简介:Naturalgascontaininghydrogensulphide(H2S)hasbeenfoundinseveralpetroliferousbasinsinChina,suchastheSichuanBasin,BohaiBayBasin,OrdosBasin,TarimBasin,etc.NaturalgaswithhigherH2Scontents(H2S>5%mol.)ismostlydistributedinboththegasreservoirsofDukouhe,Luojiazhai,PuguangandTieshanpo,whichbelongtotheTriassicFeixianguanFormationinthenortheasternSichuanBasinandthoseoftheKongdian-ShahejieformationsinthenortheasternJinxianSagoftheJizhongDepression,BohaiBayBasin.IntheSichuanBasin,theH2Scontentsofnaturalgasaverageover9%andsomecanbe17%,whilethoseoftheBohaiBayBasinrangefrom40%to92%,beingthenoneofthegasreservoirswiththehighestH2Scontentsintheworld.Basedondetailedobservationandsampleanalysisresultsofatotal5000mofcorefromover70wellsintheabove-mentionedtwobasins,especiallysulfurisotopicanalysisofgypsum,brimstone,pyriteandnaturalgas,alsowithintegratedstudyofthegeochemicalcharacteristicsofhydrocarbons,itisthoughtthatthenaturalgaswithhighH2Scontentsresultedfromthermochemicalsulfatereduction(TSR)reactions.Amongthem,thenaturalgasintheFeixianguanFormationresultedfromTSRreactionsparticipatedbyhydrocarbongas,whilethatintheZhaolanzhuangoftheJinxianSagbeingtheproductofTSRparticipatedbycrudeoil.DuringtheconsumptionprocessofhydrocarbonsduetoTSR,theheavyhydrocarbonswereapttoreactwithsulfate,whichaccordinglyresultedinthedrycoefficientofnaturalgasincreasingandthecarbonisotopesbecomingheavier.
简介:Thedefectchangesin6H-SiCafterannealingand10MeVelectronirradiationhavebeenstudiedbyusingavariable-energypositronbeam.Itwasfoundthatafterannealing,thedefectconcentrationinn-type6H-SiCdecreasedduetorecombinationwithinterstitials.Whenthesamplewasannealedat1400℃for30mininvacuum,a20-nmthicknessSilayerwasfoundonthetopoftheSiCsubstrate,thisisadirectproofoftheSiatomsdiffusingtosurfacewhenannealedathightemperaturestages.After10MeVelectronirradiation,forn-type6H-SiC,theSparameterincreasedfrom0.4739to0.4822,andtherelativepositron-trappingratewasabout27.878timesoftheoriginsample,thisshowsthattherearesomedefectscreatedinn-type6H-SiC.Forp-type6H-SiC,itisveryunclear,thismaybebecauseoftheoppositechargeofvacancydefects.