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171.
Simultaneous ground-based measurements of ozone and carbon monoxide were performed at Oki, Japan, from January 2001 to September 2002 in order to investigate the O(3) and CO characteristics and their distributions. The observations revealed that O(3) and CO concentrations were maximum in springtime and minimum in the summer. The monthly averaged concentrations of O(3) and CO were 60 and 234 ppb in spring and 23 and 106 ppb in summer, respectively. Based on direction, 5-day isentropic backward trajectory analysis was carried out to determine the transport path of air masses, preceding their arrival at Oki. Comparison between classified results from present work and results from the year 1994-1996 was carried out. The O(3) and CO concentration results of classified air masses in our analysis show similar concentration trends to previous findings; highest in the WNW/W, lowest in N/NE and medium levels in NW. Moreover, O(3) levels are higher and CO levels are lower in the present study in all categories.  相似文献   
172.
本文论述了中国东南大陆中、新生代岩浆作用的多旋回性和迁移性,构造演化与岩石系列和岩石组合的关系。前寒武纪岩石圈制约本区中、新生代岩浆作用和成矿作用,并在三种岩石围岩石学一地球物理综合模型中反映。总结了四个主要构造期岩浆作用源区特征和构造背景,并根据不同大地构造单元在碰撞造山后近南北向刊近北东向伸展裂解,从造山带挤压碰撞向伸展裂解机制转换过程探讨了中、新生代岩浆作用和壳幔演化动力学。  相似文献   
173.
东亚地区硫污染物的空间分布特征   总被引:4,自引:0,他引:4  
利用一个硫沉降模式分析了东亚地区SO2和SO42-浓度的空间分布及其特征.不同天气条件下,SO2和SO42-的浓度不同,高层SO2和SO42-的浓度分别为04—10μg/m3和02—05μg/m3;中层为40—100μg/m3和20—60μg/m3;近地层为40—300μg/m3和20—80μg/m3.分析表明,近地面浓度分布受源的影响比较明显,高层的浓度分布与湿清除过程密切相关,其浓度的低值区与降水区和云区有较好的对应.中层浓度分布体现了源、中层气流及湿清除的共同作用.  相似文献   
174.
过分省和典型地区化肥和农药使用情况对比,结合实地调查采样分析的研究方法,从不同尺度上分析了我国东南丘陵区化肥、农药扩散污染的状况及其发展趋势。结果表明,浙江、广东和福建3省化肥和农药施用量较高,引起的扩散污染也较为严重;广西、湖南、海南和江西4省化肥和农药的施用量还不高,但近期有迅猛上升的势头。  相似文献   
175.
本文在研究侵出相碎斑熔岩体产出的地质特征基础上,总结了其结构构造和组分特征的规律性变化,建立了四种形式的相模式。  相似文献   
176.
Tai Lake (Ch: Taihu) has attracted international attention forcyanobacteria blooms. However, the drivers of cultural eutrophication, especially long-term socio-economic indicators have been little researched. The results of research demonstrate how socio-economic development affected quality of water and how it has been improved by anthropogenic activities. This study described variability in indicators of water quality in Tai Lakeand investigated thedrivers. Significant relationships existed between concentrations of annual mean total nitrogen (TN), total phosphorous (TP), chemical oxygen demand (COD) and biological oxygen demand (BOD), and population, per capital gross domestic production (GDP) and sewage discharge (p?<?0.05). However, mechanisms causing change varied among TN, TP, COD and BOD. Before 2000, the main contributors to increases in concentrations of TN were human population, GDP and volumes of domestic sewage discharges. After 2000, discharges of industrial sewage become the primary contributor. After 1998, the regressions of annual mean TN, TP and COD on per capital GDP, population and domestic sewage discharge were reversed compared to the former period. Since 1999, an apparent inverted U-shaped relationship between environmental pollution and economic development has developed, which indicated that actions taken by governments have markedly improved quality of water in Tai Lake. The statistical relationship between BOD and per capital GDP didn’t conform to the Kuznet curve. The U-shaped Kuznet curve may offer hope for the future that with significant environmental investments a high GDP can be reached and maintained without degradation of the environment, especially through appropriate management of industrial sewage discharge.  相似文献   
177.
利用源示踪技术计算日本和韩国低层大气SO2和PSO4来源   总被引:1,自引:0,他引:1  
利用区域空气质量模式CAMx中的PAST(源示踪技术)对2010年东亚地区的总硫(SO2+PSO4)的源-受体关系进行了模拟计算. 模拟区域内共设定43个源区,其中在中国领土范围内设定了33个源区. 在源-受体关系计算中,将日本本岛分为北部、中部和南部三部分,分别设为受体区域,同时还将远离陆地的海洋背景点冲绳和韩国济州岛设为受体点.模拟结果表明,日本本岛北部、中部和南部的总硫来源存在一定的差异:日本本国的贡献率分别为73.8%、77.1%和65.9%,中国的贡献率分别为23.5%、20.2%和25.8%. 韩国本土总硫的本国贡献率为67.8%,中国的贡献率为27.2%. 对韩国济州岛和日本冲绳而言,二者总硫的本国贡献率均为26.0%,远低于日、韩两国的其他地区,不能代表国家间跨界输送的总体状况. 受体区域跨界输送的总硫季节变化明显,而且各区域的变化趋势也并不一致,其中日本南部地区和韩国本土1月最强,7月最弱;日本北部和中部地区在4月最强,1月最弱. 跨界传输的总硫对日本和韩国总硫贡献量小于2.5 μg/m3.对于日、韩两国影响较大的中国源区主要为山东、河北、江苏、辽宁等地,各源区对于日、韩总硫贡献量的季节变化明显. 东亚地区低空总硫的传输通量空间分布与利用CAMx模拟的2010年日本和韩国总硫的源-受体关系结果相一致.   相似文献   
178.
Mercury emissions from forest fires in countries bordering the Mediterranean Sea have been estimated on the basis of satellite observations for the year 2006. The assessment has been done by means of the Moderate Resolution Imaging Spectroradiometer (MODIS) products (MOD12Q1, MOD14A2, MOD15A2, MOD44B). Estimates show that wild fires have burnt 310,268 ha in the Region, affecting by 45% the Mixed Forest and by 37% the Evergreen Needleleaf Forest and the Evergreen Broadleaf Forest. The amount of biomass burned was about 66,000 Mg for the Evergreen Needleleaf Forest, 72,000 Mg for the Evergreen Broadleaf Forest and 196,000 Mg for the Mixed Forest. The total amount of mercury released to the atmosphere in the Mediterranean countries accounted for 4.3 Mg year−1 with Italy, France, Austria, Bulgaria, Algeria, Spain and Croatia being the most contributing countries with annual emission ranging from 330 to 970 kg year−1. The maximum release of Gaseous Elemental Mercury (GEM) and particulate mercury (Hg(p)) in the region occurred in July with 1,218 kg. The uncertainty of our estimates is comparable with that associated to current assessments of mercury emissions from major industrial sources.  相似文献   
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