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  • 简介:ThecomparativenumericalandanalyticalanalysisofscintillationindicesofthevortexLaguerre–GaussianbeamandthenonvortexdoughnutholeandGaussianbeamspropagatingintherandomlyinhomogeneousatmospherehasbeenperformed.Ithasbeenfoundthatthedependenceofthescintillationindexattheaxisoftheopticalvortexontheturbulenceintensityatthepathhastheformofaunitstep.Ithasbeenshownthatthebehaviorofscintillationsinthecrosssectionsofvortexandnonvortexbeamsdifferswidely.DespitethescintillationindexofvortexbeamshasbeencalculatedonlyforthesimplestLG10mode,theobtainedresultsarequitegeneral,becausetheydemonstratethemainpropertiesinherentinscintillationsofvortexbeamsofanytype.

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  • 简介:Basedonthetheoryofcomplexfunctionandtheprincipleofhomogenization,harmonicdynamicsstressofaradiallyinfiniteinhomogeneousmediumwithacircularcavityisinvestigated.Duetothesymmetry,wavevelocityisassumedtohavepower-lawvariationintheradialdirectiononly,andtheshearmodulusisconstant.TheHelmholtzequationwithavariablecoefficientisequivalentlytransformedintoastandardHelmholtzequationwithageneralconformaltransformationmethod(GCTM).Thedisplacementsandstressfieldsareproposed.Numericalresultsshowthatthewavenumberandtheinhomogeneityparameterofthemediumhavesignificanteffectsonthedynamicstressconcentrationaroundthecircularcavity.Thedynamicstressconcentrationfactor(DSCF)becomessingularwhentheinhomogeneityparameterofmediumisclosetozero.

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  • 简介:Thispaperisconcernedwiththethermoelasticbehaviorsofanelasticmediumwithvariablethermalmaterialproperties.Theproblemisinthecontextoffractionalorderheatconduction.Thegoverningequationswithvariablethermalpropertieswereestablishedbymeansofthefractionalordercalculus.Theproblemofahalf-spaceformedofanelasticmediumwithvariablethermalmaterialpropertieswassolved,andasymptoticsolutionsinducedbyasuddentemperatureriseontheboundarywereobtainedbyapplyinganasymptoticapproach.Thepropagationsofthermoelasticwaveandthermalwave,aswellasthedistributionsofdisplacement,temperatureandstresseswereobtainedandplotted.Variationsinthedistributionswithdifferentvaluesoffractionalorderparameterwerediscussed.Theresultswerecomparedwiththoseobtainedfromthecaseofconstantmaterialpropertiestoevaluatetheeffectsofvariablematerialpropertiesonthermoelasticbehaviors.

  • 标签: 下线 服务 迁移
  • 简介:在沥滤的Pb之间的关系当在它的团结的形式的水泥在酸媒介被沥滤时,有时间的集中和答案pH被分析。团结的形式,增加方法的水泥,和Pb团结上的水和度的粒子尺寸的效果也被调查。试验性的结果显示水泥快速被溶解,形成有好吸附的C-S-H胶化或硅的酸大音阶的第五音并且在酸媒介含水。当cement-Pb团结了时,形式在一个醋酸盐答案被沥滤,含水的产品与时间侵蚀,Pb集中因此在开始稍微增加。然后,一些Pb离子被最新产生的硅的酸大音阶的第五音吸收,C-S-H。其它生产Pb(哦)为第二等的团结的2降水,在超过二个小时的一沥滤的时间在Pb集中导致渐渐的减少。而且,团结的形式的粒子尺寸在Pb溶解上有重要效果。当增加的水泥的数量是低的时,与不到9.5的pH,团结影响原来的水泥粉末的顺序,水泥含水的粉末,和cement-Pb团结了形式。当水泥的增加的数量与超过11的pH增加时,在团结上增加方法的效果减少,并且团结的形式比其它好一些。

  • 标签: 水泥固化体 重金属铅 酸性介质 浸出特性 C-S-H凝胶 凝固形态
  • 简介:AnindexingmethodforrapidevaluationoftheseismicvulnerabilityofinfilledRCframebuildingsinJordanisproposed.Themethodaimsatidentifyinglowandmediumriseresidentialbuildingsassafeorinneedoffurtherdetailedevaluation.Followingarapidvisualscreening,thebuildingisassignedaBasicCapacityIndex(BCI);fiveperformancemodifiersareidentifiedandmultipliedbytheBCItoarriveattheCapacityIndex(CI)ofthebuilding.ACapacityIndexlowerthanalimitCIvalueindicatesthatthescreenedbuildingcouldexperiencemoderateearthquakedamagewhereasahighervalueimpliesthatminordamage,ifany,wouldtakeplace.Toestablishthebasicevaluationparameters;fortyRCframebuildingswereselected,designedandanalyzedusingstaticnonlinearanalysisandincorporatingtheeffectofinfillwalls.Effectsofseismicity,localsiteconditions,horizontalirregularities(setbacksandre-entrantcorners),verticalirregularities(softstoryatgroundfloorlevel)andoverhangsontheseismicperformanceoflocalbuildingswereexamined.Assessmentformsweredesignedandusedtoevaluateandrank112samplebuildings.About40%ofthesurveyedbuildingswerefoundtobeinneedofdetailedevaluationtobetterdefinetheirseismicvulnerabilities.

  • 标签: SEISMIC VULNERABILITY RAPID assessment capacity in
  • 简介:Thethermalshockproblemsinvolvedwithfractionalordergeneralizedtheoryisstudiedbyananalyticalmethod.TheasymptoticsolutionsforthermalresponsesinducedbytransientthermalshockarederivedbymeansofthelimittheoremofLaplacetransform.Aninfinitesolidwithacylindricalcavitysubjectedtoathermalshockatitsinnerboundaryisstudied.Thepropagationofthermalwaveandthermalelasticwave,aswellasthedistributionsofdisplacement,temperatureandstressesareobtainedfromtheseasymptoticsolutions.Theinvestigationontheeffectoffractionalorderparameteronthepropagationoftwowavesisalsoconducted.

  • 标签: 分数阶 圆柱形 弹性行为 弹性介质 冲击问题 极限定理
  • 简介:WereportontheexperimentalrealizationofCerenkovsum-frequencygenerationacrossthematerialdispersioninaone-dimensional,periodicallypoledferroelectriccrystal.Threeschemesofsum-frequencygeneration,confinedonlyinthevicinityofdomainwallsandintheformofnonlinearCerenkovradiation,aredemonstratedinnormal,degenerated,andanomalous-dispersion-likeconfigurations.Weexploittheirphase-matchinggeometries,whichexhibitawholescenariooftheevolutionofCerenkovradiationvaryingwiththedispersionrelationshipamongtheinteractionwaves.Inaddition,twosetsofconicalsum-frequencygenerationwithdifferentradiusandcenteraredemonstrated,whichresultfromscatteringassistantphase-matchingprocesses.

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  • 简介:BackgroundPrematureventricularcontractions(PVCs)arefrequentlyseeninchildren.However,therearelesssystematicandlongerfollowing-upstudiesexaminingtheprognosisofPVCsinchildren.TheaimofthisstudywastoevaluatethemediumtolongtermprognosisofPVCsinchildhoodandwhetherthereisadifferentialprognosisindifferentprimarydiseasesofPVCs.MethodsThisstudyreviewedthedataof106pediatricpatients(49F/57M,7.5±3.8years)seenattheAffiliatedHospitalofQingdaoUniversitywiththediagnosisofPVCsbetween1999and2005.Dataondemographics,clinicalpresentation,laboratorytests,andechocardiogramsofpatientswereextractedfromtheavailableclinicalrecords.ResultsAtotalof35(33.0%)childrenpresentedwithPVCsduetomyocarditis,7(6.6%)duetocardiomyopathies,7(6.6%)duetomitralvalveprolapse(MVP),10(9.4%)duetooperationforcongenitalheartdisease(O-CHD),16(15.2%)duetoleftventricularfalsetendons(LVFT),and31(29.2%)duetounknowncause.HolterdidnotshowPVCsduringfollow-upperiodin100%ofmyocarditispatients,57%ofcardiomyopathypatients,71%ofMVPpatients,60%ofO-CHDpatients,88%ofLVFTpatients,87%ofunknowncausepatients.ThePVCsdisappearedin93%ofpatientswhodidnotuseanti-arrhythmicdrugsandin76%ofpatientswhousedantiarrhythmicdrugs.Therewasnoasignificantdifferenceinprognosisbetweenmyocardialnutritioncombinedwithintravenousinjectionofimmunoglobulin(IVIG)groupandpropafenonegroup.ConclusionsPVCscausedbydifferentprimarydiseaseshasafavorableprognosisinchildren.Usually,thePVCswillreduceevendisappearduringfollow-up.ThepatientswithPVCsduetomyocarditisshouldbepreferredusemyocardialnutrientcombinedwithIVIG.

  • 标签: 预后 室性 随访 PVCs 抗心律失常 先天性心脏病
  • 简介:ThisworkprovidesacomprehensivetheoreticalanalysisofMHDunsteadyfreeconvectionviscoelasticfluidflowthroughaporousmedium.Themediumistreatedasincompressibleandopticallytransparent.Theflowofthefluidisinitiatedbyshearingactionofthemovingwallwithtimedependentsuction.Radiativeheatflowisconsideredintemperatureequation.Thecouplednonlinearproblemhasbeensolvedasymptotically.Approximatesolutionshavebeenobtainedforthemeanvelocity,meantemperatureusingmultiparameterperturbationtechnique.Theoriginalityofthepresentstudyistoinvestigatetheeffectofviscoelasticpropertyofthefluid(WaltersB?model)ontheflowandheattransferphenomenawhentheflowispermeatedthroughaporousmediumwithuniformporousmatrixsubjecttotransversemagneticfieldandtimedependentfluctuativesuctionattheboundarysurface.Thecaseofviscousflowhasbeendiscussedasaparticularcaseoncomparisonwiththeresultreportedearlieranditisingoodagreement.Flowreversalisindicatedincaseofviscoelasticfluidwithhighheatcapacityinthepresenceofmagneticfield.Thehighercoolingoftheplateincaseofviscoelasticflowalsocausesaflowreversal.

  • 标签: 粘弹性流体 时间依赖性 流体流动 多孔介质 平行板 无限大