Lainauksen selitys
1.Tinywaves.HanLiuXiang's"NewPreface·MiscellaneousII":"Introducethefiber,raisethemicrowave,breakthebreezeandperish."TangXuhun's"FanWuyunxi"poem:"Anxiouslyminglingtheaxles,themicrowavesurgingthefishingtube."SongZhuxiThepoem"Xiqing":"Raisethehighwillows,Lushuiandmicrowaves."JunQing"AutumnFu·HaiNiangNiang":" Aina kun on kirkas aamu tai hiljainen kuunvalkoinen yö, merimikroaaltoilma ei ole iloinen."
2.Stillaftermath.HanSimaXiangru's"FengZenWen":"Forever,youwillhavetheturbulentflow,raisethemicrowave,befamous,andluxuriant."TheSouthernDynastiesLiangZhongrong's"ShiPin"volume:"InYongjiatime,preciousyellowandold,alittlevacantTalking.Inthecurrentchapter,Ihavetakencareoftherhetoric,indifferent,indifferenttoJiang'stable,microwaveisstillpassedon."JuanXie"Preface ":"JingCongZhiandYangZhi,Yi harkitseemikroaaltouunia."
3.Referstothewoman'seyewaves.ThreeKingdomsWeiCaoZhi's"LuoShenFu":"Unscrupulousmediatoreceivejoy,askthemicrowavetopasswords."QingHuangZunxian"DuLiaoGe":"Therearepeopleinthemicrowavethroughthemicrowave,lotusandlotus!LetmegivemychaiLuanXitogivemeCuiConch,lotus!"GaoXu'spoem"GiveShenXiaoze":"Themelancholyladytakesapicture,andIwouldliketoentrustmythoughtstothemicrowave."
4.Physicsterms.Referstoelectromagneticwaveswithshorterwavelengths.Suchas:radiocommunicationreferstoelectromagneticwaveswithawavelengthbetween1millimeterand1meter.
Mikroaallonpituus
Thefrequencyofmicrowaveisbetween300MHz-300GHz,andthewavelengthisbetween1millimeterand1meter.Itisthecollectivenameofdecimeterwave,centimeterwaveandmillimeterwave.Thefrequencyofmicrowavesishigherthanthatofgeneralradiowaves,andisoftenreferredtoas"ultra-highfrequencyradiowaves."Asakindofelectromagneticwave,microwavealsohaswave-particleduality.Theenergyofmicrowavequantumis199×l0-25～1.99×10-22Joule.
Mikroaaltouunin ominaisuudet
Thebasicpropertiesofmicrowavesusuallypresentthreecharacteristics:penetration,reflection,andabsorption.Forexample:Forglass,plasticandporcelain,microwavesalmostpassthroughwithoutbeingabsorbed.Forwaterandfood,itwillabsorbmicrowavesandheatitself.Formetalthings,microwaveswillbereflected.
Fromthepointofviewofelectronicsandphysics,theelectromagneticspectrumofmicrowavehasthefollowingimportantcharacteristicsthataredifferentfromotherbands:
Läpäisy
Microwavehaslongerwavelengththanotherelectromagneticwavesusedforradiantheating,suchasinfraredandfarinfrared,soithasbetterpenetrability.Whenthemicrowavepenetratesthemedium,duetothecertaininteractionbetweenthemicrowaveenergyandthemedium,withthemicrowavefrequencyof2450MHz,themoleculesofthemediumwillvibrate2.45billiontimespersecond,andthemoleculesofthemediumwillrubagainsteachother.Theincreaseinthetemperatureofthemediumcausestheinsideandoutsideofthemediumtoheatupalmostatthesametime,formingabodyheatsourcestate,whichgreatlyshortenstheheattransfertimeinconventionalheating,andwhentheconditionisthatthemediumlossfactorandthemediumtemperaturearenegativelycorrelated,theinsideandoutsideofthematerialHeatinguniformly.
Valikoiva lämmitys
Theabilityofasubstancetoabsorbmicrowavesismainlydeterminedbyitsdielectriclossfactor.Thesubstancewithalargedielectriclossfactorhasastrongabilitytoabsorbmicrowaves,onthecontrary,asubstancewithasmalldielectriclossfactorhasaweakabilitytoabsorbmicrowaves.Duetothedifferenceinthelossfactorofeachsubstance,microwaveheatingshowsthecharacteristicsofselectiveheating.Differentsubstanceshavedifferentthermaleffects.Thewatermoleculeisapolarmoleculewithalargedielectricconstant,anditsdielectriclossfactorisalsolarge,andithasastrongabilitytoabsorbmicrowaves.Thedielectricconstantsofproteinsandcarbohydratesarerelativelysmall,andtheirabilitytoabsorbmicrowavesismuchsmallerthanthatofwater.Therefore,forfood,theamountofwatercontenthasagreatinfluenceonthemicrowaveheatingeffect.
Pieni lämpöhäiriö
Themicrowaveheatsthedielectricmaterialinstantaneously,andthetemperaturerisesquickly.Ontheotherhand,theoutputpowerofthemicrowavecanbeadjustedatanytime,thetemperatureriseofthemediumcanbechangedwithoutinertness,andthereisno"wasteheat"phenomenon,whichisextremelyconducivetotheneedsofautomaticcontrolandcontinuousproduction.
Likelight
Themicrowavewavelengthisveryshort,andthesizeisrelativelylargerthanthatofordinaryobjectsontheearth(suchasairplanes,ships,automobiles,buildings,etc.)Muchsmaller,oronthesameorderofmagnitude.Makesthecharacteristicsofmicrowavesimilartogeometricoptics,theso-calledlight-likeness.Therefore,theuseofmicrowavescanreducethesizeofcircuitcomponents;makethesystemmorecompact;itcanbemadeintoasmallsize,narrowbeam,strongdirectivity,andhighgainantennasystem,whichcanacceptweakreflectionsfromvariousobjectsonthegroundorspaceSignaltodeterminethepositionanddistanceoftheobjectandanalyzethetargetcharacteristics.
Becausethemicrowavewavelengthhasthesamemagnitudeasthesizeoftheobject(thewirelessdeviceinthelaboratory),thecharacteristicsofthemicrowavearesimilartothelongerwaves,whichistheso-calledquasi-longwave.Forexample,microwavewaveguidesaresimilartoreceiversinradio;hornantennasandslotantennasaresimilartotransmittersinradio;microwaveresonatorsaresimilartoradioresonators.
Ionisoimaton
Thequantumenergyofmicrowavesisnotlargeenoughtochangetheinternalstructureofmaterialmoleculesordestroythebondsbetweenmolecules(somematerialsExcept:Ifmicrowavecanregeneratewasterubber,itistochangethemolecularbondofwasterubberthroughmicrowave).Thereisalsothewayofphysics.Manyresonancephenomenaofmolecularnucleiundertheactionoftheperiodicforceoftheappliedelectromagneticfieldoccurinthemicrowaverange.Therefore,themicrowaveprovidesaneffectiveresearchmethodforexploringtheinternalstructureandbasicpropertiesofmatter.Ontheotherhand,usingthisfeature,manymicrowavedevicescanalsobemade.
Informatiivinen
Becausethemicrowavefrequencyisveryhigh,theusablefrequencybandisverywide,uptohundredsorevenwithasmallrelativebandwidth.Ongigahertz.Thisisunmatchedbylow-frequencyradiowaves.Thismeansthattheinformationcapacityofmicrowaveislarge,somodernmulti-channelcommunicationsystems,includingsatellitecommunicationsystems,workinthemicrowavebandalmostwithoutexception.Inaddition,microwavesignalscanalsoprovidephaseinformation,polarizationinformation,andDopplerfrequencyinformation.Thisisveryimportantinapplicationssuchastargetdetectionandremotesensingtargetfeatureanalysis.
Mikroaaltotuotanto
Microwaveenergyisusuallyobtainedbydirectcurrentor50Hzalternatingcurrentthroughaspecialdevice.Therearemanykindsofdevicesthatcangeneratemicrowaves,buttheyaremainlydividedintotwocategories:semiconductordevicesandelectricvacuumdevices.Anelectricvacuumdeviceisadevicethatuseselectronstomoveinavacuumtocompleteenergyconversion,oriscalledanelectrontube.Amongtheelectricvacuumdevices,therearemagnetrons,multi-cavityklystrons,microwavetriodes,tetrodes,travelingwavetubes,etc.thatcangeneratehigh-powermicrowaveenergy.Magnetronsandklystronsaremainlyusedinthefieldofmicrowaveheating,especiallyinindustrialapplications.
Mikroaaltouuton periaate
Anewlydevelopednewtechnologythatusesmicrowaveenergytoincreasetheextractionrate.Itsprincipleisthatinthemicrowavefield,thedifferenceintheabilitytoabsorbmicrowavesmakescertainareasofthematrixmaterialorcertaincomponentsintheextractionsystembeselectivelyheated,sothattheextractedmaterialisseparatedfromthematrixorsystemandentersthemedium.Amongtheextractantswithsmallelectricalconstantandrelativelypoormicrowaveabsorptioncapacity;microwaveextractionhasthecharacteristicsofsimpleequipment,wideapplicationrange,highextractionefficiency,goodreproducibility,timesaving,reagentsaving,andlowpollution.Inadditiontothepretreatmentofenvironmentalsamples,itisalsousedinfieldssuchasbiochemistry,food,industrialanalysisandnaturalproductextraction.InChina,therearerelativelyfewresearchreportsonmicrowaveextractiontechnologyusedinChineseherbalmedicineextraction.
Themechanismofmicrowaveextractioncanbeanalyzedfromthefollowingthreeaspects:①Theprocessofmicrowaveradiationistheprocessofhigh-frequencyelectromagneticwavespenetratingtheextractionmediumtothemicrotubulebundleandadenocytesysteminsidethematerial.Duetotheabsorptionofmicrowaveenergy,thetemperatureinsidethecellwillriserapidly,sothatthepressureinsidethecellexceedsthecapacitythatthecellwallcanwithstandexpansion.Asaresult,thecellrupturesandtheactiveingredientsinsideitfreelyflowoutanddissolveatalowertemperature.Intheextractionmedium.Throughfurtherfiltrationandseparation,thedesiredextractcanbeobtained.②Theelectromagneticfieldgeneratedbythemicrowavecanacceleratethediffusionrateofthemoleculesoftheextractedcomponentfromthesolidinteriortothesolid-liquidinterface.Forexample,whenwaterisusedasasolvent,undertheactionofamicrowavefield,watermoleculeschangefromahigh-speedrotationstatetoanexcitedstate,whichisahigh-energyunstablestate.Atthistime,thewatermoleculeseithervaporizetostrengthenthedrivingforceoftheextractedcomponents,orreleasetheirownexcessenergybacktothegroundstate,andthereleasedenergywillbetransferredtothemoleculesofothersubstancestoacceleratetheirthermalmovement,therebyshorteningtheextractedcomponentsThetimeforthemoleculestodiffusefromtheinsideofthesolidtothesolid-liquidinterface,asaresult,theextractionrateisincreasedseveraltimes,andtheextractiontemperaturecanbereducedtomaximizethequalityoftheextract.③Becausethefrequencyofmicrowaveisrelatedtothefrequencyofmolecularrotation,microwaveenergyisakindofnon-ionizingradiationenergythatcausesmolecularmotionduetoionmigrationanddipolerotation.Whenitactsonmolecules,itcanpromotemolecularrotation.Movement,ifthemoleculehasacertainpolarity,itcanproduceinstantaneouspolarizationundertheactionofthemicrowavefield,andmakethepolaritychangemovementataspeedof2.45billiontimes/s,therebyproducingbondvibration,tearingandparticlesThefrictionandcollisionbetweenthecellsandrapidlygeneratealargeamountofheatenergy,whichpromotestheruptureofthecells,causingthecellfluidtooverflowanddiffuseintothesolvent.Inmicrowaveextraction,thedifferenceintheabilitytoabsorbmicrowavescanmakecertainareasofthematrixmaterialorcertaincomponentsintheextractionsystembeselectivelyheated,sothattheextractedmaterialisseparatedfromthematrixorsystemandentersthematerialwithasmallermedium.Inextractionsolventswithrelativelypoorelectricalconstantandmicrowaveabsorptioncapacity.〖Picturedescription:Thesimulatedfinitecosmicmicrowavebackgroundradiationimage,thematchingcircleshavethesamecoldandhotdistribution.〗
Lämpövaikutus
Thethermaleffectofmicrowavesonorganismsreferstothephysiologicaleffectsonorganismscausedbytheheatingofbiologicaltissuesorsystemscausedbymicrowaves.Thethermaleffectismainlyduetothefactthattherearepolarmoleculesintheorganismthatarerepeatedlyorientatedandrotatedrapidlyundertheactionofmicrowavehigh-frequencyelectricfieldtogenerateheatbyfriction;theionsinthebodywillalsoconvertvibrationenergyintoheatwhentheyarevibratedundertheactionofmicrowave;generalmoleculeswillalsoabsorbmicrowaveenergyandmakeThermalmovementenergyincreases.Ifthebiologicaltissueabsorbslessmicrowaveenergy,itcanuseitsownthermalregulationsystemtoradiatetheabsorbedmicrowaveenergy(heat)tothewholebodyoroutsidethebodythroughthebloodcirculation.Ifthemicrowavepowerisverystrong,themicrowaveenergyabsorbedbythebiologicaltissueismorethantheenergythatthebiologicalbodycanemit,whichwillcausethebodytemperatureoftheparttorise.Theincreaseoflocaltissuetemperaturewillproduceaseriesofphysiologicalreactions,suchastheexpansionoflocalbloodvesselsandtheaccelerationofbloodcirculationthroughthethermalregulationsystem,enhancedtissuemetabolism,enhancedleukocytephagocytosis,andpromotionoftheabsorptionanddissipationofpathologicalproducts.
Ei-lämpövaikutus
Thenon-thermaleffectofmicrowavereferstoothereffectsbesidesthermaleffect,suchaselectriceffect,magneticeffectandchemicaleffect.Undertheactionofthemicrowaveelectromagneticfield,somemoleculesintheorganismwilldeformandvibrate,whichwillaffectthefunctionofthecellmembrane,changetheelectricalstatusoftheliquidinsideandoutsidethecellmembrane,causechangesinbiologicalfunctions,andaffectthecentralnervoussystem.Microwavesinterferewiththerhythmofbioelectricity(suchasECG,EEG,myoelectricity,nerveconductionpotential,cellmembranepotential,etc.),whichwillcauseaseriesofdisorderssuchasheartactivity,brainnerveactivity,andendocrineactivity.Peoplestilldon'tknowmuchaboutthenon-thermaleffectsofmicrowaves.Whentheorganismisirradiatedbystrongmicrowavepower,thethermaleffectisthemainone(generallybelievedthatthepowerdensityat10mW/cm2willproducemoremicrothermaleffect.Andthehigherthefrequency,thelowerthethresholdintensityofthethermaleffect.);Long-termlowpowerdensity(below1mW/cm2)microwaveradiationmainlycausesnon-thermaleffects.
Lämmitysperiaate
Microwavesareelectricwaveswithfrequenciesrangingfrom300MHzto300GHz.Thewatermoleculesintheheatedmediumarepolarmolecules.Undertheactionofarapidlychanginghigh-frequencyelectromagneticfield(microwave),itspolarityorientationwillchangewiththechangeoftheexternalelectricfield.Theeffectofthespinmotionofwatermoleculesiscaused.Atthistime,thefieldenergyofthemicrowavefieldisconvertedintoheatenergyinthemedium,whichincreasesthetemperatureofthematerialandgeneratesaseriesofphysicalandchemicalprocessessuchasheatingtoachievethepurposeofmicrowaveheatinganddrying.
Sterilointimekanismi
Microwavesterilizationistheresultofthecombinedeffectofthethermalandbiologicaleffectsofelectromagneticfields.Thethermaleffectofmicrowaveonbacteriaistochangetheprotein,sothatthebacterialosetheirnutrition,reproductionandsurvivalconditionsanddie.Thebiologicaleffectofmicrowaveonbacteriaisthatthemicrowaveelectricfieldchangesthepotentialdistributionofthecellmembranesection,whichaffectstheelectronandionconcentrationaroundthecellmembrane,therebychangingthepermeabilityofthecellmembrane.Therefore,thebacteriaaremalnourished,unabletometabolizenormally,cellstructureandfunctiondisorder,andgrowthanddevelopmentareinhibited.Anddeath.Inaddition,theribonucleicacid[RNA]anddeoxyribonucleicacid[DNA],whichcancausebacteriatogrownormallyandstablyreproducegenetically,arecausedbytherelaxation,breakageandrecombinationofseveralhydrogenbonds,therebyinducinggeneticmutations,orchromosomalaberrationsorevenbreaks.
Muut sovellukset
Electromagneticwaveswithamicrowavewavelengthbetween1mand1mm(correspondingfrequencyisabout300MHzto300GHz).Thissectionoftheelectromagneticspectrumincludesthedecimeterwave,centimeterwave,andmillimeterwavebands.Inradarandconventionalmicrowavetechnology,Latinalphabetcodesareoftenusedtoindicatefinerbanddivisions.
Theaboveregardingthewavelengthorfrequencyrangeofmicrowavesisatraditionalconvention.Fromtheperspectiveofthedevelopmentofmodernmicrowavetechnology,itisgenerallybelievedthatelectromagneticwavesshorterthan3mm(thatis,millimeterwavesabove100GHz)belongtothemicrowaverangeandareanimportantfieldofmodernmicrowaveresearch.
Fromthepointofviewofelectronicsandphysics,theelectromagneticspectrumofmicrowavehassomecharacteristicsdifferentfromotherbands.Thecharacteristicofmicrowaveinelectronicsisthatitswavelengthisrelativelymuchsmallerthanthesizeofmanyobjectsontheearthandcommonlyuseddevicesinlaboratories,oronthesameorderofmagnitude.Thisisdifferentfromordinaryradiowavesthatpeoplearealreadyfamiliarwith,becausethewavelengthofordinaryradiowavesismuchlargerthanthesizeofordinaryobjectsontheearth.Whenthewavelengthismuchsmallerthanthesizeofobjects(suchasairplanes,ships,rockets,buildings,etc.),thecharacteristicsofmicrowavesaresimilartothoseofgeometricoptics.Usingthisfeature,high-directivitysystems(suchasparabolicreflectors)canbemadeinthemicrowaveband.Whenthewavelengthandthesizeoftheobject(suchastheradioequipmentinthelaboratory)areofthesamemagnitude,thecharacteristicsofthemicrowavearesimilartothelongerwave.Forexample,themicrowavewaveguideissimilartothereceiverintheradio;thehornantennaandtheslotantennaaresimilarAtransmitterinaradio;amicrowavecavityissimilartoaradiocavity.Thecharacteristicthatthewavelengthandtheobjectsizeareatthesameorderofmagnitudeprovidesaseriesoftypicalelectromagneticfieldboundaryvalueproblems.
Inphysics,manyresonancephenomenainmolecular,atomicandnuclearsystemsoccurintherangeofmicrowaves.Therefore,microwavesprovideeffectiveresearchmethodsforexploringthebasicpropertiesofmatter.
Näistä ominaisuuksista johtuen teknologiasarjat, kuten mikroaaltojen generointi, vahvistus, emissio, vastaanotto, lähetys, ohjaus ja mittaus eroavat emäkaistoista (näkymikroaaltoputki, mikroaaltouunin mittaus jne.).
Microwavehasbecomeatechnicalscience,whichbeganinthe1930s.Theformationofmicrowavetechnologyismarkedbythepracticalapplicationofwaveguides.Theinventionofseveralformsofmicrowavetubes(klystron,magnetron,travelingwavetube,etc.)isanothersign.
DuringtheSecondWorldWar,microwavetechnologydevelopedbyleapsandbounds.Duetotheneedsofwar,thefocusofmicrowaveresearchwasonradar,whichledtotheresearchanddevelopmentofmicrowavecomponentsanddevices,high-powermicrowavetubes,microwavecircuits,andmicrowavemeasurement.Untiltoday,microwavetechnologyhasbecomeamaturesubjectbothintheoryandtechnology,andasubjectthatcontinuestodevelopindepth.
Thesolidificationofmicrowaveoscillatorsourcesandtheintegrationofmicrowavesystemsaretwoimportantdirectionsforthedevelopmentofmodernmicrowavetechnology.Theadvancementofsolid-statemicrowavedevicesintermsofpowerandfrequencyhasmadetheconventionalmicrowavetubesinmanymicrowavesystemshavebeenorwillbereplacedbysolid-statesources.Thedevelopmentofsolid-statemicrowavesourceshasalsopromotedtheresearchofmicrowaveintegratedcircuits.
Thefrequencycontinuestoadvancetoahigherrange,whichisstillamajortrendinmicrowaveresearchanddevelopment.Theresearchanddevelopmentoflasersinthe1960shascrossedthegapbetweensub-millimeterwaves(far-infrared)andinfraredandpenetratedintotheelectromagneticspectrumofvisiblelight.Usingconventionalmicrowavetechnologyandquantumelectronicsmethods,ithasbeenabletogenerateradiationpowerintheentireelectromagneticspectrumfrommicrowavestolight.However,atcertainfrequenciesandfrequencybandsinthemillimeter-wave-infraredgap,sufficientcoherentradiationpowercannotbeobtainedforpracticalsystems.
Theapplicationrangeofthedevelopmentofmicrowavecontinuestoexpand.Themostimportantapplicationsofmicrowavesareradarandcommunications.Radarisnotonlyusedfornationaldefense,butalsofornavigation,meteorologicalmeasurement,geodeticsurvey,industrialinspectionandtrafficmanagement.Communicationapplicationsaremainlymodernsatellitecommunicationandconventionalrelaycommunication.Radiotelescopesandmicrowaveacceleratorsareofgreatsignificancetotheresearchofphysicsandastronomy.Millimeter-wavemicrowavetechnologyprovidesaneffectivemethodforplasmameasurementtocontrolthermonuclearreactions.Microwaveremotesensinghasbecomeanimportantmethodforstudyingcelestialbodies,meteorology,geodesy,andresourceexploration.Theresearchofmicrowaveinindustrialproductionandagriculturalscience,aswellastheresearchanddevelopmentofmicrowaveinbiology,medicine,etc.havereceivedmoreandmoreattention(seemicrowaveapplication,microwaveenergyapplication,microwavemedicalapplication,etc.).
Microwaveandotherdisciplinesinterpenetrateeachothertoformanumberofimportantedgedisciplines,suchasmicrowaveastronomy,microwavemeteorology,microwavespectroscopy,quantumelectrodynamics,microwavesemiconductorelectronics,microwavesuperconductingelectronics,etc.Itisrelativelymature.Theresearchandapplicationofmicrowaveopticshasbecomeanactivefield.Thedevelopmentofmicrowaveoptics,especiallythedevelopmentofopticalfibertechnologysincethe1970s,hasthesignificanceoftechnologicalchange(seemicrowaveandradiofrequencyspectroscopy).
Commonlyusedwirelesstransmissionmediaaremicrowave,laserandinfrared.Communicationmediaisalsocalledtransmissionmedia.Itisusedtoconnectnetworkdevicesincomputernetworks.Transmissionmediacangenerallybedividedintowiredtransmissionmediaandwirelesstransmissionmedia.!
Intheory,microwavescanactasaweapontostrikeanyelectronicsystem,paralyzingcars,airplanes,andnuclearpowerplants.Inaddition,microwaveweaponscanalsocauseaburningsensationwithoutcausingcasualties,andcanbeusedtodispersepeople.
Thetransmitterinstalledonthemaincontrolstill-pipe.Thewaveguidestructureintheelectromagnetapplicator(cavity)comesfromenergycoupling.Thereflectedelectromagneticenergyisdependentonthesizeofthecavityandthedielectricheatingoftheheatingproduct.Theamountofelectromagneticenergyreflectedbytheuseofthetunercanbeminimizedtoimproveefficiencyandachievetheoptimizationoftheheatingeffect.