In this review, we summarize the literature from the warm deserts of North America and consider leaf (Anet), soil (Rs), and plant community (aboveground net primary productivity; ANPP) studies from the Mojave, Sonoran, and Chihuahuan Deserts to determine if common trends exist across measurement scales that can be utilized to effectively manage the warm deserts. Furthermore, we investigate the potential management strategies that may increase carbon sequestration or minimize carbon losses in this region. We begin by describing the warm deserts in the southwestern United States and consider climate change projections for this region. We then examine how climate change may affect NEE and carbon sequestration.

关键词：大气；碳存储；空气管理

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This project was motivated by the continuing need to improve ambient air quality. As of December 2012, more than 74 million Americans live in areas that violate the National Ambient Air Quality Standard for fine particulate matter (or PM2.5). Organic aerosol often contributes between 30 and 60% of ambient fine particulate matter. However, the sources of ambient organic aerosols are not well understood and state-of-the-art chemical transport models often underpredict the measured organic aerosol concentrations by a factor of 2 or more. Better understanding of the sources of organic aerosols may be needed for the development of effective control strategies. This report describes results from a three-phase test program that characterized the emissions from on-road gasoline vehicles, on-road diesel vehicles, and small off-road engines. The overarching goal of the project was to investigate the atmospheric transformations of mobile source emissions to better quantify their contribution to ambient PM levels in other words to link tailpipe to ambient. This was done by characterizing the tailpipe emissions from in-use sources and by investigating the atmospheric evolution of the emissions using dilution tunnels and smog chambers.

关键词：大气；空气污染；燃料控制

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Previous work by us and others demonstrates induction of a systemic pro-inflammatory and pro-coagulant state in response to inhalation of environmental particulate matter. Our work demonstrated PM exposure activated platelets to a enhanced state of reactivity and suggested this could be a key factor in adverse cardiovascular events. This project evaluated pulmonary inflammation and systemic inflammatory and platelet responses to fine and ultrafine (PM2.5) ambient particulate matter collected from an urban (Sacramento) and rural (Davis) location. The objective of these experiments was to determine whether prior chelation of transition metals with deferoxamine mesylate (DFM) or binding of bacterial source endotoxin by polymyxin B reduced pulmonary and systemic responses to PM2.5. We hypothesized those inflammatory responses to a more transition metal rich urban source PM2.5 would be inhibited more by metal chelation while rural source PM2.5 would be more affected by endotoxin binding. Adult mice were given intratracheal instillations of collected PM2.5 and pulmonary pathology, systemic cytokine concentrations, and platelet activation were evaluated 24 hours later. To better assess contributions of aromatic hydrocarbons, oxidants or pro-inflammatory responses to biologically active material like endotoxin, we used laser capture microscopy to probe specific anatomic locations in lung for gene responses associated with each of these components.

关键词：大气；环境污染；健康

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This project was an initial effort to investigate the feasibility of an instrument combining real-time atmospheric particle composition measurements using an ATOFMS (Atmospheric Time-Of-Flight Mass Spectrometer) such as those performed by Prathers group at the University of California, San Diego (UCSD) with multi-wavelength scattering measurements of the type investigated by Sorensen et al., of Kansas State University (KSU). In this Phase I effort we proposed to investigate near-angle scattering and the possibility of integration of a multi-wavelength scattering instrument into the UCSD ATOFMS. After an initial optical design and calculations, we discovered issues with the theory of measurement and with mechanical integration. Evidence emerged that the method of multi-wavelength scattering is only efficacious for spherical particles, while most atmospheric particles are non-spherical fractal aggregates. We also determined that the integration of the detector into existing ATOFMS instruments would be severely limited by volume constraints, and additional volume would require prohibitive additional pumping compared with the existing ATOFMS systems. Based on this evidence, we decided not to pursue a Phase II effort.

关键词：大气；光子；气溶胶

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According to the NRC and the USGCRP, changes in the earth's climate--including higher temperatures, changes in precipitation, rising sea levels, and increases in the severity and frequency of severe weather events--are under way and expected to grow more severe over time. These impacts present significant risks to the nation's energy infrastructure. Economic losses arising from weather-related events--including floods, droughts, and storms--have been large and are increasing, according to USGCRP. Adaptation--an adjustment to natural or human systems in response to actual or expected climate change--is a risk-management strategy to help protect vulnerable sectors and communities that might be affected by climate change. GAO was asked to examine the vulnerability of the nation's energy infrastructure to climate change impacts. This report examines: (1) what is known about potential impacts of climate change on U.S. energy infrastructure; (2) measures that can reduce climate-related risks and adapt energy infrastructure to climate change; and (3) the role of the federal government in adapting energy infrastructure and adaptation steps selected federal entities have taken. GAO reviewed climate change assessments; analyzed relevant studies and agency documents; and interviewed federal agency officials and industry stakeholders, including energy companies at four sites that have implemented adaptive measures.

关键词：大气；能源；气候变化

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关键词：氨氧化古菌；CANON；生物膜；活性污泥；丰度；多样性

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关键词：热处理；高固；猪粪；甲烷；巴氏消毒

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关键词：厌氧折流板反应器；膜生物反应器；生活污水；脱氮除磷；节能降耗

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主要研究了不同浓度的天然溶解性有机物（DOM）对单片膜被动采样技术的影响。结果表明，DOM的存在会影响膜吸附有机污染物的能力：当lgKow为3~5时，DOM对膜吸附有机物的影响较小；当lgKow>5.5时，DOM会显著增强膜的吸附能力，同时，通过低密度聚乙烯膜（LDPE）被动采样技术对太子河流域3个表层沉积物的孔隙水进行多环芳烃类（PAHs）和邻苯二甲酸酯类（PAEs）监测。结果表明，所选取的几种目标污染物在各监测点均有不同程度的检出，最后，利用商值法对太子河流域的PAHs和PAEs进行生态风险评价。结果表明，荧蒽超过水生生态基准值，其生态风险较大。

关键词：多环芳烃；邻苯二甲酸酯；溶解性有机物；被动采样；风险评价

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本研究通过对厌氧折流板反应器（ABR）改进，使其成为厌氧与好氧组合一体化工艺，实现耦合运行。对连续流条件下其好氧颗粒污泥形成机制进行了研究。将ABR末端隔室分别改为曝气池与沉淀池，并分别在厌氧区和好氧区接种厌氧颗粒污泥和普通活性污泥，保持好氧区C/N为2，COD容积负荷逐渐由1.5kg﹒(m3﹒d)-1提高至2.0kg﹒(m3﹒d)-1，沉淀池HRT逐步由2.0h缩短至0.75h。研究表明，经110d的运行，在好氧区中成功培养结构致密、沉降性能良好（平均沉降速率为20.8m﹒h-1）的淡黄色颗粒污泥。在好氧区沉淀时间为0.75h、COD容积负荷为2.0kg﹒(m3﹒d)-1的条件下，系统稳定运行时具有较好的脱氮除磷效果，COD、NH4+ -N、TP和TN的去除率分别为90%、80%、65%和45%。研究表明，因沉淀时间缩短而不断提高的选择压、维持较高的有机负荷是好氧颗粒污泥形成的主要驱动力。

关键词：ABR；CSTR；好氧颗粒污泥；形成机制；除污效能

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