简介:Theballisticpropertiesofalowsolidloadingcompositesolidpropellantfamily(Butalites)wasstudiedexperimentallybyusingpropellantformulationsbasedonhydroxy-terminatedpolybutadienepre-polymer(HTPB)asfuelbindermainbackbone,monoandbi-modalsystemammoniumperchlorateoxidizer(AP),copperchromite(CC)asburningrateacceleratorandaluminumpowder(Al)asmetallicfuel.HigherpressuresandAPcontentsaswellassmallerAPparticlesizewerefoundtoincreaseburningrate.ThesamebehaviorverifiedwithAlandCCaddition.AsignificantincreaseofburningratewasrecordedwhenCCaddedtothealuminizedformulationscomparedwiththenon-aluminizedofthesameoxidizersolidloadingandparticlesize.
简介:Motioncontrolcanbeconsideredasthesynergisticcollaborationofmechanicalandelectricalengineering,computerscienceandinformationtechnologytoapplyacontrolledforcetoachieveusefulmotioninfluidorsoiledelectromechanicalsystems.Withthedevelopmentofcomputer,electronics,andautomaticcontroltheory,motioncontrolcomestoanewstage.Greatapplicationsarebasedonthecharacteristics,stemmingfromadvantagesofelectronicsandmoderncontroltechnologyachievements,havingaverygoodloadmatchingproperty.Currently,microprocessor-basedcontrollersareinvariablyusedinmostapplicationsofdriveelectronics.Theobjectofthisworkistodesignapositioncontrolmechanismsystem,whichcanbeusedintestsectionoflowspeedwindtunnel.Systemloadspecificationsandperformancerequirementsaregiven.Acomprehensivestudyofmathematicalmodelingofthemechanismcomponentsisgiven.Procedureforselectionofvariouscomponentswithoptimumparametersisdiscussed.Afterselectionandcalculationofsystemparameterstomeettheperformancerequirements,aPIDcontrolmethodisadopted.
简介:Researchsituationofeco-designisanalyzed,andthenthoughtsandmethodsofeco-designarediscused.Theeco-designincludespackagingmodularization,dematerialization,energy-savingandbio-simulation.