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简介：通过DSC和同步辐射WAXS技术测定了结晶温度对iPP和TMB-5/iPP结晶行为的影响.结果表明,随等温结晶温度升高,iPP总结晶度变化不大,但是β晶型含量降低的同时α晶型含量增加.TMB-5是一种具有温度依赖的选择性成核剂,当等温结晶温度高于140℃时,含TMB-5成核剂的iPP的β晶型的含量急剧降低.本文进一步探讨了TMB-5对iPP结晶行为影响的机理.

简介：Aseriesof5-aminolevulinicacidanditsalkylestermethanesulfonateswasexploitedtophotodynamictherapy(PDT)ofhumanlymphocyticcells,U-937invitro.ThePDTefficiencyisinfluencedbytheconcentrationandincubationtime.Generally,forALAanditsalkylestermethanesulfonates,thecellsurvivalratedecreasesandtheaccumulationabilityofPpIXincreaseswiththeconcentrationandincubationtime.Wefoundthatthelongercarbonchainmethanesulfonates(C5-S,C6-S,C8-S)exhibitbetterPDTeffectthanALAmethanesulfonate.ThispossiblyprovidesapromisingroutetotheclinicalapplicationofPpIX-mediatedPDTtocancercell.

简介：4,4-Dialkyl-2-oxazolin-5-onesarepreparedbyonestepreactionof2-oxazolin-5-onewiththemagnesiummethylcarbonate(MMC)andalkyIhalides.Itisanovelandconvenientmethodforsynthesisofα,Υ-disubstitutcdα-aminoacidbyhydrolysisof4,4-dialkyl-2-oxazolin-5-ones.

简介：TheexternalsurfaceofHZSM-5zeolitewaspassivatedbyliquidsiliceousdepositionandbyacidicsitespoisoningwithlepidine,respectively.Thenmethanol-to-hydrocarbons(MTH)reactionwasinvestigatedovertheaboveas-preparedcatalystsandthedissolublecokeontheseusedcatalystswasanalyzedbyGC-MS,tostudytheroleoftheexternalsurfaceofHZSM-5inthecatalyticreaction.ComparisonwiththeexperimentalresultsbasedonparentZSM-5showedthattheproductdistributionofMTHreactionwasobviouslyinfluencedbytheexternalsurface.Evidenceswerelistedasfollows:(1)thefinalproductonparentHZSM-5showedhigheraromaticselectivity,lowerolefinselectivity,lowerratioofC2/C3+aliphaticsandhigherratioofC3/C4+aliphaticsthanthereactionmixtureproducedbythesolecatalysisofacidicsitesinHZSM-5channel;(2)alittleofpentamethylbenzeneandhexamethylbenzeneintheproductonparentHZSM-5,wasproducedviamulti-methylationofmethylbenzeneontheexternalsurface.TheaboveconclusionmayalsobesuitableforMTHreactionoverotherzeoliteswith10-ringchannel.

简介：为它的高氧化抵抗，钇硅酸盐是为在在1600°C上面的温度的carbon-fiber-reinforcedcomposites的保护的涂层的一个重要候选人。一个新奇方法，由一起沉淀组成，弄干水花，热处理和plasma-densification，被开发准备Y2SiO5粉末为热喷洒。作文，形态学和综合Y2SiO5粉末的流动能力被XRD，SEM和霍尔流量计分别地调查。结果证明综合Y2SiO5粉末与高纯净是将近球形的。分别地，Y2SiO5粉末的明显的密度和流动能力是1.87g/cm3和37s/50g它为大气的血浆喷洒导致多达80%的高免职效率。

简介：<正>"整式与分式"这部分内容,主要涉及的考点有:整式与分式的概念和运算,因式分解和分式的基本性质.试题难度为低、中档,题型多以选择题、填空题、计算题的形式出现,着重考查基础知识、基本技能和基本方法.近年来中考的热点是化简、求值的考查,旨在让学生通过探索灵活、简捷的解法,提高分析问题的能力.因此,在复习中我们要掌握整式与分式的运算法则并能灵活应用,提高运算能力、观察能力、解决实际问题

简介：π-/π+ratiowasfoundtobeasensitiveprobetothehigh-densitybehaviorofthesymmetryenergybyusingseveraltransportmodels.However,asshowninFig.1,atbeamenergiesbelowthepionproductionthreshold,theeffectsofin-mediumnucleon-nucleonscatteringcrosssection(whichisstillcontroversial)stronglyaffectthevalueofπ??/π+ratio[1].Itisthusnecessarytodoacomparativestudyoftheeffectsofthein-mediumNNcrosssectionandtheeffectsofthesymmetryenergyonpionproductioninheavy-ioncollisionsatlowerbeamenergies.

简介：采用拉曼光谱原位分析、扫描探针显微镜、扫描电镜和X射线能谱研究了Ce-5％（质量分数）La合金在空气中的氧化过程。

简介：如果图G的一个正常染色满足染任意两种颜色的顶点集合导出的子图是一些点不交的路的并,则称这个正常染色为图G的线性染色.图G的线性色数用1c（G）表示,是指G的所有线性染色中所用的最少颜色的个数.本文证明了对于每一个最大度为△（G）且围长至少为5的平面图G有1c（G）≤[△（G）/2]＋5,并且当△（G）{7,8,…,14}时,1c（G）≤[△（G）/2]＋4.

简介：ＳＴＵＤＹＯＮＴＨＥＲＥＡＲＲＡＮＧＥＭＥＮＴＲＥＡＣＴＩＯＮＯＦ５－ＡＭＩＮＯ－１－ＡＭＩＮＯＣＡＲＢＯＮＹＬ－１，２，ＡＮＤＩＴＳＡＮＡＬＯＧＵＥＳ￥ＲｏｎｇＪｉａｎＬＵ；ＨｕａＺｈｅｎｇＹＡＮＧ；ＢａｏＹｉｎｇＱＩＡＮ；ＨａｉＹａｎＤＥＮＧ（Ｎ...

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简介：ThecokedepositiononHZSM-5/SAPO-34compositecatalystshasbeenstudiedintheconversionofethanoltopropylene.TheHZSM-5/SAPO-34compositecatalystsweresynthesizedbyhydrothermalmethod（ZS-HS）andfullyblending（ZS-MM）.TheusedcatalystswerecharacterizedbyXRD,N2adsorption–desorption,TGA,TPO,elementalanalysis,FTIRandXPS.ThecokingkineticsonbothZS-HSandZS-MMhasbeeninvestigatedandtheircokingrateequationswereobtained.TheusedZS-MMcatalysthadhigheramountofcokeandlowernC:nHthantheusedZS-HS.90%ofthecokewasdepositedinthemicroporesofZS-HS,whilealmost45%ofthecokelocatedinthemicroporesofZS-MM.ThecokedepositedonZS-HScatalystwasmainlygraphite-likecarbonspecies,whereasdehydrogenatedcokespecieswasthemajoronZS-MM.ThecokingactivationenergyofZS-MMwaslowerthanthatofZS-HS,andthecokingrateonZS-MMwasfasterthanonZS-HS.Inaddition,theregenerationofZS-MMcatalystshowedthatithadagoodhydrothermalstability.Thedifferencesoncokingbehaviorsonthetwocatalystswereduetotheirdifferentacidicpropertiesandtextures.

简介：Highqualitypoly(5-cyanoindole)(P5CI)filmswereelectrosynthesizedbydirectanodicoxidationof5-cyanoindoleonstainlesssteelsheetinthemixedelectrolytesofborontrifluoridediethyletherate(BFEE)anddiethylether(EE)(byvolume1:1)+0.05molL~(-1)Bu_4NBF_4.Thefilmformedcanbepeeledofftheelectrodeintofreestandingfilms.TheadditionofEEintoBFEEcanimprovethesolubilityofmonomer.P5CIfilmsobtainedfromthismediumshowedexcellentelectrochemicalbehaviorwithconductivityof10~(-2)Scm~(-1).Structuralstudiesshowedthatthepolymerizationof5-cyanoindoleoccurredatthe2,3position.As-formedP5CIfilmswerethoroughlysolubleinstrongpolarorganicsolventdimethylsulfoxide(DMSO)whilepartlysolubleintetrahydrofuran(THF)oracetone.FluorescencespectralstudiesindicatedthatP5CIwasagoodblue-lightemitter.

简介：设H为G的一个生成子图,(G,H)的一个BB-k-染色是指一个映射f:V(G)→{1,2,…,k},当uv∈E(H),|f(u)-f(v)|≥2;当uv∈E(G)\E(H),|f(u)-f(v)|≥1.定义(G,H)的BB色数x_b(G,H)为最小的整数k,使得(G,H)是BB-k可染的.本文研究了对于任意的连通,非二部平面图G,且G没有5-圈,都存在一棵生成树T,使得x_b(G,T)=4.

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简介：Zn/ZSM-5（NZ2）andZn/Ni/ZSM-5（NZ3）asthecatalystsformethanoltoaromatics（MTA）weresynthesizedbyasimpleultrasonicimpregnation.ThetexturalandacidpropertiesofallcatalystswerecharacterizedusingXRD,HRTEM,NH3-TPD,Py-IR,XPS,XRFandTGtechniques.TheXRDandHRTEMresultsshowedthatthebasiczeolitestructureswerenotaffectedmuchwiththeincorporationofZnandNispecies.However,greatchangeshavetakenplaceinacidproperties.ThePy-IRandXPSresultsindicatedthattheZn-Lewisacidsites（ZnOH+species）,whichhavestrongerinteractionwiththezeoliteframeworkcomparedwithZnOspecies,weregeneratedattheexpenseofBacidsiteswiththeincorporationofzincspecies.Moreover,theproductanalysisresultsshowedthattheincorporationofzincspeciespromotedtheprimaryaromatizationbyenhancingthedehydroaromatizationandsuppressingthecrackingandsubsequentH-transferreaction.Furthermore,theadditionofNispecieswellinhibitedthelossofzincspeciesbyconvertingpartialZnOspeciestoZnOH+species,andthusimprovedthearomatizationactivityandcatalyststability.ThecatalyticperformanceresultsshowedthattheNZ3possesshigherconversionofmethanolinalongertimeandloweraveragerateofcokeformationcomparedwithNZ2.Inaddition,theNZ3alsoexhibitedthehighestyieldofBTXasthereactionproceeds.

简介：Polymer-supportedRCpCpTiCl2(Cp=η^5-C5H4;RCp=η^5-RC5H4)havebeenpreparedandreducedbyi-C3H7MgBrinsitu，thenusedincatalyticisomerizationof1,5-hexadiene.Theisomerizationof1,5-hexadieneleadstoamixtureofcyclicandlinearproducts.Theratioofcyclictolinearproductdependsonthenatureofthesupporterandthesubstituentonthecyclopentadienylring.Theformercontributesthemost,forexample,silicasupportedCp2TiCl2gavecyclic-linearratioof99/1,whileforpolymer-supportedCp2TiCl2species,linearcompoundsarethemajorproductsandtheratioofcyclictolinearproductchangeswithdifferentRgroupsonthecyclopentadienylring.

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简介：CarbondepositionduringmethanoltohydrocarbonsleadstothequickdeactivationofZSM-5catalystanditisoneofthemajorproblemsforthistechnology.DecreasingthecrystalsizeorintroducingmesoporesintoZSM-5zeolitescanimproveitsdiffusionpropertyanddecreasethecokeformation.Inthispaper,nano-sizedZSM-5zeolitewithintercrystallinemesoporescombiningthemesoporousandnanosizedstructurewasfabricated.Forcomparison,themesoporousZSM-5andnano-sizedZSM-5werealsoprepared.ThesecatalystsampleswerecharacterizedbyXRD,BET,NH3-TPD,TEM,Py-IRandTGtechniquesandusedontheconversionofmethanoltogasolineinafixed-bedreactoratT=405°C,WHSV=4.74h-1andP=1.0MPa.Itwasfoundthattheexternalsurfaceareaofthenano-sizedZSM-5zeolitewithintercrystallinemesoporesreached104m2/g,largerthanthatofmesoporousZSM-5(66m2/g)andnanosizedZSM-5(76m2/g).Catalyticlifetimeofthenano-sizedZSM-5zeolitewithintercrystallinemesoporeswas93h,whichwasonlylongerthanthatofmesoporousZSM-5(86h),butshorterthanthatofnanosizedZSM-5(104h).Strongaciditypromotedthecokeformationandthusdecreasedthecatalyticlifetimeofthenano-sizedZSM-5zeolitewithintercrystallinemesoporesthoughitpresentedlargeexternalsurfacethatcouldimprovethediffusionproperty.Thespecialzeolitecatalystwasfurtherdealuminatedtodecreasethestrongacidity.Afterthis,itscokeformationratewasslowedandcatalyticlifetimewasprolongedto106hbecauseofthelargeexternalsurfaceareaanddecreasedweakacidity.Thisspecialstructuralzeoliteisapotentialcatalystformethanoltogasolinereaction.