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   119篇
  免费   18篇
  国内免费   1篇
安全科学   30篇
废物处理   1篇
环保管理   33篇
综合类   34篇
基础理论   24篇
评价与监测   8篇
社会与环境   6篇
灾害及防治   2篇
  2023年   1篇
  2021年   6篇
  2020年   7篇
  2019年   9篇
  2018年   5篇
  2017年   13篇
  2016年   7篇
  2015年   10篇
  2014年   5篇
  2013年   4篇
  2012年   6篇
  2011年   7篇
  2010年   7篇
  2009年   7篇
  2008年   6篇
  2007年   8篇
  2006年   5篇
  2005年   1篇
  2004年   3篇
  2003年   1篇
  2002年   1篇
  2001年   2篇
  2000年   3篇
  1999年   2篇
  1998年   2篇
  1995年   1篇
  1987年   2篇
  1980年   2篇
  1979年   2篇
  1977年   1篇
  1976年   1篇
  1972年   1篇
排序方式: 共有138条查询结果,搜索用时 15 毫秒
131.
SUMMARY

A water crisis is looming in the Nile Basin in the near future due to higher population growth rates, greater affluence, and higher demand for water by agriculture and industry. There is no basin-wide agreement among the ten Nile Basin states and the existing rules of international water management are complicated and are not equipped to handle any future water conflicts in the Nile Basin. This paper reviews the existing water sharing arrangements among the Nile Basin countries, examines areas of potential conflict over future water use, and suggests possible areas of cooperation that will ensure equitable use of the Nile waters. The paper concludes by (1) appealing for formulation of good water development policies to deal with growing water needs such as water quality protection, efficiency of water delivery and efficiency of water use; and (2) calling for human resources development and technology transfers that are critical for good management and efficient use of the water resources of the Nile.  相似文献   
132.
Despite the efforts to enhance knowledge transfer in organizations, success has been elusive. It is becoming clear that in many instances employees are unwilling to share their knowledge even when organizational practices are designed to facilitate transfer. Consequently, this paper develops and investigates a novel construct, knowledge hiding. We establish that knowledge hiding exists, we distinguish knowledge hiding from related concepts (knowledge hoarding and knowledge sharing), and we develop a multidimensional measure of this construct. We also identify several predictors of knowledge hiding in organizations. The results of three studies, using different methods, suggest that knowledge hiding is comprised of three related factors: evasive hiding, rationalized hiding, and playing dumb. Each of these hiding behaviors is predicted by distrust, yet each also has a different set of interpersonal and organizational predictors. We draw implications for future research on knowledge management. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
133.
ABSTRACT: This paper is a computer simulation analysis of an agricultural nonpoint pollution problem. Computer modeling is a universally applicable tool that can be used for establishing the linkages between and the quality of agricultural runoff in both surface and subsurface flow. The tradeoffs between the costs of soil conservation practices and water quality are reported, and the economic implications of such tradeoffs are discussed. Soil and nutrient losses resulting from crop production practices are analyzed using a field-scale computer simulation model (CREAMS). No-till planting, reduced tillage, and sod waterway systems are more cost effective than other practices for controlling soil and nutrient runoff losses. Nitrate leaching losses are increased slightly by most soil conservation practices. Terrace systems and permanent vegetative cover impose the greatest societal cost for water quality protection. Public cost sharing and tax incentives encourage farmers to adopt expensive structural practices, and policies are needed to get cost-effective practices implemented on critical acreage. Extensive treatment of land is necessary for agricultural best management practices (BMPs) to significantly improve water quality in areas that are intensively farmed.  相似文献   
134.
ABSTRACT As availability of funds in the federal budget for water development has decreased recently, pressure has increased for state and local governments to pay a larger share of the costs. In this situation a difficult question immediately arises-what is the capability of state and local governments to pay a larger share? Of course, there is no easy answer. Expenditures of public funds are policy outcomes of a government's political process in which political, economic, legal and other factors are involved in complex relationships. The traditional sources of capital funds for state and local governments include bond proceeds, tax revenues, and federal financial aid (state aid is also a major source of local government funds). The issuing of bonds is hampered by a variety of legal debt limitations, but there are means for circumventing the limitations. State and local governments vary widely in amounts of taxable resources available and in the extent to which these resources have been tapped. More effective use of revenue resources could be made in some cases. New sources of capital funds for water development ought to be considered-a fee on the use of water per se, for example. Costs associated with water use currently are imposed to cover development costs, but a state might impose additional use fees earmarked for a state water development fund.  相似文献   
135.
本文通过分析“淮河流域环境与健康监测网”获取的环境监测科学数据特征,并结合我国环境监测科学数据共享的现状和存在的问题,根据环境监测科学数据的5个基本要素,对构建面向社会公众、面向科学研究的多部门环境监测科学数据共享体系进行了探索研究.  相似文献   
136.
Climate equity is a crucial but difficult element in negotiations on a post-2012 climate regime. With respect to the trading of greenhouse gas emissions the equity aspect is considered in the Kyoto Protocol which demands that emissions trading should be supplemental to domestic abatement efforts. The question arises whether a linking of the European Union Emissions Trading Scheme (EU ETS) to non-EU emission trading schemes or the Clean Development Mechanism (CDM) could have an impact on principles of climate justice and thus potentially affect ongoing negotiations. In this study, we present the results of a three step analysis: In a first step, it estimates mid-term greenhouse gas emission entitlements for Annex B and Non-Annex B countries for the year 2020 which keep within reach a stabilization of the CO2 concentration at 450 ppmv in the long-term. In the second step, the resulting emission entitlements are used as an input to an economic partial-equilibrium model in order to assess the shift of abatement efforts under different scenarios of linking the EU ETS. In a third step, we analyze the outcome of the economic model with respect to the future trend of European per capita emissions under the current EU ETS relative to different scenarios of linking the EU ETS. The model results indicate that European per capita emissions have to be reduced to a considerably smaller extent if a linking of the EU ETS is accompanied by an optimal design of the National Allocation Plans and if low-cost CO2 permits became available via the CDM to a large extent.
B. BrounsEmail:
  相似文献   
137.
随着城市化进程的加快,苏州地区的大气污染已从煤烟型污染转变为复合型污染,大气中的多种污染因子在不利气象条件下形成灰霾天气.本文基于2010年污染源普查及已有相关研究成果,开展苏州市二氧化硫、氮氧化物、烟尘、粉尘的排放评价,包括排放总量、工业排放量、交通排放量、生活排放量等;分析火电、钢铁、有色、石化、水泥、化工、交通等重点行业主要污染因子分担率,分析单位面积、单位人口排放强度,为苏州市开展大气污染治理工作提供一定参考.  相似文献   
138.
Assessing the scope and severity of threats is necessary for evaluating impacts on populations to inform conservation planning. Quantitative threat assessment often requires monitoring programs that provide reliable data over relevant spatial and temporal scales, yet such programs can be difficult to justify until there is an apparent stressor. Leveraging efforts of wildlife management agencies to record winter counts of hibernating bats, we collated data for 5 species from over 200 sites across 27 U.S. states and 2 Canadian provinces from 1995 to 2018 to determine the impact of white-nose syndrome (WNS), a deadly disease of hibernating bats. We estimated declines of winter counts of bat colonies at sites where the invasive fungus that causes WNS (Pseudogymnoascus destructans) had been detected to assess the threat impact of WNS. Three species undergoing species status assessment by the U.S. Fish and Wildlife Service (Myotis septentrionalis, Myotis lucifugus, and Perimyotis subflavus) declined by more than 90%, which warrants classifying the severity of the WNS threat as extreme based on criteria used by NatureServe. The scope of the WNS threat as defined by NatureServe criteria was large (36% of Myotis lucifugus range) to pervasive (79% of Myotis septentrionalis range) for these species. Declines for 2 other species (Myotis sodalis and Eptesicus fuscus) were less severe but still qualified as moderate to serious based on NatureServe criteria. Data-sharing across jurisdictions provided a comprehensive evaluation of scope and severity of the threat of WNS and indicated regional differences that can inform response efforts at international, national, and state or provincial jurisdictions. We assessed the threat impact of an emerging infectious disease by uniting monitoring efforts across jurisdictional boundaries and demonstrated the importance of coordinated monitoring programs, such as the North American Bat Monitoring Program (NABat), for data-driven conservation assessments and planning.  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