmann constant was empirically verified. From the relationship of this constant with biocenological variables, we derived a probable ecological equation of state under stationary and quasi-stationary conditions. This equation of state is homeomorphic with regard to the ideal gas state equation, and it is useful to infer the value of some biocenological parameters whose direct measurement is difficult, as biomass, energy and dispersal. According to these results, ecosystem assessment from conventional thermostatistics is plausible and empirically verifiable. This approach offers useful analytical tools for the conservation and restoration of ecosystems.  相似文献   
107.
长江流域重要保护物种分布格局与优先区评价   总被引:3,自引:2,他引:1  
开展大尺度重要物种的保护优先区研究对于提高生物多样性保护效率十分重要. 选取1 020个物种(包括植物568种、哺乳动物142种、鸟类168种、两栖动物57种、爬行动物85种)为长江流域重要保护物种. 在分析重要保护物种类群分布格局的基础上,利用系统保护规划与专家参与的方法,提出了长江流域物种保护的27个保护优先区.保护优先区总面积占流域面积的41.8%,涵盖了重要保护物种973种,占全部重要保护物种数目的95.4%.建议以保护优先区为基本单元,开展有关生物多样性保护研究及保护区群的建设.   相似文献   
108.
The Partners in Flight North American Landbird Conservation Plan provided estimates of population sizes for 448 landbird species using a multiplicative model. Input parameters in this calculation included the area of state × Bird Conservation Region polygons, area-specific mean Breeding Bird Survey counts circa 1995, and adjustment factors for the distance over which species may presumably be correctly counted, the assumed pairing of singing males with non-singing females, and variability in the propensity of birds to sing over the course of the survey day. I assessed the sensitivity of this population calculation to changes in the input parameters. I assessed both local and global sensitivity of the model to changes in the parameters with Monte Carlo one-at-a-time simulations and the Fourier amplitude sensitivity test (FAST). Monte Carlo simulations were an estimate of local model sensitivity whereas FAST estimated global model sensitivity, accommodating the potential shared variance between model parameters. Monte Carlo simulations suggested population estimates were 39% more sensitive to changes in the detection distance adjustment than to the other parameters; the other parameters were nearly equal in their contribution to model sensitivity. Conversely, FAST analysis determined that each of the input variables aside from the pair adjustment provided roughly equal contributions to variability in population estimates. The most efficient means for improving continental population estimates for birds surveyed by the Breeding Bird Survey will be through increased scrutiny of the species-specific distance detection and time-of-day adjustments and improved understanding in the spatial and temporal variability in the mean Breeding Bird Survey count.  相似文献   
109.
Abstract:  There is a pressing need to find both locally and globally relevant tools to measure and compare biodiversity patterns. Traditional ecological knowledge (TEK) is important to biodiversity monitoring, but has a contested role in preliminary biodiversity assessments. We examined rapid participatory rural appraisal (rPRA) (a tool commonly used for local needs assessments) as an alternative to surveys of vascular plants conducted by people with local knowledge. We used rPRA to determine the local-knowledge consensus on the average richness, diversity, and height of local grasses and trees in three habitats surrounding Boumba, Niger, bordering Park-W. We then conducted our own vascular plant surveys to collect information on plant richness, abundance, and structure. Using a qualitative ranking, we compared TEK-based assessments of diversity patterns with our survey-based assessments. The TEK-based assessments matched survey-based assessments on measures of height and density for grasses and trees and tree richness. The two assessments correlated poorly on herb richness and Simpson's D value for both trees and grasses. Plant life form and gender of the participant affected the way diversity patterns were described, which highlights the usefulness of TEK in explaining local realities and indicates limitations of using TEK as a large-scale assessment tool. Our results demonstrate that rPRA can serve to combine local-knowledge inquiry with scientific study at a cost lower than vascular plant surveys and demonstrates a useful blunt tool for preliminary biodiversity assessment.  相似文献   
110.
分析了江苏生物多样性保护现状,解读了省委办公厅、省政府办公厅《关于进一步加强生物多样性保护的实施意见》,主要涵盖完善政策法规、优化空间格局、提升系统稳定性、构建监测评估体系、提升安全管理水平、创新开发利用机制、严格执法监督评估、推动公众参与等8大工作任务,加强生态岛试验区、生态安全缓冲区等10大领域政策创新,整体提升全省生态系统质量。  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