简介:Aconoscopicholography-based3Dmeasurementsystemforanalyzingthedefectsonthesurfaceofsteelplateswasintroducedinthispaper.Thehardware,whichisautomatedthroughsoftware,performssamplingofthesteelplatesurface.Throughthesoftwareinterface,point-clouddataofthesteelplatesurfaceareobtainedandreconstructedtoforma3Dimageofthesteelplatesurface.Thesoftwareallowsautomaticanalysisofsteelplatesurfacedefectsthroughidentificationofthebulgesanddepressions.Inaddition,thesoftwarecanalsoautomaticallycalculatethedefectinformation,suchasthedeepestpoint,volume,openingarea,openinglength,andsoon,therebydeterminingthedefectsize.Theresultsdeterminedbythis3Dmeasurementsystemwerefoundtobeingoodagreementwiththeactualvalues.
简介:Anewefficientmeshlessmethodbasedontheelement-freeGalerkinmethodisproposedtoanalyzethestaticdeformationofthinandthickplatestructuresinthispaper.Usingthenew3Dshell-likekinematicsinanalogytothesolid-shellconceptofthefiniteelementmethod,discretizationiscarriedoutbythenodeslocatedontheupperandlowersurfacesofthestructures.Theapproximationofallunknownfieldvariablesiscarriedoutbyusingthemovingleastsquares(MLS)approximationschemeinthein-planedirections,whilethelinearinterpolationisappliedthroughthethicknessdirection.Thus,differentboundaryconditionsaredefinedonlyusingdisplacementsandpenaltymethodisusedtoenforcetheessentialboundaryconditions.TheconstrainedGalerkinweakform,whichincorporatesonlydisplacementdegreesoffreedom(d.o.f.s),isderived.Amodified3Dconstitutiverelationshipisadoptedinordertoavoidoreliminatesomeself-lockingeffects.Thenumericefficiencyoftheproposedmeshlessformulationisillustratedbythenumericexamples.
简介:Thispaperstudiesthree-dimensionaldiffractionofobliquelyincidentplaneSHwavesbytwininfinitelylongcylindricalcavitiesinlayeredporoelastichalf-spaceusingindirectboundaryelementmethod.Theapproachisvalidatedbycomparisonwiththeliterature,andtheeffectsofcavityinterval,incidentfrequency,andboundarydrainageconditiononthediffractionarestudiedthroughnumericalexamples.Itisshownthat,theinteractionbetweentwocavitiesissignificantandsurfacedisplacementpeaksbecomelargewhentwocavitiesareclose,andthesurfacedisplacementmaybesignificantlyamplifiedbytwincavities,andtheinfluencerangewithlargeamplificationcanbeaswideas40timesofthecavityradius.Surfacedisplacementsindryporoelasticcaseandsaturatedporoelasticcaseswithdrainedandundrainedboundariesareevidentlydifferentundercertaincircumstances,andthedifferencesmaybemuchlargerthanthoseinthefree-fieldresponse.
简介:我们对采自墨西哥湾的一个3D野外数据集进行了面向目标的波动方程偏移速度分析(target-orientedwave—equationmigrationvelocityanalysis)。我们并没有采用原始的地表数据集,而是采用了专门针对速率分析而合成的一个新数据集,计算了盐下地层速度。新的数据集是在不聚焦的初始目标图像的基础上,通过一个全新的3D广义Born波场模型而产生的,这个波场模型可以通过模拟零地下偏移域和非零地下偏移域(zeroandnonzerosubsurface—offsetdomain)的图像而较好的保持速度的动力学特征。面向目标的反演方法大幅度减小了3D波动方程偏移速度分析的数据集规模和计算域(computationdomain),并极大地提高了其效率和灵活性。我们用合成的新数据集进行了微分相似性优化Ⅻ睡rentialsemblanceoptimization(DSO)1,以此优化盐下地层速度。改进的速度模型明显增强了盐下地层反射的连续性,并且产生了平滑的角域共成像道集(angle—domaincommon—imagegathers)。
简介:摘要目的观察维生素D3治疗日光性皮炎的临床疗效。方法随机分组,采用肌肉注射维生素D3配合常规治疗30例,与单纯采用常规治疗30例对照观察。结果治疗组中痊愈21例,显效7例,有效2例,愈显率为93.3%;对照组中痊愈15例,显效8例,有效6例,无效1例,愈显率为76.7%。两组愈显率比较有显著差异(x2=4.16,p<0.05)。结论维生素D3治疗日光性皮炎疗效显著。