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简介：Anenvironmentallyfriendlyprecursor,adenosine,hasbeenusedasadualsourceofCandNtosynthesizenitrogen-dopedcarboncatalystwith/withoutFe.Ahydrothermalcarbonizationmethodhasbeenusedandwateristhecarbonizationmedia.Themorphologyofsampleswith/withoutFecomponenthasbeencomparedbyHRTEM,andtheresultshowsthatFecanpromotethegraphitizationofcarbon.Furtherelectro-chemicaltestshowsthattheoxygenreductionreaction(ORR)catalyticactivityofFe-containingsample(C–FeN)ismuchhigherthanthatoftheFe-freesample(C–N).Additionally,theintermediatesofC–FeNformedduringeachsyntheticprocedurehavebeenthoroughlycharacterizedbymultiplemethods,andthefunctionofeachprocedurehasbeendiscussed.TheC–FeNsampleexhibitshighelectro-catalyticstabilityandsuperiorelectro-catalyticactivitytowardORRinalkalinemedia,withitshalf-wavepotential20mVlowerthanthatofcommercialPt/C(40wt%).Itisfurtherincorporatedintoalkalinepolymerelectrolytefuelcell(APEFC)asthecathodematerialandledtoapowerdensityof100mW/cm~2.

简介：<正>在亚洲的东方,巍然屹立着一个泱泱大国。在她广袤的土地上,孕育着一代代黄皮肤的龙的传人,演绎着无尽的风云传奇。她的辉煌让人侧目,人们在晨曦中瞥见她的侧影,轻吐她的名字:"C—H—I—N—A"。

简介：Westudythegeneralrepresentationsofpositivepartialtranspose(PPT)statesinCKCMCN.ForthePPTstateswithrank-Nacanonicalformisobtained,fromwhichasufficientseparabilityconditionispresented.

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简介：TheeffectofTi(C,N)onpropertiesoflow-carbonMgO-Cbrickswasinvestigated.Thephasecompositionandthemicrostructureofthematrixoflow-carbonMgO-CbrickcontainingTi(C,N)werestudiedbyXRDandSEManalysistogetherwithEDS.TheresultsshowedthatTi(C,N)distributedinthematrixoflow-carbonMgO-Cbrickuniformlyafterbeingtreatedat1600℃for3hincokepowderbed,andTi(C,N)andMgOformedasolidsolution.Afterthetreatmentat1600℃for3hincokepowderbed,thebulkdensityandcoldcrushingstrengthoflow-carbonMgO-CbrickwithTi(C,N)decreased,andtheapparentporosityandlinearchangerateofspecimensincreased.Theoxidationresistanceoflow-carbonMgO-CbrickwithTi(C,N)wassuperiortothatoflow-carbonMgO-Cbrickwithnoadditives,butinferiortothatoflow-carbonMgO-CbrickwithAlpowder.TheslagresistanceofthespecimenwithTi(C,N)wasexcellentaswell.

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简介：Thisarticleprovestheexistenceofsingulardirectionsofvaluedistributiontheoryforsometranscendentalholomorphiccurvesinthen-dimensionalcomplexprojectivespacePn(C).Anexampleisgiventocomplementtheseresults.

简介：采用新颖的碳热还原和氮化前驱体法制备Ti（C，N）晶须，通过X射线衍射仪（XRD）、扫描电子显微镜（SEM）对样品表征分析，结果表明，在1250℃条件下，产物主要相成分是Ti（C，N）晶须，含有少量的Ni和TiN成分，晶须直径为100～200nm，反应温度低于1250℃时，钛的氧化物还原不充分，而过高的温度也不能促进Ti（C，N）纳米晶须的形成。

简介：ThepaperdefinesanextendedCesàrooperatorTgwithholomorphicsymbolgintheunitballBofCnasWhereg(z)=∑j=1∑nzjg/zjistheradialderivativeofg.Inthispaper,theauthorcharacterizesgforwhichTgisbounded(orcompact)ontheBlochspaceBandthelittleBlochspaceB0.

简介：ＱＵＡＬＩＴＡＴＩＶＥＳＴＵＤＹＯＦＳＩＡＬＯＭＵＣＩＮＳＣＨＡＮＧＥＳＤＵＲＩＮＧＮ－ＭＥＴＨＹＬ－Ｎ－ＮＩＴＲＯＳＯＵＲＥＡ－ＩＮＤＵＣＥＤＣＯＬＯＮＩＣＣＡＲＣＩＮＯＧＥＮＥＳＩＳＩＮＭＩＣＥＷａｎｇＱｉａｎｇ王强；ＷａｎｇＹｕａｎｈｅ王元和；...

简介：在纳米科学中,材料的性质与其分子结构相关,可通过拓扑指数计算得到其物理化学性质.作为一种常见结构,纳米管结已被广泛应用于材料科学及相关工程中.因此,有必要计算它对应分子结构的化学指数,结果给出纳米管结Cas（C）-CaR（C）[m,n,p]的几类基于度的化学指数的精确计算公式.作为补充结论,研究了H-环烃纳米片[4n,2m]的第四原子键连通指数.所得理论结果在材料制造工程中具有潜在的应用价值.

简介：ThesubmicronpowdermixturesofTiC-TiN-WC-Mo-C-Nisinteredat1400℃orbelowinvacuumwerestudiedbyX-raydiffraction(XRD),scanningelectronmicroscopy(SEM)andtransmissionelectronmicroscopy(TEM)analyses.TheresultsshowedthatMo2Cformedat800℃orbelow.BothWCandMo2Cdisappearedat1200℃,andTiNdisappearedat1250℃.Inaddition,thevariationsoflatticeconstantsofthetitaniumcarbonitrideandnickelbinderphasewithsinteringtemperaturewereexperimentallyobtained,andthereasonwasanalyzed.

简介：Thec-JunN-terminalkinases(JNKs)areclassicstress-activatedproteinkinases.ManycellularstresseshavebeenshowntostimulateJNKactivation.Inthisreview,wefocusonribotoxicstressesbasedontheirmultiplebiologicalpotenciesincludinganti-HIV-1activity.Someofthefunctionsofribotoxinsandthesignalingtransductionpathwaythatmediatedarementioned.Differentfromotherstimulators,ribotoxicstressesactonspecialmotifsof28SrRNAintranslationallyactivemammalribosomes.BindinganddamagingonthemotifleadstoJNKactivationandsubsequentlybiologicalresponsetothesignalinitiator,whichisnamedribotoxicstressresponse.

简介：Thepresentpapershowsthatforanysequenceofrealnumberswithinfinitedistinctelements{λ_n},therationalcombinationof{x~λ}arealwaysdenseinC_[0,1].

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简介：本文就n-C4H9-Br制备实验的反应过程以及分别用KBr和NaBr制备n-C4H9-Br时出现的不同实验现象和结果进行了探讨。提出KBr的溶解速率比NaBr的溶解速率小是产生不同实验现象和结果的原因，并通过用块状NaBr进行对比实验得到验证。用块状的NaBr有利于提高n-C4H9-Br的产率。

简介：SupposethatDisaboundeddomainwithapiecewiseC^1smoothboundaryinC^n.Letψ∈C^1+α(δD).ByusingtheHadamardprincipalvalueofthehigherordersingularintegralandsolidanglecoefficientmethodofpointsontheboundary,wegivethePlemeljformulaofthehigherordersingularintegralwiththeBoehner-Martinellikernel,whichhasintegraldensityψ.Moreover,bymeansofthePlemeljformulaandmethodsofcomplexpartialdifferentialequations,wediscussthecorrespondingCauehyboundaryvalueproblemwiththeBoehner-Martinellikernelonaclosedpiecewisesmoothmanifoldandobtainitsuniquebranchcomplexharmonicsolution.

简介：Fivehumicfractionswereobtainedfromauniformly^15N-labelledsoilbyextractionwith0.1molL^-1Na4P2O7,0.1molL^-1NaOH,andHF/HCl-0.1molL^-1NaOH,consecutively,andanalyzedby^13Cand^15NCPMASNMR(crosspolarizationandmagicanglespinningnuclearmagneticresonace).Comparedwiththoseofnativesoilshumicfractionsstudiedasawholecontainedmorealkyls,methoxylsandO-alkyls,being27%-36%,17%-21%and36%-40%,respectively,butfeweraromaticsandcarboxyls(bein14%-20%and13%-90%,respectively),Amongthosehumicfractions,thehumicacid(HA)andfulvicacid(FA)extractedby0.1molL^-1Na4P2O7containedslightlymorecarboxylsthancorrespondinghumicfractionsextractedby0.1molL^-1NaOH,andtheHAextactedby0.1molL^-1NaOHaftertreatmentwithHF/HClcontainedtheleastaromaticsandcarboxyls.Thedistributionofnitrogenfunctionalgroupsofsoilhumicfractionsstudiedwasquitesimilartoeachotherandalsoquitesimilartothatofhumicfractionfromnativesoils.Morethan75%oftotalNineachfractionwasinamidefrom,with9%-13%presentasaromaticand/oraliphaticaminesandtheremainderasheerocyclicN.

简介：基于双连续半群概念,引入一致双连续半群序列概念,借助Laplace变换和Trotter-Kato定理,考察双连续n次积分C余弦函数与C-预解式之间的关系,得到逼近定理的稳定性条件,进而得出双连续n次积分C余弦函数逼近定理.从而对Banach空间强连续半群逼近定理和双连续半群逼近定理进行了推广,为相应抽象的Cauchy问题提供了解决方案.