简介:LuminescencelifetimeofCe(Ⅲ)forCe0.9RE0.1P5O14,whereREdenotesrareearthionsotherthanCe(Ⅲ),wasmeasuredbymeansofthetime-correlatedsinglephotoncountingtechnique.Ithasbeenfoundthatthelifetimedataarecapableofelucidatingtheenhancementorquenchingofcerium(Ⅲ)luminescencebyalienREions(otherthanCe)indoublydopedceriumpentaphosphatecrystal.
简介:利用Ta2O5-NaF-C混合粉末为原料,采用碳热还原法在石墨表面制备不同形态的碳化钽晶须,利用SEM和XRD对晶须的形貌、结构与成分进行观察与分析,采用热力学计算与实验验证相结合的方法研究不同形貌碳化钽晶须的生长机制。结果表明:TaC晶须存在不同的生长机制,当原料粉末添加量较少时,石墨表面主要生长出圆柱状晶须伴有头部液滴状结构,原料粉末添加量较多时得到规则的四方柱状结构晶须,也存在2种不同形貌晶须并存的情况。圆柱状晶须为VLS(气-液-固)生长机制;四方柱状TaC晶须为VS(气-固)生长机制。在VLS机制中,催化液滴的主要成分为NaTaO3。
简介:Loadingdistributionforheavyplatemillistofindoptimalcontrolsolutionsunderthegrantedperformanceindicatorsandconstraintsincludingmillcapacityandhypothesisofrollingmodels.Thesolutionsarequitedifferentfordifferentperformanceindicators.Inthearticle,theperformanceindicatorsandsequentialquadraticprogramming(SQPforshortbelow)methodsemployedin5000mmheavyplatemillofBaoSteelarepenetratinglyanalyzed.Generally,theSQPmethodisaneffectiveandfastwaytosolvethenonlinearprogrammingproblemswithsmallormediumscaleconstraints.Earlyin1976,HanputforwardtheSQPmethodforthefirsttimeandPowellmadeitperfectandaccomplishedthealgorithmin1977.Infact,SQPmethodwastoturnanonlinearprogrammingproblemtoaseriesofsubsetofquadraticprogrammingproblems.Inthealgorithm,eachiterationstepistosolveonequadraticprogrammingproblem.Theoptimalsolutionswillbegraduallyapproachedafterquadraticprogrammingproblemsweretotallysolved.Whensolvingthequadraticprogrammingproblem,theactivesetstrategywereemployedwhichturnedtheconstrainedquadraticprogrammingproblemtounconstrainedquadraticprogrammingproblem.Theactivesetstrategymadethewholequadraticprogrammingproblembesolvedbyaleastsquareproblem.Andfinally,thematrixoftheleastsquareproblemwouldbedecomposedbyQmatrixandRmatrix.AfterQmatrixandRmatrixwereobtained,theoptimalsolutionswouldbefinallyfound.Forloadingdistribution,theperformanceindicatorswerecomposedbyplateshapeanddraftofeachpass.Plateshapeisrepresentedbyrollingforcegraduallyreducedpassbypasswithatunablefactor.Themillcapacityisanotherperformanceindicatorrepresentedbydraftofeachpass.Forheavyplatemill,themillcapacityhereisthemotormoment.Forheavydraft,themotorwouldbeoverloadedespeciallyforthefirstseveralpasses;forsmalldraft,themotorwouldbeloadedslightly.Allthesewouldnotbepermittedtohappenwhen
简介:Loadedonthecordierite,therareearthdopedcompositecatalystwaspreparedbysol-gelmethodcombinedwithdippingtechnique.TakingOrthodichlorobenzeneasmodel,thecatalystwasusedtoremovethedioxinsofthewastegas.Theresultsshowedthatat280℃andgasspacevelocitybeing8000h-1,theorthodichlorobenzenecouldberemovedeffectivilybythepreparedCeO2-TiO2-V2O5compositecatalystwhoseactivitywasremarkablyenhancedbythedopingofCe,whiletheindustrialside-streamtestofdioxinsfromrefuseincinerationsmokeindicatedthatthedecompositionratecouldreachabove93%underthesameconditions.
简介:采用Al-5Ti-B变质剂对过共晶Al-18Si合金进行反向变质处理,用光学显微镜观察合金的组织与形貌,研究变质剂加入量、变质温度和冷却速度对初晶硅的尺寸、形态和面积分数以及共晶组织的影响。研究表明:当Al-5Ti-B加入量(质量分数)为0.3%时,变质处理后Al-18Si合金中的初晶硅和共晶硅尺寸明显减小,初晶硅的面积分数减小;与其相比,变质剂加入量增加到0.6%时,初晶硅尺寸变化不明显,但共晶硅进一步细化;随冷却速率降低,变质处理后Al-18Si合金中初晶硅相的数量减少,但Si颗粒尺寸明显增大,并且共晶硅细化;与Al-18Si合金在720℃变质相比,该合金在780℃变质处理时,初晶硅的尺寸增大,但初晶硅的面积分数显著减小;合金在850℃变质处理后初晶硅的尺寸、面积分数都比720℃变质处理后明显减小;随变质温度升高,Al-Si合金中的共晶硅明显细化。
简介:Baosteel's5mheavyplateplantwassuccessfullytestedonMarch1,2005.Sincethen,theHeavyPlatePlantofBaosteel(hereinafterreferredtoas'theplant')hasbeenencouragingitsemployeestostudyandtracetheadvancedheavyplatetechnologies,tryingtofindouttherulesofheavyplateproductionanditsqualitycontrol.TheplanthasgraduallymasteredthismodernheavyplateplantandensuredthatBaosteel'sproductionofheavyplatesgrewyearbyyear,with1.41Mtproductputinstoragein2007.Theplanthasfocusedondevelopingnewtechnologiesandproducts,meanwhileenhancingitscapacity.Ithasproducedaseriesofplateproducts,whichcanbeusedinmanufacturingshiphulls,pipelines,bridges,buildings,boilersandpressurevessels.