·高被引论文摘要·

2017-01-26 14:05
中国学术期刊文摘 2017年12期

·高被引论文摘要·

被引频次:304

中国城市光化学烟雾污染研究

张远航,邵可声,唐孝炎,等

根据在兰州西固石油化工区、北京燕山石油化工区、北京地区和广州地区开展的光化学烟雾研究,讨论我国城市光化学烟雾的污染状况及其污染特征,探讨光化学烟雾的形成机制,并预测城市光化学烟雾的发展趋势。结果表明,上述地区存在严重的光化学烟雾污染,控制我国光化学烟雾污染的有效途径是降低NOx排放;北京中关村大气 O3最大小时浓度不仅逐年递增,而且出现 O3最大值的时间也提前,说明大气光化学活性增强;随着机动车保有量的迅猛增加,一些大城市的大气污染已逐渐由煤烟型转向机动车尾气污染型,或成为具有二者综合的污染特征。

光化学烟雾;臭氧;空气质量

来源出版物:北京大学学报:自然科学版, 1998, 34(2-3): 392-400

被引频次:242

我国城市地区机动车污染现状与趋势

谢绍东,张远航,唐孝炎

摘要:北京、广州和上海近 10多年机动车保有量年均增长速率分别为 164%,165%和 134%,这些城市大约80%的CO和40%的NOx来自于机动车排放。其结果是导致城区大气环境近10 a来NOx浓度逐年上升,已成为广州和北京等少数特大城市的首要污染物;街道大气环境中NOx和CO日均浓度远远超过国家大气环境质量二级标准,其污染程度比城区整体环境更为严重;已存在严重的光化学烟雾污染,预测表明城区未来大气环境中O3浓度的高低取决于机动车的排放量。因此,我国城市地区大气污染正由煤烟型污染向机动车尾气污染转化。关键词:机动车排气污染;光化学烟雾;机动车保有量;城市地区

来源出版物:环境科学研究, 2000, 13(4): 22-38

被引频次:178

灰霾天气的形成与演化

吴兑

摘要:由于经济规模迅速扩大和城市化进程加快,大气气溶胶污染日趋严重,由气溶胶造成的能见度恶化事件越来越多,这些人类活动排放的污染物,包括直接排放的气溶胶和气态污染物通过化学转化与光化学转化形成的细粒子二次气溶胶,可形成灰霾(特指人类活动源排放的大气污染物诱发的低能见度事件),致使能见度下降。我国东部地区灰霾天气迅速增加,灰霾天气的本质是细粒子气溶胶污染,与光化学烟雾相关联,形成灰霾天气的气溶胶组成非常复杂。近年来由于灰霾天气日趋严重引发的环境效应问题和气溶胶辐射强迫引发的气候效应问题,广泛地引起科学界、政府部门和社会公众的关注,而成为热门话题。文章讨论了目前对灰霾天气的认识,灰霾的定义与判别标准,灰霾天气与光化学烟雾、气象条件的关系,也涉及灰霾天气对人体健康的影响。展望了灰霾研究的前景与主要研究方向和内容。

关键词:灰霾天气;形成与演化;细粒子污染;灰霾定义;灰霾标准

来源出版物:环境科学与技术, 2011, 34(3): 157-161

被引频次:173

我国汽车排气污染现状与发展

范秀英,张微,韩圣慧

摘要:从汽车保有量、油品消耗、污染物排放和重点城市大气环境质量等方面分析了我国汽车污染现状及2000年和2010年2个时段的发展趋势,从节能、净化和管理的角度初步分析了削减汽车污染物排放的综合对策。

关键词:汽车保有量;汽车污染;污染分担率

来源出版物:环境科学, 1996, 17(4): 80-96

被引频次:151

北京大气中NO、NO2和O3浓度变化的相关性分析

安俊琳,王跃思,李昕

摘要:臭氧(O3)是城市污染大气中的首要光化学污染物,其变化规律与氮氧化物(NOx=NO+NO2)关系密切。采用49C臭氧分析仪和42CTL氮氧化物分析仪对北京城区O3和NOx浓度进行了连续观测,时间为2004-08—2005-07。结果显示,O3和Ox(O3+NO2)浓度在午后15 : 00左右出现峰值,NOx呈双峰态日变化,在07 : 00 和23 : 00左右出现峰值。不同季节污染物的浓度变化存在差异,O3和NOx浓度分别在夏季和冬季达到最大。NOx浓度存在 100×10-9(体积分数)的“分界点”,NOx低浓度时以NO2为主,NOx高浓度时NO占大部分。OX区域贡献和局地贡献存在明显的季节变化,前者主要受区域背景O3的影响,在春季最大,后者主要受局地NOx光化学反应的制约,在夏季最强,同时OX组分呈现显著的昼夜差异。

关键词:城市大气污染;光化学氧化剂;臭氧;区域贡献;局地贡献

来源出版物:环境科学, 2007, 28(4): 706-711

被引频次:96

北京地区严重大气污染的气象和化学因子

刘小红,洪钟祥,李家伦,等

摘要:利用北京325 m气象塔进行了大气污染物O3、NOx、CO和气象要素的同步观测,对影响大气污染的气象和化学因子进行了分析,探讨大气污染物变化的规律,为城市空气污染预报提供理论基础。

关键词:长江口;表层沉积物;重金属;环境评价

来源出版物:环境科学, 2008, 29(9): 2405-2412

被引频次:89

城市臭氧浓度分布特征

殷永泉,李昌梅,马桂霞,等

摘要:近地面层臭氧(O3)研究是当今环境科学领域的前沿课题之一,随着汽车尾气排放 NOx和碳氢化合物的增加,在日光照射等条件下导致低层大气中 O3浓度明显增高,面临光化学烟雾污染的威胁,开展环境空气中O3监测与分析对防治大气污染有十分重要的意义。利用2003年6个月的臭氧(O3)自动连续监测数据,对山东大学校园内 O3浓度的频率分布、日变化、月变化等特征进行分析。实验结果表明,O3小时平均浓度达到《环境空气质量标准》(GB 3095—1996)二级标准的频率为96.88%;O3浓度呈明显的日变化,一般在下午浓度较高,上午和夜晚较低;O3浓度的最高值出现在6月份,这与辐射强烈,温度高有关;天气条件也影响O3浓度,一般晴天时O3浓度高,多云、阴雨天气O3浓度低。

关键词:臭氧;环境空气;辐射

来源出版物:环境科学, 2004, 25(6): 16-19

被引频次:87

上海夏季近地面臭氧浓度及其相关气象因子的分析和预报

谈建国,陆国良,耿福海,等

摘要:为了揭示城市近地面臭氧浓度的变化特征及其相关气象因素,尝试进行近地面臭氧浓度预报。通过对2005年夏季(6—9月上旬)上海徐家汇地区近地面臭氧的观测与分析,建立了用于夏季臭氧浓度预报和高浓度臭氧污染事件预警的一种简便、实用的统计回归方法。结果表明:天气条件对臭氧形成具有明显的作用,臭氧浓度晴天最大、多云天次之、阴雨天最小;臭氧具有明显的日变化特征,12 : 00—14 : 00之间为最大值,凌晨3 : 00—5 : 00之间有一很小的次峰,5 : 00—6 : 00之间为最小值。产生高浓度臭氧污染是多项因子的综合结果,一般在高压系统的影响下,晴天少云,紫外辐射较强,相对湿度较低,气温较高,地面和高空吹偏北风,且风速较小的情形时容易产生高浓度臭氧污染。引进高浓度臭氧潜势指数和风向影响指数两个指标,并综合考虑多种气象要素,通过逐步回归建立的臭氧浓度预报方程,对逐日最大臭氧浓度具有较好的拟合效果和可预报性。

关键词:臭氧浓度;气象因子;变化特征;臭氧预报

来源出版物:热带气象学报, 2007, 23(5): 515-520

被引频次:75

臭氧污染胁迫对农作物生长与产量的影响

金明红,黄益宗

摘要:对国内外近地层大气的臭氧污染现状进行讨论,综述臭氧对农作物生长的影响。作物受O3伤害最典型的症状为叶片上散布棕色或黄褐色的细密点状斑、坏死斑。在O3的胁迫下,作物呼吸作用增强,光合作用受抑制。O3对叶片膜保护系统、气孔开度、氮代谢、糖类、脂类和其它物质的代谢也有影响。O3对农作物产生危害的同时,也往往导致农作物产量下降。

关键词:臭氧;农作物;生长;产量;影响

来源出版物:生态环境, 2003, 12(4): 482-486

被引频次:64

北京地区臭氧污染的来源分析

王雪松,李金龙,张远航,等

摘要:光化学烟雾污染是影响北京地区夏季空气质量的一个重要环境问题。利用区域空气质量模式(CAMx)对2000年6月底至7月初发生在北京地区的臭氧污染过程进行模拟,运用臭氧源识别技术(OSAT)和地区臭氧评估技术(GOAT),量化了不同地区的污染源排放对北京市城近郊区臭氧污染的贡献,探讨了周边地区排放的臭氧贡献方式问题,分析了北京地区臭氧污染的化学机制特征。研究表明,北京地区臭氧污染分布存在显著差异,并且具有明显的区域性特征,定陵地区的超标臭氧主要受到城近郊区烟羽的严重影响(占 55%),城近郊区则除了受到北京市的前体物排放影响外(占

46%),来自天津市、河北省南部地区的贡献往往也占有重要份额;周边地区对北京市城近郊区的贡献中,直接输入的臭氧约占7层,其余部分以输入前体物的方式贡献臭氧;北京城近郊区的臭氧生成主要受挥发性有机物控制,而在远郊区县和农村地区臭氧生成对氮氧化物变得更为敏感。对北京地区臭氧污染的源排放控制,需要综合考虑各种臭氧来源和不同贡献方式的重要性,以及臭氧生成机制的变化规律。

关键词:北京;臭氧;源贡献;源排放

来源出版物:中国科学B辑:化学, 2009, 39(6): 548-559

被引频次:1482

来源出版物:Lancet, 2002, 360(9341): 1233-1242被引频次:787

Rethinking organic aerosols: Semivolatile emissions and photochemical aging

Robinson, Allen L; Donahue, Neil M; Shrivastava, Manish K; et al.

Abstract:Most primary organic-particulate emissions are semivolatile; thus, they partially evaporate with atmospheric dilution, creating substantial amounts of low-volatility gas-phase material. Laboratory experiments show that photo-oxidation of diesel emissions rapidly generates organic aerosol, greatly exceeding the contribution from known secondary organic-aerosol precursors. We attribute this unexplained secondary organic-aerosol production to the oxidation of low-volatility gas-phase species. Accounting for partitioning and photochemical processing of primary emissions creates a more regionally distributed aerosol and brings model predictions into better agreement with observations. Controlling organic particulate-matter concentrations will require substantial changes in the approaches that are currently used to measure and regulate emissions.

来源出版物:Science, 2007, 315(5816): 1259-1262

被引频次:715

Evaluated kinetic, photochemical and heterogeneous data for atmospheric chemistry 5. IUPAC Subcommittee on gas kinetic data evaluation for atmospheric chemistry

Atkinson, R; Baulch, DL; Cox, RA; et al.

Abstract:This paper updates and extends previous critical evaluations of the kinetics and photochemistry of gas-phase chemical reactions of neutral species involved in atmospheric chemistry. The work has been carried out by the authors under the auspices of the IUPAC Subcommittee on Gas Phase Kinetic Data Evaluation for Atmospheric Chemistry. Data sheets have been prepared for 658 thermal and photochemical reactions, containing summaries of the available experimental data with notes giving details of the experimental procedures. For each reaction, a preferred value of the rate coefficient at 298 K is given together with a temperature dependence where possible. The selection of the preferred value is discussed and estimates of the accuracies of the rate coefficients and temperature coefficients have been made for each reaction. The data sheets are intended to provide the basic physical chemical data needed as input for calculations which modelatmospheric chemistry. A table summarizing the preferred rate data is provided, together with an appendix listing the available data on enthalpies of formation of the reactant and product species. We have also included for the first time in this series of evaluations a section on heterogeneous reactions of importance in atmospheric chemistry.

关键词:air pollution; atmospheric chemistry; chemical kinetics; data evaluation; gas phase; heterogeneous atmospheric reactions; photoabsorption cross-section, photochemistry; quantum yield; rate coefficient

来源出版物:Journal of Physical and Chemical Reference Data, 1997, 26(3): 521-1011

被引频次:405

Multimodel ensemble simulations of present-day and near-future tropospheric ozone

Stevenson, DS; Dentener, FJ; Schultz, MG; et al.

Abstract:Global tropospheric ozone distributions, budgets, and radiative forcings from an ensemble of 26 state-of-the-art atmospheric chemistry models have been intercompared and synthesized as part of a wider study into both the air quality and climate roles of ozone. Results from three 2030 emissions scenarios, broadly representing “optimistic,” “likely,” and “pessimistic” options, are compared to a base year 2000 simulation. This base case realistically represents the current global distribution of tropospheric ozone. A further set of simulations considers the influence of climate change over the same time period by forcing the central emissions scenario with a surface warming of around 0.7 K. The use of a large multimodel ensemble allows us to identify key areas of uncertainty and improves the robustness of the results. Ensemble mean changes in tropospheric ozone burden between 2000 and 2030 for the 3 scenarios range from a 5% decrease, through a 6% increase, to a 15% increase. The intermodel uncertainty (±1 standard deviation) associated with these values is about ±25%. Model outliers have no significant influence on the ensemble mean results. Combining ozone and methane changes, the three scenarios produce radiative forcings of ﹣50, 180, and 300 mW m-2, compared to a CO2forcing over the same time period of 800-1100 mW m-2. These values indicate the importance of air pollution emissions in short-to medium-term climate forcing and the potential for stringent/lax control measures to improve/ worsen future climate forcing. The model sensitivity of ozone to imposed climate change varies between models but modulates zonal mean mixing ratios by ±5 ppbv via a variety of feedback mechanisms, in particular those involving water vapor and stratosphere-troposphere exchange. This level of climate change also reduces the methane lifetime by around 4%. The ensemble mean year 2000 tropospheric ozone budget indicates chemical production, chemical destruction, dry deposition and stratospheric input fluxes of 5100, 4650, 1000, and 550 Tg(O3) yr-1, respectively. These values are significantly different to the mean budget documented by the Intergovernmental Panel on Climate Change (IPCC) Third Assessment Report (TAR). The mean ozone burden (340 Tg(O3) is 10% larger than the IPCC TAR estimate, while the mean ozone lifetime (22 days) is 10% shorter. Results from individual models show a correlation between ozone burden and lifetime, and each model's ozone burden and lifetime respond in similar ways across the emissions scenarios. The response to climate change is much less consistent. Models show more variability in the tropics compared to midlatitudes. Some of the most uncertain areas of the models include treatments of deep tropical convection, including lightning NOx production; isoprene emissions from vegetation and isoprene’s degradation chemistry; stratosphere-troposphere exchange; biomass burning; and water vapor concentrations.

来 源 出 版 物 : Journal of Geophysical Research-Atmospheres, 2006, 111(D8): D08301

被引频次:585

A review of surface ozone background levels and trends

Vingarzan, R

Abstract:A survey of the literature was conducted to review historical and current surface ozone data from background stations in Canada, United States and around the world for the purpose of characterizing background levels and trends, present plausible explanations for observed trends and explore projections of future ozone levels. The annual ozone cycle at background sites in the Northern Hemisphere is characterized by a spring maximum, peaking during the month of May. Although presently there is no concensus as to the origin of the spring maximum, evidence supports both enhanced photochemistry in the free troposphere and stratospheric input. Modern day annual average background ozone concentrations over the midlatitudes of the Northern Hemisphere range between approximately 20-45 ppb,with variability being a function of geographic location, elevation and extent of anthropogenic influence. Annual median ozone levels at Canadian background stations fall between 23 and 34 ppb, a range similar to that reported for low-elevation background stations in the United States and around the world. Comparisons of ozone levels with those measured over a century ago indicate that current levels have increased by approximately two times. Although current trends are not uniform, there is some indication that background ozone levels over the midlatitudes of the Northern Hemisphere have continued to rise over the past three decades, and that this rise has been in the range of approximately 0.5%-2% per year. Rising trends were steeper in the 1970s and 1980s compared to the 1990s, which have seen either a leveling off or a decline in the magnitude of these trends. Model sensitivity studies indicate that the rise in NO, emissions account for the greatest increase in background ozone levels over the past three decades. A substantial component of the background ozone concentration in western North America may be due to long-range transport of Asian pollution, especially during the spring months. Model projections using IPCC emission scenarios for the 21st century indicate that background ozone may rise to levels that would exceed internationally accepted environmental criteria for human health and the environment.

关 键 词 :background ozone; ozone trends; spring maximum; tropospheric ozone; ozone projections

来源出版物:Atmospheric Environment, 2004, 38(21): 3431-3442

被引频次:306

What controls tropospheric ozone?

Lelieveld, J; Dentener, FJ

Abstract:We have applied a global three-dimensional chemistry-transport model to quantify the photochemistry of tropospheric O3and compare the main source categories. We simulated a 15 year period (1979-1993) on the basis of the European Centre for Medium-Range Weather Forecasts meteorological reanalyses and a time- varying emission data set. We calculate that stratosphere-troposphere exchange (STE) strongly contributes to O3in regions where the photochemistry is quiescent. Since such regions play a minor role in radiative and chemical processes, we argue that STE-derived O3is much less important than is suggested by its column abundance. By distinguishing between photochemical pathways in the model we calculate that tropospheric O3in the extratropical Northern Hemisphere is strongly affected by industrial and fossil fuel-related emissions. In the tropics and Southern Hemisphere, natural emissions still play a major role. Our model results indicate a less important role for man-made biomass burning emissions than previous analyses. Further, the results show that tropospheric O3trends are strongly influenced by transports of pollution and by meteorological variability. Scenario calculations for the year 2025 suggest that man-made emissions at low northern latitudes, in particular in southern and eastern Asia, will become a very strong tropospheric O3source in the next decades. This will influence O3levels on a hemispheric scale so that despite pollution regulations in Europe and North America, surface O3will continue to grow.

来源出版物:Journal of Geophysical Research-Atmospheres, 2000, 105(D3): 3531-3551

被引频次:291

Megacities and atmospheric pollution

Molina, MJ; Molina, LT

Abstract:About half of the world’s population now lives in urban areas because of the opportunity for a better quality of life. Many of these urban centers are expanding rapidly, leading to the growth of megacities, which are defined as metropolitan areas with populations exceeding 10 million inhabitants. These concentrations of people and activity are exerting increasing stress on the natural environment, with impacts at urban, regional and global levels. In recent decades, air pollution has become one of the most important problems of megacities. Initially, the main air pollutants of concern were sulfur compounds, which were generated mostly by burning coal. Today, photochemical smog-induced primarily from traffic, but also from industrial activities, power generation, and solvents-has become the main source of concern for air quality, while sulfur is still a major problem in many cities of the developing world. Air pollution has serious impacts on public health, causes urban and regional haze, and has the potential to contribute significantly to climate change. Yet, with appropriate planning, megacities can efficiently address their air quality problems through measures such as application of new emission control technologies and development of mass transit systems.

来源出版物:Journal of the Air & Waste Management Association, 2004, 54(6): 644-680

被引频次:283

A meta-analysis of time-series studies of ozone and mortality with comparison to the national morbidity, mortality, and air pollution study

Bell, ML; Dominici, F; Samet, JM; et al.

Abstract:Background: Although many time-series studies of ozone and mortality have identified positive associations, others have yielded null or inconclusive results, making the results of these studies difficult to interpret. Methods: We performed a meta-analysis of 144 effect estimates from 39 time-series studies, and estimated pooled effects by lags, age groups, cause-specific mortality, and concentration metrics. We compared results with pooled estimates from the National Morbidity, Mortality, and Air Pollution Study (NMMAPS), a time-series study of 95 large U.S. urban centers from 1987 to 2000. Results: Both meta-analysis and NMMAPS results provided strong evidence of a short-term association between ozone and mortality, with larger effects for cardiovascular and respiratory mortality, the elderly, and current-day ozone exposure. In both analyses, results were insensitive to adjustment for particulate matter and model specifications. In the meta-analysis, a 10-ppb increase in daily ozone at single-day or 2-day average of lags 0, 1, or 2 days was associated with an 0.87% increase in total mortality (95% posterior interval = 0.55% to 1.18%), whereas the lag 0 NMMAPS estimate is 0.25% (0.12% to 0.39%). Several findings indicate possible publication bias: meta-analysis results were consistently larger than those from NMMAPS; meta-analysis pooled estimates at lags 0 or 1 were larger when only a single lag was reported than when estimates for multiple lags were reported; and heterogeneity of city-specific estimates in the meta-analysis were larger than with NMMAPS.

来源出版物:Epidemiology, 2005, 16(4): 436-445

被引频次:274

Effect of rising Asian emissions on surface ozone in the United States

Jacob, DJ; Logan, JA; Murti, PP; et al.

Abstract:The effect of increasing fossil fuel combustion in eastern Asia on surface O3air pollution in the United States is examined with a global three-dimensional tropospheric chemistry model. Tripling of Asian anthropogenic emissions from 1985 to 2010 is expected to increase monthly mean O3concentrations by 2-6 ppbv in the western United States and by 1-3 ppbv in the eastern United States, the maximum effect being in April-June. This increase would more than offset the benefits of 25% domestic reductions in anthropogenic emissions of NOxand hydrocarbons in the western United States. Asian influence may be less under the stagnant conditions leading to violations of the U.S. air quality standard. Nevertheless, our results suggest that a global perspective is necessary when designing a strategy to meet regional O3air quality objectives.

来源出版物:Geophysical Research Letters, 1999, 426(14): 2175-2178

Air pollution and health

Brunekreef, B; Holgate, ST

The health effects of air pollution have been subject to intense study in recent years. Exposure to pollutants such as airborne particulate matter and ozone has been associated with increases in mortality and hospital admissions due to respiratory and cardiovascular disease. These effects have been found in short-term studies, which relate day-to-day variations in air pollution and health, and long-term studies, which have followed cohorts of exposed individuals over time. Effects have been seen at very low levels of exposure, and it is unclear whether a threshold concentration exists for particulate matter and ozone below which no effects on health are likely. In this review, we discuss the evidence for adverse effects on health of selected air pollutants.