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排序方式: 共有816条查询结果,搜索用时 15 毫秒
621.
我国自2013年实施《大气污染防治行动计划》以来,大气细颗粒物(PM2.5)特别是硫酸盐浓度迅速下降,但硝酸盐浓度降幅较小,大气中过量的氨气(NH3)是维持硝酸盐居高不下的主要因素.迄今,我国生态环境部门尚未将NH3纳入常规观测,以往有关NH3和气溶胶铵盐(NH4+)的研究多是分别进行的,缺少同步观测.由于NH3和NH...  相似文献   
622.
Persistent bioaccumulative and toxic (PBT) pollutants are chemical contaminants that pose risks to ecosystems and human health. For these reasons, available tissue contaminant data from the US EPA Environmental Monitoring and Assessment Program’s National Coastal Assessment were examined to estimate to what areal extent PBTs are found in US estuarine resources. The data document composite, whole-body tissue chemical concentrations for 736 sampling sites across Northeast, Southeast, Gulf of Mexico, and West Coast estuaries. Tissue chemical concentrations were compared to US EPA non-cancer risk guidelines for recreational fishers, because of a lack of ecological guidelines for these chemical concentrations. Samples were analyzed for 23 PAH compounds, 21 PCB congeners, 6 DDT derivatives and metabolites, 14 chlorinated pesticides (other than DDT) and 13 metals, including mercury. Total PCBs were found to exceed recreational fisher guidelines most frequently (31% of samples evaluated), followed by mercury (29%), total PAHs (21%), and DDT and its metabolites, DDD and DDE (11%). Toxaphene, cadmium and dieldrin were found but in fewer than 1% of the samples.  相似文献   
623.
江苏省太湖流域国家考核断面污染来源调查与评价   总被引:2,自引:0,他引:2  
从水系关联和地域分布特征出发,将江苏省太湖流域53个国控考核断面归类划分为京杭大运河片区、入湖河流片区等6大片区,全面调查和系统分析水质状况和断面的污染来源,并提出对策建议,为环境管理提供决策支持。  相似文献   
624.
In this paper, the global agricultural land use model Kleines Land Use Model is coupled to an extended version of the computable general equilibrium model (CGE) Global Trade Analysis Project in order to consistently assess the integrated impacts of climate change on global cropland allocation and its implication for economic development. The methodology is innovative as it introduces dynamic economic land-use decisions based also on the biophysical aspects of land into a state-of-the-art CGE; it further allows the projection of resulting changes in cropland patterns on a spatially more explicit level. A convergence test and illustrative future simulations underpin the robustness and potentials of the coupled system. Reference simulations with the uncoupled models emphasise the impact and relevance of the coupling; the results of coupled and uncoupled simulations can differ by several hundred percent.
Francesco BoselloEmail: Email:
  相似文献   
625.
通过多年在粤港空气监控系统中的O3自动监测实践,阐述了O3标准气浓度传递认证的范例性解决方案,并在O3气体样品输送、O3分析仪器性能维护及在线检查校准用标准气等方面提出了实用的技术方法。  相似文献   
626.
This essay builds from Samantha Senda-Cook's 2013 article, “Materializing Tensions,” to explore the material rhetorics of the so-called “social trails” of the Apostle Islands National Lakeshore. These improvised, foot-worn pathways, diverging from and running alongside official Park Service trails, materialize a tension between what Michel de Certeau termed “strategies” and “tactics,” revealing how both are always at play in park and preserve trailspace and how the movements of the individual trail walker actualize and perpetuate a common concept of place. The study demonstrates and advocates close rhetorical attention to material aspects of the biophysical environment and the way that physical traces of many individuals over time can influence the subsequent actions and interpretations of others. The final discussion argues that as further tensions in trailspace rhetorics are identified rhetorical analysis must not fail to account for them.  相似文献   
627.
Exposure to endocrine disrupting chemicals such as bisphenol A (BPA) and phthalates is prevalent among children and adolescents, but little is known regarding important sources of exposure at these sensitive life stages. In this study, we measured urinary concentrations of BPA and nine phthalate metabolites in 108 Mexican children aged 8–13 years. Associations of age, time of day, and questionnaire items on external environment, water use, and food container use with specific gravity-corrected urinary concentrations were assessed, as were questionnaire items concerning the use of 17 personal care products in the past 48-h. As a secondary aim, third trimester urinary concentrations were measured in 99 mothers of these children, and the relationship between specific gravity-corrected urinary concentrations at these two time points was explored. After adjusting for potential confounding by other personal care product use in the past 48-h, there were statistically significant (< 0.05) positive associations in boys for cologne/perfume use and monoethyl phthalate (MEP), mono(3-carboxypropyl) phthalate (MCPP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), and in girls for colored cosmetics use and mono-n-butyl phthalate (MBP), mono(2-ethylhexyl) phthalate (MEHP), MEHHP, MEOHP, and mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), conditioner use and MEP, deodorant use and MEP, and other hair products use and MBP. There was a statistically significant positive trend for the number of personal care products used in the past 48-h and log-MEP in girls. However, there were no statistically significant associations between the analytes and the other questionnaire items and there were no strong correlations between the analytes measured during the third trimester and at 8–13 years of age. We demonstrated that personal care product use is associated with exposure to multiple phthalates in children. Due to rapid development, children may be susceptible to impacts from exposure to endocrine disrupting chemicals; thus, reduced or delayed use of certain personal care products among children may be warranted.  相似文献   
628.
坚持人与自然和谐共生、建设美丽中国是新时代中国特色社会主义建设的基本方略之一。本文从十九大报告提出的生态文明建设战略任务出发,诠释了新时代中国特色社会主义生态文明建设的特征,结合中国未来发展蓝图,提出了新时代生态文明建设的战略目标,深入分析了新时代建设生态文明和美丽中国的四大战略任务背景和要求。  相似文献   
629.
新制定的国家《煤炭工业污染物排放标准》将于2006年10月1日正式实施。该标准是基于技术而制订的,它是国家水污染物排放标准体系的重要组成部分。概要介绍该标准的制订思路、技术方法以及确定排放限值的技术依据。  相似文献   
630.
In Europe, sustainable development (SD) is pursued with not one but two overarching strategies, i.e., the so-called Lisbon and SD strategies. While the Lisbon Strategy is a genuinely European response to global economic and social pressures, SD strategies are national efforts corresponding with international (mainly United Nations) guidance to better coordinate and integrate economic, social and, in particular, environmental policies. The present paper explores the vertical coordination and coherence of the two pan-European strategies. After reviewing the international background of SD strategies and the EU origins of the Lisbon strategy, the paper characterizes and compares the governance architectures of the two strategies. With a solid background on how vertical policy integration functions in the two processes, the paper then shows how this affects the coherence of respective strategy structures and monitoring indicators. Based on an extensive empirical stocktaking study of the objectives and indicators in Lisbon and SD strategies across Europe it is shown that, despite the stronger European coordination through the Open Method of Coordination, the Lisbon process entailed only slightly more coherent national strategies than international guidance did in the context of SD strategies. Thus, the paper concludes that the influence international organizations such as the UN and the OECD have on national policy-making must not be underestimated.  相似文献   
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