简介：ConstructingareasonablereactionkineticmodelforCr-containingwasteincinerationisofhighsignificancetostudytheeffectofvariousfactors,suchastemperature,Cl,onitshexavalentchromiumcompounds.Inthispaper,aprimaryCr/H/Air/ClreactionkineticmodelisbuiltandstudiedbyGaussian03codewithquantumchemistrytheory.Numericalresultsshowthattherearetwooverallreactionsinthemodel,eachofthetwooverallreactionsconsistsoftheirrespectivetwoelementaryreactions.Sothetwooverallreactionsshouldbeomittedfromthemodel.Instead,thefourelementaryreactionsshouldbeaddedintheCr/H/Air/Clreactionkineticmodel.Theactivationenergiesofthefourelementaryreactionsarealsocalculated.

简介：一直以来，主要采用重量法测定BHP（Basichydrogenperoxide）废液中氯化钾的浓度，一般要经过酸化、蒸发、烘干至称重才能得到分析结果，耗时长，操作繁琐。离子色谱法测定常见阴离子（F^-，Cl^-，NO3^-，SO4^2-等）以简便、快速、灵敏而著称，如果将离子色谱法引入BHP废液的分析，无疑将大大减少工作量，节约工作时间，提高工作效率。但是BHP废液碱性很强、过氧化氢浓度较高并且含有机稳定剂，必须预先进行样品前处理。实验采用电炉加热、灼烧分解，C18过滤有机物的前处理方法，

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简介：利用芯片CL1502作为反馈控制芯片设计了一款高效的14WLED恒流驱动电源。详细介绍了该电源电路中每一元件的计算及选择。结合CL1502说明书及电感电流临界模式的特点,详细给出了该电源方案中的核心元件—电感的设计步骤。应用该方案设计的电源效率可达91%,电流的输出精度可达±3%,整机成本不到1.3元,具有极高的性价比。

简介：利用2种杂化的密度泛函DFT方法（BHLYP和B3LYP）,2种纯DFT方法（BLYP和BP86）,以DZP＋＋为基函数对Cl2O5/Cl2O5-的平衡构型进行了量子化学计算,研究了它们的几何构型、相对能量和振动频率,并对Cl2O5/Cl2O5-体系的电子亲和势进行了理论预测.

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简介：IntroductionInthepastseveralyears,muchresearchworkhasbeendoneforthesynthesisofC-fusedbicyclo-β-lactamcompoundsandaconcise“DoubleAnnulation”procedurehasbeendeveloped.Theβ-lactamringisformedbytheclassicalStaudingerreaction［1—3］betweenα-(alkylthio)acylchlorideandanequivalentα,β-unsaturatedimine.Thesulfurringissubsequentlyfusedontotheβ-lactamunitbymeansofahalogen-promotedheterocyclizationprocess［4—6］.ThisprocedurewasappliedtothesynthesisofpenemasillustratedinFig.1.TheobtainedX-penemsareakindofimportantintermediatesforsynthesizingaseriesofβ-lactamcompounds,forexample,theyarecarboxylatedbycouplingreactionsontheCatomwhichislinkedtohalagen,formingpenem［7］.Animportantpurposeintheresearchfieldistoprobeintonewβ-lactammedicines.

简介：送检地下水水型为HCO3^--SO4^2--Ca^2＋-（Mg^2＋）型，酸碱度为中性、水介质属氧化型（Eh=640my）、低矿化，样品水中各项水质分析项目为，K^＋＋Na^＋，Ca^2＋，Mg^2＋，Fe^3＋，Cl^-，SO4^2-，HCO3^-，CO3^2-，NO3^-，OH^-；所对应分析值为0．670×10^-3，1．200×10^-3，0．400×10^-3，1．79×10^-3，0．036×10^-3，0．88×10^-3，2．074×10^-3，10^-5.863，0．035×10^-3，10^-7.07。

简介：为了明确团聚现象及表面性质对ZnS纳米材料发光性质的影响，采用SiO2对ZnS材料进行了表面修饰，并对ZnS及ZnS／SiO2复合材料的光学性质进行对比研究。采用吸收光谱分析了包覆前后光吸收性质的差异，发现SiO2包覆后ZnS纳米材料的带边由333nm红移至360nm。为了研究ZnS纳米材料与ZnS／SiO2纳米复合材料的光发射性质，分别对含纳米材料的水溶液样品及粉末样品的发光光谱进行了采集。对比研究的结果表明，SiO2包覆后ZnS纳米材料在蓝紫光区的发光得到了明显增强。以氙灯作为激发光源所获得荧光光谱显示ZnS／SiO2粉末样品发光的积分强度增大为原来的17．5倍，但相同条件下针对溶液样品的测试结果显示其发光强度只增大了1．1倍，这种增强可用SiO2的存在抑制了ZnS纳米粒子间的团聚来解释，且这一推断由325nm紫外激光激发下获得的光致发光数据进行了验证。

简介：IntheinterlayerexpansionofthelayeredzeoliteprecursorCOK-5,aSn,salt,bis(2,4-pentanedionate)-dichlorotin[Sn(acac)2Cl2],insteadofasilylatingagentwasusedtolinkthelayersat180°C.Theobtainedmaterial,whichisdesignedasSn-COE-5,showsashiftofthefirstXRDreflection,whichisverysimilartothatofCOK-5interlayerexpandedwithdichlorodimethylsilane(DCDMS),indicatinganincreaseininterlayerdistance.X-raydiffraction(XRD),N2sorptionisotherms,inductivelycoupledplasma(ICP),andX-rayphotoelectronspectroscopy(XPS)supporttheincorporationofisolatedSnsitesinthesample.Intheconversionofglucosetolevulinicacid,Sn-COE-5exhibitsmuchhigheractivitythanCOK-5,whichisduetothepresenceofLewisacidicsitesintheSn-COE-5.

简介：Acylationreactionofanthracenewithoxalylchlorideinthepresenceof[Emim]C1-A1C13ionicliquidhasbeeninvestigated.Pure1,2-aceanthryenedione,whichisusedasintermediateoffunctionalaromaticpolymermaterial,wasobtainedbyrecrystallingthereactionmixturewithaetherandwasdeterminedbyGC/MS,1HNMRandFTIRanalysis.Theinfluencesofvariousparameters,suchasthecontentsofAlCl3in[Emim]C1-A1C13,theamountofacylationagent,amountof[Emim]C1-A1C13,reactiontemperatureandreactiontimewereinvestigated.Theoptimumconditionswereasfollows:themolarfractionofA1C13inionicliquid[x(AlCl3)]being0.67,molarratioofionicliquidtoanthracenebeing2:1,molarratioofoxalylchloridetoanthracenebeing2:1,reactiontemperaturebeing40℃andreactiontimebeing6h.Underaboveconditions,theyieldandselectivityof1,2-aceanthrylenedionecanreach91.5%and98.3%respectively.Furthermore,[Emim]C1-A1C13ionicliquid,comparedwithmetalhalidessuchasAlCl3,wasfoundtocatalyzethereactionasanovelenvironmentalfriendlycatalystandsolventandcanbereused.

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.

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简介：Kineticsofchloride/sulfate,chloride/nitrateandnitrate/sulfateforwardexchangesandreverseexchangesatsolutionconcentrationsof1N,0.2Nand0.02Non201×7strongbaseanionexchangeresin,respectively,havebeenexaminedat25℃.Itisfoundthattheforwardandthereverseexchangeratesofthetwogivenionsatlowsolutionconcentration,respectively,underidenticalconditionscanbecontrolledbydifferentmechanisms,whilethoseathighsolutionconcentrationareallcontrolledbyparticlediffusion.Theternaryexchangeratesofsulfate/(chloride+nitrate)andnitrate/(chloride+sulfate)havealsobeenexamined.

简介：为验证CO_2探测仪光学设计的合理性和可行性，采用单通道模拟样机，利用太阳光加漫反射板模式对大气光谱进行实验测试，并在实验室对单通道模拟样机进行光谱定标。利用光谱配准算法对两种方法得出的谱线位置进行匹配计算，结果表明：在吸收线深度稳定位置的配准峰值点偏差小于0．006nm，满足算法的精度要求。此种方法不仅验证了匹配算法的有效性，也验证了光学系统设计的合理性和可行性，为以后的光谱仪设计提供了理论与实验数据。

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简介：Anovelgas-phaseelectrocatalyticcellcontainingalow-temperatureprotonexchangemembrane(PEM)wasdevelopedtoelectrochemicallyconvertCO2intoorganiccompounds.TwodifferentCu-basedcathodecatalysts(CuandCu-C)werepreparedbyphysicalvapordepositionmethod(sputtering)andsubsequentlyemployedforthegas-phaseelectroreductionofCO2atdifferenttemperatures(70-90℃).ThepreparedelectrodesCuandCu-CwerecharacterizedbyX-raydiffraction(XRD),X-rayphotoemissionspectroscopy(XPS)andscanningelectronmicroscopy(SEM).Asrevealed,CuispartiallyoxidizedonthesurfaceofthesamplesandtheCuandCu-Ccathodiccatalystswerecomprisedofaporous,continuous,andhomogeneousfilmwithnanocrystallineCuwithagrainsizeof16and8nm,respectively.Theinfluenceoftheappliedcurrentandtemperatureontheelectro-catalyticactivityandselectivityofthesematerialswasinvestigated.Amongthetwoinvestigatedelectrodes,thepureCucatalystfilmshowedthehighestCO2specificelectrocatalyticreductionratesandhigherselectivitytomethanolformationcomparedtotheCu-Celectrode,whichwasattributedtothehigherparticlesizeoftheformerandlowerCuO/Curatio.Theobtainedresultsshowpotentialinterestforthepossibleuseofelectrical「enewableenergyforthetransformationofCO2intovaluableproductsusinglowmetalloadingCubasedelectrodes(0.5mgCucm2)preparedbysputtering.

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简介：Inthiswork,MoOxpromotedIr/SiO2catalystswerepreparedandusedfortheselectivehydrogenolysisoftetrahydrofurfurylalcohol(THFA)to1,5-pentanediolinacontinuousflowreactor.Theeffectsofdifferentnoblemetals(Ir,Pt,Pd,Ru,Rh),supportsandIrcontentswerescreened.Amongtheinvestigatedcatalysts,4wt%Ir-MoOx/SiO2withaMo/Iratomicratioof0.13exhibitedthebestcatalyticperformance.ThesynergybetweenIrparticlesandthepartiallyreducedisolatedMoOxspeciesattachedonthemisessentialfortheexcellentcatalyticperformanceofIr-MoOx/SiO2.ThecatalystexhibitedabetterhydrogenolysisefficiencyofTHFAwiththeselectivityof1,5-pentanediolof65%–74%ataconversionofTHFAof70%–75%whentheinitialTHFAconcentrationisrangingfrom20wt%and40wt%.AndhighersystempressurewasalsoinfavoroftheconversionofTHFA.Duringastabilitytest,theconversionofTHFAand1,5-pentanediolyieldoverIr-MoOx/SiO2decreasedwithreactiontime,whichcanbeexplainedbytheleachingofMospeciesduringthereaction.