This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, orusefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement,recommendation, or favoring by the United States Government orany agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

关键词：大气；燃料燃烧；废气排放

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In China, motor vehicle emissions have been identified as the major source of urban air pollution. Thus, estimation of emissions and their impact on air quality is necessary. Vehicle emissions vary strongly with region and depend on local vehicle operation and emission performance. This paper uses the MOVES (Motor Vehicle Emission Simulator) model, released by the US. Environmental Protection Agency, for the estimation of vehicle emission factors in Shanghai, China. To achieve a convincing emission result, vehicle operation is extracted from massive taxi Global Positioning System (GPS) data, and the emission inventory from MOVES is revised according to China's vehicle emission standards. In addition, deterioration factors are calculated on the basis of vehicle condition. Comprehensive emission factors are generated for Shanghai light-duty vehicles at various average speed levels. The results indicate that emission factors for hydrocarbons, carbon monoxide, and oxides of nitrogen of in-use light vehicles in China are 0.1 to 0.25 g/km, 4 to 7 g/km, and 0.4 to 0.8 g/km, respectively. These amounts are 15, 1.9, and 5.9 times higher than those in the United States, respectively. By 2012, the Environmental Protection Bureau had established 10 monitoring sites in Shanghai and released data for real-tune concentrations of particulate matter less than 2.5 μm in diameter, particulate matter less than 10 μm in diameter, nitrogen dioxide (NO_2), and sulfur dioxide to the public. On the basis of the new release of data, a field study estimating near-road air quality was conducted with MOVES and the air dispersion model AERMOD. The concentration result shows that the accuracy of near-road NO_2 estimation is improved with taxi GPS data and the revised MOVES emission inventory. The study explores the extended application of MOVES by offering a procedure for applying MOVES in non-U.S. regions.

关键词：大气；空气污染；出租车

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Improving the efficiency of urban traffic operations along arterials is a priority for many agencies because congestion affects the movement of people and goods in many cities. Advanced traffic management systems are being implemented to optimize traffic signal timing in congested corridors. Pedestrians and transit users are even more exposed to vehicle emissions than are drivers. However, pedestrian exposure to traffic emissions is typically not a consideration when traffic signal timing decisions are made. The relationship between exposure to air pollution and traffic signal timing has not yet been fully explored or modeled. This paper quantifies the factors that contribute to concentrations of sidewalk-level particulate matter (1.0 to 2.5 μm in diameter) at a busy intersection along an urban arterial in Portland, Oregon. The study is the first research effort to combine real-world, detailed traffic signal timing data (at 5-s intervals) and air pollutant concentration data. Several types of variables are included in the statistical analysis: traffic signal timing variables, weather-related variables, traffic volume and composition variables, and variables associated with bus presence and characteristics. Statistical results show the importance of signal timing variables, traffic volumes, and queuing.

关键词：大气；颗粒物；交通信号

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We performed comparative studies to establish favorable spectral regions and measurement wavelength combinations in alternative bands of CO2 and O2, for the sensing of CO2 mixing ratios (XCO2) in missions such as ASCENDS. The analysis employed several simulation approaches including separate layers calculations based on pre-analyzed atmospheric data from the modern-era retrospective analysis for research and applications (MERRA), and the line-byline radiative transfer model (LBLRTM) to obtain achievable accuracy estimates as a function of altitude and for the total path over an annual span of variations in atmospheric parameters. Separate layer error estimates also allowed investigation of the uncertainties in the weighting functions at varying altitudes and atmospheric conditions. The parameters influencing the measurement accuracy were analyzed independently and included temperature sensitivity, water vapor interferences, selection of favorable weighting functions, excitations wavelength stabilities and other factors. The results were used to identify favorable spectral regions and combinations of on/off line wavelengths leading to reductions in interferences and the improved total accuracy.

关键词：大气；温室气体；温度影响

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Indigenous populations are projected to face disproportionate impacts as a result of climate change in comparison to nonindigenous populations. For this reason, many American Indian and Alaska Native tribes are identifying and implementing culturally appropriate strategies to assess climate impacts and adapt to projected changes. Traditional ecological knowledge (TEK), as the indigenous knowledge system is called, has the potential to play a central role in both indigenous and nonindigenous climate change initiatives. The detection of environmental changes, the development of strategies to adapt to these changes, and the implementation of sustainable land-management principles are all important climate action items that can be informed by TEK. Although there is a significant body of literature on traditional knowledge, this synthesis examines literature that specifically explores the relationship between TEK and climate change. The synthesis describes the potential role of TEK in climate change assessment and adaptation efforts. It also identifies some of the challenges and benefits associated with merging TEK with Western science, and reviews the way in which federal policies and administrative practices facilitate or challenge the incorporation of TEK in climate change initiatives. The synthesis highlights examples of how tribes and others are including TEK into climate research, education, and resource planning and explores strategies to incorporate TEK into climate change policy, assessments, and adaptation efforts at national, regional, and local levels.

关键词：大气；空气污染；气候变化

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Establishing adequate RF (Radio Frequency) connectivity is the basic requirement for the proper operation of any wireless network. In a mobile wireless network it is a challenge for applications and protocols to deal with connectivity problems, as links might get up and down frequently. In these scenarios, having knowledge of the node remaining connectivity time can avoid unnecessary or even unuseful control/data messages transmissions. The current paper presents the so-called Genetic Machine Learning Approach for Link Quality Prediction, or simply GMLA, which is a solution to forecast the remainder RF connectivity time in mobile environments. Differently from all related works, GMLA allows building connectivity knowledge to estimate the RF link duration without the need of a pre-runtime phase. This allows to apply GMLA at unknown environments and mobility patterns. Its structure combines a Classifier System with a Markov chain model of the RF link quality. As the Markov model parameters are discovered on-the-fly, there is no need of a previous history to feed the Markov model. Obtained simulation results show that GMLA is a very suitable solution, as it outperforms approaches that use geographical positioning systems (GPS) and also approaches that use link-quality prediction, such as BD and MTCP. GMLA is generic enough to be applied to any layer of the communication protocol stack, especially in the link and network layers.

关键词：移动无线网络；射频连接预测；分类系统

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This chapter describes the physicochemical mechanisms that formulate the air quality over the Mediterranean region and the resulted impacts on the regional climate. At first, a detailed description of the teleconnections and regional flow patterns that dominate in the region is provided. The dominant flow patterns during the different seasons of the year determine the transport paths of air pollutants and aerosols towards and across the study area. The analysis on the characteristics of the air pollution transport is separated for the different parts of the Mediterranean region (eastern, western and entire), since the sources of pollutants that reach at different points in the region vary, while specific pollutant transport paths may influence the wider Mediterranean area. Similarities and differences in patterns are discussed. The air quality over the region, as recorded from black/organic carbon, ozone, aerosol observations, is extensively discussed, along with seasonal variabilities and annual trends. There is particular discussion on the suspension of naturally-produced aerosols and especially desert dust particles in the region and their spatial influence on the aerosol levels. At the last part of the chapter, the major impacts of the transport and transformation processes (natural and anthropogenic pollutants) on the regional climate are discussed. The impacts of aerosols are distinguished in direct (the impacts on radiation budget), health (the amounts of inhaled particles and impacts on health) and indirect effects (impacts on clouds and precipitation), are discussed on qualitative and quantitative way.

关键词：大气；气候变化；空气污染

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Environmental concerns have led to numerous regulations that have dramatically decreased the reported production and use of mercury in the United States since the 1980s. Government legislation and subsequent industry actions have led to increased collection of mercury-containing materials and the recovery of mercury through recycling. Mercury emissions have been reduced and effective alternatives to mercury products have been developed for many applications. This study updates and quantifies the changes in demand, supply, use, and material flow for mercury in various sectors in the United States that have taken place since 1996.

关键词：大气；废气转化；环境保护

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Catalytic processes are today practiced on a vast scale to convert basic feedstocks (today largely petroleum, gas, and coal based) into fuels, plastics, agricultural chemicals, pharmaceuticals, foods, paints/coatings, and numerous other materials that underpin our economy and well-being. Catalysts are also used extensively to provide a cleaner environment by treating automotive and industrial (e.g., power plant) exhausts and water-borne effluents. Indeed, it has been estimated that more than 50% of the US GDP derives from catalytic processes. In the past several years, it has become apparent that the US energy supply and demand picture has shifted dramatically, and that a major scientific research and development effort must be mounted to maintain US economic leadership and our quality of life. The challenges are to use and convert more abundant, lower cost/lower quality, and more sustainable feedstocks into the products we need with unprecedented energy- and atom-efficiency. The need to develop more efficient, cleaner and greener catalytic processes is grand challenge of national import.

关键词：大气；气体净化；空气健康

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Anthropogenic sources of air pollution emissions include a number of sectors and activities e.g., fossil fuel and biofuel combustion in industrial and residential areas, transportation (road, rail, air and ships), waste disposal, industrial processes, agricultural activities, solvent production and usage. Emissions of greenhouse gases (GHGs), such as Carbon dioxide (CO_2), methane (CH_4) and nitrous oxide (N_2O) are a major concern from climate change perspective. This because they obstruct the escape of infrared (heat) energy to outer space by absorbing them and leading to increase in earth's temperature along with other climatic changes (Bond et al. 2004). Anthropogenic activities annually attribute to an estimated 3%, 64%, and 24% of global emissions of CO_2, CH4 and N_2O, respectively (Duxbury 1994). Megacities contribute a major portion in these global emissions. As reported by Butler et al. (2008) megacities account for approximately between 9% and 12% of the global emissions of CO, NO_X, and NMVOC.

关键词：大气；温室气体；环境保护

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