简介:摘要:环氧树脂生产过程中会产生大量有机废气,如环氧氯丙烷(C3H5ClO)、甲苯(C6H5CH3)等。当前,一般在工业生产中采用吸附法对有机废气进行处理,因此吸附剂的选取非常关键,直接影响有机废气处理效果。木炭作为一种吸附材料被使用,已有很长时间。其主要利用内部复杂的微细孔道结构吸附其他物质,已广泛应用于水源净化和防毒面具中。为了提高碳材料的吸附性能,科学家不懈努力,探索具有优异吸附性能的新型碳材料。20世纪60年代,人们开始研究活性炭纤维,美国首先成功研制出黏胶基活性炭纤维,揭开了高效吸附功能材料的新篇章。此后,人们相继开发出聚丙烯腈基活性炭纤维、酚醛基活性炭纤维(PACF)和沥青基活性炭纤维等。
简介:月球是地球唯一的天然卫星,早期学者认为地月系统是普遍存在的行星一卫星系统的一员,但是月球又有许多特征,如质量异常大,挥发分和Fe元素亏损等,传统理论难以解释这些特征。因此,针对月球的起源提出了四种学说:捕获理论,共增生理论,分裂理论和大碰撞假说。目前对大碰撞假说研究较多,但研究者们始终无法较好解释地月系统氧同位素的高度一致等特征。本文试探性提出新的月球起源分裂模型,能较好的解释某些月球特征,引起研究者们对月球起源新的思考。
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简介:Glacierinventorycompilationduringthepast20yearsandmodificationsofthatfortheEasternPamirandBanggongLakeindicatethatthereare46,342modernglacierswithatotalareaandvolumeof59415km2and5601km3respectivelyinChina.Theseglacierscanbeclassifiedintomaritimeandcontinental(includingsub-continentalandextremelycontinental)types.ResearchesshowthatglaciersinChinahavebeenretreatingsincetheLittleIceAgeandthemasswastagewasacceleratedduringthepast30to40years.BeinganimportantpartofglaciologicalstudiesinChina,icecoreclimaticandenvironmentalstudiesonTibetanPlateauandintheAntarcticahaveprovidedabundant,highresolutioninformationaboutpastclimaticandenvironmentalevolutionovertheTibetanPlateauandAntarctica.ExceptfordifferentparametersrecordedinicecoresrelatingtoclimateandenvironmentchangesonTibetanPlateau,recordsfromicecoresextractedfromdifferentglaciersshowthatthediscrepanciesinclimaticandenvironmentalchangesonthenorthandsouthpartsoftheplateaumaybetheconsequenceofdifferentinfluencingeffectsfromterrestrialandsolarsources.GlaciologicalandmeteorologicalphenomenaimplythatLambertGlaciervalleyisanimportantboundaryofclimateintheeastAntarctica,whichisthoughttobeconnectedwithcyclonicactivitiesandCircum-polarWavesovertheAntarctica.
简介:PermafrostinChinaincludeshighlatitudepermafrostinnortheasternChina,alpinepermafrostinnorthwesternChinaandhighplateaupermafrostontheTibetanPlateau.Thehighaltitudepermafrostisabout92%ofthetotalpermafrostareainChina.Thesouthboundaryorlowerlimitoftheseasonallyfrozengroundisdefinedinaccordancewiththe0℃isothermallineofmeanairtemperatureinJanuary,whichisroughlycorrespondingtothelineextendingfromtheQinlingMountainstotheHuaiheRiverintheeastandtothesoutheastboundaryoftheTibetanPlateauinthewest.SeasonalfrozengroundoccursinlargepartsoftheterritoryinnorthernChina,includingNortheast,North,NorthwestChinaandtheTibetanPlateauexceptforpermafrostregions,andaccountingforabout55%ofthelandareaofChina.Thesouthernlimitofshort-termfrozengroundgenerallyswingssouthandnorthalongthe25°northernlatitudeline,occurringinthewetandwarmsubtropicmonsoonclimaticzone.Itsareaislessthan20%ofthelandareaofChina.