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941.
基于对2008年新颁布的7个行业12个污染物排放标准与原执行排放标准的比较,总结了新标准制定的特点,指出新标准执行的关键是充分掌握企业所处的地理位置、建厂时间、生产工艺、污染物排放去向等。提出正确选用标准、监测能力的开发、监管的加强是执行新标准时尚须解决的问题。  相似文献   
942.
利用真空瓶现场采样并结合单颗粒气溶胶质谱(SPAMS)技术,对主流品牌汽油车和柴油车排放细颗粒物进行组分分析和源谱构建。结果表明:汽、柴油车尾气源谱特征整体较为相似,相似度均值达到0.88,均以碳和钙为主要特征组分;部分柴油车特征源谱中硫酸盐特征较为明显,碳组分中OC特征突出;汽油车源谱特征中磷酸盐特征相对突出,且碳组分中短链元素碳占比较高。根据建立的源谱进行实际道路观测,结合风速、风向等气象要素分析,2021年2月1日—24日观测点位对应的移动源占比为33.5%,其中汽油车贡献21.0%,柴油车贡献12.5%。  相似文献   
943.
More than 60 coal samples, predominantly from the principal coalfields of England and Wales (25) and Scotland (30), were analysed for lead by AAS and for stable lead isotopes by ICPMS. While the average lead content of Scottish coal, 23.9mg kg–1, was more than double that of coal from England and Wales, 11.0mg kg–1, the corresponding mean 206Pb/207Pb ratios (± 1 s.d.) were nearly identical, at 1.181±0.011 and 1.184±0.006, respectively. In the light of the lead isotopic signatures of British coals and of both indigenous (206Pb/207Pb 1.17) and imported Australian (206Pb/207Pb 1.04) lead ores, an approach based on estimated lead emissions from these sources and the deconvolution of the historical lead and 206Pb/207Pb records preserved in lake sediments, peat bogs and archival herbage material indicates that coal combustion became an increasingly significant contributor to atmospheric lead deposition in the UK during the period 1830–1930, especially after the onset of Englands decline as a major location of lead mining and smelting in the late19th Century. Since 1930 and the introduction of leaded petrol, the atmospheric 206Pb/207Pb ratio in the UK has been strongly influenced by carexhaust emissions of comparatively 206Pbdepleted lead of predominantly Australian origin, counterbalanced to some extent by coalcombustion emissions of lead, although these have fallen dramatically since the mid1950s. Nevertheless, with the introduction and substantial uptake of unleaded petrol in the UK during the last decade, even the declining releases from coal, along with contributions from other sources, are continuing to affect the atmospheric lead content and 206Pb/207Pb ratio.  相似文献   
944.
Spatial variability of ammonium and nitrate in soils near a poultry farm   总被引:1,自引:0,他引:1  
This paper assesses the distribution of ammonium (NH4+) and nitrate (NO3-) nitrogen deposition in native bushland soil adjacent to an open ventilated poultry farm. The farm is located in Thirlmere 150 km south west of Sydney, Australia. A total of 104 geographically referenced soil cores were obtained from the study area. Soil pH, electrical conductivity (EC), NH4(+) - and NO3(-)-nitrogen concentrations were analysed for variable trends at three depths, i.e. 0-30, 30-60, and 60-90 cm. Significantly higher concentrations of the two nitrogen forms and EC were observed nearer to the farm in the surface soil samples (0-30 cm). The distribution of NH4+, NO3- and EC were all correlated in surface samples throughout the study area. There was no indication of NH4+ and NO3- leaching within soil profile sampled and it appears that weeds and native vegetation had utilised the accumulated nitrogen. The level of N deposition adjacent to the poultry farm decreased downwind due to dispersion of plume and to the buffering effects from the bushland.  相似文献   
945.
A Real-Time Single Particle Mass Spectrometer, RSMS-3, was deployed to Wilmington, Delaware to study regional and local contributions to fine and ultra-fine urban particulate matter (PM). Approximately two-thirds of PM1 consisted of internally mixed secondary aerosol. The remaining one-third was externally mixed including biomass burning (13%), fossil fuel combustion (7%) and various industrial sources (13%). In this last group, particle classes containing specific combinations of transition and/or heavy metals gave wind-rose plots consistent with specific point sources. For example, particles containing V and Ni were detected from different wind directions than those containing V and Fe. Samples from two industrial emission stacks, a steel manufacturing facility 10 km away and a coal-fired electrical power generation facility 5 km away, were analyzed and compared to the ambient data set. In each case, a direct correlation was found: a Pb–Zn–K–Na class for the steel manufacturing facility and an Fe–La/Ce class for the power generation facility. The ambient particle classes showed additional small signals from secondary components indicating atmospheric processing. Ambient particle classes containing only a subset of these elements, such as Zn only, Fe only and Pb–K only, were nonspecific, that is, the wind-rose plots were more diffuse and the particles could not be mapped to individual sources. The merits of stack sampling as an aid to interpreting single particle data sets are discussed.  相似文献   
946.
This work evaluates the influence of energy consumption on the future air quality in Beijing, using 2000 as the base year and 2008 as the target year. It establishes the emission inventory of primary PM10, SO2 and NOx related to energy utilization in eight areas of Beijing. The air quality model was adopted to simulate the temporal and spatial distribution of each pollutant concentration in the eight urban areas. Their emission, concentration distribution, and sectoral share responsibility rate were analyzed, and air quality in 2008 was predicted. The industrial sector contributed above 40% of primary PM10 and SO2 resulting from energy consumption, while vehicles accounted for about 65% of NOx. According to the current policy and development trend, air quality in the eight urban areas could become better in 2008 when the average concentrations of primary PM10, SO2 and NO2 related to energy utilization at each monitored site are predicted to be about 25, 50 and 51 μg/m3, respectively. Translated from China Environmental Science, 2005, 25(6): 746–750 [译自: 中国环境科学]  相似文献   
947.
分析了机动车排气检测与维修的现状及存在问题 ,并提出建设有中国特色的I/M管理制度。  相似文献   
948.
通过对中国环境标志计划由来和发展以及环境标志定义的介绍,阐述了中国环境标志标准遵循的原则、框架及标准类别,介绍了中国环境标志认证制度和模式,分析了中国环境标志计划的实施对相关行业节能减排的促进作用,说明了中国环境标志计划已成为国家推动节能减排和循环经济战略的重要手段。  相似文献   
949.
INTRODUCTION: This exploratory study investigated the relationship between vision obstructions from body pillars and lane-change crashes. METHODS: The vision obstructions were quantified by measuring, from the driver's perspective, the horizontal angular sizes and locations of the driver-side A-, B-, and C-pillars. The sample consisted of 21 vehicle models, including 13 passenger cars, 6 SUVs, 1 minivan, and 1 pickup truck. To control for driver differences, going-straight crashes were used for comparison, with the dependent variable being the ratio of lane-change crashes to going-straight crashes. The analysis used North Carolina crash data. RESULTS: The results of a multiple regression indicate that the relative frequency of lane-change crashes tended to increase with both wider A-pillars and with A-pillars located farther away from straight ahead. IMPACT ON INDUSTRY: The finding supports the hypothesis that visibility obstructions due to A-pillars have safety implications.  相似文献   
950.
不同城市机动车尾气排放比较及数据可分享性评价   总被引:1,自引:2,他引:1  
宋宁  张凯山  李媛  陈琳 《环境科学学报》2011,31(12):2774-2784
针对我国绝大多数城市缺乏机动车相关基础数据的实际国情,探讨一种基础数据共享的可能性,用于城市机动车尾气排放清单的计算.以北京、上海、天津及成都4个城市为例,通过综合这些城市现有的机动车相关的基础数据(如机动车保有量,车龄分布,基于驾驶特征的发动机比功率(VSP),外界环境等),运用模型预测他们的机动车尾气排放并和相应城...  相似文献   
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