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   189篇
  免费   30篇
  国内免费   8篇
安全科学   14篇
环保管理   59篇
综合类   98篇
基础理论   8篇
污染及防治   7篇
评价与监测   20篇
社会与环境   17篇
灾害及防治   4篇
  2024年   2篇
  2023年   6篇
  2022年   6篇
  2021年   6篇
  2020年   14篇
  2019年   5篇
  2018年   2篇
  2017年   16篇
  2016年   19篇
  2015年   20篇
  2014年   6篇
  2013年   8篇
  2012年   7篇
  2011年   18篇
  2010年   11篇
  2009年   6篇
  2008年   10篇
  2007年   8篇
  2006年   10篇
  2005年   2篇
  2004年   6篇
  2003年   5篇
  2002年   8篇
  2001年   2篇
  2000年   1篇
  1999年   8篇
  1998年   4篇
  1996年   3篇
  1995年   2篇
  1992年   1篇
  1989年   1篇
  1985年   1篇
  1978年   1篇
  1977年   1篇
  1971年   1篇
排序方式: 共有227条查询结果,搜索用时 15 毫秒
41.
Over the past decade, the emission standards and fuel standards in Beijing have been upgraded twice, and the vehicle structure has been improved by accelerating the elimination of 2.95 million old vehicles. Through the formulation and implementation of these policies, the emissions of carbon monoxide (CO), volatile organic compounds (VOCs), nitrogen oxides (NOx), and fine particulate matter (PM2.5) in 2019 were 147.9, 25.3, 43.4, and 0.91 kton in Beijing, respectively. The emission factor method was adopted to better understand the emissions characteristics of primary air pollutants from combustion engine vehicles and to improve pollution control. In combination with the air quality improvement goals and the status of social and economic development during the 14th Five-Year Plan period in Beijing, different vehicle pollution control scenarios were established, and emissions reductions were projected. The results show that the emissions of four air pollutants (CO, VOCs, NOx, and PM2.5) from vehicles in Beijing decreased by an average of 68% in 2019, compared to their levels in 2009. The contribution of NOx emissions from diesel vehicles increased from 35% in 2009 to 56% in 2019, which indicated that clean and energy-saving diesel vehicle fleets should be further improved. Electric vehicle adoption could be an important measure to reduce pollutant emissions. With the further upgrading of vehicle structure and the adoption of electric vehicles, it is expected that the total emissions of the four vehicle pollutants can be reduced by 20%-41% by the end of the 14th Five-Year Plan period.  相似文献   
42.
土壤、地下水和地表水等污染治理成本通常较高,但修复后会带来众多直接和间接效益,因此,在进行修复决策和环境损害评估时应当予以综合考虑。文章对环境修复成本效益分析的定义、目的和方法进行了阐述,并结合具体案例解释了环境修复成本效益分析的具体过程。修复成本通常依据价格指南、费用估算模型/软件、类似工程经验、承包商报价等进行估算,修复效益可采用享乐价格法,根据个人意愿为环境支付的费用,进行计算。案例研究结果表明,环境修复效益及其受益方并不是单一的,在进行较大规模的环境修复决策时,应由政府进行干预,并积极寻求各利益相关方的配合,综合评估其经济可行性。在环境损害评估中,也应形成多方协调机制,科学合理地评价修复方案的费用和效益,合理确定赔偿数额。  相似文献   
43.
在对历史环境问题进行梳理回顾的基础上,对新常态下作为典型资源型经济省份的山西省面临的环境保护形势进行了分析,并从实施绿色发展战略、改善环境质量、深化环境管理体制创新、加强环境监管、培育生态环保市场主体5个方面给出了基本的策略建议,以期为制定山西省"十三五"环境保护规划提供参考。  相似文献   
44.
农用地土壤环境分类管理研究   总被引:1,自引:0,他引:1  
通过分析国内外农用地土壤环境分类管理经验,结合我国土壤环境质量状况,以土壤环境风险管控为主线,将农用地土壤分为优先保护类、安全利用类和严格管控类3个类别,并提出相应的分类管理措施,保障农产品质量安全和人体健康。  相似文献   
45.
Abstract:  Regional conservation planning increasingly draws on habitat suitability models to support decisions regarding land allocation and management. Nevertheless, statistical techniques commonly used for developing such models may give misleading results because they fail to account for 3 factors common in data sets of species distribution: spatial autocorrelation, the large number of sites where the species is absent (zero inflation), and uneven survey effort. We used spatial autoregressive models fit with Bayesian Markov Chain Monte Carlo techniques to assess the relationship between older coniferous forest and the abundance of Northern Spotted Owl nest and activity sites throughout the species' range. The spatial random-effect term incorporated in the autoregressive models successfully accounted for zero inflation and reduced the effect of survey bias on estimates of species–habitat associations. Our results support the hypothesis that the relationship between owl distribution and older forest varies with latitude. A quadratic relationship between owl abundance and older forest was evident in the southern portion of the range, and a pseudothreshold relationship was evident in the northern portion of the range. Our results suggest that proposed changes to the network of owl habitat reserves would reduce the proportion of the population protected by up to one-third, and that proposed guidelines for forest management within reserves underestimate the proportion of older forest associated with maximum owl abundance and inappropriately generalize threshold relationships among subregions. Bayesian spatial models can greatly enhance the utility of habitat analysis for conservation planning because they add the statistical flexibility necessary for analyzing regional survey data while retaining the interpretability of simpler models.  相似文献   
46.
2013年11月16日能源基金会(美国)主办的"重塑蓝天:空气质量管理国际研讨会"在北京召开,环境保护部原总工程师、中国环境科学学会副理事长杨朝飞受会议主办方委托做了总结讲话。本文根据杨总工的讲话录音整理以飨读者。  相似文献   
47.
"十三五"时期,我国通过政策和法制改革有效地促进了污染防治和生态环境保护工作。"十四五"时期,须进一步加强政策和法制的针对性和灵活性,从充分性和均衡度两个方面提升我国区域、流域和行业生态环境国家治理的综合绩效。为此,需要发挥党内法规和国家立法的相互支持作用,促进国家立法的有效实施;中央与地方签订行政协议,调动地方深入开展生态环保工作的积极性;推进流域与区域的专门立法或者协同立法,通过体制制度和机制的集成创新促进实际问题的解决;按照流域与区域生态环保目标设立生态环境标准,体现生态环保工作的针对性和因地制宜性;实行"法定义务+企业承诺"履行制度,因企制宜地落实各生产经营单位的生态环保责任;国家需要总结和推广一些地方探索和有效实施的灵活性工作制度,并发挥市场机制对生态环境资源和生态环保产业发展的调节作用。  相似文献   
48.
ABSTRACT .A summary is presented of remarks made at a conference held at Louisiana Tech University on the possibility of diverting some of the Mississippi River water to Texas and New Mexico. The Texas Water Plan which has initiated the diversion possibility is discussed and particular reference is made to the activities of the federal and state agencies directly responsible for determining various aspects of the diversion study. These agencies include the Texas Water Development Board, Texas Water Quality Board, Louisiana Department of Public Works, State Engineer's Office of New Mexico, Mississippi River Commission, and the Bureau of Reclamation.  相似文献   
49.
/ Public participation in environmental management decisions has frequently led to conflict. This paper examines the role of environmental values in fueling these conflicts, based on a data base and sample content analysis of written public comments solicited in 1994 regarding the highly contentious Clinton Forest Plan (also known as Option 9) proposed for management of federal forests in the US Pacific Northwest. The analysis considered whether those respondents favoring more versus less environmental protection than was offered in Option 9 held entirely different values, identifying which antagonistic values appeared to be most fundamental and where (if at all) values consensus occurred. It also compared values emanating from respondents within and outside the affected region, although few major differences were detected in this regard. Results suggest that strong values differences did exist among those preferring greater versus less environmental protection, in particular as concerned the extent, form, and spatial and temporal scope of justification of their positions, their ideas of forests, and the appropriate role of people in forest management. Disagreement concerned far more than purely environmental values: a major point of difference involved human benefits and harms of the proposed forest plan. Indeed, both sides' positions were overridingly anthropocentric and consequentialist-a values orientation that almost inevitably spells conflict in light of the commonly differentiated social impacts of environmental management decisions. Although public involvement in environmental management thus cannot be expected to lead to a clear and consensual social directive, the Pacific Northwest case suggests that viable environmental management solutions that take this range of values into account can still be crafted.KEY WORDS: Environmental values; Public participation; Clinton Forest Plan; Pacific Northwest  相似文献   
50.
中国环境监测总站未来十年发展构想   总被引:1,自引:0,他引:1  
阐述了总站未来十年发展的指导思想、目标和原则,明确了总站未来十年发展的重点业务领域,介绍了实现构想的保证措施和重点建设项目。  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