The Pearl River Delta (PRD) is one of the most industrialized, urbanized and populated regions in China, and thus has been long suffering from severe air pollutions. Space data provide a unique perspective for investigating the atmospheric environment at a regional scale. By utilizing multiple satellite retrievals from 2005 to 2013, this study presented, for the first time, the spatial patterns and temporal trends of typical air pollutants over PRD and its vicinity. As viewed from space, aerosol optical depth (AOD), NO2 and SO2 all had their higher values at the central part of PRD, and showed clear descending gradients as moving to the outskirt of this region. As to the inter-annual variation, all these pollutants had decreasing trends in PRD during the study period, which generally agreed with the relevant in situ measurements. However, the satellite retrievals differed from ground measurements when addressing NO2 and SO2 in the vicinity of PRD. This work also provides the inter-comparison among PRD and three other metropolitan clusters in China: PRD had relatively high AOD, moderate NO2 and low SO2 levels, and it was the only region achieving the effective reduction of NO2 and SO2 during last decade. Unlike the previous three pollutants, HCHO observed by satellite showed very special patterns: it had a relatively homogeneous spatial distribution over both of PRD and its vicinity, and presented an opposite increasing trend from 2005 to 2010. Moreover, PRD had the highest HCHO level among all the metropolitan clusters, hinting a considerable contribution of biogenic origins of HCHO in PRD.
AUTOMATIC METHODS OF ANALYSIS by M. Valcárcel and M. D. Luque de Castro, Volume 9 in series Techniques and Instrumentation in Analytical Chemistry, Elsevier Science Publishers, Amsterdam (1988), 560 pages, US$ 131.50 SELF‐DIFFUSION IN ELECTROLYTE SOLUTIONS: A CRITICAL EXAMINATION OF DATA COMPILED FROM THE LITERATURE by R. Mills and V. M. M. Lobo, Volume 36 published in the series Physical Sciences Data, Elsevier, Amsterdam (1988), 354 pages, US$ 134.25 相似文献
Preliminary mineral magnetic results from a pilot project investigating the suitability of roadside tree leaves as depositories
of vehicular pollution are presented. Tree leaf surfaces (Lime: Tilia europaea; Sycamore: Acer pseudoplatanus) at four roadside and one woodland location in Wolverhampton, UK, have been monitored (July 2003 to November 2003). Mineral
magnetic technologies have revealed spatial variations of particulate pollution concentration throughout the conurbation and
data analysis indicates that magnetic concentration parameters are suitable proxies for fine particulate pollution, which
are particularly hazardous to health. Site-specific traffic management and associated vehicle behaviour appear to be chiefly
responsible for the magnetic concentration differences between sites. Magneto-biomonitoring in this way allows the high-resolution
spatial mapping of particulate matter (PM) pollution, which may also benefit epidemiology in better assessing exposure to
vehicular-derived particulates. Given the speed, measurement sensitivity and non-destructive nature of the technique, it is
proposed that this low-cost approach offers some advantages over centralised monitoring stations to monitor urban roadside
particulate pollution. 相似文献
Many studies explore the feasibility of co-existence between genetically modified (GM) and conventional (non-GM) crops. An important research topic in these studies is the process of outcrossing, i.e., the process of gene flow via pollen flow from GM to non-GM crops. In this paper, we address a new modelling approach to define the environmentally driven processes of outcrossing for maize from existing empirical datasets. In particular, we use equation discovery methodology that combines background knowledge and empirical data from several studies. We induce models that predict the degree of outcrossing rate between the donor (GM) and the recipient (non-GM) maize field from the distance between the fields and the local wind characteristics (speed, direction and duration). This results in highly accurate models, for which both variables (distance and wind) are essential and of roughly equal importance. 相似文献