简介：
简介：TheextractionofCe(Ⅳ)inH2SO4/H3PO4systemwasinvestigatedsystematicallyusingbifunctionalionicliquidextractants(Bif-ILES)[A336][P507],[A336][P204]and[A336][C272]inn-heptane.TheeffectsofH2SO4concentration,extractantconcentrationandsalting-outagentconcentrationwereobservedindetail.TheextractionmechanismofCe(Ⅳ)inH2SO4/H3PO4systemwasobtained.ThecomparisonwithotherextractantssuchasCyanex923,TBPwasalsostudied.Thermodynamicfunctionsoftheextractionreactionwerecalculated,showingthattheextractionwasanexothermicprocess.TheseparationofCe(Ⅳ)fromRE(Ⅲ)andTh(Ⅳ)wasalsoinvestigated.TheresultindicatedthatCe(Ⅳ)couldbeselectivelyextractedinthissystem.CePO4nanoparticleswereobtainedintheprocessofstrippingusingH2O2inH2SO4/H3PO4system.X-raydiffraction(XRD),scanningelectronmicroscopy(SEM)andspectroscopywereadoptedforthecharacterizationofthesample.
简介：Inthispaper,varioustechniquesincludingBET,XRD,SEMandXPSwereusedtostudythesinteringofpureandLa2O3-dopedtitania.Theexperimentalresultsshowthatsinteringoftitaniaproceedsviavolumediffu-sion.Addingoflanthanumoxidedecreasestherateofsinteringandhindersthephasetransitionfromanatasetorutilecrystalbystrongsurfaceinteractionbetweenthemixedcrystals(La4Ti9O24,La0.66TiO2.99)andTiO2.
简介：Nanostructuredγ-Al2O3withhighsurfaceareaandmesoporousstructurewassynthesizedbysol-gelmethodandemployedascatalystsupportfornickelcatalystsinmethanereformingwithcarbondioxide.ThepreparedsampleswerecharacterizedbyXRD,N2adsorption-desorption,TPR,TPO,TPH,NH3-TPDandSEMtechniques.TheBETanalysisshowedahighsurfaceareaof204m2g-1andanarrowpore-sizedistributioncenteredatadiameterof5.5nmforcatalystsupport.TheBETresultsrevealedthatadditionoflanthanumoxidetoaluminumoxidedecreasedthespecificsurfacearea.Inaddition,TPRresultsshowedthatadditionoflanthanumoxideincreasedthereducibilityofnickelcatalyst.Thecatalyticevaluationresultsshowedanincreaseinmethaneconversionwithincreasinglanthanumoxideto3mol%andfurtherincreaseinlanthanumcontentdecreasedthecatalyticactivity.TPOanalysisrevealedthatthecokedepositiondecreasedwithincreasinglanthanumoxideto3mol%.SEMandTPHanalysesconfirmedtheformationofwhiskertypecarbonoverthespentcatalysts.AdditionofsteamandO2todryreformingfeedincreasedthemethaneconversionandledtocarbonfreeoperationincombinedprocesses.
简介：Inthispaperwereportachemicaloscillationcatalyzedby[Ni(Me2[14]1,3-dieneN4)]2+(Me2[14]l,3-dieneN4denotes2,3-dimethyl-l,4,8,ll-tetraazacyclotetradeca-1,3-diene)inBrO3--pyruvicacid-H2SO4system.Thedomainoftheexistenceoftheoscillationwasobtained.Theeffectsofinitialconcentrationofthecomponentsontheoscillationwerestudied.Thefeaturesoftheoscillationsweredescribedindetail.WealsoexaminedtheeffectsofAg+,Hg2+,CCl4,freeradicalinhibitors,etc.ontheosillations.
简介：
简介：TheinfluenceofNa2SO4ontheformationofZnOwhiskerswasinvestigatedinthispaper.ZnOwhiskerswithaspectratiosofupto50weresynthesizedbydissolvingε-Zn（OH）2precursorinNaOH/Na2SO4solutionatroomtemperature,followedbyagingoftheresultingsolutionat140℃for6h.Fouriertransforminfraredspectroscopy,Ramanspectroscopy,andX-rayphotoelectronspectroscopyanalysesrevealedthatSO42-ionswereprimarilyadsorbedonthe（100）planeoftheZnOwhiskersviaanouter-spherecomplexconfiguration（O-H…O）,therebypromotingtheone-dimensionalgrowthofZnOwhiskersalongthec-axis.
简介：Reactionsofthe6-hydroxy-thiopyrano[3,4-c]pyridine-5-carbonitrilederivative1withα-halo-carbonylcompoundsgavetheortho-substitutedintermediates2a-cwhichwereconvertedintofuro[2,3-b]thiopyrano[4,3-d]pyridines3a-cbyfusionofafuranmoietyunderbasicconditions.Furthercyclizationof3a-cledtoafusionofapyrimidinering,yieldingthetetracyclicproducts6,7and8.Inaddition,condensationof6withvariousaromaticaldehydesaffordedthecorrespondingimines9a,b.Mannichreactionof7gaveproducts10a,b.
简介：BasedonthetechniqueforpreparingLaCl3viadirectpyrolysisofrareearthchloridesolution,ajetpyrolysisreactorwasdesignedandtheintra-reactortemperatureandchemicalreactionswerenumericallysimulatedusingcomputationalfluiddynamics(CFD)technique.Theresultsshowthattheflowratevariationatthefuelinletdoesnotlargelyaffectthetemperatureinthereactor,whiletheincreaseinexternalpressureatthematerialinletrapidlydecreasestheaveragetemperature,Venturitemperature,andoutlettemperature.TheCH4andO2insidethereactorarecombustedcompletely,andwhenthematerialinletpressureis\90Pa,theLaCl3isfullypyrogenated.ThecontentsofCO2,La2O3,andHClfluctuateneartheVenturitubeandfinallystabilize.La2O3contentattheoutletisinatop-to-bottomgradient.
简介：AseriesofLa2O3/MCnylonnanocompositeswerepreparedviainsitupolymerization.Theeffectsofcontentofnano-La2O3onthemechanicalpropertiesofnanocompositeswerestudied.Dispersionofnano-La2O3inMCnylonmatrixwasobservedwithSEM.ThecrystalstructureofnanocompositeswascharacterizedbymeansofXRD.SEManalysisshowsthatLa2O3nanoparticlesareuniformlydispersedinMCnylonmatrixandlittleclusteringexistswhenthecontentofnano-La2O3islowerthan1%,however,whenthecontentofnano-La2O3ismorethan1%,itbeginstocluster.XRDanalysisindicatsthatnano-La2O3doesnotchangethecrystalstructureofMCnylon.Mechanicalpropertiestestsshowthatthetensilestrength,elongationatbreak,impactstrength,flexuralstrength,andflexuralmodulusofnanocompositesfirstincreasethendecreaseasthecontentofnano-La2O3isincreased.Whenthecontentofnano-La2O3is0.5%,thetensilestrengthandelongationatbreakofnanocompositesreachmaximum,whichare17.9%and52.1%higherrespectivelythanthoseofMCnylon.Whenthecontentofnano-La2O3is1.0%,theimpactstrength,flexuralstrengthandflexuralmodulusofnanocompositesreachmaximum,whichare36.6%,12.7%and16.3%higherrespectivelythanthoseofMCnylon.
简介：1ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｒａｒｅｅａｒｔｈｃｏｂａｌｔａｌｌｏｙｓｈａｖｅｔｈｅｐｏｔｅｎｔｉａｌｆｏｒｍａｋｉｎｇｔｈｅｍａｇｎｅｔｉｃａｎｄｍａｇｎｅｔｏｏｐｔｉｃａｌｍａｔｅｒｉａｌｓ.Ｓｏｆａｒ,ｔｈｅｒａｒｅｅａｒｔｈｃｏｂａｌｔａｌｌｏｙｆｉｌｍｓａｒｅｓｕｂｓｔａｎｔｉａｌｌｙｐｒｏｄｕｃｅｄｂｙｓｐｕｔｔｅｒｉｎｇｏｒｖａｃｕｕｍｐｌａｔｉｎｇ.Ｉｆｓｕｃｈｆｉｌｍｓａｒｅｐｒｅｐａｒｅｄｂｙｅｌｅｃｔｒｏｄｅｐｏｓｉｔｉｏｎｉｎｓｔｅａｄ,ｐｒｏｄｕｃｔｉｏｎｅｆｆｉｃｉｅｎｃｙｗｏｕｌｄｂｅｉｍｐｒｏｖｅｄａｎｄｔｈｅｃｏｍｐｏｓｉｔｉｏｎｏｆｔｈｅａｌｌｏｙｃｏｕｌｄｂｅｃｏｎｔｒｏｌｌｅｄ.Ｂｅｃａｕｓｅｔｈｅｏｘｉｄａｔｉｏｎｒｅｄｕｃｔｉｏｎｐｏｔｅｎｔｉａｌｓｏｆｒａｒｅｅａｒｔｈｅｌｅｍｅｎｔｓａｒｅｖｅｒｙｎｅｇａｔｉｖｅ,ｏｒｇａｎｉｃｓｏｌｖｅｎｔｓｍａｙｂｅｕｓｅｄａｓｅｌｅｃｔｒｏｌｙｔｉｃｍｅｄｉａ.ＥｌｅｃｔｒｏｄｅｐｏｓｉｔｉｏｎｏｆＧｄＣｏａｎｄＳｍＣｏｉｎｏｒｇａｎｉｃｓｏｌｕｔｉｏｎｓｈａｓｂｅｅｎｒｅｐｏｒｔｅ...
简介：TheeffectsofSO2,SO3ondenovosynthesisofpolychlorinateddibenzo-p-dioxins(PCDDs)anddibenzofurans(PCDFs)werestudiedusingmodelflyashesincorporatingcopperoxideandactivatedcarbon.ItwasfoundthattheinhibitiveeffectofSO2onPCDD/FsformationissimilartothatofSO3.Toinvestigatetheinhibitionmechanism,CuSO4formationsfrombothCuOandCuCl2wereexamined.TheabilityofSO3toconvertCuCl2andCuOonasilicasupportintosulfateismuchstrongerthanthatofSO2.However,replacingsilicabyactivatedcarbonleadstoamuchhighconversionofCuCl2toCuSO4inthepresenceofSO2.ThepromotionbyactivatedcarbonisexplainedbythereductionofCuCl2toCu2Cl2andtheeventualconversionofCu2Cl2intoCuSO4isthemaininhibitionmechanismofSO2ondenovosynthesisofPCDD/Fs.
简介：提出问题:Zn+H2SO4的反应研究问题:(读者怎样研究?想后再看)研究问题程序:学生独立研究——小组研究——班集体研究原理研究:若是少量锌与过量浓硫酸反应:
简介：Thetitlecomplex,[La(baec)1/2(H2btec)1/2(H2O)]n(H4btec=1,2,4,5-benzenetetracarboxylicacid)(1)wassynthesizedbythehydrothermalreactionof1,2,4,5-benzenetetracarboxylicdianhydridewithLa(NO3)3·6H2OinH2O,andcrystallizesinthetriclinicsystem,spacegroupP-1withα=0.64403(3)nm,b=0.94500(4)nm,c=0.96380(5)nm,α=88.535(2)°,β=100.314(2)°,γ=76.6470(10)°,V=1.69968(10)nm^3,Z=2,andfinalR=0.0274,Rw=0.0735.In1,eachLa(Ⅲ）ioniscoordinatedbyeightoxygenatomsfromsixcarboxylategroupsandonecoordinatedwatermolecule.TwodifferentcoordinstionmodesofH4btecwerePresentinthestructure,oneofwhichcontainstwoprotonatedcarboxylategrougpstobalancethecharge.
简介：Treatmentof4-amino-3-(1-aryl-5-methyl-1,2,3-triazol-4-yl)-5-mercapto-1,2,4-triazoles/2-amino-5-(1-aryl-5-methyl-1,2,3-triazole-4-yl)-1,3,4-thiadiazoleswithbenzaldehyde,acetoneandω-bromoacetophenonewastestedandcompared.ThetitlecompoundsSchiffbases,amides,imidazolo[2,1-b]-1,3,4-thiadiazolesand7H-s-triazolo[3,4-b]-1,3,4-thiadiazineshavebeenconfirmedbyelementalanalyses,^1HNMR,IRandMSspectra.AllthecompoundshavealsobeenscreenedfortheirantibacterialactivitiesagainstB.subtilis,S.aureusandE.coli.
简介：<正>卡佩罗终于驾临皇马了,这个当年在伯纳乌球迷嘘声中下课的冠军教练竟然成为百年皇马走出困境的最大希望。和当年离开罗马时一样,卡佩罗带来了自己战术体系中最重要的球员——埃莫森。失去马克莱莱被认为是皇马转会市场上最大的失误所在,皇马高层由于吝啬法国人的加薪要求而不得不花巨资寻求其替代者,可问题的结症在于无论是格拉维森还是加西亚都无法给予后防线足够的保护。穆里尼奥在获得巴拉克和舍瓦后完全没有表现出想像中的喜悦,相反社区盾杯的失利让他还在为中场布置而伤神。最近几年,4-2-3-1双后腰阵形在欧洲几大豪门间相继流行起来,而传统的4-4-2两翼齐飞却不断受到冷落,连边路之王
客服QQ：30444492琼网文【2021】1550-113号
增值电信业务经营许可证：琼B2-20210322
出版物经营许可证：新出发龙华出字第(2021)009号
广播电视节目制作经营许可证：(琼)字第00779号
版权所有 ©2002-2024 期刊网 琼ICP备2021005105号
![A chemical oscillating reaction in NaBrO<b style='color:red'>3</b>-pyruvic acid-H<b style='color:red'>2</b><b style='color:red'>SO</b><b style='color:red'>4</b>-[Ni（Me<b style='color:red'>2</b>[14]1,3-diene N<b style='color:red'>4</b>）]<b style='color:red'>2</b>+ system](/image/thesis5 "A chemical oscillating reaction in NaBrO<b style='color:red'>3</b>-pyruvic acid-H<b style='color:red'>2</b><b style='color:red'>SO</b><b style='color:red'>4</b>-[Ni（Me<b style='color:red'>2</b>[14]1,3-diene N<b style='color:red'>4</b>）]<b style='color:red'>2</b>+ system")
![Synthesis of thiopyrano[<b style='color:red'>4</b>',<b style='color:red'>3</b>':<b style='color:red'>4</b>',5']pyrido[<b style='color:red'>3</b>',<b style='color:red'>2</b>':<b style='color:red'>4</b>, 5]furo[<b style='color:red'>3</b>,2-d]pyrimidines](/image/thesis8 "Synthesis of thiopyrano[<b style='color:red'>4</b>',<b style='color:red'>3</b>':<b style='color:red'>4</b>',5']pyrido[<b style='color:red'>3</b>',<b style='color:red'>2</b>':<b style='color:red'>4</b>, 5]furo[<b style='color:red'>3</b>,2-d]pyrimidines")
![Hydrothermal Synthesis and Structure of a New <b style='color:red'>3</b>D Lanthanide—Carboxylate Framework,[<b style='color:red'>La</b>（btec）1／<b style='color:red'>2</b>（H<b style='color:red'>2</b>btec）1／<b style='color:red'>2</b>（H<b style='color:red'>2</b>O）]n（H<b style='color:red'>4</b>btec=1,<b style='color:red'>2</b>,<b style='color:red'>4</b>,5—Benzeneteracarboxylic acid）](/image/thesis16 "Hydrothermal Synthesis and Structure of a New <b style='color:red'>3</b>D Lanthanide—Carboxylate Framework,[<b style='color:red'>La</b>（btec）1／<b style='color:red'>2</b>（H<b style='color:red'>2</b>btec）1／<b style='color:red'>2</b>（H<b style='color:red'>2</b>O）]n（H<b style='color:red'>4</b>btec=1,<b style='color:red'>2</b>,<b style='color:red'>4</b>,5—Benzeneteracarboxylic acid）")
