简介：AlNthinfilmsirradiatedwith100MeVU,95MeVArand84MeVCionsfromtheHIRFL-SFC(HeavyIonResearchFacilityinLanzhou)wereinvestigatedbyInfraredspectraandRamanspectra.ItappearedA1（TO),A1（LO),E1（To）andE2PhononvibrationabsorptionmodetoirradiatedsamplesinFig.1.652cm??1isvibrationabsorptionpeakofAlN，withtheincreaseofirradiationdose,thevibrationabsorptionbandappearacertainbroadeningphenomena.Lightercarbonionirradiationonthevibrationabsorptionbandbroadeningoftheimpactisnotbig.670cm??1isthetransverseopticalphononabsorptionpeakoftheE1(TO),afterirradiation,thevibrationabsorptionpeakandthebroadenAl-Nkeyintoanorganicwhole.249and660cm??1istheE2(low)andE2(high)

简介：Awatt-classbackwardwaveoscillatorisproposed,usingtheconcisesinewaveguideslow-wavestructurecombinedwithapencilelectronbeamtooperateat220GHz.Firstly,thedispersioncurveofthesinewaveguideiscalculated,then,theoscillationfrequencyandoperatingvoltageofthedevicearepredictedandthecircuittransmissionlossiscalculated.Finally,theparticle-in-cellsimulationmethodisusedtoforecastitsradiationperformance.Theresultsshowthatthisnovelbackwardwaveoscillatorcanproduceover1-Wcontinuouswavepoweroutputinafrequencyrangefrom210GHzto230GHz.Therefore,itwillbeconsideredasaverypromisinghigh-powermillimeter-wavetoterahertz-waveradiationsource.

简介：Toreducemechanicalvibrationsinducedbybigerrorscompensation,anewsoftwarecompensationmethodbasedonanimproveddigitaldifferentialanalyzer(DDA)interpolatorforstaticandquasi-staticerrorsofmachinetoolsisproposed.BasedonprincipleoftraditionalDDAinterpolator,aDDAinterpolatorisdividedintocommandgeneratorandcommandanalyzer.Therearethreetypesoferrors,consideringthedifferenceofpositionsbetweencompensationpointsandinterpolationsegments.Accordingtotheclassification,errorsaredistributedevenlyindataprocessingandcompensatedtocertaininterpolationsegmentsinmachining.On-lineimplementationresultsshowthattheproposedapproachgreatlyimprovespositioningaccuracyofcomputernumericalcontrol(CNC)machinetools.

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简介：Thispaperinvestigatesthetemperaturefielddistributionandthermalfocallengthwithinalaserdiodearray(LDA)end-pumpedYVO4/Nd:YVO4rectangularcompositecrystal.AgeneralexpressionofthetemperaturefielddistributionwithintheNd:YVO4rectangularcrystalwasobtainedbyanalysingthecharacteristicsoftheNd:YVO4crystalandsolvingthePoissonequationwithboundaryconditions.ThetemperaturefielddistributionsintheNd:YVO4rectangularcrystalfortheYVO4/Nd:YVO4compositecrystalandtheNd:YVO4singlecrystalareresearchedrespec-tively.CalculatingthethermalfocallengthwithintheNd:YVO4rectangularcrystalwasdonebyananalysisoftheadditionalopticalpathdifferences(OPD)causedbyheat,whichwasveryidenticalwithexperimentalresultsinthispaper.ResearchresultsshowthatthemaximumrelativetemperatureontherearfaceoftheNd:YVO4crystalinthecompositecrystalis150Kandthethermalfocallengthis35.7mmwhentheoutputpoweroftheLDAis22W.Inthesamecircumstances,theexperimentalvalueofthethermalfocallengthis37.4mm.Sotherelativeerrorbetweenthetheoreticalanalysisandtheexperimentalresultisonly4.5%.Withthesameconditions,thethermalfocallengthoftheNd:YVO4singlecrystalis18.5mm.SotherelativerateofthethermalfocallengthbetweentheYVO4/Nd:YVO4crystalandtheNd:YVO4crystalis93%.So,thethermalstabilityoftheoutputpowerandthebeamqualityoftheYVO4/Nd:YVO4laserismoreadvantageousthanthelaserwithNd:YVO4singlecrystal.

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