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991.
992.
我国几种典型树种非甲烷烃类的排放特征 总被引:18,自引:3,他引:18
采用封闭式采样法和带有预浓缩及程序升温装置的熔融毛细管柱气相色谱仪,对我国的松、柏、杨、槐等几种典型树种排放非甲烷烃类(NMHC)的组成和排放速率进行了定性和定量测定,初步确定了不同树种和的特征物种和排放规律,结果表明,针叶树种和阔叶树种排放的NMHC组成差别很大,各树种的排放规律除了与自身的结构和生理活动等在内在因素有关外,还在不同程度上受到外界因素(主要是温度和光强)的影响,一般温度越高,光强 相似文献
993.
制定恶臭物质排放标准的原则和方法 总被引:1,自引:0,他引:1
本文叙述了制定恶臭物质排放标准的技术原则、计算方法和公式.同时以天津为例,介绍了对恶臭排放标准计算公式中的主要参数选取及确定系数的方法经验. 相似文献
994.
995.
996.
徐新华 《生态与农村环境学报》1997,(3)
对1990年江浙沪地区人为氨排放进行了统计计算,结果表明江浙沪地区人为氨排放总量为769.30kt,主要的氨来源为化肥的使用、家畜以及能源的消耗,其中家畜占300%、化肥使用占250%、能源消耗占258%。江浙沪地区单位面积排放强度为3.65t/km2,而人均排放量为626kg/人。 相似文献
997.
Nitric oxide emission from a typical vegetable field in the Pearl River Delta, China 总被引:1,自引:0,他引:1
Croplands contribute to atmospheric nitric oxide (NO), but very limited data are available about NO fluxes from intensively managed croplands in China. In this study, NO fluxes were measured in a typical vegetable field planted with flowering Chinese cabbage (Brassica campestris L. ssp. Chinensis var. utilis Tsen et Lee), which is the most widely cultivated vegetable in Guangdong province, south China. NO emission drastically increased after nitrogen fertilizer application, and other practices involving loosening the soil also enhanced NO emission. Mean NO emission flux was 47.5 ng N m−2 s–1 over a complete growth cycle. Annual NO emission from the vegetable field was about 10.1 kg N ha−1 yr−1. Fertilizer-induced NO emission factor was estimated to be 2.4%. Total NO emission from vegetable fields in Guangdong province was roughly estimated to be 11.7 Gg N yr−1 based on the vegetable field area and annual NO emission rate, and to be 13.3 Gg N yr−1 based on fertilizer-induced NO emission factor and background NO emission. This means that NO emission from vegetable fields was approximately 6% of NOx from commercial energy consumption in Guangdong province. 相似文献
998.
999.
Chan-Wei Wu Rong-Horng Chen Jen-Yung Pu Ta-Hui Lin 《Atmospheric environment (Oxford, England : 1994)》2004,38(40):7093
Ethanol–gasoline-blended fuel was tested in a conventional engine under various air–fuel equivalence ratios (λ) for its performance and emissions. The amount of fuel injection was adjusted manually by an open-loop control system using a CONSULT controller. It was found that without changing throttle opening and injection strategy, λ could be extended to a leaner condition as ethanol content increased. The results of engine performance tests showed that torque output would increase slightly at small throttle valve opening when ethanol–gasoline-blended fuel was used. It was also shown that CO and HC emissions were reduced with the increase of ethanol content in the blended fuel, which resulted from oxygen enrichment. At an air–fuel equivalence ratio slightly larger than one, the smallest amounts of CO and HC and the largest amounts of CO2 resulted. It was noted that under the lean combustion condition, CO2 emission was controlled by air–fuel equivalence ratio; while under the rich combustion condition, CO2 emission is offset by CO emission. It was also found that CO2 emission per unit horse power output for blended fuel was similar or less than that for gasoline fuel. From the experimental data, the optimal ethanol content in the gasoline and air–fuel equivalence ratio in terms of engine performance and air pollution was found. 相似文献
1000.
Sergey Kakareka Sergey Gromov Jozef Pacyna Tamara Kukharchyk 《Atmospheric environment (Oxford, England : 1994)》2004,38(40):7101-7109
As the result of our research, the specific procedures to use emission factor methodology were developed and applied for trace metal emission evaluation into the atmosphere over the territory of the former Soviet Union. The existing data on heavy metal emissions were revised as background information from official sources and expert estimations. Source categories and different initial information as well as the concept of spatial emission distribution were defined and observed. The calculated atmospheric emissions of lead, cadmium and mercury were produced among the main source categories of 12 NIS countries for 1990, 1995 and 1997, using modified emission coefficients.Total cadmium emissions into the atmosphere from determined source categories were estimated as 388.4 tonnes in 1990 for the whole domain with reduction by up to 207.0 tonnes per year for 1997. Mercury emissions were estimated as equal to 303.2 tonnes in 1990 and 159.8 tonnes in 1997. Lead emission amounted to 24903.0 tonnes in 1990, and 9652.5 tonnes in 1997.The results of the evaluation demonstrated the general trends of atmospheric heavy metal emissions with a greater decrease during the first half of the 1990s followed later by the rather stable level to be explained by recession in industrial activity and fuel consumption in NIS in that period. The significant spatial variations of atmospheric emissions over vast territories are described based on the results of their distribution according to 1×1 degree grid with remarkably higher values in the location of industrial cities. 相似文献