简介:C/C-SiC复合材料是新一代高性能刹车材料,在高速列车、飞机和重型汽车等高能载制动领域具有广阔的应用前景。介绍了C/C-SiC复合材料的制备方法,分析了各种制备方法的优缺点。从材料的物相组成和使役条件两方面分析了C/C-SiC刹车材料摩擦磨损性能的影响因素,介绍了C/C-SiC刹车材料的优化设计,并对未来的研究方向、研究重点进行了展望。
简介:瞄准使用自然地存在的巨大的数量的一个协议为nanostructured浪费例如落叶,果皮和鸡蛋壳合成材料被建议。在这研究,把自然地存在的膜用作支持的一条绿合成线路为nanostructured和多孔的金属的合成被开发--或金属氧化物碳合成电影。不同金属性的离子(公司2+,Ni2+,Fe3+,Mn2+或Cu2+)能容易在Co/C的形成被吸附到鸡蛋膜和跟随的锻烧过程结果上,Ni/C,Fe3O4/C,MnO/C或Cu/Cu2O/CuO/C合成电影。电气化学的研究证明如此的合成电影将在精力领域里有潜在的应用程序。这个方法将为化学合成提供一个一般绿概念并且对全球持续未来有益。
简介:Tomeettheincreasingdemandforadvancedmaterialscapableofoperationover2000℃forfuturethermalprotectionsystemsapplication,C/C—ZrC—SiCcompositeswerefabricatedbyreactivemeltinfiltration(RMI)withZr,Simixedpowdersasrawmaterials.ThestructuralevolutionandformationmechanismoftheC/C—ZrC-SiCcompositeswerediscussed,andthemechanicalpropertyoftheas-preparedmaterialwasinvestigatedbycompressiontest.TheresultsshowedthataftertheRMIprocess,aspecialstructurewithZrC-SiCmulti-coatingasouterlayerandZrC-SiC-PyCceramicsasinnermatrixwasformed.ZrCandSiCrichareaswereformedinthecompositesandonthecoatingsurfaceduetotheformationofZr-SiintermetalliccompoundsintheRMIprocess.MechanicaltestsshowedthattheaveragecompressionstrengthoftheC/C-ZrC-SiCcompositeswas133.86MPa,andthecarbonfibersinthecompositeswerenotseriouslydamagedaftertheRMIprocess.
简介:综合C-phycocyanins(CPC)做了硅石简历材料被SEM和赌注表面区域分析测量描绘。CPC的形态学做了硅石简历材料显示硅石簇的表面被很多硅石粒子与一种平均尺寸形成在30和40nm之间。硅石本身是有2.95nm的平均毛孔直径的多孔的结构。有他们的直径的毛孔为84.07%的不到5nm报道。另外,CPC能作为一根荧光灯的蛋白质探针被利用监视蛋白质封装的影响并且在硅石矩阵学习矩阵和蛋白质相互作用和蛋白质的稳定性。蛋白质封装硅石材料的申请要求简历分子在潜在地相反的工业条件上保留简历活动和稳定性。在答案或在硅酸盐矩阵的CPC在相片漂白由紫外光线罐头结果照耀,而在硅石的蛋白质少些被影响。在缓冲区答案的CPC的测量相片损坏率常数是比在硅石矩阵的CPC的快25倍的。然而,在硅石矩阵或磷酸盐缓冲区的CPC的一生是未受影响的。这些研究建议CPC的那个陷阱进硅石矩阵能不仅维持他们的生物活动而且显著地改进他们的相片稳定性。
简介:Defectsofpolymer-derivedSi-C-OfiberswereintensivelystudiedbytheSEMandTEMtechniquesandtheiroriginationswerealsodiscussedonthebasisoffactorsexperiments.Thedefectswerefoundmainlyintheformofstrumaes,pitsandsplitsonsurfacesaswellasmicroflawnetworks,porosityclustersandinclusionsinthebulk.Factorsexperimentsrevealthatanonuniformoraninsufficientcuringwouldresultinlarger-sizedstru-maesorinteriormicroflaws.Gasevolutionratesduetodifferentfiringrateshaveagreatinfluenceontheformationofinternalmicrofiawsorporosityclustersandsomeoxidation-inducedpitsorsplitsmaybeformedonsurfacesbe-causeoratraceofoxygenorwatervaporaccumulatedfromtheflowinginertatmosphereduringpyrolysis.
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简介:效果形态学,水晶结构和composites由反应milling准备了的Mg/C的氢吸着性质上的瞬间被学习。传播电子显微镜(TEM)与瞬间的增加准备的那Mg/Ccomposites有粒子尺寸的nanoscale关于在3以后的20-120nm的观察表演milling的h不到1MPaH2。MgH2有四面的水晶组织支配在里面有倾斜的六角形的棱柱的几何形状的材料。从X光检查衍射(XRD)和内容学习的氢,瞬间和微晶的碳在支持加氢率上有synergistic效果在里面反应milling过程。从微分扫描calorimetric(DSC)研究,除氢作用达到顶点有瞬间的Mg/C材料的温度被降低到299-340?
简介:Inthepastfewdecades,manynovelnon-metaldopedZnOmaterialshavedevelopedhastyinterestduetotheiradaptablepropertiessuchaslowrecombinationrateandhighactivityunderthesolarlightexposure.Inthisarticle,wecompiledrecentresearchadvancesinnon-metal(S,N,C)dopedZnO,emphasizingontherelatedmechanismofcatalysisandtheeffectofnon-metalsonstructural,morphological,opticalandphotocatalyticcharacteristicsofZnO.ThisreviewwillenhancetheknowledgeabouttheadvancementinZnOandwillhelpinsynthesizingnewZnO-basedmaterialswithmodifiedstructuralandphotocatalyticproperties.
简介:Asanodematerialsforlithium-ionbatteries,SiO_2isofgreatinterestbecauseofitshighcapacity,lowcostandenvironmentalaffinity.AfacileapproachhasbeendevelopedtofabricateSiO_2@Chollowspheresbyhydrolysisoftetraethylorthosilicate(TEOS)toformSiO_2shellsonorganicspheretemplatesfollowedbycalcinationsinairtoremovethetemplates,andthentheSiO_2shellsarecoveredbycarbonlayers.ElectronmicroscopyinvestigationsconfirmhollowstructureoftheSiO_2@C.TheSiO_2@ChollowsphereswithdifferentSiO_2contentsdisplaygradualincreaseinspecificcapacitywithdischarge/chargecycling,amongwhichtheSiO_2@CwithSiO_2contentof67wt%exhibitsdischarge/chargecapacitiesof653.4/649.6mAhg~(-1)over160cyclesatcurrentdensityof0.11mAcm~(-2).TheimpedancefittingoftheelectrochemicalimpedancespectroscopyshowsthattheSiO_2@CwithSiO_2contentof67wt%hasthelowestchargetransferresistance,whichindicatesthattheSiO_2@Chollowspheresispromisinganodecandidateforlithium-ionbatteries.
简介:Epoxyresin/Ni@Cnanoparticlecompositeswithalignedmicrostructurewerepreparedbyusingaprocedureofmagneticfieldassistedcuring.Theresultsshowthattheresistivityofcompositesexhibitsnegativetemperaturecoeffcient(NTC)effectaboveroomtemperature,andcanbeadjustedbyvaryingthecontentfillerandthemagnitudeofmagneticfieldapplied.Hill'squantumtunnelingmodelwasmodifiedtounderstandtheelectricalconductionmechanisminthecomposites.ItshowsthattheNTCeffectascribestothedominantthermalactivatedtunnelingtransportofelectronacrossadjacentnanoparticles,aswellasthelowthermalexpansivityofepoxyresinmatrix.