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1、Part2：Chapter2：CoalFormationORIGINSofCoalCoalwasformedfrompartiallydecomposed(andsubsequentlymetamorphosed变质的)plantdebris残骸whichhadcollectedinregionswherewaterlogged充满水的orswampy沼泽的conditionsprevailed.Theseconditionspreventedcompletedecayofthedebrisasitaccumulatedandeventuallyledtothematerialno
2、wknownascoal.Chapter2：CoalFormationORIGINSofCoalIngeneralterms,thedebrisconsistedoftrees,ferns（蕨类植物）,bushes灌木,lycopods石松,andseveralthousandplantspeciesthathavebeenidentifiedincoalbeds.Similartypesofplantremains残骸maybefoundinalltypes(ranks)ofcoalbut,ofcourse,therelativeamountsvaryconsiderably.O
3、nthisbasis,itisnotsurprisingthatcoaldiffersmarkedlyincompositionfromonelocaletoanother.Chapter2：CoalFormationThequestionsare（1）Whataretheplantcomponents？（2）Howwascoalformedfromplants？Section1Materialsofcoalformation1、Coalwasformedfromplants.Themakeupoftheorganicportionofplantsconsistsofcarbohy
4、drates（碳水化合物）,lignin（木质素）,fattycompounds（脂类化合物）andproteins（蛋白质）but,ofcourse,therelativeamountsofeachoftheseconstituentsvariesgreatlywiththeparticularspeciesofplantaswellastherelativestageofgrowthoftheplant.Section1Materialsofcoalformation1.1LigninLigninhasbeenconsideredthemostimportantsubstanc
5、einvolvedinthetransformationofplantconstituentsintocoal.Whilethemolecularstructureofligninremainslargelyunknownandspeculative推测的,someinformationhasbeenaffordedbytheidentificationofmorespecificmoleculesfromtheligninsofvariousplants.coniferylalcoholsinapylalcoholp-coumarylalcohol针叶树的松柏醇落叶树的芥子醇乔木
6、的－香豆醇Section1MaterialsofcoalformationThelignincontentofplantsmayfallwithintherange10-35%w/wwhileinwoodymaterialtheligninmaybewithinthenarrowerrangeof25-30%w/wLigninSection1Materialsofcoalformation1.2CarbohydratesCarbohydratesareagroupofcompoundswithcommonfeatures,egmonosaccharides单糖disacchari
7、des二糖，trisaccharides三糖,morelikely,thehighmolecularweightpolysaccharides多糖.Thesimplesugars,ormonosaccharides,arethebuildingblocksofthemorecomplexcarbohydrates.Sugarsareactuallypolyhydric多羟基alcoholscontainingfivetoeightcarbonatoms.Section
