INTRAPARTICLE DIFFUSION EFFECTS IN FISCHER-TROPSCH SYNTHESIS Ⅱ.EFFECTS OF PARTICLE SIZE,TEMPERATURE AND PORE STRUCTURE

lntroductionThccatal}'stcffcctivenessfactorismainl}'affectcdb}'itsporcstructurc-butthcparticlesizeandtcmperaturearcaIsoimportantforthediffesionandrcactionUnderindustrialopcrationconditionsforthcstrongl}'exothermicFischcr-Tropschs}nthcsis(FTS)reaction,temperaturedistributionalongcataI}ticbedisccrtainl}ununiform.andthus,theeffectivcncssfactorsarenaturall}'changcd.Whatisimportantisthatthccffectivcncssfactorsarestrictl}'detcrmincdb}'thcparticlcsizeandcorrcspondingporcparameters.lnvcstigationsont…     

KINETICS OF THE CARBONYLATION OF METHANOL IN A MECHANICALLY AGITATED REACTOR

lntroductionThclox"-tcmpcraturcs)nthcsisofmcthanolfroms}'nthcsisgasviamcth}'lformatcconsistsofcarbon}'IationofMc0Htomcth}'lformatc(McF)(bclox`l()O"C).andhydr0gcnol\'sisofMcF(bclot"2OO"C)totx"oMcOHasshox`nbclo`"fCH30H C0=HC0OCH;l(l)HC00CH3 2H2=2CH3OH(2)Wcrcfcrtothisasthctx"o-stcpmcthanoIs}nthesis.Thccarbonylationofmcthanolisahomogcncousl}'catal}'zcdrcactionusingalkalimctalmethoxidesascataIystsinthellquidphasc.Thct},picalrcactionconditionsarc60~90"Cand3.O~5.OMPa.Thercactionisanex…     

EFFECT OF ThO_2 ON SrCO_3/BaSO_4 CATALYST IN OXIDATIVE COUPLING OF METHANE

IntroductionSincethepioneeringt"orkofKcllcrandBh.,i.IlI.theoxidativccoupl1ngofmethane(0CM)hasrcceivedx`orldt`.idcattcntion.Sofar-man}'kindsofcatal}'stsfor0CMhavcbecndeveIoped.0nthcbasisofextensivelitcrature,thccatal}'stsfor0CMboastssomccommonfcaturesasfolIo``sl2lf(l)thebasicityofcatalyst,(2)thestabilit}'ofcarbonateoncatal}'stsuffocc,(3)`"atcr-rcsistingpropcrt}',(4)conductionofox3'gcnions,(5)Psemiconductorundcrhightempcraturc.Thcscbricfl}'gcncralizcthccharactcristicsof0CMcataly'sts.butnot…     

Electrochemical Determination of Rate Constants for Reactions of OH and its Application in the Evaluation of Anti-Oxidant Actions of Rheum

Hydrop'lradicals(OH)areu'ideI}'implicatedasamajordamagingsPeciesinfrCeradicalpatho1ogi-"=.ItisimPOrtanttoknou'second-orderrateconstantsforreachonsofmoleculesinqueinonl`ithOH.PUlseradio1ysisisthebesttechniqueforthi5aim"',however,itSfacilitiesareexpensivetosetupandoPerateandnotat'ailabletomanyscientists.Thereareotherpublishedmethods,includingspectrophotometricanalysis'.fluorescenceanalysis'etc..Howeter,noelectTochemicalmethedhasbeenrePOrtedtodatoThechemisto'b}u)hjchtheinihalproductsofOHa…     

Nucleophilic Aromatic Substitution of Nitrobenzenes with Nitrite Ion

Substituteddiphen}'lethers(SDE)areimportantmonomersforprepdringresins'heatresistantfilmsand1iquidcO-stalfibers.TheinvestigationonthereactionofSDEi5ofgreatimPOrtanceindet'elopingnet"macromolecularmaterials.lnl97()'s,Heinzetalfl-2]rePOFtedthatinaproticpoIarsolvent,nitrobenzenessubstitutedwithelcctroIlt`ithdrawinggroupsreacttvithalkalisaltstogi\'erymmetricaISDETl1eauthorsusedX.-C6H4-NO2a5thegenera1formu1aforsubstitutednitrobenzenes(SNB).t`hereX.standsforhalides.nitrile'acet}l.carboryl,…     

CHARACTERIZATION AND CATALYTIC BEHAVIOR OF WATER-SOLUBLE PHOSPHINE RHODIUM (I) COMPLEX

IntroductionInhomogcncouscatal}-sis*arccurrentproblcmisthcseparationofthcorganicproductsfromtheactivecatal}'stThcapplicationoft`atersolubletransitionmctalcomplcxcsf0rcataI}ticrcactionshasrcccntl}'attractcdconsidcrablcattcntio.lI~3l.Thcx"atcr-solubleligandsarcslightl}'solublcinorganicmcdia-allot"ingthccatal}'sistobccarricdoutinat\"o-phascs}'stcm.Catal\'strccovcry'isthuscasil}'achievcdb}'dccantationandseparationofthctx"ophascs.Thctris(sodiumm-sulfophcn}-l)-phosphinc,P(m-C6fuS03Na)3(abbr.asTP…     

TPSR STUDIES OF THE ACTIVATION OF METHANE ON SUPPORTED PLATINUM CATALYSTS

1yttroductionIMcthancactivationisoncofthemostintriguingsubjectsinheterogencouscatal}'sisbccauscmcthancisathcrmod}namicall}'stabIccompoundt`ithanoblcgas-likeconfiguration.0fintcrcstsisthcrcccntt"orkreportcdb}'KocrtsIll,BeIguedl21.andYanl3ltthosucccssfull}'convcrtnaturalgasintohighcrh}.drocarbonsb}'thctt"o-stcproutcinwhichnaturalgasisfirstthcrmall}'activatcdonthctransitionmctalcatal}.stsatmoderatctemperature.Toasccrtainthcnaturcofrcactionsofmcthane.thcactivationofmcthaneisextensivel)'invcstiga…     

EFFECT OF SOLVENT ON ZEOLITE SYNTHESIS

Introductionltistvellknox`nthath}'drothcrmalcn'stallizationisaconventionaltechniqueforzeoliteandmolccularsicvcs}nthcsls.Watcrassolvcntplaystheroleofminerali.ation[ll.Inl985,BibbyandDalcrcportedfirstl}'thes}'nthcsisofsilica-sodaliteinethyleneglycolsol.e.tl2l.Sincetllcn,man}'kindsofzeolitcst"ercpreparedinnon-aqueoussystemsHott'ever,noinformationonthcinfluenccofsolvcntonzcolitcsynthesishasbecnreported.Inthispapcr,t"crcportanintcrcstingcxamplc.Incascsofnosolventandusingx`atcr,cth}'lcneglycolandc…     

STUDIES OF TPSR AND PULSE REACTION OF METHYL IODIDE ON SILICA-SUPPORTED NOBLE METAL CATALYSTS

IntroductionAttcn1ptstoclucidatcthcmcchanismofCtOh}drogcnationontransitionmctalcatal\stsbyusingprobcmoIcculcscanbctraccdbacktoatlcastascarl}'asl95ll]lAlthoughthistcchniqucisanindircctx"a}'ofstud}'ingsurfaccrcactionmcchanisms.itallot"sustostud}'inslIusurfaccrcactionsundcrccrtainconditionsx"hichusualI}'cannotbcprobcdb}'morcdirectinstrumcntalmcthodssuchassurfaccspcctrosc0pictcchniqucsOfintcrcstisthcreccntt"orkrcp0rtcdb}'Bclgucdl2l'KocrtsI3jandYa.l4j\"hoachict'cdthcconvcrsionofmethanctotbrmC2~…     

First Synthesis of(±)-3-(5-Hydroxy-4-Methyl-7-Isopropyl-3E,7-Octadienyl)-△~2-Butenolide

1nl994,DiazandHerzgroup[1]isolatedthreeneu'farnesane-basedlactones1,2and3fromtllep1antGochnotioglutinosa(Don)donexHook.etArn.grot"ninAIgentina.WehavereportedthefirstS}fnthesisof(i)-2inearl}'articlel=1.Hereinxt'ett'ishtodescribethefirsttotalSynthesisof(I)-lstartingfromgeraniolasitsracemicform.Theq'l1theticrouteisdetailedinthefollouingscheme.Tlleaceb'lpr0lectedgeraniol(AldricI1Co.)x"asconvertedtotheenal5usingSeO2/I-BuOOH9'steminrcfluxi11get11}'lalc0l10lI4].Tl1cli[lli1l111cnolatett'asge1…     

Synthetic Studies on Diarylheptanoids──Syntheses of 1,7-Bis(4-Hydroxyphenyl)-1,4,6-Heptatriene-3-One and Acetogenin G

NaturaldiarylheptanoidsJreagroupofcompoUI1dswhichhavegeneralstructUreAr-C7-Ar'.ExPerimentssh0t"thatthe}'havestr0ngbi0achvihes,5uchasanhiallanunatoryanhrpasmodicandanhhePtatotosiceffectS,the}areusedastradihonalmedicineinAsial'-=].l,7his(4-hydroxyPhenyl)-l.4.6-hePtatriene-3-one(l)andaecrogeninG(2)tvereisolatedfromfreshrhizomesofturmeric(Cureun0do))IeslicaVal.)andstembafkofA.grseUnIl"].reSPechvel}iSofarasweknoWthe9nthesesofthesetWonatUralcomPOundshaven0tbeenreP6rtedyet.Herein,wewishtor…     

EFFECTS OF BINDERS ON THE PRODUCTION OF LIGHT ALKENES FROM SYNGAS OVER K-Fe-MnO/SILICALITE-2 CATALYST Ⅱ. MODIFICATION EFFECT OF Al_2O_3 BINDER ON CO HYDROGENATION

lntroductionInordcrtoselcctivcl}'produccIightoIcfinsfroms}'ngas.thcbinderusedforimprovingthecatal}'ststrcngthshouldbcfavorabIcforprimary'formingofligl1tolcfinsfroms}ngasandforprohibitingsidereactionsoflightoIcfi.sIll.lthasbccnshownthattheundesirablcstrengthofsilicalitc-2zcolitccanbcimprovcdb}addingbindcrs.Hot`ycver.thcadditionofthcbinder`"illcauscsomcchangcsinthcph}'sical-chcmicalstatcofthecatal}ticactivemetalas``cllasitscatal}ticbcha.io,ll'2I.InourprcviouspaperTiO2wasprovedtobcadcsirablcbi…     

A New One-Pot Synthesis of Macroheterocycles Using Mannich Reaction

Inrecentyears,doube-imedazacrowneil1ershavebeenwidel}StUdiedtonilndcnaturallyocCUrrngionoPhoresbypresentingacationttiththree-dimensiollal,intramoleeularmpofbinderingsitesasdothemptandsorsPherandsIl'2l.DuringthepaStdecade,therearemanyreportSabouttheirophesisI"l.EsPeeallyhaceBag~etalusedtheMtrichreachontoSynthesizetheantinomethylatingagentsonandco[4'5].AvarietyofannedazacrowmethershaxebeenpreparedtostUdytheircationseleedvihesbytreatInentof(II)ormpwithappropriatecompoundsI"'l.Recently,X…     

Application of Rayleigh Light Scattering Spectroscopy to the Determination of Proteins Using Bromo-Pyrogallol Red

ThoughRa}-leighlightscattering(RLS)hasbeenextensi\'el}'stUdiedandappliedforman}'years-itisrarelyusedinanal}ticalcheIinap'.Recenh}'.Huangetal.usedRLSforanal}ticalpUrpOse5todeterndnethequaLnhhesofnucleicacidswitha.o'V-6-tetra-(4-drieth}l-anunoniumphen}'l)porphyrinf11Itisalsofoundthatlightscattenngofbromo-P}Togallolredisenhancedgreah}'b}'proteins.andbasedonmis.anewproteinassa}'methodisputforward.msmethodisatleast3o-foldmoresensiti1-ethant-heconunonlyusedproteinassa}'s[2-31ffeSspectIacyig-1…     

EFFECTS OF PROMOTERS ON CATALYTIC PERFORMANCE OF Pt-Sn/MgAl2O4 CATALYST FOR PROPANE DEHYDROGENATION IN THE PRESENCE OF STEAM

IntroductionCatal}-tiedch}-drogcnationoflightalkancshasgreatindustrialimportancebecauseitrcprcscntsanalternativeforobtainingalkcncsforpci}.mcriZationandotherorganics}'nthcscsfromlot"costsaturatedh}'drocarbonfeedstocks.SomeprocessessuchasCATOFIN.OLEFLEX.Ph…     

DNA Cleavage by Copper (Ⅱ) Complexes Without added Coreactants

Thedevelopmentofreagentswhichhydrolyticallycleave11ucleicacids"lidermildconditionsiscurrentlyattractinggreatinterestillthetieldofartiticialnucleases'-'.Whilemall}lreagentshavebeedsuccessfullyapplied.toDNAhydrolysis;.illershavebeenit-c'l'ersuccesseswithDNA'duetoitsrelativel}'highh}idrolyticstabilit}"(thepseudo-firsl-orderrateconstantt'Orthenollenzymatichydrolysisofphospllodiestersisextropolatedtobe2x10-"'h-=at24tandPH7.4').Theexceptionalstabilit}fofphosphodiestershasbeensuggestedasonereason…     

The New Synthesis of Azo Urea from Substituted Semicarbazide

AzocompouIldsare1'en'importantinorganicchemistn'.The}hax'ebeenx"idel}'utilizedasd}resandanal}1icreagents.1andcanalsobeusedinmatenalofnon-linor0ptics.materialofopticsinf0rmationstoringinlaserdish.andd}-est`-ithoilsolubilib'inphotochrom}inmoderntechnologi'.2Recent1)'man}notett'orth}studiesshol`thatazobenzenederit'ah1'espossessven'goodophcrememberingandphotoelectncproPerties.OPtical-su'itchjngandimagestoragecanbemadebyazobenzeneliquidcn'stalfilm.3Otheru'iseazocomP0undscanbeusedinthermotropicliq…     

Synthesis and Diastereomeric Analysis of Uridine 2’,3’-Cyclic Phosphite

Projectsupportedbyagrant(#29472069)fromTheNationalNaturalScienceFoundationofChina.Nucleoside2',3'-cyclicphoSPhatesareproductinti1eANAll}'drolysiscatal}2edbyribonucleases.ChedricalmodfficahononthephosPhategroupprOducesdiastereomersttihlRPandSPconfigUrhon'the}'canserveasusefulprobeforinvestigationoftheenn'maticreachoncourseandstereocheAnstn'.Asreportedb}'Ecksteinandco-t"orkers.'-#RNaseA.xt'llichhyd1olyzesP}vimidil1enucleoside2',3'-cyclicphoSPhatetoproduceP}vimjdinenucleoside3'-pllospl…     

Sensitization of Microporous Nanocrystalline TiO_2 Electrode with Quantum Sized RuS2 Particles

SensitizationoflargebandgapsemiconductorelectrOdetx,ithorganicd}eandinorga-nicmateriaIshasbeeneXtensivel}'studiedox'ertbepastdecade.Recentl}'GratZe1andco.'orke,[l]deteloPedanettkindofsolarcellbasedond)'esen5itizedsemiconductorelectrodecomprisedofnanocry'stalIineparticles.Thenanocn'stallinesemiconductorelectrodepossesseshighl}'porousstructUreandmuchlargersurfacethanconx)enhona1plaincn'stalelectrodesothatel7enlessthanonemonola)yerthedyecou1dalmostcompletel}'absorbtheincidentlightintheabsorpti…     

SELECTIVE PRODUCTION OF C_2 AND C_3ALCOHOLS FROM SYNTHESIS GAS

IntroductionTheaimofprcscllt\t-orbisthedot'clopmcntofcatal}-stsu'hicharchighl}'sclccti\'ctothes"nthcsisofCZandC3alcoholsfronls}'llgas.Cocatal}'stscanenhancetheproductionofCZalcohol.butthe}'arcalsoacti\'cfortheF-Ts}.nthcsisint'hichtheproductdistributionfol…