APS考试复习资料材料科学

朽木易折，金石可镂。千里之行，始于足下。第页/共页材料科学MaterialScience你在“工程力学”这门课中都学习了哪些知识？Whatdidyoulearninthecourse“EngineeringMechanics”?Mechanicscanbedividedintostatics,kinematicsanddynamics.Themechanicsbranchrelatedwithmyprofessionismaterialmechanics.Andstaticsisthefoundationofmaterialmechanics.SoduringthiscoursewelearnaboutStaticmechanicsfirstthenlearnaboutMaterialsmechanics.关于静力学，你都学习了哪些知识？WhatknowledgehaveyoulearnedaboutStaticmechanics?Firstly,welearnedsomebasicconceptofEngineeringMechanics.Componentsareconstituentpartsofthemachineandstructure.Whenaforceisappliedtoanobject,itmaychangethesizeanddirectionoftheobject'svelocity,whichiscalledthemotioneffect(externaleffect).Onanotherhand,itmayalsochangetheshapeofanobject,whichiscalledthedeformationeffect(internaleffect).Inthestatics,weonlyconsiderthedeformationeffectofforce.Undertheactionofexternalforce,thesizeandshapeofthecomponentshaveachange,andthatchangecallsdeformation.Deformationofcomponentscanbedividedintotwokinds.Whentheforceisremoved,somedeformationdisappear,componentscanrecoveritssizeandshape,thosedeformationcallselasticdeformation.Whentheforceisremoved,somedeformationremain,componentscannotrecoveritssizeandshape,thosedeformationcallsplasticdeformation.Thelargerexternalforceis,thelargerdeformationhappen.Whentheexternalforcegettoobig,itmaycausethehugeplasticdeformationevenfractureofthecomponent.Obviously,thismakemachineandstructurecan'twork.Theabilityofcomponenttoresistdamage(hugeplasticdeformationandfracture)underexternalforcesiscalledstrength.Ifnotableelasticdeformationoccurs,althoughitcanberestored,butbeforeitberestored,theyalsocausemachinecan'twork.Theabilityofcomponenttoresistdeformationunderexternalforcesiscalled

rigidity.Althoughnonotabledeformationoccurs,sometimesonlytheoriginalbalancebetweenthecomponentsisbroken,themachinecannotworkproperlytoo.Theabilityofcomponentstokeeptheiroriginalbalanceunderexternalforcesiscalled

stability.Wesupposethatthereisakindofmaterial,itneverchangeitsshapeunderexternalforce,thismaterialcallsrigidbody.Rigidbodyisnotexistintherealworld.Theconditioncanlimitthedisplacementoftheobject,iscalledtheconstraint.Commonconstraintsareflexiblecable,supportsurface,hinge,etc..Twoforceswithequalsizeandoppositedirectionarenotinthesameline,arecalledforcecouple.Thenwelearnedhowtoanalyzetheforceonanobject,welearnedmanymethodstoanalyzeforce,suchasforcetranslation,forcedecomposition,forcesynthesis.关于材料力学，你都学习了哪些知识？WhatknowledgehaveyoulearnedaboutMaterialsmechanics?Whenaexternalforceisappliedtoanobject,objectproduceacorrespondinginternalforcetoagainstit.Thedensityofinternalforceiscalledstress,itisusedtodescribethesizeofinternalforceonunitarea.Thecorrespondingdeformationcausedbyexternalforceiscalledstrain.Whenmaterialsinelasticregion,thestressandstrainareindirectproportion(linearrelationship)(Hooke'slaw),andtheratioofstressandstrainiscallElasticmodulus.Ifthedirectionofstressandstrainaresamewithexternalforce,theycalldirectstress(σ)anddirectstrain(ε).Ifthedirectionofstressandstrainareverticalwithexternalforce,theycalltangentialstress(τ)andtangentialstrain(γ).Welearntheinternalforce,stressandstrainofthematerialunderdifferentforces,suchasstretching,compressing,shearing,torsion,bending.ThenwelearnedalittleaboutStressanalysis,Breakingstrengththeory,Yieldstrengththeory.你在“高分子材料研究主意”这门课中都学习了哪些知识？Whatdidyoulearninthecourse“ResearchMethodsofPolymericMaterials”?Thiscurriculumexplainsseveralmethodsforresearchingpolymer’sstructure,morphology,propertiesandmolecularmotion.Researchingmethodsofpolymercanbedividedintothreetypes,theyarespectralanalysis,thermalanalysisandmicroscopicanalysis.关于波谱分析，你都学习了哪些知识？Whatknowledgehaveyoulearnedaboutspectralanalysis?Welearntwoimportantandcommonlyusedspectralanalysis,theyareinfraredspectroscopy,nuclearmagneticresonancespectroscopy.Whenthetemperatureisaboveabsolutezero,moleculesareincontinuousmotion,motioncanbedividedintotranslation,rotationandvibration.Thevibrationsofmoleculesneedtoabsorbinfraredhavethesamefrequencywiththefrequencyofvibrationtoobtainenergy.Differentgroups,havedifferentvibrationfrequencies,alsoabsorbinfraredindifferentfrequencies.Usinginfraredirradiationmaterial,itcanbefoundthattherearesomeinfraredincertainfrequencyhavebeenabsorbedbythematerial.Inthatway,wecangetwhatgroupsarethereinthatmaterial.Inastrongmagneticfield,theatomicnucleusofahydrogenatomnuclearwilloccuratransition.Thetransitionneedtoabsorbaelectromagneticwave(Hertzwave)incertainfrequencytoobtainenergy.Thehydrogenatomindifferentchemicalenvironmentabsorbelectromagneticwaveindifferentfrequency.Throughthemeasurementofthefrequencyandnumberoftheelectromagneticwaveisabsorbedbyhydrogenatom,Wecanknowhowmanydifferentkindsofhydrogenatomsarethereinthemoleculeofthatmaterial,andtheproportionofthem.关于热分析，你都学习了哪些知识？Whatknowledgehaveyoulearnedaboutthermalanalysis?Themostcommonmethodofthermalanalysisisthermalgravimetricanalysis(TG).TGistoputthematerialonthescalethathastheheatingfunction,measuretheweightofthematerialatdifferenttemperatures.ThroughTGwecangettheheatresistanceofmaterials.Anotherimportantmethodofthermalanalysisisdifferentialthermalanalysis(DTA).DTAcanmeasurematerialisabsorbingheatorreleasingheatunderacertaintemperature.Throughthatinformation,wecananalyzethestateandbehaviorofmaterialunderthattemperature.关于显微分析，你都学习了哪些知识？Whatknowledgehaveyoulearnedaboutmicroscopicanalysis?Teachermainlyintroduceustwokindscommonlyusedmicroscopicanalysis,theyaretransmissionelectronmicroscopy(TEM)andscanningelectronmicroscopy(SEM).你在“材料工程与工程基础”这门课中都学习了哪些知识？Whatdidyoulearninthecourse“FundamentalsofMaterialsScienceandEngineering”?Materialscanbedividedintofourkinds,theyareMetallicmaterials,Inorganicnon-metallicmaterials,Polymermaterials,Compositematerials.Materials'developmentandprogressofhumancivilizationarecloselylinked."Materialsscience"conceptisproposedinthebeginningofthe1960swhentheUnitedStatesdevelopedthesatellitesandmissiles.Oneofthecoreofmaterialsscienceandengineeringisresearchingtherelationshipbetweenmaterialsorganization,structureandperformance.Ontheotherhand,materialsscienceandengineeringalsoisapracticalsubjectservingtheeconomicconstruction.MaterialsScienceandEngineeringisconnectedwithphysics,chemistry,metallurgy,computationalmathematicsandothersubjects.Materialsscientistsbelievethatmaterialsscienceandengineeringhasfiveelements,theyarecomposition,structure,preparation,propertyandusingperformance.Propertiesofmaterialscanbedividedintotwocategories,theyareprocessingperformanceandusingperformance.Thiscourseintroducessomemainperformancesincludemechanicalpropertieslike:elasticity,plasticity,strength,hardness,toughness,wearresistance,etc;andotherslike:electricalproperties,magneticproperties,thermalproperties,corrosionresistance,etc.Differentmaterialshavedifferentatomicstructureanddifferentbondsbetweenatoms,whichiswhytheyhavedifferentproperties.Thiscourseintroducesthefivemajoraspects(composition,structure,preparation,propertyandusingperformance)ofthefourcategoriesmaterials(Metallicmaterials,Inorganicnon-metallicmaterials,Polymermaterials,Compositematerials),focusonhigh-molecularmaterials.Atlast,theteacherdescribessomeresearchofnewmaterials.高等数学（AdvancedMathematics）It’snotonlytellushowtoadd,subtract,multiply,anddividewholenumbers,fractions,decimals,andpercentages,actually,Mathematicsisastudyofpatternsandrelationships;ascienceandawayofthinking;anart,characterizedbyorderandinternalconsistency;alanguage,usingcarefullydefinedtermsandsymbols大学生思想修养（MoralCultivationofcollegestudents）Thiscoursemainlytalkedaboutmoraleducationandvalueeducationtothecollegestudent,alotofrealitystoriesaretoldintheclasstomakeusconsciousofrightthingsandthewrong,inaword,It’saimistoteachustobegoodpeople.体育（P.E）(1,2,3)Inourschool,youcanchose1kindofsporttolearneachyear,IlearnedtennisballinmyfroshyearandIlikeditverymuch,bythemay,nadirismyfavouritesportsstars.Then,kickboxingismychoiceinthesecondyear,youknow,IwanttobemorestrongsoIcanprotectmyselfandthepeopleIcareaboutwhensomethingbadhappened,hehe.计算机文化基础（SoftwareTechniqueFoundationDesign）Ilearnedsomebasicideas