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91.
长江三角洲地区大气O3和PM10的区域污染特征模拟   总被引:14,自引:10,他引:14  
以TRACE-P污染源资料及上海市地方排放清单为基础,采用Models-3/CMAQ环境空气质量模型和中尺度气象模式MM5,模拟研究了2001-01和2001-07长三角近地面二次污染物O3及PM10的浓度分布及输送状况,并以上海市国控点2001年冬、夏季各10 d的小时监测数据对模型进行了验证.验证结果显示,Models-3/CMAQ对O3和PM10的模拟结果与监测值的相关系数分别为0.77和0.52;一致性指数分别达到0.81和0.99.模型对O3小时最高浓度的估算偏低27%,标准偏差为-3.1%;对PM10小时平均浓度的估算偏低10%,标准偏差为46%.模型已具备再现和模拟长三角大气污染输送过程的能力,且误差落在可接受的范围之内.模拟结果显示,2001-07长三角区域16个主要城市中,有14个城市O3小时最大浓度超过国家二级标准,高浓度O3可覆盖苏南和浙北广大区域.2001-01泰州、扬州、南京、镇江、常州等城市受本地排放源和北部大气污染输送的影响显著,大气PM10日均浓度超过PM10国家二级标准.长三角地区环境空气质量与污染类型受大气污染传输与化学转化的影响十分明显.夏季太阳辐射较强时,南部城市排放的污染物常以二次污染物的形式影响下风向城市;太阳辐射较弱的情况下,则以一次污染物输送为主的形式影响周边地区.冬季长三角区域颗粒物污染总体水平较高,这与我国北方地区排放的颗粒物在西北风作用下向长三角输送造成的影响密切相关.长三角地区的大气污染已逐渐从局地转为区域问题.  相似文献   
92.
Spatial closures like marine protected areas (MPAs) are prominent tools for ecosystem-based management in fisheries. However, the adaptive behavior of fishermen, the apex predator in the ecosystem, to MPAs may upset the balance of fishing impacts across species. While ecosystem-based management (EBM) emphasizes the protection of all species in the environment, the weakest stock often dominates management attention. We use data before and after the implementation of large spatial closures in a North Pacific trawl fishery to show how closures designed for red king crab protection spurred dramatic increases in Pacific halibut bycatch due to both direct displacement effects and indirect effects from adaptations in fishermen's targeting behavior. We identify aspects of the ecological and economic context of the fishery that contributed to these surprising behaviors, noting that many multispecies fisheries are likely to share these features. Our results highlight the need either to anticipate the behavioral adaptations of fishermen across multiple species in reserve design, a form of implementation error, or to design management systems that are robust to these adaptations. Failure to do so may yield patterns of fishing effort and mortality that undermine the broader objectives of multispecies management and potentially alter ecosystems in profound ways.  相似文献   
93.
Environmental Science and Pollution Research - Risks of heavy metal exposure from contaminated indoor dust constitute a major threat to human health. In this paper, heavy metals in deposited indoor...  相似文献   
94.
Population sinks present unique conservation challenges. The loss of individuals in sinks can compromise persistence; but conversely, sinks can improve viability by improving connectivity and facilitating the recolonization of vacant sources. To assess the contribution of sinks to regional population persistence of declining populations, we simulated source–sink dynamics for 3 very different endangered species: Black‐capped Vireos (Vireo atricapilla) at Fort Hood, Texas, Ord's kangaroo rats (Dipodomys ordii) in Alberta, and Northern Spotted Owls (Strix occidentalis caurina) in the northwestern United States. We used empirical data from these case studies to parameterize spatially explicit individual‐based models. We then used the models to quantify population abundance and persistence with and without long‐term sinks. The contributions of sink habitats varied widely. Sinks were detrimental, particularly when they functioned as strong sinks with few emigrants in declining populations (e.g., Alberta's Ord's kangaroo rat) and benign in robust populations (e.g., Black‐capped Vireos) when Brown‐headed Cowbird (Molothrus ater) parasitism was controlled. Sinks, including ecological traps, were also crucial in delaying declines when there were few sources (e.g., in Black‐capped Vireo populations with no Cowbird control). Sink contributions were also nuanced. For example, sinks that supported large, variable populations were subject to greater extinction risk (e.g., Northern Spotted Owls). In each of our case studies, new context‐dependent sinks emerged, underscoring the dynamic nature of sources and sinks and the need for frequent re‐assessment. Our results imply that management actions based on assumptions that sink habitats are generally harmful or helpful risk undermining conservation efforts for declining populations.  相似文献   
95.
应用Models-3/CMAQ研究长三角区域大气污染及输送   总被引:3,自引:0,他引:3  
选用美国国家环保局第3代空气质量模式(Models-3,/CMAQ),配合中尺度气象模式(MM5)进行研究,模拟了2001年1、7月份长江三角洲区域冬夏季典型天气条件下大气层二次污染物臭氧及颗粒物的浓度分布及输送状况。采用2001年冬.夏季各10d的小时监测数据对模式验证。结果表明,Models-3/CMAQ对O3、PM10的模拟相关系数分别为0.77和052;一致性指数分别达到081和0.99。模型对于O3略微低估,标准偏差为-31%,而对于PM10则有所高估,标准偏差为46%。对长三角7月份O3浓度及1月份PM10的模拟结果显示,7月份长三角区域16个主要城市O3日均浓度集中在0.043~0.086mg/m^3之间,其中,泰州、扬州.湖州、镇江O3月日均浓度相对较高,均超过0.064mg/m3o模拟时段内O3最高小时浓度达0.276mg/m^3。1月份整个模拟区域PM10月日均浓度为O056mg/m^3,其中,南京市PM10日均浓度最高,达0.080mg/m^3模拟时段内PM10最高小时浓度达0.432mg/m^3研究表明,长三角地区存在明显的污染物输送现象,大气污染已经从局地污染转化为区域污染。  相似文献   
96.
Osteogenesis imperfecta type II was diagnosed prenatally by analysis of DNA obtained from chorionic villus sampling (CVS) performed at 12 weeks of gestation in a woman who previously had had an affected child. The father had been shown to be mosaic for a mutation in the gene (COL1A2) which encodes the α2(I) chain of type I collagen. An affected fetus was predicted by detection of the mutation in amplified chorionic villus genomic DNA. Ultrasound examination at 13 weeks 4 days demonstrated femoral deformity and virtual absence of calvarial mineralization. In pregnancies at risk for osteogenesis imperfecta type II, sonographic evidence of skeletal abnormalities may be evident by 13 weeks' gestation.  相似文献   
97.
98.
长江三角洲地区大气O3和PM10的区域污染特征模拟   总被引:6,自引:1,他引:5  
以TRACE-P污染源资料及上海市地方排放清单为基础,采用Models-3/CMAQ环境空气质量模型和中尺度气象模式MM5,模拟研究了2001-01和2001-07长三角近地面二次污染物O3及PM 10的浓度分布及输送状况,并以上海市国控点2001年冬、夏季各10 d的小时监测数据对模型进行了验证.验证结果显示,Models-3/CMAQ对O3和PM10的模拟结果与监测值的相关系数分别为0.77和0.52;一致性指数分别达到0.81和0.99.模型对O3小时最高浓度的估算偏低27%,标准偏差为-3.1%;对PM10小时平均浓度的估算偏低10%,标准偏差为46%.模型已具备再现和模拟长三角大气污染输送过程的能力,且误差落在可接受的范围之内.模拟结果显示,2001-07长三角区域16个主要城市中,有14个城市O3小时最大浓度超过国家二级标准,高浓度O3可覆盖苏南和浙北广大区域.2001-01泰州、扬州、南京、镇江、常州等城市受本地排放源和北部大气污染输送的影响显著,大气PM10日均浓度超过PM10国家二级标准.长三角地区环境空气质量与污染类型受大气污染传输与化学转化的影响十分明显.夏季太阳辐射较强时,南部城市排放的污染物常以二次污染物的形式影响下风向城市;太阳辐射较弱的情况下,则以一次污染物输送为主的形式影响周边地区.冬季长三角区域颗粒物污染总体水平较高,这与我国北方地区排放的颗粒物在西北风作用下向长三角输送造成的影响密切相关.长三角地区的大气污染已逐渐从局地转为区域问题.  相似文献   
99.
Many tropical corals have declined in abundance in the last few decades, and evaluating the causal basis of these losses is critical to understanding how coral reefs will change in response to ongoing environmental challenges. Motivated by the likelihood that marine environments will become increasingly unfavorable for coral growth as they warm and become more acidic (i.e., ocean acidification), it is reasonable to evaluate whether specific phenotypic traits of the coral holobiont are associated with ecological success (or failure) under varying environmental conditions including those that are adverse to survival. Initially, we asked whether it was possible to identify corals that are resistant or sensitive to such conditions by compiling quantitative measures of their phenotypic traits determined through empirical studies, but we found only weak phenotypic discrimination between ecological winners and losers, or among taxa. To reconcile this outcome with ecological evidence demonstrating that coral taxa are functionally unequal, we looked beyond the notion that phenotypic homogeneity arose through limitations of empirical data. Instead, we examined the validity of contemporary means of categorizing corals based on ecological success. As an alternative means to distinguish among functional groups of corals, we present a demographic approach using integral projection models (IPMs) that link organismal performance to demographic outcomes, such as the rates of population growth and responses to environmental stress. We describe how IPMs can be applied to corals so that future research can evaluate within a quantitative framework the extent to which changes in physiological performance influence the demographic underpinnings of ecological performance.  相似文献   
100.
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