简介：Transparenthydroxyapatite(HAp)ceramicswiththegrainsizeranging86-1300nmweresuccessfullysynthesizedbysparkplasmasintering(SPS)at925-1200℃.Allthesampleachievedfinaldensityhigherthan99.7%.ThephasestabilitywasidentifiedbyX-raydiffraction(XRD)andFouriertransforminfraredspectroscopy(FTIR).TheexperimentalresultsindicatethatthereisnodecompositionordehydroxylationduringtheSPSprocesses.TheinfluencesofmicrostructurerefinementonthehardnesswereinvestigatedusingHallPetch(H-P)relationship,andthehardnessoftransparentHApceramicincreaseswiththedecreaseofgrainsize.Itisdemonstratedthatthegrainboundariesanddefectsplayimportantrolesonthehardness.

简介：ThemicrostructuresoftheSaxidomuspurpuratusshellwereobserved.Itwasfoundthattheinnerandmiddlelayersoftheshellarecomposedofcrossedlamellae,whiletheouterlayerexhibitsporousstructures.Withthecharacteristicstructureofeachlayer,thehardnessofinnerlayerwithnarrowdomainsincrossedlamellarstructureisthehighest,andthatofmiddlelayerwithwidedomainsislower,whiletheouterlayerhasthelowesthardness.Thedamagemorphologiesoftheindentationschangealot,dependingnotonlyuponthemagnitudeoftheindentationload,butalsoupontheorientationbetweentheindentationdirectionandthecrossedlamellaeinthemicrostructureoftheshell,whichillustratestheanisotropyinmechanicalpropertiesofsuchshells.

简介：Thetheoryofparameterizedcomputationandcomplexityisarecentlydevelopedsubareaintheoreticalcomputerscience.Thetheoryisaimedatpracticallysolvingalargenumberofcomputationalproblemsthataretheoreticallyintractable.Thetheoryisbasedontheobservationthatmanyintractablecomputationalproblemsinpracticeareassociatedwithaparameterthatvarieswithinasmallormoderaterange:Therefore,bytakingtheadvantagesofthesmallparameters,manytheoreticallyintractableproblemscanbesolvedeffectivelyandpractically.Ontheotherhand,thetheoryofparameterizedcomputationandcomplexityhasalsoofferedpowerfultechniquesthatenableustoderivestrongcomputationallowerboundsformanycomputationalproblems,thusexplainingwhycertaintheoreticallytractableproblemscannotbesolvedeffectivelyandpractically.Thetheoryofparameterizedcomputationandcomplexityhasfoundwideapplicationsinareassuchasdatabasesystems,programminglanguages,networks,VLSIdesign,parallelanddistributedcomputing,computationalbiology,androbotics.Thissurveygivesanoverviewonthefundamentals,algorithms,techniques,andapplicationsdevelopedintheresearchofparameterizedcomputationandcomplexity.Wewillalsoreportthemostrecentadvancesandexcitements,anddiscussfurtherresearchdirectionsinthearea.

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简介：ThemicrostructureandhardnessoftheHAZina800MPagradeultra-low-carbonmicroalloyedsteelwerestudied.Theresultsindicatethattheheataffectedzone(HAZ)oftheRPC(Relaxation-Precipitation-Controlling)steelpossessesacontinuousgradientstructure,andcanbeclassifiedintothreezones,i.e.CGHAZ(coarse-grainHAZ),FGHAZ(fine-grainHAZ)andICHAZ(intercriticaltemperatureHAZ).ThemicrostructuresintheHAZareallcomposedofbainite-likestructure.ThemicrostructareintheCGHAZmainlyconsistsoflath-likebainiteandgranularbainite.Theinfluencesofheatinputandt8/5onthehardnessintheHAZofRPCsteelarenotable.Withtheincreaseofheatinputandt8/5,thesofteningtendencyofHAZbecomesobvious.ThehardeningphenomenonthatnormallyoccursintheCGHAZdoesnottakeplacewiththissteelintherangeofexperimentalconditions.ThesofteningintheICHAZisboundtooccur.Henceappropriateweldingtechnologiesneedtobeselected.

简介：InthispaperweprovethatthesinglemachinecommonduedateweightedtardinessproblemisNP-hard.

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简介：ThemicrostructuresandVickershardnessatroomtemperatureofarc-meltingprocessedintermetallicsofMo5Si3-MoSi2hypoeutecticalloyandhypereutecticalloyannealedat1200℃fordifferenttimewereinvestigated.LamellarstructureconsistedofMo5Si3(D8m)phaseandMoSi2(C11b)phasewasobservedinallthealloys.ForMo5Si3-MoSi2hypoeutecticalloy,thelamellarstructurewasfoundonlyafterannealinganddevelopedwellwithfinespacingontheorderofhundrednanometersafterannealingat1200℃for48h.Butwhentheannealingtimewasupto96h,thewell-developedlamellarstructurewasdestroyed.ForMo5Si3-MoSi2hypereutecticalloy,thelamellarstructurewasfoundbothbeforeandafterannealing.Howeverthevolumefractionandspacingofthelamellarstructuredidnotchangesignificantlybeforeandafterannealing.Theeffectsoftheformation,developmentanddestructionoflamellarstructureonVickershardnessofalloyswerealsoinvestigated.WhenMo5Si3-MoSi2hypoeutecticalloyannealedat1200℃for48h,theVickershardnesswasimprovedabout19%comparedwiththatwithoutannealingandformationoflamellarstructure.ThehighestVickershardnessofMo5Si3-MoSi2hypereutecticwasincreasingabout18%whenannealingat1200℃for48h.

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简介：Inconel718superalloycoatingwaspreparedonamartensiticsteelsubstratebycoldgasdynamicspraying(CGDS).Microstructureandmicro-hardnessofthecoatingwerecharacterizedbymeansofscanningelectronicmicroscope(SEM),energydispersivespectrometer(EDS),andmicro-hardnessandnano-indentationtests.Theresultshaveindicatedthatthecoating’sthicknesscanreachmorethan300μm,andthereexistsagoodinterfacialcohesionbetweenthecoatingandthesubstrate.Thequantityandsizeofthedefectsatthebottom,middleandtopareasincreasegradually.ThereisnosignificantchangetotheoriginalmicrostructureoftheInconel718superalloyparticleaftertheprocessofCGDS;andanobvioustorsionaldeformationontheparticle’sprofileisproducedwhilelittledeformationatthecenterpartoccurs.Themicro-hardnessofthecoatingatthebottom,middleandtopareasdecreasesinturn.Comparedwiththebottomarea,themicro-hardnessofthemiddleandtopareasdecreasesbyabout10%and21%,respectively.Thenano-hardnessofthecoatingismuchlowerthantheoriginalparticle,whichdecreasesbyabout13.5%atthebottomareaand28%atthetoparea,respectively.Thedistributionofmicro-defectsisanimportantfactortothemicro-hardnessofthecoating.

简介：氧化物分散加强了铜合金由于他们热、电的传导性，高温度的力量和微观结构稳定性的优秀联合是吸引人的。迄今为止，到他们的制造的state-of-art是内部氧化(IO)过程。在这份报纸，氧化铝分散加强了铜(ADSC)Cu-2.5vol%Al2O3的名字的作文的粉末被反应milling(RM)生产是一个在原处煤气固体的反应过程的过程。为电、机械的性质调查的体积ADSC合金被sintering并且此后获得热挤出。在热巩固过程以后，充分使增加密度的粉末协议能被获得。单个-Al2O3阶段和侧面拓宽效果根据X光检查衍射(XRD)的结果是明显的；ADSC的HRB坚硬能象95一样高；结果应该在铜矩阵在脱臼和谷物边界上被归因于nano-Al2O3的卡住的效果。ADSC合金的电的传导性是55%IACS(国际退火铜标准)。热巩固的材料的房间温度坚硬近似在在900点为1h退火以后被维持

简介：Thetransformationinducedplasticity(TRIP)steelseffectoccursbecauseofthemartensitictransformationofretainedausteniteduringplasticdeformation,anditprovidesthesteelwithexcellentstrengthandductility.Whileweldingremainsavitalpartofautobodymanufacturing,theweldabilityofTRIPsteelsisproblematic,andthispreventsitsadoptionformanyapplicationsintheautomotiveindustry.Thispresentworkstudiestheeffectsofweldingandpost-weldheattreatmentonthemicrostructureof...

简介：Atomized,pre-alloyedTi—24Nb—4Zr—7.9Sn(wt%)powderwasusedtofabricatesolid,prototypecomponentsbyelectronbeammelting(EBM).Vickersmicroindentationhardnessvalueswereobservedtoaverage2GPafortheprecursorpowderand2.5GPaforthesolid,EBM-fabricatedproducts.Thepowderandsolidproductmicrostructureswereexaminedbyopticalandelectronmicroscopy.X-raydiffractionanalysesshowedthattheyhadbccβ-phasemicrostructure.However,itwasfoundbytransmissionelectronmicroscopythattheEBM-fabricatedproducthadplatemorphologywithspace~100—200nm.Althoughthecorrespondingselectedareadiffractionpatternscanbeindexedbyβ-phaseplusα'-martensitewithorthorhombiccrystalstructure,thedark-fieldanalysesfailedtoobservethea'-martensite.Suchphenomenonwasalsofoundindeformedgummetalsandexplainedbystress-induceddiffusionscatteringduetophononsoftening.

简介：(Cu60Zr30Ti10)98Y2bulkmetallicglass(Φ4mm×70mm)wasobtainedsuccessfullybycoppermouldcoolingandspraying-casting,andsomesampleswereisothermallyannealedattemperaturesof473and623K,whichwaslowerthantheglasstransitiontemperature(Tg)for1h.Microstructureandpropertiesofas-castandannealedsampleswerestudied.Crystallizationphases(Cu10Zr7andCuZr)wereobservedinannealedsamples,andthespeciesandfractionofthesephasesincreasedwithincreasingannealingtemperature.Mic...

简介：我们使用了联合代理人改进在小麦稻草粒子和UF树脂之间的结合的能力的silane，并且调查了表面性质(wettability和表面粗糙)和用与由联合代理人内容和稻草/白杨木头粒子比率的silane影响了的白杨木头相结合的结合UF的小麦稻草(TriticumaestivumL.)做的particleboard的坚硬。我们在0，5%和10%的三个层次在稻草的四不同比率生产了一个分层的particleboard面板到白杨木头粒子(0%，15%，30%和45%小麦稻草)和silane联合代理人内容。粗糙大小，平均粗糙(R),平均数peak-to-valley高度(Rz),和根平均数平方粗糙(Rq)被使用跟踪技术的一支好尖笔在unsanded样品上测量。我们由使用连接到一个数字照相机和计算机系统的角度计获得了接触角度大小。包含白杨粒子的更大的数量的板与控制样品相比有优异坚硬并且有更低的wettability。与有的silane的更高的数量做的面板降低R<潜水艇class=“a-plus-plus”>q值。