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简介：Speckleinterferometryisanefficientmethodtoanalyzeavibration.Incetrainconditions,thistechniquehassomeoutsandingadvantage,andneednotstrictshock-proofcondition,comparedwiththeholographicmethodformeasuringvibration,Therefors,itissuitabletoanayyzeavibrationwithalogaramplitude.Real-timeinterferometryisarapidandsimplemethodformeasuringvibrationofabody,givesspecklepatterncontainingamplitudedistributionofbody-surface.Bymeansoftime-averagedmethod.thespecklepatternisrecordedinFouriertransformplane.orvibra-tionlinesareseendirectlywitheyes,soastoanalyzeefficientlyampitude.phase,andmod-elofavibration.Thispaperdeducestheintensitydistributionfunctionwithreal-timemethod,andgivesexpermentaldemonstrationofvibrationbody-thevibrationlineswithdifferentfrequencies.

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简介：Anewsetupofmeasuringtemperatureisdeveloped,whichtheprobeisamicro-powerconsumptiveonewithCMOScircuitandisdrivenbyopticalpower.Fortransmittingthemeasuredsignalandopticalsignalinalongdistance,thefibertechnologyisappliedinthissetup.

简介：Theacousticperformanceofthestructureformeasuringcavitationnoiseistheoreticallyanalysed,andtwojudgingcriteriaoftheacousticperformanceofSTW（soundtransmissionwindow）arepresentedinthispaper.OneisofimpedancematchingbetweenworkingliquidandSTW:ρ1C1=ρ2C2.Theotherisofmaximumfrequency（orminimumwavelength）ofcavitationnoisespectrum:fmax≤c/60D(orλmin/D≥60).Ifeitherofthecriteriaismetreliablemeasuredresultsofcavitationnoisewillbeobtained.Thetheoreticalresultsareverifiedthroughexperi-ments.Accordingtothecriteria,thepaperanalysestheacousticperformanceofroutinelyusedplexiglassSTW.Theresultsshowthatintheresearchofclearwatercavitationtheimpedanceratio,2.18,doesnotsatisfyρ1C1=ρ2C2,andfmax≤C/60Dhardlyholdsforactualcavitationnoisespectrum.Therefore,plexiglassSTWisnotgoodenoughforsoundtransmission.Fromthispointofview,polyethyleneisbettersoundtransmissionmaterialthanplexi-glass.

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简介：Lasttimeweintroducedsomelaboratoryapparatuscommonlyusedtomeasuremass，temperatureandthevolumeofliquids．Onethingneedstobementionedhere．Whenwaterorsomesolutionisplacedinaglassvessel，it

简介：地震计算断层摄影术(CT)方法从节扫描首先在医药科学使用了的X光检查的基本原则被导出。方法在分开的地上凿穿记录在射击和接收装置之间的P波浪到达。用从2D的速度信息地震P波浪到达倒置，我们能在岩石和土壤身体中决定速度的分发。这篇论文介绍使用地震CT方法为隧道工程并且到检测岩石的结构的一个实际盒子为做第一到达时间反复的倒置利用SIRT算法。与另外的探索方法相比，它更有效、精确。

简介：Basedontotalreflectionprinciple,acompactliquid-refractiveindexmeasuringequipmentwasdesignedandfabricated,inwhichadiodelaserwasusedaslightsourceandacharge-coupleddevice(CCD)asphotodetector.Theinfluenceonmeasurementaccuracyofthewavelengthshiftandintensityfluctuationofthediodelaserweresurmountedbyaneffectivefeedbackmethod.Itiscrucialwhetherthediodelasercouldbeusedinsuchasystem.

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简介：Animpulseresponsetechniquehasbeeninvestigatedbyapplicationtotheopenscreensforobtainingsoundtransmissionloss.ThemeasurementsofsuchscreensaccordingtoISO140werealsopresented.ThepredictedresultscalculatedbyamodelwhichisbasedonHuygen’sprincipleandKirchhoff’sformulationhaveshowngoodagreementswiththeresultsobtainedbyimpulsemethod.Themethodrequiresnospecialistacousticfacilitiesandmeasurementsystemscanbeportable.

简介：Thisstudyseekstoevaluatethecomparativeproductivityof32listedtourismcompanieswhicharethemainsuppliersofChinatourism,usingthepopularmethodologyknownasthedataenvelopmentanalysis(DEA).ThisstudyanalyzestheproductivityoflistedtourismcompaniesfrombusinessandregionaspectsbasedonthecalculationofMalmquistindex.Theresultsshowthat(1)theoverallproductivityisnon-efficient(0.954);(2)theproductivityofaccommodationandcateringisbiggest,whichshowsthetourismdevelopsquicklywithsupportsfromtechnology;(3)theproductivityinwesternChinaishighest,wheretheeconomyandtourismattractionarebetterthanotherregions;and(4)theefficiencydifferencesamongthelistedtourismcompaniesarenotsignificant,andtheyattributetothescaleeffi-ciency,thatistheinputofthefinance,resource,talentsandpolicy.

简介：Amulti-functionsamplingsystemhasbeensetupinShanghaiShip&ShippingResearchInstitute(SSSRI)whereatestonthefluctuatingpressureoftwopropellermodelswerecarriedout.Thispaperdealswithastudyonthetechnicalproblemsconcerningthemeasurementandanalysistechniquesinvolvedinthetest.Thesamplingandprocessingprocedureofsignalisoneofthemajorfactorsaffectingtheac-curacyandstabilityofthepredictionoffluctuatingpressureinducedbypropeller.Integral-peri-odsampling,highenoughsamplingfrequencyandsuitableresolutionmustbekeptinsamplingandprocessing.Theprocedureofsamplingandprocessingshouldbevalidatedbystandardsignalcorrespondingtothebladefrequencyofdifferentordersincomparativetests.

简介：Whenexposedtointenseelectromagneticfields,thequantumvacuumisexpectedtoexhibitpropertiesofapolarizablemediumakintoaweaklynonlineardielectricmaterial.Variousschemeshavebeenproposedtomeasuresuchvacuumpolarizationeffectsusingacombinationofhigh-powerlasers.Motivatedbyseveralplannedexperiments,weprovideanoverviewofexperimentalsignaturesthathavebeensuggestedtoconfirmthispredictionofquantumelectrodynamicsofrealphoton–photonscattering.

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简介：Thetructure,equivalentcircuit,noisesoucesofsiliconphotodiodeareanalyzed.Inordertoimprovethemeasuringlinearity,wemustchoosethesiliconphotodiodewithalargeRd,smallRsandI0andunderanoperationstateofoutputshort-circuit.Wemustlettheoperationamplifierworkinthecurrent-voltagetransferform.Alsoweanalyzedtheeffectsoftheinputnoisevoltage,theinputnoisecurrent,theinputoffsetvoltage,theinputoffsetcurrentoftheoperationamplifierandthenoisesofthesiliconphotodiodeonthecombinedcircuitoftheoperationamplifierwiththesiliconphotodiode.Consideringthesefactors,wecandesignthedetectivecircuitwithhighresponse,sensitivity,stability,linearityandSNR.

简介：为特级的粒子的数字集中大小，一个冷凝作用原子核柜台(计算机数值控制)经常被使用。有一个白轻喷雾器分光计和一个被动收集者的一个新计算机数值控制模块的联合在10nm的全面尺寸范围以内做粒子数字的可能的精确解决时间的决心到40m并且在集中直到105particles/cm3。与喷雾器分光计，一颗高解决时间的粒子尺寸决心在直到105particles/cm3的一样的高数字集中的0.340m的尺寸范围也是可能的。