简介:ICSED(ImprovedClusterShadeEdgeDetection)algorithmandothervariousmethodstoaccuratelyandefficientlydetectedgesonsatellitedataarepresented.ErrorratecriterionisusedtostatisticallyevaluatetheperformancesofthesemethodsindetectingoceanicfeaturesforbothnoisefreeandnoisecontaminatedAVHRR(AdvancedVeryHighResolutionRadiometer)IRimagewithKuroshio.Also,practicalexperimentsindetectingtheeddyofKuroshiowiththesemethodsarecarriedoutforcomparison.ResultsshowthattheICSEDalgorithmhasmoreadvantagesthanothermethodsindetectingmesoscalefeaturesofocean.Finally,theeffectivenessofwindowsizeofICSEDmethodtooceanicfeaturesdetectionisquantitativelydiscussed.
简介:IR-TRACC传感器主要用于WorldSID假人各部位压缩偏移量的数据采集,而假人内部IR-TRACC传感器位移换算方法使用存在偏差,传感器灵敏度标定系数拟合度不高,且没有特定的IR-TRACC传感器标定设备,造成传感器标定灵敏度系数偏差较大。为解决上述问题,对IR-TRACC传感器位移计算及标定方法进行了研究,利用几何法得到了传感器位移换算公式,设计了一种实用简便且精度较高的传感器标定台,并运用最小二乘法拟合及单变量求解得到了传感器灵敏度标定系数的最优解。标定结果表明,经上述方法及算法标定得到的传感器灵敏度标定系数,曲线拟合的最大非线性误差较小。
简介:Forthedevelopmentoffiberopticsfortherangefrom0.2to50.0μm,oneneedslight-stable,nonhygroscopic,ductilecrystalsthatwouldbetransparentwithinthisspectralrangeandhavealackofcleavage,andfromwhichtheflexibleinfrared(IR)fibersareextruded.Thecrystalsbasedonsolidsolutionsofsilverandmonadicthalliumhalidesmeettheconditionslistedabove.Consequently,bydifferentialthermalandxrayanalyses,westudytheTlBr–TlIphasediagramusingthecrystalswithoptimalcompositions,whichwegrowourselves.Wealsomanufacturelight-stablenanocrystallineIRfibersthataretransparentatlongerwavelengthscomparedwithAgCl–AgBrfibers.
简介:AnewlygrownBaGa4Se7crystalhasbeensynthesizedviatheBridgman-Stockbargertechnique.Thisnewcrystalhasadvantagesofhighnonlinearoptics(NLO)coefficients,highlaserdamagethresholds,andwidetransparentregions.TheBaGa4Se7crystalhasbrightapplicationprospectsasanonlineargainmediuminmid-infraredandterahertzregions.Inthispaper,thecrystallinestructureandsyntheticmethodoftheBaGa4Se7crystalareintroduced.Therefractiveindicesandabsorptioncoefficientsalongthreedielectricaxesbetween0.1THzand1.0THzarealsoobtained.Theterahertzdifferencefrequencygeneration(THz-DFG)characteristicsbasedontheBaGa4Se7crystalinthefrequencyrangeof0.1THzto1.0THzareanalyzedtheoreticallyandthephase-matchingconditionsarecalculated.TheapplicationofBaGa4Se7crystalsinterahertzwavegenerationisalsodiscussed.
简介:Theconformationofpolymersatthesolid-liquidinterfacehasbeenthesubjectofconsiderableinterestinthefundamentaltheoryandappliedpractice.Inpaintsandprintinginks,dispersionsofpigmentorfillerpowdersinpolymericbindersolutionshavetobemaintainedinthecolloidalstate.Oneofthestabilizingmechanismsforpaintisthestericstabilization.Ontheotherhand,intheformationreactionofpolymeratthesolid-liquidinterfacetookplacebetweenmonomersolutionsandsolid
简介:Electrolysisofammoniainalkalineelectrolytesolutionwasappliedfortheproductionofhydrogen.BothPt-loadedNifoamandPt-IrloadedNifoamelectrodeswerepreparedbyelectrodepositionandservedasanodeandcathodeinammoniaelectrolyticcell,respectively.TheelectrochemicalbehaviorsofammoniainKOHsolutionwereindividuallyinvestigatedviacyclicvoltammetryonthreeelectrodes,i.e.bareNifoamelectrode,Pt-loadedNifoamelectrodeandPt-IrloadedNifoamelectrode.ThemorphologyandcompositionofthepreparedNifoamelectrodewereanalyzedbyscanningelectronmicroscopy(SEM)andX-raydiffraction(XRD).Effectsoftheconcentrationofelectrolytesolutionandtemperatureofelectrolyticcellontheelectrolysisreactionwereexaminedinordertoenhancetheefficiencyofammoniaelectrolysis.Thecompetitionofammoniaelectrolysisandwaterelectrolysisinthesamealkalinesolutionwasfirstlyproposedtoexplainthechangesofcellvoltagewiththeelectrolysisproceeding.Atvaryingcurrentdensities,differentcellvoltagescouldbeobtainedfromgalvanostaticcurves.Thelowcellvoltageof0.58V,whichislessthanthepracticalelectrolysisvoltageofwater(1.6V),canbeobtainedatacurrentdensityof2.5mA/cm2.Basedonsomeexperimentalparameters,suchastheappliedcurrent,theresultingcellvoltageandoutputofhydrogengas,thepowerconsumptionpergramofH2producedcanbeestimated.
简介:WehaveUV-inscribedfiberBragggratings(FBGs),long-periodgratings(LPGs),andtiltedfibergratings(TFGs)intomid-IR2μmrangeusingthreecommonopticalfibergratingfabricationtechniques(two-beamholographic,phasemask,andpoint-by-point).ThefabricatedFBGshavebeenevaluatedforthermalandstrainresponse.IthasbeenrevealedthattheFBGdeviceswithresponsesinmid-IRrangearemuchmoresensitivetotemperaturethanthatinnear-IRrange.Toexploretheuniquecladdingmodecouplingfunction,wehaveinvestigatedthethermalandrefractiveindexsensitivitiesofLPGsandidentifiedthatthecoupledcladdingmodesinmid-IRrangearealsomuchmoresensitivetotemperatureandsurroundingmediumrefractiveindexchange.The45°tiltedfibergratings(45°-TFGs)aspolarizingdevicesinmid-IRhavebeeninvestigatedfortheirpolarizationextinctioncharacteristics.Asefficientreflectionfiltersandin-cavitypolarizers,themid-IRFBGsand45°-TFGshavebeenemployedinfiberlasercavitytorealizemulti-wavelength2μmTm-dopedCWandmodelockedfiberlasers,respectively.
简介:AmultisensordistributedextendedKalmanfilteringalgorithmispresentedfornonlinearsystem,inwhichthedynamicequationofthesystemandtheequationsofsensor’smeasurementsarelinearizedintheglobalestimateandglobalpredictionrespectivelyandthesuboptimalglobalestimatebasedonallavailableinformationcanbereconstructedfromtheestimatescomputedbylocalsensorsbasedsolelyontheirownlocalinformationandtransmittedtothedatafusioncenter.Ananalysisofthepropertiesofthealgorithmpresentedhereshowsthattheglobalestimatehashigherprecisionthanthelocaloneandsmallerlinearizationerrorthantheexistingmethod.Finally,anapplicationofthealgorithmtoradar/IRtrackingofamaneuveringtargetisillustrated.Simulationresultsshowtheeffectivenessofthealgorithm.