简介：-Thetemperaturedistributionsobtainedbydifferentmethodsofanalysisforsolvingthermaltransferofreinforcedconcrete(R.C.)submarineoiltanks(RCSOT),includingflatwallmethod,cylinderwallmethodandfiniteelementmethod,arecomparedwiththeexperimentaldataofthermaltransferofRCSOT.Theprecisionandscopeofapplicabilityofdifferentmethodsarediscussed.TheprincipleforselectinganalysismethodforsolvingthermaltransferofRCSOTisgiven.TheanalyticalandexperimentaltemperaturedistributionsshowthatthewallofRCSOTshouldconsistofdoublewallsandemptyspacebetweenthemshouldbefilledwithsandorotherheatinsulationmaterialstoreducethetemperaturedifferenceofthewallandtopreventconcretefromcracking.

简介：Thispaperdiscussestheresultsoftestsontheshearcapacityofreinforcedconcretecolumnsstrengthenedwithcarbonfiberreinforcedplastic(CFRP)sheet.ThesheartransfermechanismofthespecimensreinforcedwithCFRPsheetwasstudied.ThefactorsaffectingtheshearcapacityofreinforcedconcretecolumnsstrengthenedwithCFRPsheetwereanalyzed.Severalsuggestionssuchasthenumberoflayers,widthandtensilestrengthoftheCFRPsheetareproposedforthisnewstrengtheningtechnique.Finally,asimpleandpracticaldesignmethodispresentedinthepaper.Thecalculatedresultsofthesuggestedmethodareshowntobeingoodagreementwiththetestresults.ThesuggesteddesignmethodcanbeusedinevaluatingtheshearcapacityofreinforcedconcretecolumnsstrengthenedwithCFRPsheet.

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简介：Adesignmethodofreinforcedconcrete(R.C.)offshoreplatformswithnonlinearfiniteelementanalysisisproposed.Accordingtothemethod,acomputerprogramisdeveloped.Inthisprogramnonlinearconstitutiverelationshipsandstrengthcriteriaofconcreteandsteelbarsareincluded,andtheprogressivecrackingandcrushingoftheconcretearetakenintoaccount.Basedonthestressdistributionobtainedbythenonlinearfiniteelementanalysis,theamountofreinforcementinthecontrolsectionscanbecomputedandadjustedautomaticallybytheprogramtosatisfytherequirementofthedesign.Theamountofreinforcementrequiredinthecontrolsections,whichareobtainedwiththenonlinearfiniteelementanalysis,isagreeabletothatobtainedintheexperiment.ThisshowsthatthedesignmethodofR.C.offshoreplatformwiththenonlinearfiniteelementmethodproposedbytheauthorsisreliableforpracticaluse.

简介：Inthispaper,thestabilityofaconcavesphericalstembulkheadunderthepumpingloadwhenstilllyingattheslipwayisanalyzed.Thestabilityofthesphericalstembulkheadwithdifferentshellthicknessandreinforcingformsisdiscussed.Accordingtotheresultsofstabilityanalysis,theoptimizationdesignofthesphericalstembulkheadstabilityisperformed.Onthebasisofconsideringthemachiningtechnicalrequirementsofthebulkhead,arationaldesignofthesphericalstembulkheadstructureisobtained.Thispaperhasacertainvaluetothedesignofsubmarine'ssphericalstembulkhead.

简介：Thepolypropylene(PP)nanocompositesfilledwithpretreatedhalloysitenanotubes(HNTs)werepreparedbythemelt-blendingmethod.Beforefilling,theas-receivedHNTspowderwasatfirstpurifiedandthenmodified.ThecharacterizationtestsshowedthatthepurifiedHNTshadlessimpurityandmoreuniformporesizedistributionandthesurfacehydrophobicityofthemodifiedHNTswasobviouslyimproved.ThemechanicalandtribologicalpropertiesofthePP/HNTsnanocompositeswereextensivelyinvestigated.Theresultsshowedthatthetensile,bendingandnotchedimpactstrengthofthePP/HNTsnanocompositeswassomewhatimproved,butthewearresistanceofthePP/HNTsnanocompositeswasobviouslyenhanced.

简介：TheRightWordsattheRightTime汇集了美国各行各业成功人士的语录。他们都回忆了人生路上改变自己命运的一句话或几句话，包括小时侯来自长辈的鼓励，特别是来自干妈妈的鼓励。雅芳公司女总裁AndreaJung回忆起的是母亲曾对她说过的一句话“Giriscandoabsolutelyanythingboyscando．Awomancanreachany

简介：<正>London24November2004MotheristhemostbeautifulwordintheEnglishlanguage,accordingtoasurveyofover40,000overseasvotersandlearnersofEnglishatBritishCouncilteachingcentres.ThesurveywasconductedbytheBritishCounciltocoincidewithits70thanniversarycelebrations.TheBritishCouncilaskedover7,000learnersin46countrieswhattheyconsideredtobethemost

简介：Speakervariabilityisanimportantsourceofspeechvariationswhichmakescontinuousspeechrecognitionadifficulttask.Adaptingautomaticspeechrecognition(ASR)modelstothespeakervariationsisawell-knownstrategytocopewiththechallenge.AlmostallsuchtechniquesfocusondevelopingadaptationsolutionswithintheacousticmodelsoftheASRsystems.Althoughvariationsoftheacousticfeaturesconstituteanimportantportionoftheinter-speakervariations,theydonotcovervariationsatthephoneticlevel.Phoneticvariationsareknowntoformanimportantpartofvariationswhichareinfluencedbybothmicro-segmentalandsuprasegmentalfactors.Inter-speakerphoneticvariationsareinfluencedbythestructureandanatomyofaspeaker'sarticulatorysystemandalsohis/herspeakingstylewhichisdrivenbymanyspeakerbackgroundcharacteristicssuchasaccent,gender,age,socioeconomicandeducationalclass.Theeffectofinter-speakervariationsinthefeaturespacemaycauseexplicitphonerecognitionerrors.Theseerrorscanbecompensatedlaterbyhavingappropriatepronunciationvariantsforthelexiconentrieswhichconsiderlikelyphonemisclassificationsbesidespronunciation.Inthispaper,weintroducespeakeradaptivedynamicpronunciationmodels,whichgeneratedifferentlexiconsforvariousspeakerclustersanddifferentrangesofspeechrate.Themodelsarehybridsofspeakeradaptedcontextualrulesanddynamicgeneralizeddecisiontrees,whichtakeintoaccountwordphonologicalstructures,rateofspeech,unigramprobabilitiesandstresstogeneratepronunciationvariantsofwords.EmployingthesetofspeakeradapteddynamiclexiconsinaFarsi(Persian)continuousspeechrecognitiontaskresultsinworderrorratereductionsofasmuchas10.1%inaspeaker-dependentscenarioand7.4%inaspeaker-independentscenario.

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简介：一半房间潜力(HCP)；与氯化钠做的增强的具体标本的腐蚀电流在电气化学的氯化物抽取(ECE)以后被决定。试验性的结果证明当ECE处理被移开时，HCP变得更否定；腐蚀电流在ECE处理前与那些相比变得更大，然后，HCP断然变；腐蚀电流与时间减少。在30天ECE处理以后，标本在暴露的钢附近由于足够的氧的存在转到大约100mV的cored的HCP锁，要不是核心un的标本，更长的时间，大约二个月，是被订。在在ECE处理以后的一样的标本的不同的层的非同类的HCP分发可能导致钢的第二等的腐蚀。

简介：SurfacePenetratingRadar(SPR)isarecentlydevelopedtechnologyfornon-destructivetesting.Itcanbeusedtoimageandinterprettheinnerstructureofthereinforcedconcrete.ThispapergivesthedetailsaboutacompactandhandheldSPRdevelopedrecentlyforreinforcedconcretestructuredetection.Thecenteroperationfrequencyoftheradaris1.6GHz.Notonlyithasfastacquisitionability,butalsoitcandisplaythetestingresultontheLCDscreeninreal-time.Thetestingresultsshowthattheradarhasapenetratingrangeofmorethan30cm,andalateralresolutionbetterthan5cm.Theperformancevalidatesthattheradarcanmeettheapplicationrequirementsforreinforcedconcretestructuredetection.

简介：Onebranchofstructuralhealthmonitoring(SHM)utilizesdynamicresponsemeasurementstoassessthestructuralintegrityofcivilinfrastructures.Inparticular,modalfrequencyisawidelyadoptedindicatorforstructuraldamagesinceitssquareisproportionaltostructuralstiffness.However,ithasbeendemonstratedinvariousSHMprojectsthatthisindicatorissubstantiallyaffectedbyfluctuatingenvironmentalconditions.Inordertoprovidereliableandconsistentinformationonthehealthstatusofthemonitoredstructures,itisnecessarytodevelopamethodtofilterthisinterference.Thisstudyattemptstomodelandquantifytheenvironmentalinfluenceonthemodalfrequenciesofreinforcedconcretebuildings.Dailystructuralresponsemeasurementsofatwenty-twostoryreinforcedconcretebuildingwerecollectedandanalyzedoveraone-yearperiod.TheBayesianspectraldensityapproachwasutilizedtoidentifythemodalfrequenciesofthisbuildinganditwasclearlyseenthatthetemperatureandhumidityfluctuationinducednotablevariations.Amathematicalmodelwasdevelopedtoquantifytheenvironmentaleffectsandmodelcomplexitywastakenintoconsideration.BasedonaTimoshenkobeammodel,thefullmodelclasswasconstructedandotherreduced-ordermodelclasscandidateswereobtained.Then,theBayesianmodalclassselectionapproachwasemployedtoselecttheonewiththemostsuitablecomplexity.Theproposedmodelsuccessfullycharacterizestheenvironmentalinfluenceonthemodalfrequencies.Furthermore,theestimateduncertaintyofthemodelparametersallowsforassessmentofthereliabilityoftheprediction.Thisstudynotonlyimprovestheunderstandingaboutthemonitoredstructure,butalsoestablishesasystematicapproachforreliablehealthassessmentofreinforcedconcretebuildings.

简介：Asystematicalsimulationhasbeencarriedoutontheindentationcreeptestonparticle-reinforcedcomposites.Thedeformation,failuremechanismsandlifeareanalyzedbythreereasonablemodels.Thefollowingfivefactorshavebeenconsideredsimultaneously:creeppropertyoftheparticle,creeppropertyofthematrix,theshapeoftheparticle,thevolumefractionoftheparticleandthesize(relativesizetotheparticle)oftheindentationindenter.Forallthecases,thepowerlawrespectingtotheappliedstresscanbeusedtomodelthesteadyindentationcreepdepthrateoftheindenter,andthedetailexpressionshavebeenpresented.Thecomputersimulationprecisionisanalyzedbythetwo-phasemodelandthethree-phasemodel.Twoplacesofthestressconcentrationarefoundinthecomposites.Oneisaheadoftheindentationindenter,wherethehighstressstateisdeducedbytheedgeoftheindenterandwilldecreaserapidlyneartoasteadyvaluewiththecreeptime.Theotheroneisattheinterface,wherethehighstressstateisdeducedbythemisfitofmaterialpropertiesbetweentheparticlesandmatrix.Ithasbeenfoundthatthecreepdissipationenergydensityotherthanastressparametercanbeusedtobethecriteriontomodelthedebondingoftheinterfaces.Withthecriterionofthecriticalcreepdissipationenergydensity,apowerlawtotheappliedstresswithnegativeexponentcanbeusedtomodelthefailurelifededucedbythedebondingofinterfaces.Theinfluencesoftheshapeoftheparticlesandthematchingofcreeppropertiesofparticleandmatrixcanbediscussedforthefailure.Withacrackmodel,thefurthergrowthofinterfacecrackisanalyzed,andsomeimportantexperimentalphenomenacanbepredicted.Thefailuremechanismwhichtheparticlewillbepunchedintomatrixhasbeenalsodiscussed.Thecriticaldiflerencesbetweenthecreeppropertiesoftheparticlesandmatrixhavebeencalculated,afteraparameterhasbeendefined.Intheviewofcompetitionoffailure

简介：AnewtypeofSiO_2-MgO-CaO(SMC)whiskerwasusedtomodifyhighdensitypolyethylene(HDPE).Themeltingbehaviorandcrystallinitywereinvestigatedbydifferentialscanningcalorimetry(DSC).ThedispersionofwhiskersandinterfacialadhesioninthepreparedHDPE/SMCwhiskercompositeswereinvestigatedbyscanningelectronmicroscopy(SEM).Themechanicalpropertieswereevaluatedbymechanicaltestsanddynamicmechanicalanalysis(DMA).DSCdataindicatedthatthemeltingtemperatureandthecrystall...

简介：Withrespecttoobtainingtheeffectiveelasticmoduliofthecomposite,thepresenttheorydif-fersfrombothEshelby’sequivalentinclusionmethodandHill’sself-consistentone,bothofwhichonlyconsid-erthemechanicalpropertiesofthematrixandinclusions(fibers).Infact,theinclusion-inclusioninteractionismorepronouncedwhenthevolumefractionofinclusionsofthecompositeincreases.Hence,inthispapertheeffectiveelasticmoduliofthecompositearederivedbytakingintoaccounttheshapes,sizesanddistributionofinclusions,andtheinteractionsbetweeninclusions.Inaddition,itismoreconvincingtoassumeshort-fibersascylindricalinclusionsasinthepresentpaperthanasellipsoidalonesasinothers.Finally,numericalre-sultsaregiven.

简介：Electrochemicalandcorrosionbehaviourofreinforcedsteelembeddedincementpastesincorporatingdifferentamountsofsilicafumeasapartialreplacementofcementhasbeenstudiedinchlorideandsulphatesolutionsbyusingdifferentelectrochemicaltechniques.Theresultsindicatethat,whilesteelpassivitydegreeislowinthecontrolsamples'uponsoakinginthecorrosivemedia,ithasbeenhighihsamplesincorporatingsilicafumeandincreasedwithincreasingsilicafumecontent.Theimprovementeffectofsilicafumemaybeattributedtotheporesolutionstructureofthecementpaste,whichlimitsthemobilityofaggressiveionsnearthesurfaceofthesteel.Themechanismofsteelcorrosionduetochlorideandsulphateattackandpassivationeffectofsilicafumearediscussed.

简介：Chitosan/cellulosenanocrystals(CS/CNCs)composites与计算机数值控制的不同内容被准备。由于计算机数值控制和计算机数值控制的同类的分散，CS的透明性很好被保留，CS的全面机械性质显著地被改进。而且，因为CS和计算机数值控制是biocompatible材料，获得的composites潜在地是noncytotoxic和罐头的房间增长测试表演满足生物医学的应用的安全要求。这些优点在商业塑料的地里铺平CS的潜在的应用的道路并且鼓励CS同样环境友好的材料和生物医学的材料的使用。

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