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Vlassis A. Karydis Alexandra P. Tsimpidi Christos Fountoukis Athanasios Nenes Miguel Zavala Wenfang Lei Luisa T. Molina Spyros N. Pandis 《Atmospheric environment (Oxford, England : 1994)》2010,44(5):608-620
A three dimensional chemical transport model (PMCAMx) is applied to the Mexico City Metropolitan Area (MCMA) in order to simulate the chemical composition and mass of the major PM1 (fine) and PM1–10 (coarse) inorganic components and determine the effect of mineral dust on their formation. The aerosol thermodynamic model ISORROPIA-II is used to explicitly simulate the effect of Ca, Mg, and K from dust on semi-volatile partitioning and water uptake. The hybrid approach is applied to simulate the inorganic components, assuming that the smallest particles are in thermodynamic equilibrium, while describing the mass transfer to and from the larger ones. The official MCMA 2004 emissions inventory with improved dust and NaCl emissions is used. The comparison between the model predictions and measurements during a week of April of 2003 at Centro Nacional de Investigacion y Capacitacion Ambiental (CENICA) “Supersite” shows that the model reproduces reasonably well the fine mode composition and its diurnal variation. Sulfate predicted levels are relatively uniform in the area (approximately 3 μg m?3), while ammonium nitrate peaks in Mexico City (approximately 7 μg m?3) and its concentration rapidly decreases due to dilution and evaporation away from the urban area. In areas of high dust concentrations, the associated alkalinity is predicted to increase the concentration of nitrate, chloride and ammonium in the coarse mode by up to 2 μg m?3 (a factor of 10), 0.4 μg m?3, and 0.6 μg m?3 (75%), respectively. The predicted ammonium nitrate levels inside Mexico City for this period are sensitive to the physical state (solid versus liquid) of the particles during periods with RH less than 50%. 相似文献
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蓝藻水华暴发已成为全球性生态环境问题。太湖作为流域重要的水源地,2007年蓝藻水华事件的暴发引起公众的高度关注。运用问卷调查法,研究无锡市区489名公众的太湖蓝藻水华生态风险感知特征及其主要影响因素。研究结果表明:蓝藻水华生态风险被公众知觉为总体风险是陌生和完全可控的;蓝藻水华暴发原因是陌生和不可控的,这是引起公众风险意识的主要因素。影响公众蓝藻水华生态风险感知水平的主要因素有媒体、信息和个体因素。报纸广播电视是主要的媒体因素。信息因素有灾害信息、灾害治理信息、政府防范措施信息。灾害治理信息的影响作用最大,其次是灾害信息和政府防范措施信息。不同性别、年龄段、教育程度、收入水平及职业的人群,对不同类别的风险信息关注程度不同,影响到个体风险偏好的不同。研究结果有助于决策者更全面地理解蓝藻水华风险的本质,开展风险沟通,针对不同特征的人群选择有效的风险管理方案。〖 相似文献
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Development Potentials and Policy Options of Biomass in China 总被引:7,自引:0,他引:7
Biomass, one of the most important renewable energies, is playing and will continue to play an important role in the future
energy structure of the world. This article aims to analyze the position and role, assess the resource availability, discuss
the geographic distribution, market scale and industry development, and present the policy options of biomass in China. The
resource availability and geographical distribution of biomass byproducts are assessed in terms of crop residues, manure,
forest and wood biomass byproducts, municipal waste and wastewater. The position of biomass use for power generation is just
next to hydropower among types of renewable energy in China. The potential quantity of all biomass byproducts energy in 2004
is 3511 Mtce (Mtce is the abbreviation of million tons of coal equivalents and 1 Mtce is equal to106 tce.), while the acquirable quantity is 460 Mtce. Biomass energy plays a critical role in rural regions of China. The geographical
distribution and quantity of biomass byproducts resources depends mainly on the relationship between ecological zones and
climate conditions. Our estimation shows that the total quantity of crop residues, manure, forest and wood biomass byproducts,
municipal waste and wastewater resources are 728, 3926, 2175, 155 and 48240 Mt (million tons), respectively. Crop residues
come mainly from the provinces of Henan, Shandong, Heilongjiang, Jilin and Sichuan. All manure is mainly located in the provinces
of Henan, Shandong, Sichuan, Hebei and Hunan. Forest and wood biomass byproducts are mainly produced in the provinces or autonomous
regions of Tibet, Sichuan, Yunnan, Heilongjiang and Inner Mongolia, while most of municipal waste mainly comes from Guangdong,
Shandong, Heilongjiang, Hubei and Jiangsu. Most of wastewater is largely discharged from advanced provinces like Guangdong,
Jiangsu, Zhejiang, Shandong and Henan. Biomass byproducts’ energy distribution also varies from province to province in China.
Based on the analysis of the market scale and industry development, the article argues that China’s biomass energy industry
is still at a very early stage of development and that Feed-in Tariffs (FIT) might be the best policy option for China to
promote its development of biomass energy. A successful enforcement of FIT in China needs some policy combination of special
capital subsidies, R&D funding, tax incentives and pricing. 相似文献
556.
乡村旅游在实践中正从边缘化向系列化发展。沂蒙山区是全国水土流失重点治理区,针对沂蒙山区乡村旅游资源状况,分析了沂蒙山区发展乡村旅游的市场条件,认为生态脆弱区发展乡村旅游应遵循经济多元复合化发展与内源发展的原则,建构纵向深化与横向附加开发模式,具体提出乡村旅游开发途径,即旅游内容特色化、耦合化,旅游服务网络化、规范化的深化途径与附加旅游教育和旅游养生内容等途径。 相似文献
557.
工业是国民经济高速发展的主要推动力,而其所造成的环境污染也成为影响环境保护的突出问题。文章通过分析大通县环境问题现状,就大通县工业经济发展与环境保护如何实现"双赢"提出了对策建议。 相似文献
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Laboratory batch and column experiments were conducted to investigate the immobilization of phosphorus (P) in soils using synthetic magnetite nanoparticles stabilized with sodium carboxymethyl cellulose (CMC-NP). Although CMC-stabilized magnetite particles were at the nanoscale, phosphorus removal by the nanoparticles was less than that of microparticles (MP) without the stabilizer due to the reduced P reactivity caused by the coating. The P reactivity of CMC-NP was effectively recovered when cellulase was added to degrade the coating. For subsurface non-point P pollution control for a water pond, it is possible to inject CMC-NP to form an enclosed protection wall in the surrounding soils. Non-stabilized “nanomagnetite” could not pass through the soil column under gravity because it quickly agglomerated into microparticles. The immobilized P was 30% in the control soil column, 33% when treated by non-stabilized MP, 45% when treated by CMC-NP, and 73% when treated by both CMC-NP and cellulase. 相似文献