简介:Inordertobetterunderstandthecompositionalandstructuralcomplexityofdissolvedorganicmatter(DOM)macromoleculesandprovidemechanisticinformationonthebindingofhydrophobicorganiccontaminants(HOCs)toDOM,wefractionatedlargeamountsoflakewaterintothreehydrophobicDOM-fractions.Thevariationofthepartitioningcoef?cients(KDOC)ofpyreneatdifferentpHlevelswasexaminedby?orescencequenchingtitration.Resultsshowthat,relativetothemorepolaracidicDOM-fractions,thehydrophobicneutralfractionexhibitsahighersorptionabilitytopyrene.Generally,thesorptionofpyrenetothethreehydrophobicfractionsisstronglypH-dependent.TheKDOCvaluesofpyrenegenerallyincreasewithdecreasingpHlevels,whichisespeciallyobviousinthesorptionofpyrenetothefulvicacidfractions,suggestingthatthebindingiscontrolledbyhydrophobicinteractions.Themechanismsunderlyingthebindingofpyrenetothehydrophobicfractionswerealsodiscussed.Ourdataarebene?cialtofurtherunderstandingthebindingofHOCstoDOMandhowithasbeenaffected,whichmayresultinmoreaccuratepredictionsofKDOC.
简介:2015年7月3日新疆皮山Ms6.5级地震灾区地处塔里木盆地南缘,该地自然条件恶劣,经济极为落后,灾区农村的民房除了抗震安居工程建设的房屋外,还有大量抗震性能较差的民居,在地震中受损严重,经济损失较大。灾区大部分位于山前溢出带,地下水位浅、地基土层软弱等场地条件对地震动有放大作用,震害影响范围较大。灾后重建中应继续加大安居富民工程的经费投入力度。灾区北部人口密集,地基土层软弱,工程地质条件差,建议在今后的安居富民建设中加强地基处理。