简介：ＮｏｎｄｅｓｔｒｕｃｔｉｖｅｔｅｓｔｏｆｗｅｌｄｒｅｓｉｄｕａｌｓｔｒｅｓｓｅｓｂｙａｃｏｕｓｔｏｅｌａｓｔｉｃｔｅｃｈｎｉｑｕｅＪｉａｏＦｕｊｉｅ；ＺｈａｎｇＷｅｎｊｕｎａｎｄＹｕａｎＺｈｉｋａｎｇ（ＳｈａｎｇｈａｉＵｎｉｖｅｒｓｉｔｙｏｆＥｎｇｉ...

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简介：Structuralfinger-jointed(FJ)lumberwasusedmainlyinstructuralapplicationsincludingglue-laminatedbeamsandwoodenI-joistsandmorerecentlyinparallelchordwoodtrusses.ThepaperevaluatedstrengthpropertiesofstructuralFJlumberbythreenondestructivemethods(edge-wisebending,longitudinalandtransversalvibration)inordertofindanalternativetotraditionalevaluationmethods.LumberwassawnfromthelogsfollowingapatterntypicallyusedinChinatomaximizethevolumeofrecover...

简介：一个高速度的X光检查非破坏性的察觉者在这份报纸被设计。X光检查非破坏性的察觉的原则被分析，并且高速度的X光检查非破坏性的察觉者的一个一般系统计划被建议。Virtex-4系列Fx12FPGA芯片被用来设计它的硬件电路，PowerPC405嵌入系统被开发，处理算法的高速度的图象被使用编译它的处理软件，并且TCP/IP协议被采用编译通讯软件，认识到高速度的X光检查信号聚会，处理并且传播。试验性的结果显示察觉者能在关联词工业地里与钢电线绳被用于生产线的长途、联机的非破坏性的察觉，例如矿，港口和码头。当察觉者的调查宽度是1.6m时，conveyer带的跑的率能完成6m/s。

简介：TheIsodynetechniquebasedonthescatteredlightscanningfromathinlaserbeamcanbeusedtoobtaintheinformationinsidetheloadedobjectintheroomtemperaturenondestructively,soitisaverypowerfultechniquein3Dstressanalysis.Theproblemsarehowtointerprettheinformationandhowtogetsufficientinformationfromthefewinterferencefringe.Birefringencephaseshifttechniquecandistinguishthefringeordersautomaticallyandenrichtheinformationin256graylevelsbetweenmaximandminimlightintensity.InthepapertheIsodynebirefringencephaseshiftmethodwithanobliqueincidenceandequilibriumequationispresented,bywhichthe3DstressesinthemiddleplaneofaplatewithUshapenotchareseparatedsuccessfully.

简介：BeamresponsesunderanimpactNDTloadarestudiedusingtheFourierandLaplacetransforms.Numericalcomputationisperformedforaparametricstudyofbeamandloadparameters.Itisshownthatunderanimpactload,thetimedurationfordisplacementtovanishistentimeslongerthanthatforvelocityandacceleration.Themaximumresponseisachievedfirstinacceleration,followedbyvelocity,andfinallydisplacement,allofwhichoccurbeforetheimpactloadisremoved.Atthemomentthattheimpactloadisremovedfromthebeam,thereisadiscontinuityinthevelocityandaccelerationresponses,butnotindisplacementresponse.TheeffectofKandphonbeamresponseismuchlesssignificantthanthatofEIandC,whichhavesimilareffectonbeamresponse.AsEIincreases,peakvaluesofdisplacement,velocityandaccelerationresponsedecrease.TheeffectofKonbeamresponseonlybecomesappreciableaftertheimpactloadisremoved.WhilethepeakofdisplacementremainalmostunchangedasKincreases,thedisplacementresponsedecaystozerofasterforlargeKvaluesthanforsmallKvalues.

简介：Resonanceflexuralvibration(FastFourierTransform,FFT),ultrasonicwave(Pundit)andstresswave(Metriguard)techniqueswereexaminedasmeansofevaluatingthestaticmodulusofelasticity(MOE)andpredictingthemodulusofrupture(MOR)offinger-jointedlumberspecimensmadewithfourkindsofEucalyptus(Eucalyptus.citriodora,E.exserta,E.grandisxE.urophyllaandE.grandis).DynamicMOEwascalculatedfromfrequencyandtimeobtainedfromforcedvibrationsandsoundsinducedinthefourspeciesoffinger-jointedspecimens.ItwasfoundthatcorrelationcoefficientsbetweendensityandstaticMOEanddynamicMOEwerestatisticallysignificantatthe0.01level.AnditwasalsofoundthatthethreenondestructivetechniquescanproviderapidandaccuratemeanstodeterminetheMOE,andthedynamicMOEwasmoreaccuratetopredictstaticMOEthandensity.ButthecorrelationcoefficientbetweendynamicMOE,staticMOEandMORwerelowerthanresultsreportedbyotherresearchersforsolidwood,andwerenotstatisticallysignificant.ItcanbeconcludedthatthethreenondestructivetechniquesareusefulforevaluatingtheMOE,butnotsuitableforpredictingtheMORoffinger-jointed.

简介：MoS_2,MoSe_2andWSe_2thinflakeswerefabricatedbythestandardmicromechanicalcleavageprocedures.ThethicknessandtheopticalcontrastoftheatomicthindichalcogenideflakesonSiO_2/Sisubstratesweremeasuredbyatomicforcemicroscopy(AFM)andspectroscopicellipsometer.Arapidandnondestructivemethodbyusingreflectionspectrawasproposedtoidentifythelayernumberof2DlayeredtransitionmetaldichalcogenidesonSiO_2(275nm)/Sisubstrates.Thecontrastspectraof2DnanosheetswithdifferentlayernumbersareinagreementwiththeoreticalcalculationsbasedonFresnel'slaw,indicatingthatthismethodprovidesanunambiguousandnondestructivecontrastspectrafingerprintforidentifyingsingle-andfew-layeredtransitionmetaldichalcogenides.Theresultswillgreatlyhelpinfundamentalresearchandapplication.