雨课堂学堂在线学堂云《Functional Materials（长安大学 ）》单元测试考核答案

注：不含主观题第1题判断题(5分)Whenthetemperatureisabsolutezero,thehighestenergylevelintheenergybandofasolidfilledwithelectrons.EFiscommonlyused.Forthesolidsample,thevacuumenergyleveliseasytochangebecauseofitsrelationwiththesurfacecondition,sothisenergylevelisusedasthereferencelevel.Chapter2homework第1题单选题(5分)Whichofthefollowingarepolarizationmechanisms？AElectronpolarization

B

IonpolarizationC

Steeringpolarization

DAlloftheabove第2题判断题(5分)Thephenomenonthattheinsulatinglayerbetweentwosuperconductorscanmakesuperconductingcurrentpassthroughiscalledsuperconductivetunnelingeffect.Chapter3homework第1题判断题(5分)Resistancematerialisakindofconductivematerialwithhighresistivity,includingprecisionresistancematerialandresistancesensitivematerial.

第2题判断题(5分)

Theconductivityofconductorisσ≥10^5S/mandtheconductivityofsemiconductorsis10^-8~10^4S/mChapter4homework第1题单选题(2分)Whatarethetwotypesofdopedsemiconductors?AN-typeandP-typeBN-type

CP-type

Dnoneoftheabove第2题判断题(1分)Intrinsicsemiconductorsarepuresemiconductorswithoutanyimpurities.Thepurityisabove99.999999%.Features:valenceelectronsarenoteasytobreakawayfromnuclearbondageandbecomefreeelectrons.Theintrinsicsemiconductorshavepoorconductivityandtheholesandelectronsappearinpairs.第3题判断题(1分)Whenexcited,theelectronenergychangesfromtheconductionbandtothevalenceband,formingaconductivephenomenonChapter5homework第1题判断题(3分)Accordingtotheirchemicalcomposition,cryogenicsuperconductorscanbedividedintoelementsuperconductors,alloysuperconductorsandcompoundsuperconductors.TheircriticaltemperaturesarerelativelylowandtheirsuperconductivitymechanismcanbeexplainedbyBCStheory.Therefore,theyarealsocalledconventionalsuperconductorsortraditionalsuperconductors第2题多选题(4分)Whatarethe

criticalparametersofsuperconductors?

ACriticalparameterBCriticalmagneticfieldHCCInsulationDLowmanufacturingdifficulty正确答案：AB第3题判断题(3分)Criticalparameter:criticaltemperatureTc:thetemperatureatwhichasuperconductorchangesfromanormallyconductingstatetoasuperconductingstate.Chapter6homework第1题判断题(3分)Permanentmagneticmaterialsarecharacterizedbyhighcoercivityandwidehysteresisloop.第2题判断题(3分)Whenafinitesizesampleismagnetizedbyanexternalmagneticfield,thefreemagneticpolesatbothendsproduceamagneticfieldwiththesamemagnetizationdirection,whichiscalleddemagnetizationfield.第3题判断题(4分)Whentheexternalmagneticfieldisremoved,mostorallofthemagnetismofsoftmagneticmaterialswillnotbelost,andthecoercivityisverylarge.Chapter7homework第1题多选题(4分)Whatarethefactorsaffectingtheluminousintensity?ACrystalstructureBactivatorCexcitationsourcetypeDmagazinetype正确答案：ABCD第2题判断题(3分)Itwasoriginallyintendedtoamplifylightanditswayofamplification.Nowitisusedasalightwavewithgoodqualityandcharacteristicfrequencyemittedbyaspecialoscillator.第3题判断题(3分)Iron,cobalt,nickelandotherluminescentmaterialsusuallycontainmetalatomsChapter8homework第1题判断题(2分)Thepyroelectricbodymusthaveauniquepolaraxis,whilethepiezoelectricbodyisnotrequired;andthepyroelectriceffectofthepyroelectricbodyiscausedbytemperaturechanges第2题多选题(4分)WhataretheapplicationsofpiezoelectricceramicsAUnderwateracoustictransducerisanimportantapplicationofpiezoelectricmaterialsBPiezoelectricmaterialsarewidelyusedinultrasoundtechnology

CHighvoltagegenerator

Dgoodcoherence正确答案：ABCChapter9homework第1题判断题(3分)Hydrogencanbeusedasfuelwithhighhydrogencontentandhighcalorificvalue.第2题判断题(3分)Hydrogen

iseasytobeactivatedandhaslargehydrogenstoragecapacity;第3题判断题(4分)Theheatofformationforhydrogenstorageshouldbeaslargeaspossible,whilethatforheatstorageshouldbeassmallaspossible;Chapter10homework第1题判断题(3分)Undertheactionofasingleexternalforce,themartensitere-orientsinthedirectionofstress,whichresultsinthepreferredorientationofmartensite.第2题判