简介:重要努力在在水泥揭示thaumasite形成的机制被作了,它继续与歧义和纠纷是充满的。化学方法被采用综合纯C3S,C2S,C3A,ettringite,和thaumasite,和X光检查衍射(XRD),拉曼光谱学和红外线的光谱学(红外)被用来从另外的水合物识别thaumasite。调查thaumasite形成的直接线路,C3S,C2S,石膏,和钙碳酸盐被用来准备水泥粘贴以便ettringite形成的干扰能被避免。thaumasite形成的间接线路被考虑C3thaumasite上的A或ettringite内容形成。结果证明那个thaumasite罐头毫无疑问在适当条件下面当忍受铝的矿物质或ettringite不在时被产生,当ettringite存在支持thaumasite形成时。没有证据在这个工作支持异构的成核线路。方法在这提到工作能肯定被用来调查thaumasite形成的机制,这被结束,并且thaumasite能形成由直接并且woodfordite线路。
简介:催化nanomotors是带机载的催化剂并且在溶液把本地化学燃料变换成机械工作的nano-to-micrometer-sized致动器。这催化剂以及游泳行为展出了的结构指示的几何学的地点。nanomotors能在器官的分子自然地发生,联合自然、人工的部分到形式混血儿nanomotors或完全人工。制造技术由指导electroplating,平版印刷术,物理蒸汽免职,和其它预付生长方法的模板组成。各种各样的物理、化学的推进机制被建议了包括diffusiophoresis,水泡推进,界面的紧张坡度,和自我电气泳动向运动解释行为。通过热调整在外部域,催化合金,和运动控制之上基于的控制和操作也被讨论。催化nanomotors与是实际的结束目标代表令人激动的工艺的挑战能在nanoscale执行许多任务的功能的nanomachines。
简介:增加焊接穿入的A-TIG的机制被使用我们为不锈钢开发了的激活的流动学习。流动和焊接水池的温度领域上的流动的效果被PHOENICS软件模仿。它证明没有流动,液体流动将沿着焊接水池然后在下面的表面是外面的,导致flatter焊接水池形状。与流动,氧,从否定价值把表面紧张毕业生的温度依赖改变到积极价值,能在焊接穿入上引起重要变化。液体流动将沿着向中心然后在下面的焊接水池的表面是里面的。这个液体流动模式高效地把热转移到焊接根并且生产相对深、狭窄的焊接。这个变化是穿入增加的主要原因。而且,弧建设能引起焊接宽度变得更狭窄并且变得更深的穿入,但是这不是穿入增加的主要原因。焊接水池表面和弧侧面的液体流动上的流动的效果在焊接的常规TIG并且在由使用高速度的摄像机焊接的A-TIG被观察。液体流动行为被微集中的X光检查传播录像观察系统在实时规模设想。结果显示与更狭窄的宽度和更深的穿入导致焊接祷告的更强壮的里面的液体流动模式能显然在焊接的A-TIG的情况中被识别。流动能在焊接水池改变液体流动的方向。它与模拟结果有一个好协议。
简介:Ferrumniobatewassynthesizedbysolid-phasesinteringmethodinavacuumcarbontubefurnaceat1300℃for180min.ThephasetransformationofferrumniobatecarbothermalreductionprocesswasstudiedbyXRD.ThereductionreactionsofferrumniobateindifferenttemperaturestagesweredeterminedbytheTG-DSCcurve.Meanwhile,accordingtotheTGcurve,thereactionkineticsparameterswerecalculatedbyA.W.Coatsintegrationandthecontrolstepsindifferenttemperaturestageswereascertained.Theresultsshowedthatthereductionofferrumniobatestartsatthetemperatureof1000℃,andthereductionprocesscarriesoutintwostepsaccordingtosinteringtemperature.Inatemperaturerangeof1000-1238℃(thefirststep),themainreductionproductsareNbO2andFe;thekineticequationofinitialstageis[-ln(1-α)]4=kt,controlledbynucleationgrowth,andtheapparentactivationenergyis388kJ/mol;withthetemperatureincreasing,thekineticequationisα+(1-α)ln(1-α)=kt,whichistheValensitwo-dimensionaldiffusionkineticequation,andtheapparentactivationenergyis264.4kJ/mol.Themainreactioninarangeof1238-1344℃(thesecondstep)isthereductionofNbO2toNbC,thekineticequationis[(1-α)-1/3-1]2=kt,whichiscontrolledbythethree-dimensionaldiffusion,andtheapparentactivationenergyis482.7kJ/mol.
简介:作为水泥,磨擦在粒子特征和水泥的机械性质上帮助的修改triethanolamine的效果被学习,并且它的反应机制被红外,希腊语的第六个字母潜力,SEM,XRD和TG-DTA分析。结果证明为有0.015%修改triethanolamine(M茶)的水泥的332个m粒子的内容被12.4%增加,并且有0.03%M茶的水泥的压缩力量被5.5和8.2MPa分别地在3和28天增加。并且在水泥上磨擦和M茶的改进效果比triethanolamine好。机制分析显示出那M茶不仅氨基并且氢氧根茶组织,而且有酉旨,羰基,容易与水泥矿物质的金属离子结合的carboxyl组,导致那M茶能支持表面吸附并且在表面和粒子的裂缝节防护不饱和的费用,因此,粒子重聚被阻止,磨擦效率被改进。水泥上的M茶的改进主要躺因为它能与石膏和水支持或导致水泥矿物质的水和反应,它加速水和产品的形成,然后改进水泥水和产品的结构和形态学,因此,产品结构的一致性和紧密被增加。
简介:ThebasestructureofinsituTiCP/Fecompositesfabricatedunderindustrialconditionwaschangedbydifferentheattreatments.Erosiveweartestswerecarriedoutandtheresultswerecomparedwiththatofwear-resistantwhitecastiron.TheresultssuggestthatthewearresistanceoftheinsituTiCp/Fecompositeishigherthanthatofwear-resistantwhitecastironunderthesanderosivewearcondition.Thewearmechanismofthewear-resistantwhitecastironwasacycleprocessthatbasesurfacewaswornandcarbideswereexposed,thencarbideswasbrokenandwearpitsappeared.WhilethewearmechanismofinsituTiCp/FecompositewasacycleprocessthatbasesurfacewaswornandTiCgrainswereexposedanddropped.ThewearresistanceofinsituTiCp/Fecompositewaslowerthanthatofwear-resistantwhitecastironundertheslurryerosivewearcondition.Undersuchcircumstance,thematerialwasnotonlyundergoneerosivewearbutalsoelectrochemistryerosionduetothecontactwithwaterinthemedium.Thewearbehaviourscanbeacombinationoftwokindsofwearandthesanderosivewearisworsethanslurryerosivewear.
简介:Carbidesinaseriesofcold-weldingweldmetalswerestudiedbymeansofSEM,TEMandEPMA,andtheformingmechanismofcarbidewasproposedaccordingtotheirdistributionandmorphology.Duetotheirdifferentcarbide-formingtendency,NbandTicouldcombinewithCtoformparticulatecarbideinliquidweldmetalanddepletedthecarboncontentinmatrix,whileVinducedthecarbideprecipitatedalonggrainboundary.ButtoomuchNborTialoneresultedincoarsecarbideandpoorstrengthenedmatrix.WhensuitableamountofNb,TiandVcoexistedinweldmetal,bothuniformlydistributedparticulatecarbideandwellstrengthenedmatrixcouldbeachieved.Itwasproposedthatthecarbidenucleatedontheoxidewhichdispersedinliquidweldmetal,andthengrewintomulti-layercomplexcarbideparticlesbyepitaxialgrowth.Atdifferentsites,carbideparticlesmaypresentasdifferentmorphologies.
简介:在不同水和年龄和它充满力量的生长法律获得似水泥的材料的水和产品的作文和微观结构,合成似水泥的材料的最佳的比例根据波特兰水泥32.5R镇静的水泥clinker的化学作文被决定,CSA42.5sulphoaluminate水泥和二石膏(CS)。在不同水和年龄的合成似水泥的材料的描述被NMR,XRD和SEM技术进行。水和的机制被探索。测试的压缩力量随水和年龄的增加逐渐地堵住增加,这被显示出。合成似水泥的材料的微观结构能在水和过程从Al-O八面体被变成Al-O四面体。与Si-O四面体和Al-O四面体形成的含水的碱aluminiumsilicate。Si-O四面体的聚合的度逐渐地增加了,并且似水泥的材料的结构的力量继续增加。clinker矿物质的衍射山峰逐渐地与水和年龄的延期减少了。完全含水的CaSO4在导致了似水泥的材料的高早的力量的水和期间在船尾生产。合成似水泥的材料的早水和产品是在船尾与针酒吧结构。主要中间和最后一水和产品是有稠密的棱柱的形状的CSH胶化和CH胶化。合成似水泥的材料的显微镜的毛孔逐渐地减少了并且改进了充满块的以后的力量。强壮的支持我的外面被为区域提供。
简介:Thetensile-shearfailurezoneofthelaminateddampingsteelsheetwasinvestigatedbyscanningelectronmicroscopyandX-rayphotoelectronspectroscopy.Itisfoundthatthereexistscohesivefailureinpolymersandwichandsub-boundaryfailurebetweenthesteelsheetandthepolymer.Thesub-boundarylayerisdominantlypolymermaterial.Thetensile-shearfailureofthelaminateddampingsteelsheetisaprocessduringwhichthecrazesform,growupandmergeintocracks.
简介:六角形的硼氮化物陶器(h-BN)基于B的nitridation,粉末被反应sintering获得方法。结果的产品的机械性质和微观结构上的sintering温度的效果被调查,反应机制被讨论。结果证明在B和N2之间的反应在从1000瀠潨潴畬業敮'諟Iⅹe数瑣潲捳灯?的温度有力地发生了堠爭祡瀠潨潴汥'虪箿e数瑣潲捳灯?堨卐?愠摮氠晩瑥浩?敭獡牵浥湥獴
简介:ItisfoundthattheincorporationofNitriteCorrosionInhibitor(NCI)greatlyweakenstheresistanceofmixturestosulfateattack.Tostudythemechanismofthisphenomenon,inthispaper,theinfluenceofNCIadditionononthecementpasteandmicrostructurechangeofhighperformanceconcretespecimensisstudiedbymeansofquantitativeXRD,SEMtests.TheresultsdemonstratethattheincorporationofNCIacceleratestheformationof
简介:钾和磷酸盐被酸水解作用过程在低温度提取分解联系的磷和钾矿石的一种新类型。影响溶解率的主要因素被调查,例如磨上好,硫磺的酸的数量和氟化物盐,反应时间和温度,等等。同时,可溶的钾和磷酸盐的形成上的各种各样的因素的效果也被讨论。反应产品和残余被X光检查衍射(XRD)决定,扫描电子显微镜(SEM)分析和其它工具。结果证明分别地,钾和磷的溶解率在95.64wt%lessthan的一种谷物尺寸的条件下面是70wt%和93.7wt%0.074公里,9.78gg-1硫磺的酸,0.5gg-1铵氟化物,160桴???瑳畲瑣牵獥椠?慭湩慴湩摥映牯戠瑯??愠摮吠?湩楣敤瑮瀠汯牡穩瑡潩?愠摮映牯愠杮敬?景椠据摩吗??
简介:CuSmicrocrystalsweresuccessfullypreparedthroughamildsolvothermalreactioninethyleneglycol(EG)withtheassistanceofcationicsurfactantcetyltrimethylammoniumbromide(CTAB).Aninterestingmorphologyevolutionfromflower-likemicrospherestohollowmicrospheres,andfinallytosmoothnanoflakeswasobservedwhenincreasingtheamountofCTAB.TheproductswerecharacterizedbyX-raydiffraction(XRD),scanningelectronmicroscopy(SEM),transmissionelectronmicroscopy(TEM),andUV—visspectroscopy.ItwasfoundthattheamountofCTABplayedanimportantroleindeterminingthemorphologyoftheCuSmicrocrystals.Electricalmeasurementrevealsthattheas-preparedCuSmicrosphereswereofhighconductivity,whichmightfavortheirdeviceapplications.ItisexpectedthatCuSmicrocrystalswithcontrolledmorphologiesandstructureswillhaveimportantapplicationsinsolarcells.Thissimplebuteffectivemethodcouldalsobeextendedtothecontrolledgrowthofotherinorganicmicrocrystals.
简介:Aseriesofsolarradiationtestsforthepolytetrafluoroethylene(PTFE)bulkandfilmsampleswerecarriedoutusingQ-SUNXE-3-HSCtypeSolarRadiationSimulator,withthetestparametersasfollows:radiationintensityis1120W/m~2,temperatureis55℃andhumidityis70%RH.Surfacemorphology,compositionandmicrostructureofthePTFEsamplesbeforeandafterradiationtestswerecharacterizedcontrastively.EffectofsolarradiationonthetribologyandwettingpropertiesofPTFEwerealsostudiedbytribometerandcontactangletester,respectively.Theresultsshowthat,forradiatedPTFE,surfaceroughness,therelativecontentofCelement,thefrictioncoefficientsandthecontactanglewithwaterincreasedinvaryingdegrees.Inconclusion,theobviouschangeinPTFEsamplescanbemainlyattributedtobreakof(CFx)-CbondsafterbombardmentofhighenergyUVphotons,whichcausesthelossofF-richgroups,oxidation,crosslinkingandrestructuringofactiveunsaturatedgroups.
简介:
简介:在沥滤的Pb之间的关系当在它的团结的形式的水泥在酸媒介被沥滤时,有时间的集中和答案pH被分析。团结的形式,增加方法的水泥,和Pb团结上的水和度的粒子尺寸的效果也被调查。试验性的结果显示水泥快速被溶解,形成有好吸附的C-S-H胶化或硅的酸大音阶的第五音并且在酸媒介含水。当cement-Pb团结了时,形式在一个醋酸盐答案被沥滤,含水的产品与时间侵蚀,Pb集中因此在开始稍微增加。然后,一些Pb离子被最新产生的硅的酸大音阶的第五音吸收,C-S-H。其它生产Pb(哦)为第二等的团结的2降水,在超过二个小时的一沥滤的时间在Pb集中导致渐渐的减少。而且,团结的形式的粒子尺寸在Pb溶解上有重要效果。当增加的水泥的数量是低的时,与不到9.5的pH,团结影响原来的水泥粉末的顺序,水泥含水的粉末,和cement-Pb团结了形式。当水泥的增加的数量与超过11的pH增加时,在团结上增加方法的效果减少,并且团结的形式比其它好一些。
简介:Inthisstudy,highlyporousforsteritescaffoldswithinterconnectedporositiesweresynthesizedusingmulti-stepsintering(MSS)method.Thestartingpowderwasnanosizedforsterite,whichwassynthesizedfromtalcandmagnesiumcarbonatepowders.Thephasecomposition,averageparticlesizeandmorphologyoftheproducedforsteritepowderwerecharacterizedbyX-raydiffractiontechnique(XRD)andtransitionelectronmicroscopy(TEM).Forsteritescaffoldswereproducedbyfoamymethodusingpolymericsponges.MSSprocessincludingthreestepswasusedtoefficientlysintertheforsteritenanopowderswithoutdestroyingtheinitialporousstructureofpolymericsponges.TheresultsshowedthatMSStechniqueisanefficientandappropriateproceduretoproducehighlyporousforsteritescaffoldswithporesizeintherangeof100-300μm.Thecompressivestrength,compressivemodulusandporosityofC12specimen(sinteredat1650℃for1hwithsubsequentannealingat1000℃,for1000min)was1.88MPa,29.2MPa,and72.4%,respectively,whichisveryclosetothatofcancellousbone.Theapproachstudiedinthisresearchcanbedevelopedforothernanostructureceramicstoproducehighlyporousscaffoldswithinterconnectedporositiesforloadbearingapplications.