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简介:目的:研究徐长卿(CynanchumpaniculatumBge.)中C21甾体化学成分.方法:应用多种色谱柱层析法对徐长卿的乙酸乙酯部位进行化学成分的分离,并通过波谱技术鉴定化合物的结构,结果:分离鉴定了7个C21甾体化合物,分别为3β,14-dihydroxy-14β-pregn-5-en-20-one(Ⅰ),glaucogeninC(Ⅱ),glaucogeninA(Ⅲ),glaucogeninD(Ⅳ),neocynapanogeninF(Ⅴ),glaucogeninC3-O-β-D-thevetoside(Ⅵ),neoeynapanogeninF3-O-β-D-oleandropyranoside(Ⅶ).结论:化合物Ⅲ、Ⅳ、Ⅵ为首次从该植物中分离得到.
简介:Aerobicstaticpilecomposting(mechanicalturningevery3days)ofpigmanurewaspreparedat8m3windrowheaps.Sawdustwasusedasthebulkingagenttoprovideadditionalcarbonandtoincreasetheporosityofthesubstrate.TwotreatmentsatinitialC/Nratiosof30and15,respectively,weredesignedinthestudy.Dissolvedorganiccarbon(DOC),solubleNH4+-N,C/Nratiosinsolidandaqueousphases,E4/E6ratios,andseedgerminationindex(GI)weredeterminedtoevaluatethematurityoftheco-composts.Seedgerminationindex,abiologicalparameter,wassuggestedasoneofthemostreliablematurityindicatorsfororganiccompost.TheresultsshowedthatthetreatmentattheinitialC/Nratioof30reachedmaturityafter49daysofcomposting;however,thetreatmentattheinitialC/Nratioof15shouldrequirecompostingtimeoflongerthan63daystoobtainmaturation.Chemicalmulti-indicatorevaluationwasnecessary,andtheGImeasurementwastherecommendedapproachformaturityevaluationinthestudy.
简介:Catalyticcombustionofpropane-airmixturewasinvestigated.Platinumcatalystsoveraflatstainlesssteelwithγ-aluminawashcoatwereemployed.Theemployedburnerhasthreecatalystssetparalleltothemixtureflow,spacedatanintervalof5,10and15mm.Bothexperimentandnumericalsimulationweremadeatinlettemperatureof553K,inletvelocityof3to7m/sandequivalenceratioof0.3to0.5.Inthenumericalsimulation,two-dimensional,steadystatemodelwasdevelopedtocalculatethetemperatureandspeciesconcentrationingas-phase.Inthismodel.chemicalreactiononthecatalystsurfaceandthatinthegasphasewereassumedtooccurinthree-steps.Thenumericalresultsshowgoodagreementwithexperimentalresults.Itwasfoundthatthepropertiesofthecatalyststronglyaffectthecatalystsurfacetemperature.Especially,thethermalconductivityofcatalysthasagreateffect,whiletheemissivityofcatalysthaslesseffect.