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111.
European scale application of atmospheric reactive nitrogen measurements in a low-cost approach to infer dry deposition fluxes 总被引:1,自引:0,他引:1
Y.S. Tang I. Simmons N. van Dijk C. Di Marco E. Nemitz U. Dmmgen K. Gilke V. Djuricic S. Vidic Z. Gliha D. Borovecki M. Mitosinkova J.E. Hanssen T.H. Uggerud M.J. Sanz P. Sanz J.V. Chorda C.R. Flechard Y. Fauvel M. Ferm C. Perrino M.A. Sutton 《Agriculture, ecosystems & environment》2009,133(3-4):183
A European scale network was established in 2006 as part of the NitroEurope Integrated Project to infer reactive nitrogen (Nr) dry deposition fluxes, based on low-cost sampling of gaseous and aerosol species and inferential modelling. The network provides monthly measurements of NH3, NH4+, HNO3 and NO3−, as well as SO2, SO42−, HCl, Cl− and base cations at 58 sites. Measurements are made with an established low-cost denuder methodology (DELTA) as a basis to: (1) examine temporal trends and spatial patterns across Europe, (2) improve and calibrate inferential modelling techniques to estimate exchange of Nr species, (3) provide best estimates of atmospheric dry N deposition, and (4) permit an analysis of net GHG exchange in relation to atmospheric and agricultural N inputs at the European scale. Responsibility for measurements is shared among seven European laboratories. An inter-comparison of the DELTA implementation by 6 laboratories at 4 test sites (Montelibretti, Italy; Braunschweig, Germany; Paterna, Spain and Auchencorth, UK) from July to October 2006 provided training for the laboratories and showed that good agreement was achieved in different climatic conditions (87% of laboratory site-means within 20% of the inter-laboratory median). Results obtained from the first year of measurements show substantial spatial variability in atmospheric Nr concentrations, illustrating the major local (NH3) and regional (HNO3, NO3−, and NH4+) differences in Nr concentrations. These results provide the basis to develop future estimates of site-based Nr dry deposition fluxes across Europe, and highlight the role of NH3, largely of agricultural origin, which was the largest single constituent and will dominate dry Nr fluxes at most sites. 相似文献
112.
113.
农地非农化代际配置与农地资源损失 总被引:3,自引:0,他引:3
合理的资源利用要求资源配置在代际上是有效率的。在资源代际最优配置原理的基础上,建立了一个衡量农地非农化是否符合代际配置效率的宏观决策模型,对我国20世纪90年代以来的农地非农化进行了检验。结果显示,若以1989-2003年为研究区间,1989-1996年阶段东、中、西部地区的过度非农化比例分别占各自实际非农化数量的6.58%、6.84%和7.85%,反映出1989-1996年期间的农地非农化存在一定的短期行为,造成农地的过度非农化。因此,未来一段时间的农地非农化政策应该进一步控制农地非农化的速度,来保证农地资源能够在未来得到更优的利用。 相似文献
114.
CO2是《京都议定书》要求减排的6种温室气体之一,《京都议定书》还确立了有助于发展中国家获得资金和先进技术的清洁发展机制(CDM)。本文结合实际工程案例,介绍了合成氨副产CO2气的回收和利用方法,为我国氮肥行业申请CDM项目资助,回收利用CO2,减少CO2排放提供技术参考。 相似文献
115.
在水质监测中,氨氮的监测是十分重要且常见的项目之一。氨氮是释放游离氨的主要源头,而游离氨的含量上升是导致水体富营养的元凶之一,因此,监测水体中氨氮的含量是水环境监测工作的主要内容之一。随着环保意识的增强,我国开始越来越重视对自然环境的监测工作,也逐渐认识到氨氮在水体中导致的危害,开始积极开发和应用分析技术,用于监测水体中氨氮的含量及其变化趋势,为后续的资源保护、污染质量工作奠定基础。本文从常见的现代分析技术入手,分析并探讨现代分析技术在水质氨氮监测中的具体应用方式,希望可以为提升我国水质监测工作质量提供一些思路。 相似文献
116.
一个适用于区域性大气环境模拟的大气光化学模式 总被引:10,自引:2,他引:8
根据“计数物种”法对光化学反应机制的分析,建立了一个适用于区域性光化学反应模拟的模式,该模式能较好地模拟出NO_x、O_3及H_2O_2等大气光化学污染物的变化,在保证模拟准确性的同时,该模式形式简单,有利于在实际大气环境质量模拟中应用. 相似文献
117.
Linda A. Joyce Curtis H. Flather Patricia A. Flebbe Thomas W. Hoekstra Stan J. Ursic 《Environmental management》1990,14(4):489-500
The impact of timber management and land-use change on forage production, turkey and deer abundance, red-cockaded woodpecker
colonies, water yield, and trout abundance was projected as part of a policy study focusing on the southern United States.
The multiresource modeling framework used in this study linked extant timber management and land-area policy models with newly
developed models for forage, wildlife, fish, and water. Resource production was integrated through a commonly defined land
base that could be geographically partitioned according to individual resource needs. Resources were responsive to changes
in land use, particularly human-related, and timber management, particularly the harvest of older stands, and the conversion
to planted pine. 相似文献
118.
To ensure the safety of drinking water, ozone (O3) has been extensively applied in drinking water treatment plants to further remove natural organic matter (NOM). However, the surface water and groundwater near the coastal areas often contain high concentrations of bromide ion (Br?). Considering the risk of bromate (BrO3?) formation in ozonation of the sand-filtered water, the inhibitory efficiencies of hydrogen peroxide (H2O2) and ammonia (NH3) on BrO3? formation during ozonation process were compared. The addition of H2O2 effectively inhibited BrO3? formation at an initial Br? concentration amended to 350 µg/L. The inhibition efficiencies reached 59.6 and 100% when the mass ratio of H2O2/O3 was 0.25 and > 0.5, respectively. The UV254 and total organic carbon (TOC) also decreased after adding H2O2, while the formation potential of trihalomethanes (THMsFP) increased especially in subsequent chlorination process at a low dose of H2O2. To control the formation of both BrO3? and THMs, a relatively large dose of O3 and a high ratio of H2O2/O3were generally needed. NH3 addition inhibited BrO3? formation when the background ammonia nitrogen (NH3N) concentration was low. There was no significant correlation between BrO3? inhibition efficiency and NH3 dose, and a small amount of NH3N (0.2 mg/L) could obviously inhibit BrO3? formation. The oxidation of NOM seemed unaffected by NH3 addition, and the structure of NOM reflected by synchronous fluorescence (SF) scanning remained almost unchanged before and after adding NH3. Considering the formation of BrO3? and THMs, the optimal dose of NH3 was suggested to be 0.5 mg/L. 相似文献
119.
Chen Zongliang Zhang Yang Wang Yubao Zhuang Yahui KazuhikoSakamoto Katsunori Kimijim Tadao Suzuki Masahiro Uchiyam Yoshikazu Hashimoto Hisao oht Yasuaki mae NobutoshiHoriuchi Shin Suzuki 《环境科学学报(英文版)》1990,2(1):41-48
The conversion rates of SO2 to SO2-4 and NO2 to HNO3+NO3- are estimated from the field-data obtained in Beijing in summer, 1988. The results show that the conversion rate of NO2 is about four times as much as that of SO2; The conversion rates have a diurnal variation in a day. On the average, the rate of SO2 is estimated to be 4.7% h-1 during the daytime and 3.4% h-1 during the nighttime. Similarly, the rate of NO2 is estimated to be 17.2% h-1 and 12% h-1 respectively. 相似文献
120.
通过对六种植物配置方式及三种开发模式的对比试验分析,试验出了一种融水土保持效益与经济效益于一体的高效生态经济型造林模式,并探讨了灰毡毛忍冬产量与海拔高度的关系.结果表明:在自然条件恶劣的小沙江高海拔山区,采用金银花(品种为灰毡毛忍冬) 三木药材或其它草本药材,运用景观生态学原理进行设计开发,可获得很好的经济效益与社会效益,并能保持山区的可持续发展.同时还试验出了主栽树种灰毡毛忍冬在海拔1000~1400m之间时经济效益最好. 相似文献