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1.
Liu XY Xiao HY Liu CQ Li YY Xiao HW 《Environmental pollution (Barking, Essex : 1987)》2008,156(3):715-722
Nitrogen concentration and δ15N in 175 epilithic moss samples were investigated along four directions from urban to rural sites in Guiyang, SW China. The spatial variations of moss N concentration and δ15N revealed that atmospheric N deposition is dominated by NHx-N from two major sources (urban sewage NH3 and agricultural NH3), the deposition of urban-derived NHx followed a point source pattern characterized by an exponential decline with distance from the urban center, while the agricultural-derived NHx was shown to be a non-point source. The relationship between moss N concentration and distance (y = 1.5e−0.13x + 1.26) indicated that the maximum transporting distance of urban-derived NHx averaged 41 km from the urban center, and it could be determined from the relationship between moss δ15N and distance [y = 2.54 ln(x) − 12.227] that urban-derived NHx was proportionally lower than agricultural-derived NHx in N deposition at sites beyond 17.2 km from the urban center. Consequently, the variation of urban-derived NHx with distance from the urban center could be modeled as y = 56.272e−0.116x − 0.481 in the Guiyang area. 相似文献
2.
Manning WJ Paoletti E Sandermann H Ernst D 《Environmental pollution (Barking, Essex : 1987)》2011,159(12):3283-3293
Ethylenediurea (EDU) has been widely used to prevent ozone (O3) injury and crop losses in crop plants and growth reductions in forest trees. Successful use requires establishing a dose/response curve for EDU and the proposed plant in the absence of O3 and in the presence of O3 before initiating multiple applications to prevent O3 injury. EDU can be used to verify foliar O3 symptoms in the field, and to screen plants for sensitivity to O3 under ambient conditions. Despite considerable research, the mode of action of EDU remains elusive. Additional research on the mode of action of EDU in suppressing O3 injury in plants may also be helpful in understanding the mode of action of O3 in causing injury in plants. 相似文献