查看更多>>摘要：Ozone(O3)pollution has a profound impact on human health,vegetation development,and the ecological environment,making it a critical focus of global academic research.In recent years,O3 pollution in China has been on a steady rise,with ozone emerging as the sole conventional pollutant to consistently increase in concentration without any decline.This study conducted a quantitative analysis of O3 concentrations across 367 Chinese cities in 2019,examining spatial autocorrelation and local clustering of O3 levels,and investigated the diverse relationships between human activity factors and O3 concentration.The seasonal fluctuation of O3 exhibited the"M-type"pattern,with peak concentrations in winter and the lowest levels in summer.The center of O3 pollution migrated southeastward,with the area of highest concentration progressively shifting south along the eastern coast.Moreover,O3 concentration showed a strong positive correlation with population density,road freight volume,and industrial emissions,suggesting that human activities,vehicle emissions,and industrial operations are significant contributors to O3 production.The results provide comprehensive information on the characteristics,causes,and occurrence mechanism of O3 in Chinese cities that can be utilized by global government departments to formulate strategies to prevent and control O3 pollution.
查看更多>>摘要：The Gysian ophiolite of NW Iran is located at the intersection of the ophiolite belts of SE Turkey,NE Iraq,and Iran,and provides the opportunity to investigate the pre-served subduction and obduction history of an important tectonic site that has not previously been studied.The ser-pentinized peridotites of the Gysian ophiolite contain the assemblage lizardite+chrysotile+spinel/Mg-spinel with relict clinopyroxene(diopside)and very rare relict orthopy-roxene and olivine.The compositions of clinopyroxenes and spinels are more consistent with the formation of the inferred protolith harzburgites in a fore-arc or supra-subduction zone instead of an abyssal environment.The Gysian ophi-olite is a remnant of the Neo-Tethyan arc-ophiolitic system and records shallow subduction(＜50 km,indicated by the absence of antigorite)in the Late Cretaceous to Paleocene before obduction along thrust faults over the continental margin.We review the spatial trends of the metamorphic grade of the Neo-Tethyan ophiolites in this region and pro-vide detailed information about the petrology and mineral chemistry of the Gysian ophiolite.
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