简介：Variousagriculturalcropresiduesincludingcornstover,corncob,andsorghumstalkwithamoisturecontentof75wt%weresubjectedtoalongpretreatment(12-60h)withsupercriticalCO2(scCO2),atlowtemperature(50-80℃)andapressureof17.5-25.0Mpa.Thesugaryieldsfromtheenzymatichydrolysis(EH)ofthepretreatedsampleswereasmuchasthree-tofourfoldgreaterthanthoseaffordedbytherawmaterials.However,whenpretreatmentwasconductedwithinashorttime(e.g.0.5h),aspreviouslyreportedintheliterature,onlyaslightincreaseintheEHsugaryieldswasobserved.TheproposedscCO2pretreatmentmechanismdemonstratedtheroleofmoistureinthesystem.Wetting,softening,andswellingwereobservedtomainlyaffectthelignocellulosewhenasuitableamountofwaterwasadded.Finally,thesampleswereanalysedbyX-raydiffractionandscanningelectronmicroscopy,beforeandafterpretreatment,toinvestigatethechangesinthemicroscopicstructureofthebiomass.

简介：Thermoelectricityisatherrnorelatedpropertythatisofgreatimportanceinsingle-moleculejunctions.Theelectricalconductance(σ),electron-derivedthermalconductance(kel)andSeebeckcoefficient(S)ofBgo-basedsingle-moleculejunctionsareinvestigatedbyusingdensityfunctionaltheoryincombinationwithnon-equilibriumGreen'sfunction.Whenthedistancebetweentheleft/rightelectrodesis11.4A,therelationshipbetweenσandkelobeystheWiedemann-FranzlawverywellbecauseofthestronghybridizationbetweenB80molecularorbitalsandthesurfacestatesofAuelectrodes.Furthermore,thecalculatedLorenznumberisclosetothefamousvalueinmetalordegeneratesemiconductors.Inaddition,Sisonly—19.09μV/Kat300K,thusleadingtothesmallerelectron'sthermoelectriefigureofmerit(ZeiT=S^2σT/Kel).Interestingly,thestrainandchemicalpotentialcanmodulateB80-basedsingle-moleculejunctionsfromn-typetop-typewhenthecompressivestrainreaches—0.6Aorthechemicalpotentialshiftsto—0.16eV.ThismightbeattributedthatSreflectstheasymmetryintheelectricalconductancewithrespecttothechemicalpotentialandisproportionaltotheslopesofthetransmissionspectrum.