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61.
16届亚运会期间广州城区PM2.5化学组分特征及其对霾天气的影响 总被引:2,自引:14,他引:2
于2010年11月4~30日在广州城区每天昼夜各采集一个PM2.5样品.对样品进行有机碳、元素碳和水溶性离子分析,同步收集了在线PM2.5浓度、大气消光系数(bext)以及气象因子,探讨了PM2.5特征及其与大气消光系数的关系,并利用修正后的IMPROVE消光系数方程重建大气消光系数.结果发现:亚运期间PM2.5日均值质量浓度为(77.0±24.4)μg·m-3,比亚运前低27.8%.PM2.5和相对湿度是导致霾天气的重要因素.亚运期间大气消光系数为418 Mm-1,比亚运前低28.3%,(NH4)2SO4、POM(particulate organic material)和LAC(light-absorbing carbon)是主要贡献因子,贡献率达到87.0%.广州及其周边城市采取的减排措施对于缓解亚运期间广州城区的霾天气作用明显. 相似文献
62.
Shih-Yu Chang Guor-Cheng Fang Charles C.-K. Chou Wei-Nai Chen 《Atmospheric environment (Oxford, England : 1994)》2006,40(40):7796-7809
Asia is one of the major sources of not only mineral dust but also anthropogenic aerosols. Continental air masses associated with the East Asian winter monsoon always contain high contents of mineral dust and anthropogenic species and transported southeastward to Taiwan, which have significant influences on global atmospheric radiation transfer directly by scattering and absorbing solar radiation in each spring. However, few measurements for the long-range transported aerosol and its optical properties were announced in this area, between the Western Pacific and the southeastern coast of Mainland China. The overall objective of this work is to quantify the optical characteristics of different aerosol types in the Eastern Asian. In order to achieve this objective, meteorological parameters, concentrations of PM10 and its soluble species, and optical property of atmospheric scattering coefficients were measured continuously with 1 h time-resolved from 11 February to 7 April 2004 in Taipei Basin (25°00′N, 121°32′E). In this work, the dramatic changes of meteorological parameters such as temperature and winds were used to determine the influenced period of each air mass. Continental, strong continental, marine, and stagnant air masses defined by the back-trajectory analysis and local meteorology were further characterized as long-range transport pollution, dust, clean marine, and local pollution aerosols, respectively, according to the diagnostic ratios. The aerosol mass scattering efficiency of continental pollution, dust, clean marine, and local pollution aerosols were ranged from 1.3 to 1.6, 0.7 to 1.0, 1.4 and 1.4 to 2.3 m2 g−1, respectively. Overall, there are two distinct populations of aerosol mass scattering efficiencies, one for an aerosol chemical composition dominated by dust (<1.0 m2 g−1) and the other for an aerosol chemical composition dominated by anthropogenic pollutants (1.3–2.3 m2 g−1), which were similar to the previous measurements with high degree of temporal resolution. 相似文献
63.
64.
Linking irreplaceable landforms in a self‐organizing landscape to sensitivity of population vital rates for an ecological specialist
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Wade A. Ryberg Michael T. Hill Charles W. Painter Lee A. Fitzgerald 《Conservation biology》2015,29(3):888-898
Irreplaceable, self‐organizing landforms and the endemic and ecologically specialized biodiversity they support are threatened globally by anthropogenic disturbances. Although the outcome of disrupting landforms is somewhat understood, little information exists that documents population consequences of landform disturbance on endemic biodiversity. Conservation strategies for species dependent upon landforms have been difficult to devise because they require understanding complex feedbacks that create and maintain landforms and the consequences of landform configuration on demography of species. We characterized and quantified links between landform configuration and demography of an ecological specialist, the dunes sagebrush lizard (Sceloporus arenicolus), which occurs only in blowouts (i.e., wind‐blown sandy depressions) of Shinnery oak (Quercus havardii) sand‐dune landforms. We used matrix models to estimate vital rates from a multisite mark‐recapture study of 6 populations occupying landforms with different spatial configurations. Sensitivity and elasticity analyses demonstrated demographic rates among populations varied in sensitivity to different landform configurations. Specifically, significant relationships between blowout shape complexity and vital rate elasticities suggested direct links between S. arenicolus demography and amount of edge in Shinnery oak sand‐dune landforms. These landforms are irreplaceable, based on permanent transition of disturbed areas to alternative grassland ecosystem states. Additionally, complex feedbacks between wind, sand, and Shinnery oak maintain this landform, indicating restoration through land management practices is unlikely. Our findings that S. arenicolus population dynamics depended on landform configuration suggest that failure to consider processes of landform organization and their effects on species’ population dynamics may lead to incorrect inferences about threats to endemic species and ineffective habitat management for threatened or endangered species. As such, successful conservation of these systems and the biodiversity they support must be informed by research linking process‐oriented studies of self‐organized landforms with studies of movement, behavior, and demography of species that dwell in them. 相似文献
65.
为了了解干旱内陆河流域降水稳定同位素变化过程及其影响因素,基于石羊河流域荒漠区、绿洲区和山区8个站点2013年7月至2014年7月,497个降水样品氢氧稳定同位素数据及相应气象数据,研究了石羊河流域降水稳定同位素的时空变化、环境效应以及降水水汽来源.结果显示:石羊河流域局地大气水线斜率和截距表现出夏低冬高的变化趋势;降水稳定同位素表现出夏高冬低的变化趋势,从荒漠区、绿洲区到山区,稳定同位素值随海拔升高而降低,海拔效应为-0.22‰/100m,这是温度效应的另一种体现;流域降水稳定同位素表现出显著的温度效应,温度效应为0.43‰/℃,在天气尺度下受季风水汽和降水淋洗过程的影响表现出降水量效应;流域降水来源主要受西风水汽控制,夏季也会会受到季风水汽影响,冬季也受到极地气团影响. 相似文献
66.
阐述了可持续发展概念的由来和内涵 ,介绍了我国可持续发展战略 ,论述了内河运输与可持续发展的关系 ,从可持续发展角度分析了内河运输现状 ,提出了内河运输可持续发展的对策 相似文献
67.
对石笋多指标的研究有利于全面理解季风气候事件的变化特征和机制。以湖北永兴洞YX55石笋为研究对象,通过高精度U/Th定年和多指标分析重建了65~35 ka B.P.石笋灰度和稳定同位素的变化序列。在65~40 ka B.P.时段,石笋灰度、δ13C与δ18O都呈现出数个千年至亚千年尺度的变化,但δ13C变化幅度比δ18O小得多。这说明灰度和δ13C这类代表局域气候的指标,都响应于δ18O指示的Heinrich(H)事件和Dansgaard-Oeschger(DO)旋回,但响应的程度各不相同。H4期间,石笋δ13C和灰度呈现不一致变化:δ13C不像在其他H事件一样小幅振荡,而是大幅正偏(相当于其他H事件2~3倍);灰度则显示出和DO旋回一致的特征。这种δ13C/灰度与δ18O异常响应关系可能的机制是:H4期间季风强度急剧减弱,使得洞穴上覆土壤覆盖率大幅降低,从而削弱或阻止了土壤—岩溶系统的过滤能力,使石笋中杂质含量异常增加。 相似文献
68.
There is a growing recognition that scientific and social conflict pervades invasive species management, but there is a need for empirical work that can help better understand these conflicts and how they can be addressed. We examined the tensions and conflicts facing invasive Asian carp management in Minnesota by conducting 16 in-depth interviews with state and federal agency officials, academics, and stakeholders. Interviewees discussed the tensions and conflicts they saw impacting management, their implications, and what could be done to address them. We found three key areas of conflict and tension in Asian carp management: 1) scientific uncertainty concerning the impacts of Asian carp and the efficacy and non-target effects of possible management actions; 2) social uncertainty concerning both the lack of societal agreement on how to respond to Asian carp and the need to avoid acting from apathy and/or fear; and 3) the desired approach to research and management – whether it is informed by “political need” or “biological reality”. Our study of these tensions and conflicts reveals their importance to Asian carp management and to invasive species management, more broadly. We conclude with a discussion of possible ways to address these areas of tension and conflict, including the potential of deliberative, participatory approaches to risk-related decision making and the need to productively engage with apathy and fear. 相似文献
69.
Ram M. Shrestha S.C. Bhattacharya Sunil Malla 《Journal of environmental management》1996,46(4):359-372
This paper presents a review of energy use in 22 selected countries of Asia and estimates the anthropogenic emission of sulphur dioxide (SO2) for the selected countries, both at national and disaggregated sub-country regional levels. The paper also makes a comparative assessment of the Asian countries in terms of SO2emission intensity (i.e. emission per GDP), emission per capita and emission density (i.e. emission per unit area). Total SO2emission in the region was estimated to be about 38 million tons in 1990. Five countries, China, India, South Korea, Japan and Thailand, accounted for over 91% of the regional SO2emission. Coal use had the dominant share (81%) of the total emission from the region. Among the economic sectors, industry contributed the largest share (49%) to the total emissions of the selected countries as a whole, followed by the power sector (30%). These findings suggest the need for mitigation strategies focussed on the industry and power sectors of the major emitting countries in Asia. 相似文献
70.
亚青会期间南京污染气体与气溶胶中水溶性离子的分布特征 总被引:6,自引:4,他引:2
使用β射线测尘仪、EMS污染气体监测系统、安德森9级采样器和IC型离子色谱分析仪对2013年8月10~28日南京市亚青会期间PM2.5、污染气体和水溶性离子进行了观测分析.结果表明,在亚青会期间PM2.5、NO2、O3和CO的浓度分别为37.0、19.3、48.1和0.7×103μg·m-3,分别比亚青会前降低了26.0%、42.6%、36.1%和46.1%.亚青会期间,细粒子段主要水溶性离子为Na+、NH+4、Ca2+和SO2-4,占80.6%;粗粒子段主要水溶性离子为Na+、Ca2+、NO-3和SO2-4,占77.9%.Ca2+、Mg2+和NO-3在亚青会期间为双峰型分布,其余离子为三峰型分布;亚青会前和后水溶性离子均为三峰型分布.由NO-3/SO2-4的值判断亚青会前和后南京市SO2和NOx主要来自于移动源,在亚青会期间主要来自固定源. 相似文献