简介:Inrecentyears,lifecycleassessment(LCA)methodiswidelyusedingreenmanufacturing,energysaving,andemissionreductionofironandsteelproduction.BasedonthecarbonsteelLCAresearchandrelevantstandardsathomeandabroad,theapplicationofLCAinstainlesssteelinBaosteelwasstudied.Throughthestudyofstainlesssteel'sgoalandscope,lifecycleinventory,LCAandinterpretation,knowledgeandexperienceofLCA'sapplicationinstainlesssteelwasobtained.
简介:Insomesituations,theacceleratedlifetestonenvironmentalstressforelectronicproductsisnoteasilyimplementedduetovariousrestrictions,andthusengineersarelackingofdataoftheproductlifetest.Concerningthisproblem,environmentallifeoftheprintedcircuitboard(PCB)boardiscalculatedbywayofphysicsoffailure.InfluencesofthermalcycleandvibrationonPCBanditscomponentsarestudied.BasedontheanalysisofforceandstressbetweencomponentsandthePCBboardinthermalcycleeventsandvibrationevents,fourlifecomputingmodelsofpinsandsoldereddotsareestablished.Themillerdamageratioisusedtocalculatetheaccumulateddamageofapinorasoldereddot,andthentheenvironmentlifeofthePCBboardcanbedeterminedbythefirstfailedone.Finally,anexampleisusedtoillustratethemodelsandtheircalculations.
简介:ThispaperdealswiththeCauchyproblemforadoublysingularparabolicequationwithaweightedsource■whereN≥1,1
max{0,3-p-p/N}satisfying2
1,andα>N(3-p-m)-p.Wegivethesecondarycriticalexponentonthedecayasymptoticbehaviorofaninitialvalueatinfinityfortheexistenceandnon-existenceofglobalsolutionsoftheCauchyproblem.Moreover,thelifespanofsolutionsisalsostudied.更多还原
简介:教材:人教版新目标英语八年级(下)单元:HaveyoureadTreasureIslandyet?课文:ACountryMusicSongChangedHerLifeForeverTeachingobjectivesBytheendoftheperiod,theteachermustenablethestudentsto:1.Understandthepassageandmastersomereadingstrategies.2.Summarizethepassagebymakingnotesandunderliningthemainideas.3.