简介:Recentinvestigationsindicatedthatmetalscanbeeffectivelystrengthenedbynumeroustwinboundaries(TBs)withtwin/matrixlamellarthicknessesinthenanometerregime.Superiorstrength-ductilitysynergieshavebeenachievedwiththenano-twinstrengtheningmechanism.Inthistalk,thenovelnano-twinstrengtheningwillbeappliedtoaustenitesteelsincluding316LstainlesssteelandaFe-Mnsteelinordertooptimizetheirstrength-ductilitycombinations.Thesteelsareprocessedbymeansofdynamicplasticdeformation(DPD,i.e.,plasticdeformationathighstrainrates).Single-phased(austenite)bulknanostructuredsteelspecimenswereprepared,consistingofnano-sizedgrainsembeddedwithnano-scaletwinbundles.Theas-preparednanostructuredsampleswereannealedatvariousconditions,resultinginpartialrecrystallizationofthenanostructuresandformingamixturestructureofcoarse-grainsembeddedwithnano-twinbundles.Strengthandductilityoftheaustenitesteelswithdifferentamountofnano-twinbundlesareanalyzed.Measurementsshowedthenano-twinstrengthenaustenitesteelscanbesuperstrong(withyieldstrengthabove1GPa)togetherwithaconsiderableductility(elongation-to-failure>20%).
简介:Reversed-phasepaperchromatographytechniqueisusedforstudyontheextractionmechanismandsep-arationofrareearthelements.Asthestationaryphase,chromatographicpaperstripsareimpregnatedwithasolutionofmonomyristylphosphoricacid(MPA)inchloroform.Mineralacidsareusedasdevelopers.Theeffectofconcentrationofacidsand/orsaltsuponRfhasbeeninvestigated.Accordingtothere-sultsofRfvaluesforagivenrareearthelementinvariousacids,theorderofextractionabilityisHCl>HNO3>H2SO4.Atetradeffectisclearlyobserved.fortheRfvalueofrareearthelements.TheeffectsofotherparametersontheRfvalue,suchasthequantitiesofextractantretainedbythepaperandthetemperaturearealsoexamined.BasedonthedeterminationofthemolarratioofMPAtorareearthelementsandthenumberofH+ionsreleasedinextractionreaction,areasonablemechanismisproposed.Themutualseparationofheavyrareearthelementswillbebetterthanthatofthelightrareearthgroupbecauseofthelargerseparationcoefficientoftheformer.AmixtureofHo-Er-Tm-Luissuccessfullyseparatedbythepresentmethod.
简介:CeO2andCuOx-CeO2supportedpotassiumcatalystsweresynthesizedbywetnessimpregnationmethod.ThecatalystswerecharacterizedbyBET,NO-TPO,NOx-TPDandsoot-TPOmeasurements.Bythedecorationofpotassiumandcopper,themaximumsootcombustiontemperatureoftheceria-basedcatalystdecreasedto338and379°CinthepresenceandabsenceofNOunderaloosecontactmode,re-spectively.ThepronouncedlyenhancedNOoxidationabilitybycopperintroductionandNOxstoragecapacitybypotassiummodif...
简介:ThermalsimulationtestswereconductedatdifferentdeformationtemperaturesanddegreesbyaGleeblesimulator.Theresultsshowthatthealloyhashigherresistancetodeformation;withanincreaseofthedeformationtemperature,thealloy'sflowstressandmaximumvaluedecrease;withanincreaseofthedeformationdegree,boththeinitialrecrystallizationtemperatureandthecompleterecrystallizationtemperaturedecreasesharply.Whenthedeformationdegreereaches30%,60%and80%,theinitialrecrystalliza...
简介:ThephotocatalystsK4Nb6017andK4Nb6017dopedwithFe^3+andCr^3+werepreparedbysolidstatereactionandwerecharacterizedbypowderx-raydiffraction,UV-visdiffusivereflectanceandscanningelectronmicroscopy.ThephotocatalyticactivityofK4Nb6O17andK4Nb6O17dopedwithFe^3+,Cr^3+wereinvestigatedwithmethanolaselectrondonorandPtaspromotercatalystunder+400nmUVirradiation.Thedifferenceofphotocatalyticactivitybetweenthemwasalsodiscussed.TheindividualrateofhydrogenevolutionfortheK4Nb6O17,Fe-K4Nb6O17andCr-K4Nb6O17asphotocatalystsare5.35,5.00,6.25mmol·L^-1.h^-1respectively.
简介:根据生产需求设计了一种新型的阳极板夹持移动装置。该装置通过电液比例液压控制系统,精确控制移动小车和夹持装置的位置,有效克服阳极板加工中出现的跑偏现象,提高操作自动化程度与精确度,利于阳极板的后续加工。为了提高电液比例系统的位置控制精度,设计了数字增量式PID与死区非线性补偿相结合的自适应位置控制器。数字增量式PID控制器根据目标位置与实际位置之差,调整比例阀阀口大小,使得液压缸准确地跟踪目标的运动轨迹。死区补偿算法可以消除比例阀存在的死区非线性,提高响应速度。最后通过电液比例系统位置控制试验验证所提出的位置控制器。
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简介:有一致形态学的新奇红射出的K2(Ge,Si)F6:Mn4+黄磷被一起沉淀方法综合。纯K2有P636阶段>除P3m1空间组以外的mc空间组就被Si的加入在K2在房间温度的GeF6根据XRD描述。薄片状的显示出的SEM图象和为K2GeF6:Mn4+和K2(Ge,Si)F6:Mn4+黄磷分别地。光致发光刺激(PLE)和光致发光(PL)在K2GeF6:Mn4+和K2(Ge,Si)F6:Mn4+系统。并且K2有Si的GeF6:Mn4+显示出一座强壮的山峰。同时水晶的地包围Mn4+变化能在这个氟化物系统影响腐烂时间。带的设备的颜色范围基于K2(Ge,Si)F6:Mn4+和K2分别地,GeF6:Mn4+到达了多达94.58%NTSC(国家电视标准委员会)和94.386%NTSC那基于氮化物红黄磷比那高得多。在K2(Ge,Si)F6:Mn4+黄磷的所有这些原来的特征作为为改善灯光和常规白LEDs的显示质量的红黄磷为潜在的应用是合乎需要的。
简介:研究了K4169高温合金在各种工艺条件下及向熔体中加入复合细化剂时的晶粒组织.结果表明.降低浇注温度和加入复合细化剂可以明显细化冷凝后基体的晶粒和提高铸件断面等轴晶的比例。在通常的浇注温度1400℃下加入复合细化济.对合金熔体进行或不进行过热处理时.可使圆柱锭的品粒分别细化至ASTM11.7级和ASTM3.2级:断面等轴晶的比例分别达96%和99%以上.当浇注温度为1420℃,加入复合细化利并对合金熔体进行过热处理时,可使圆住锭晶粒细化至ASTMM10.5级,断面等轴晶的比例达90%以上,提出了晶粒细化的机理并对晶粒细化后断面等轴晶比例增大的现象进行了分析。