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排序方式: 共有84条查询结果,搜索用时 31 毫秒
31.
为研究稳定浓度目标下温室气体排放路径的不确定性问题,应用温室气体导致气候变化评估模型( MAGICC模型)和WRE排放情景的数据对2100年温室气体浓度控制在450和550 ppmvCO2当量目标下的排放路径及浓度变化情况进行了研究.结果显示,目标年浓度的变化取决于起始年至目标年的累计排放量和摊放路径.将排放路径峰值逐渐调整滞后时,为保证累计排放量不变,需在到达峰值后比原排放路径进行更大力度的减排.温室气体浓度在预测期内将逐渐增加,但目标年的结果变化较小,约为浓度变化最大值的1/3左右.将WRE350和WRE450排放路径的峰值分别调整至2020年和2035年时,与原排放路径相比,浓度改变的最大值分别为6.4 ppmv和22.8 ppmv,而2100年浓度的改变值分别为1.9 ppmv和7.5 ppmv.  相似文献   
32.
The loss of forest is a leading cause of species extinction, and reforestation is 1 of 2 established interventions for reversing this loss. However, the role of reforestation for biodiversity conservation remains debated, and lacking is an assessment of the potential contribution that reforestation could make to biodiversity conservation globally. We conducted a spatial analysis of overlap between 1,550 forest-obligate threatened species’ ranges and land that could be reforested after accounting for socioeconomic and ecological constraints. Reforestation on at least 43% (∼369 million ha) of reforestable area was predicted to potentially benefit threatened vertebrates. This is approximately 15% of the total area where threatened vertebrates occur. The greatest opportunities for conserving threatened vertebrate species are in the tropics, particularly Brazil and Indonesia. Although reforestation is not a substitute for forest conservation, and most of the area containing threatened vertebrates remains forested, our results highlight the need for global conservation strategies to recognize the potentially significant contribution that reforestation could make to biodiversity conservation. If implemented, reforestation of ∼369 million ha would also contribute substantially to climate-change mitigation, offering a way to achieve multiple sustainability commitments at once. Countries must now work to overcome key barriers (e.g., unclear revenue streams, high transaction costs) to investment in reforestation.  相似文献   
33.
Abstract: The 2010 biodiversity target agreed by signatories to the Convention on Biological Diversity directed the attention of conservation professionals toward the development of indicators with which to measure changes in biological diversity at the global scale. We considered why global biodiversity indicators are needed, what characteristics successful global indicators have, and how existing indicators perform. Because monitoring could absorb a large proportion of funds available for conservation, we believe indicators should be linked explicitly to monitoring objectives and decisions about which monitoring schemes deserve funding should be informed by predictions of the value of such schemes to decision making. We suggest that raising awareness among the public and policy makers, auditing management actions, and informing policy choices are the most important global monitoring objectives. Using four well‐developed indicators of biological diversity (extent of forests, coverage of protected areas, Living Planet Index, Red List Index) as examples, we analyzed the characteristics needed for indicators to meet these objectives. We recommend that conservation professionals improve on existing indicators by eliminating spatial biases in data availability, fill gaps in information about ecosystems other than forests, and improve understanding of the way indicators respond to policy changes. Monitoring is not an end in itself, and we believe it is vital that the ultimate objectives of global monitoring of biological diversity inform development of new indicators.  相似文献   
34.
战时火力发电厂防护措施优选方法研究   总被引:1,自引:1,他引:0  
针对火力发电厂的核心部位薄弱环节现状,从现代战争攻击的目标看,发电厂必须采取有针对性的防护措施。结合火力发电厂的防护措施,根据其防护性能,建立指标体系,并利用灰色关联分析建立模型。通过模型对指标体系进行分析,达到对防护措施进行优选的目的。该评估指标体系的建立及基于灰色理论评估模型的建立,对于火力发电厂防护措施的优选具有一定的现实意义,对于大坝、核电站、机场等重要目标防护措施的优选具有借鉴和参考价值。  相似文献   
35.
西北干旱区水资源的合理开发利用与优化配置是实现干旱区可持续发展目标的首要前提。论文依据可持续发展的基本原理,以柴达木盆地为例,设计了水资源优化配置的总体思路,对水资源优化配置的多目标进行竞争辨识,采用以投入产出模型、AHP法等定性为主的决策方法和以系统动力学模型、生产函数模型等定量为主的决策方法生成水资源优化配置基准方案,进而采用多目标决策方案优选的密切值模型求出了柴达木盆地宏观经济发展与水资源优化配置的最佳方案。  相似文献   
36.
Contaminated sediments are receiving increasing recognition around the world, leading to the development of various sediment quality indicators for assessment, management, remediation, and restoration efforts. Sediment chemistry represents an important indicator of ecosystem health, with the concentrations of contaminants of potential concern (COPCs) providing measurable characteristics for this indicator. The St. Louis River Area of Concern (AOC), located in the western arm of Lake Superior, provides a case study for how numerical sediment quality targets (SQTs) for the protection of sediment-dwelling organisms can be used to support the interpretation of sediment chemistry data. Two types of SQTs have been established for 33 COPCs in the St. Louis River AOC. The Level I SQTs define the concentrations of contaminants below which sediment toxicity is unlikely to occur, whereas the Level II SQTs represent the concentrations that, if exceeded, are likely to be associated with sediment toxicity. The numerical SQTs provide useful tools for making sediment management decisions, especially when considered as part of a weight-of-evidence approach that includes other sediment quality indicators, such as sediment contaminant chemistry and geochemical characteristics, sediment toxicity, and benthic macroinvertebrate community structure. The recommended applications of using the numerical SQTs in the St. Louis River AOC include: designing monitoring programs, interpreting sediment chemistry data, conducting ecological risk assessments, and developing site-specific sediment quality remediation targets for small, simple sites where adverse biological effects are likely. Other jurisdictions may benefit from using these recommended applications in their own sediment quality programs.  相似文献   
37.
生活垃圾转运站恶臭污染指标初探   总被引:4,自引:0,他引:4  
报道了广州部分垃圾转运站恶臭指标的检测结果.发现国家标准(GB14554-1993)中的单项污染物指标的测定值大多远低于标准限值,而综合指标臭气浓度普遍超标,两类指标间存在严重不符.利用SAS统计软件综合分析各指标的检测数据,结果表明,垃圾转运站臭气中恶臭指标的含量存在较大的变异,且在垃圾站内的变异程度更大;恶臭单项指标在垃圾站内和垃圾站边界点的测定均值问无显著差异;臭气浓度和恶臭单项指标整体间可能存在一定的线性关系,但和某个具体的恶臭指标的线性相关性并不显著.  相似文献   
38.
The Strategic Plan for Biodiversity 2011–2020 recognizes the increasing importance of scientific knowledge to support conservation policies and decision making. In this study, we assessed the tendency of such knowledge in the first decade of the 21st century. We carried out a systematic review of publications in biodiversity conservation, considering the following aspects: type of research, main topic of study, object of study (i.e. biodiversity organizational level, taxonomic groups and ecosystems), pressures and drivers of change, as well as geographical distribution. In total, 966 publications were analyzed within the three journals with higher academic reach in the field under study: Biodiversity & Conservation, Biological Conservation, and Conservation Biology. Our results show that there are several biases in scientific knowledge associated with the object of study, and analyzed drivers of changes, as well as geographical distribution. However, research trends are not uniform along the first decade of 21st century, as there are some differences between 2000 and 2011 regarding the main topic of the study, the spatial scale and geographical region, and the analyzed ecosystems. We finally discuss the implications of current knowledge trends in biodiversity conservation for achieving the targets delineated by the Strategic Plan for Biodiversity 2011–2020.  相似文献   
39.
王勇  程瑜  杨光春  董莹 《中国环境科学》2018,38(8):3180-3188
建立了碳排放权省区分配模型,在中国2020年和2030年碳强度目标约束下,分阶段进行碳排放权的省区分配.结果表明:2016~2020年,中国各地区碳排放权分配相差悬殊.碳排放权配额最多的5个省份分别是经济发展水平和历史碳排放量均处于全国前列的广东、江苏、内蒙古、山东和山西地区,配额最少的5个省份依次是安徽、吉林、甘肃、宁夏和贵州.同时,各地区面临不同的减排压力.山西、山东、辽宁和陕西在2016年初始节点的碳空间严重不足,需要承担较大的减排压力.而广东、江苏和上海等地减排压力相对乐观.2021~2030年,各省份的碳排放权分配与第1阶段分配结果大体一致,所有省份在2030年碳排放空间均有盈余.但是部分地区(如新疆、陕西、吉林、青海、甘肃、宁夏和贵州等)截至2030年碳排放剩余空间相对有限,按期完成减排目标仍然存在较大压力.考虑到各省区面临不同的减排任务和压力,制定差异化的减排政策并在政策上给予适当的扶持是保证中国减排目标顺利达成的关键.  相似文献   
40.
The concerns over climate change negotiation, decision texts and links to domestic policy interests of countries to keep warming within an acceptable limit have become the ‘hotspot issues’ of the United Nations Framework Convention on Climate Change (UNFCCC). Hotspot issues are the human – political economy factors which have evolved over time from negotiation texts or phrases, principles or behaviors with tendencies to influence climate negotiations yet cannot be identified with the scientific literature. Whilst big emitters have been accused as having hegemony over the negotiations, the effects of disunity amongst the parties over domestic policy interests have been overlooked. Hence the article examines the emergence of hotspot issues and how they manifest within the international climate policy regime. The Intended Nationally Determined Contributions (INDCs) of 130 countries submitted before the Paris agreement, were analyzed using the following texts: Adaptation, Mitigation, Co-benefits, Finance, Land use, Food security, Poverty, Resilience, Green growth, Green economy, Sustainable development, Biodiversity, Ecosystem services and Conservation. Of these, ‘adaptation’ was cited 2780 times, 1956 for ‘mitigation’ and 32 for ‘ecosystem services’ in the nature conservation category. Ten phases of the climate policy regime and historical hotspot issues were identified for the period 1980–2030. ‘Adaptation’ and mitigation appeared more frequently in the INDCs and correlated with each other (r = 0.56), as the two correlated further with ‘land use’ (0.50 < r < 0.60), and similarly with sustainable development (0.40 < r < 0.70) where ‘r’ is the Pearson Rank Correlation. Therefore the success of the ‘ambitious targets’ for mitigation will depend on similar ambitious goals for adaptation, land use and sustainable development. Several differences existed in the correlation of the hotspot issues within the regional geographical blocs (Africa, Asia, Europe, North America, Oceania, South America) and split along the hotspot issues yet Europe mostly oriented towards mitigation and land use, and Oceania on resilience building. These differences provide favorable conditions for increased cooperation and true multilateralism if they are properly diagnosed.  相似文献   
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