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871.
This paper explains the application of structural path analysis (SPA), an input–output-based technique for measuring flows in ecological and linked ecological–economic networks. Previous methods of input–output flow analysis have concluded with aggregate indexes relying on the summing feature of the Leontief inverse in order to completely account for throughflows along a multitude of inter-compartmental paths. This paper shows that for most linear dissipative networks, a manageable number of paths of limited length exist that cover in the order of 99% or more of total throughflow. These paths can be conveniently extracted, enumerated and ranked using SPA. 相似文献
872.
873.
Retention of trace elements in coal-fired flue gas by a novel heterogeneous agglomeration technology
Yushan Ji Xiangzheng Cui Jingchao Liu Tianle Zhang Shuzhou Wei Junfeng Zhang Yongchun Zhao Junying Zhang 《环境科学学报(英文版)》2023,35(3):234-243
Heterogeneous agglomeration (HA) is a very potential technology for coal-fired flue gas treatment.In this paper,the distribution and migration mechanisms of trace elements (TEs such as Se,As and Pb in CFPPs were studied on a 30,000 m3/hr pilot-scale experimental plat form.The influences of HA on the removal efficiency of gaseous and particulate TEs were well analyzed.The results showed that Se,As and Pb were enriched in fly ash,and their sen sitivity to particle size is quite differen... 相似文献
874.
875.
876.
课题组于2017年冬季在南京北郊开展了为期45d的雾/霾外场综合观测,并选取12月30~31日一次平流辐射雾过程,分析了气象要素、雾和气溶胶的宏微观特征.结果表明:冷平流与夜间辐射冷却造成的持续性降温为此次雾发展的主要原因,而短波辐射增强则为雾消散的主导因子;此次雾过程存在爆发性增长的特征,表现为17min内含水量的量级由10-4g/m3增加至10-1g/m3,其中雾滴数浓度的增加对其贡献率可达67%;强浓雾微物理量的时间变率波动性强,雾的水平分布存在显著的不均匀性特征;日出后的强浓雾阶段中存在纳米级气溶胶累积现象,空气动力学直径在10~50nm气溶胶的数浓度增加率可达2817cm-3/h,从二次气溶胶生成(SO2的气-粒及气-液转化过程)、输送(人为活动造成的气溶胶累积及雾中垂直向湍流的输送)等方面探讨现象出现的原因. 相似文献
877.
Angelika Poesel Douglas A. Nelson H. Lisle Gibbs John W. Olesik 《Behavioral ecology and sociobiology》2008,63(1):153-158
Tracking dispersal and migratory movements of animals over small and large spatial scales is a challenge. In birds, a promising
yet underutilized tool is the trace elemental composition of feathers. The elemental profile of a feather may reveal information
about the geographic origin of a bird provided that molting occurs on the breeding grounds and that elemental differences
exist between breeding areas. Here, we explore the use of trace elemental composition in body feathers of the Puget Sound
white-crowned sparrow Zonotrichia leucophrys pugetensis as a tool (1) to discriminate among birds collected in four different song dialect populations along a 400-km stretch of
the Pacific Northwest coast and (2) to assign males singing nonlocal dialects in one population to potential natal populations.
Inductively coupled plasma mass spectrometry detected 34 trace elements in sampled feathers and in a discriminant function
analysis seven of these elements differed among the four source populations. Half of the six nonlocal dialect singers, who
were likely to have immigrated into the focal population, were assigned to a population that matched their song dialect. Our
study suggests that feather microchemistry is a promising tool for identifying geographic origins of dispersing birds over
small geographic scales and in combination with other markers, such as song, may give insight into ecological and evolutionary
processes. 相似文献
878.
通过在一维煤粉燃烧炉上进行无烟煤添加高岭土吸附剂的燃烧实验,研究了无烟煤及其燃烧产物中18种环境有害微量元素的含量和分布;计算了高岭土在不同燃烧工况条件下对每种环境有害微量元素的吸附率.结果表明,高岭土对环境有害微量元素Cd, Pb, Sb, Sn, Ba, Co, Be, Cr, Ni, Mo, Tl, V, U, Mn, Th具有不同的吸附作用,吸附率为11.6%~500%;吸附效率与元素种类、燃烧工况等因素有关,环境有害微量元素Cd, Pb, Zn, Sb, Ba, Co, Be, Cr, Ni, Mo, Tl, V, U, Mn, Th的吸附能力,分级燃烧比不分级燃烧吸附效果更好,总吸附率差为8.4%~481%. 相似文献
879.
在分析ISO14000想要达到的目的以及ISO14000系列标准基本构成的基础上,对组织是否要申请ISO14000认证,以及什么时候申请ISO14001认证的策略作一讨论。 相似文献
880.
The content of As, Cd, Cr, Cu, Fe, Hg, Mg, Mn, Pb, and Zn was determined in Rosa damascena, Vitis vinifera, Crocus sativus, and Olea europaea L. herbal extracts produced in different areas in Greece. Samples were mineralized in a closed microwave system using nitric acid, and the concentration of all metals was determined by flame atomic absorption spectrometry. The herbal extracts contained As, Cd, Cr, Hg, Mn, and Pb at concentrations below their respective limits of detection, whereas Cu, Fe, Mg, and Zn were determined in varying quantities. The proposed method is precise and accurate, thus it can be used for the determination of metals in Rosa damascena, Vitis vinifera, Crocus sativus, and Olea europaea L. herbal extracts. 相似文献