简介:为研究通孔直径在钢管涡流检测中对检测信号的影响,开展了不同磁化强度下钢管通孔涡流检测试验,研究了不同直径通孔随磁化电流的信号变化特征。试验结果表明:通孔直径一定时,在非饱和磁化区(6~18A)内,信号幅值随电流的增加先增大后减小,相位角随电流的增加逐步上升,在饱和磁化区(20~22A)内,检测信号成形较小或严重扭曲,相位变化杂乱无章;当磁化电流一定时,信号幅值随通孔直径的增大而增大,不同直径通孔间信号相位角在非饱和磁化区(6~18A)内,最大值与最小值的极值偏差在10°~18°范围内变化,差异较小,而在饱和磁化区(20~22A)信号相位角变化起伏较大,无明显规律。试验研究结果可用于指导钢管涡流检测工程实践。
简介:为探寻能够区分矿山微震信号和爆破信号的波形特征,建立基于人工识别标准的事件数据库。人工识别的考虑因素包括:波形的重复特征、波形的衰减特征、信号的主频大小以及事件发生的具体时间。将数据库中的微震信号和爆破信号调整至同一坐标系下发现,两类事件的起振角趋。于集中在不同的区间。考虑到P波到时提取的不准确性,波形起振角难以准确计算,提出以应用线性回归拟合得到的起振趋势线斜率代替起振角。将首次峰值起振趋势线斜率和最大峰值起振趋势线斜率连同首次波峰及最大波峰的坐标列为特征参数,应用Fisher判别法,能成功实现微震事件与爆破时间的准确分离,识别正确率达到97.1%。
简介:[篇名]SignificantincreaseinmachinepartdurabilityandlongevityduetothenewpatentedLincarb,LinterprocessandLinheattechnologies,[篇名]Lasersurfacetreatmentofsteels,[篇名]ForecastingofthePhaseTransformationHardenedZoneandGorrelationInfluenceFactorsintheSurfaceHeatTreatmentbyPlasma,[篇名]Fatigueandfracturebehaviorofalasersurfaceheattreatedmartensitichigh-nitrogentoolsteel,[篇名]Theoreticalmodelsofsurfaceheattreatmentofproductsinsolarfurnaces-1:uniformradiant-energyflux。
简介:CorrelationbetweentheflnorescentmaterialsproducedbyendosymbioticpseudomonasfluorcscensFPT-9601andmicrobialcontrolofsoil-bornebacterialdiseaseusingthisstrain;CORROSIONOFALUMINUMALLOY2024BYJETFUELDEGRADINGMICROORGANISMS;Developmentandtestingofnewvolatilecorrosioninhibitorsfornultimetalsystems;Developmentofdiscbrakerotorsforheavy-andmedium-dutytrackswithhighthermalfatiguestrength;DimethylSulfideRemovalfromSyntheticWasteGasUsingaFlatPoly(dimethylsiloxane)-CoatedCompositeMembraneBioreactor。
简介:AStudyofMicrobiologicallyInducedCorrosionbySRBonCarbonSteelusingHydrogenPermeation,Alloying,DeoxidizingandInoculatingCastAlloyswithPressedPowderPseudo-MasterAlloys,Anaerobicdigestionforreductionandstabilizationoforganicsolidwasteduringspacemissions:Systemsanalysis,Anaerobicdigestionforreductionandstabilizationoforganicsolidwastesduringspacemissions:Laboratorystudies,AssessmentofmicrobialcommunityvariabilityinreplicatetubularnitrifyingbioreactorsusingPCRandTRFLPanalysis.
简介:Dampingahybridsteppingmotorwithestimatedpositionandvelocity,Gridcurrentregulationofathree-phasevoltagesourceinverterwithanLCLinputfilter,TorsionalinteractionstudiesonpowersystemcompensatedbySSSCandfixedcapacitor,Amultivariablenewcontrolsolutionforincreasedlonglinesvoltagerestorationstabilityduringblackstartup,
简介:[篇名]Magneto-OpticalStudiesoftheCriticalStatesinc-axisOrientedMgB{sub}2ThinFilmandBulkMgB{sub}2/MgNano-Composites,[篇名]TheSoreteffectonconvectioninahorizontalporousdomainundercrosstemperatureandconcentrationgradients,[篇名]Improvingtheanti-seizureabilityofSiCsealinwaterwithRIEtexturing,[篇名]Coppernanoparticleswithinamorphousandcrystallinedielectricmatrices,[篇名]In-linelaserDopplervelocimeterusingfibre-opticBragggratinginterferometricfilters,[篇名]PreparationofaUV-attenuatingagentusingamechanochemicalreaction,[篇名]DesignofanAdaptiveObserverforSensorlessVectorControlofInductionMachinesunderRegeneratingConditions,[篇名]ConflictovernaturalresourcesamongpastoralistsinnorthernKenya:alookatrecentinitiativesinconflictresolution,[篇名]Releasingnitrogenfromammoniatedligninbywhiterotfunguscometabolizesenvironmentalpollutants,[篇名]Onanalogyanddissimilarityofdependenceofstabilityonseveralparametersinflowsimulations,[篇名]Ontheexponentialstabilityofaclassofnonlinearsystemsincludingdelayedperturbations,[篇名]6-indiameterInPsinglecrystalsgrownbythehot-wall,[篇名]Swing-upControlofaTranslationalInvertedPendulumHavingRestrictedTravel,[篇名]RobustPIDRate-BasedControlforPropagationDelayVariation,[篇名]Apracticalapproachforthedesignofmultivariablecontrolsystems,[篇名]Fibersensordetectslithium。
简介:[篇名]Doublethermochemicaltreatmentintoolmanufacturingfromstructuralsteel,[篇名]Lifetimepredictionofhelicoptergears:experimentalinvestigationsandcomputermodelling,[篇名]Fluidizedbedapparatusesforthermaltreatmentandclassificationofdispersematerials,[篇名]Experimentalrigofthermochemicaltreatmentscraptires,[篇名]Thermochemicaltreatmentofsteel20khuponcyclictemperaturechanges。