简介:3DstructuralreconstructionofMohointheTangshanearthquakeareabyusinginversionofcurvedinterfaceXIAOLINGLAI(赖晓玲)XIANKANGZHANG...
简介:3Dstructureofthecrustanduppermantleinthestudiedareahasbeenanalyzedfromsurfacewavetomography.Thevelocitydistributionintheuppermostcrustissymmetricalontwosidesofthecentrallineofthesea,andcoincideswiththestructureofcrystallinebasement.TheessentialdifferenceintectonicsbetweentheEastChinaSeaandtheYellowSeamainlyliesinthatthevelocitystructuresoftheirlowercrustanduppermantleareidenticaltothoseofSouthChinaandNorthChinarespectively.Intheuppermantlethereexistsahigh-velocityzonewithanearlyEWstrikefromtheHangzhouBay,China,totheTokaraChannel,Japan,alongaboutthelatitudeof30°N.ItisfoundthatbetweentheEastChinaSeaandtheYellowSeatherearesystematicaldifferencesingeomorphology,geology,seismicity,heatflow,qualityfactorandgravityandaeromagneticanomalies,whichisrelatedtobothleft-lateralsheardislocationandright-lateraltearoftheBenioffzonefromtheHangzhouBaytotheTokaraChannel.ItisinferredthattheEastChinaSeawasformedbyCenozoicback-arcextension.TheboundarybetweentheNorthChinaandSouthChinacrustalblocksstretchesalongthesouthernpiedmontofMts.Daba-Dabie-HangzhouBay-TokaraChannel,andthesubductionzoneattheOkinawatrenchistheeasternboundaryoftheSouthChinacrustalblock.ThemovementsofthePacificplate,IndianplateanduppermantleratherthanthePhilippineplatesubductionhaveplayedadominantroleforthemoderntectonicmovementsinEastAsia.
简介:摘要:在相关研究的基础上归纳总结了建筑3D打印胶凝材料的工程性能,包括可打印性、力学性能等,其中,可打印性包括流动性、可挤出性、可建造性、凝结时间、一次打印长度、挤出形态质量等;力学性能包括抗折强度与抗压强度。此外,选取可打印性与力学性能所包含的指标作为影响因子,利用层次分析法确定了因子权重,提出了因子赋值标准及评价结果分级标准,建立了建筑3D打印胶凝材料的工程性能评价体系,并设计正交试验计算性能指标值,对材料的工程性能进行了评价,可为3D打印胶凝材料工程性能相关研究提供参考。
简介:摘要:随着技术深化发展, HXD3D型电力机车应运而生,具备多样化优势特征,但在运用中呈现一些问题。因此,本文多层次客观分析了 HXD3D型电力机车及其运用问题,提出了一些行之有效的改进措施,在改进、优化的基础上促使 HXD3D型电力机车在实际运用中安全、稳定以及经济运行。
简介:3D地震波走时计算是偏移、反偏移、层析等诸多地震勘探技术中的重要中间步骤。快速推进法计算3D地震波走时具有高效率、稳定性及适应能力强的特点,但快速推进法在震源附近区域的计算精度不高,降低了整个走时算法的计算精度。本文提出了一种联合3D走时计算方法来解决这一问题。该方法在震源附近小范围内使用计算精度较高的波前构建法计算走时,在剩余区域使用快速推进法计算走时,由于模型中绝大多数网格节点走时是通过快速推进法计算的,故新方法保留了快速推进法高效的特点,同时由于震源附近网格节点走时精度的提高,整个新算法的计算精度相对于快速推进法而言有了较大的改善。文中通过数值分析对上述结论进行了验证并使用三维岩丘模型验证了新方法的稳定性和适应能力。
简介:NonhydrostaticmesoscaleWRFandits3D-Varsystemareusedtostudyadensefogeventoccurringin13-14January2006.ThreedifferentobservationdatasetsincludingGTS(GlobalTelecommunicationSystem),AMDAR(AircraftMeteorologicalDataRelay)data,and9210dataareassimilatedintotheinitialanalysisfieldsinexperiments.Experimentswiththreedifferentassimilationtimeintervals(1,3,and6h)arealsocarriedout.Threeexperimentswithdifferentdatasetshaveallmodifiedthetemperatureandhumidityfieldofinitialfields,andthereforeshowanobviouspositiveeffectonfogsimulation.Furtherstudyindicatesthatthehumidityandstabilityofboundarylayerareimprovedobviouslyinassimilationexperiments,althoughdifferentdatasetsmakedifferentcontributiontotheanalysisfields.Themulti-timeassimilationcycleexperimentsshowthattheanalysisincrementinexperimentwith1-hintervalismorerealisticthanthatwith3-and6-hintervals.
简介:BasedonthefirstarrivalPandSdataof4625regionalearthquakesrecordedat174stationsdispersedintheYunnanandSichuanProvinces,the3-Dvelocitystructureofcrustanduppermantleintheregionisdetermined,incorporatingwithpreviousdeepgeophysicaldata.Intheuppercrust,apositiveanomalyvelocityzoneexistsintheSichuanbasin,whereasanegativeanomalyvelocityzoneexistsinthewesternSichuanplateau.TheboundarybetweenthepositiveandnegativeanomalyzonesistheLongmenshanfaultzone.TheimagesoflowercrustanduppermantleintheLongmenshanfault,Xianshuihefault,Honghefaultandothersshowthecharacteristicoftectonicboundary,indicatingthatthefaultslikelypenetratetheMohodiscontinuity.Thenegativevelocityanomaliesatthedepthof50kmintheTengchongvolcanicareaandthePanxitectoniczoneappeartobeassociatedwiththetemperatureandcompositionvariationsintheuppermantle.TheoverallfeaturesofthecrustalandtheuppermantlestructuresintheSichuan-Yunnanregionaretheloweraveragevelocityinbothcrustanduppermostmantle,thelargecrustalthicknessvariations,andtheexistenceofhighconductivitylayerinthecrustor/anduppermantle,andhighergeothermalvalue.AllthesefeaturesarecloselyrelatedtothecollisionbetweentheIndiaandtheAsiaplates.ThecrustalvelocityintheSichuan-Yunnanrhombicblockgenerallyshowsnormalvalueorpositiveanomaly,whilethenegativeanomalyexistsintheareaalongthelargestrike-slipfaultsastheblockboundary.Itisconducivetothecrustalblockside-pressingoutalongthefaults.Inthemajorseismiczones,theseismicityisrelativetothenegativeanomalyvelocity.Moststrongearthquakesoccurredintheupper-midcrustwithpositiveanomalyornormalvelocity,wherethenegativeanomalyzonegenerallyexistsbelow.
简介:Atime-domainmethodisappliedtosimulatenonlinearwavediffractionaroundasurfacepiercing3-Darbitrarybody.ThemethodinvolvestheapplicationofTaylorseriesexpansionsandtheuseofperturbationproceduretoestablishthecorrespondingboundaryvalueproblemswithrespecttoatime-independentfluiddomain.AboundaryelementmethodbasedonB-splineexpansionisusedtocalculatethewavefieldateachtimestep,andthefreesurfaceboundaryconditionissatisfiedtothesecondorderofwavesteepnessbyanumericalintegrationintime.Anartificialdampinglayerisadoptedonthefreesurfacefortheremovalofwavereflectionfromtheouterboundary.Asanillustration,themethodisusedtocomputethesecond-orderwaveforcesandrun-uponasurface-piercingcircularcylinder.Thepresentmethodisfoundtobeaccurate,computationallyefficient,andnumericallystable.
简介:摘要:随着国家和各省市相关政策的大力扶持,装配式建筑、BIM技术应用领域风起浪涌,很多设计和研究单位都开始积极促进新型建筑工业化与信息化、智能化的深度融合。文章对BIM+3D打印技术的装配式建筑进行了研究分析,以供参考。
简介:摘要:和传统打印技术相比,3D打印技术不仅速度更快,而且能够有效满足结构复杂物品的打印要求,另外该技术可以通过应用不同的材料满足不同的打印要求。正是因为该技术具有这些优势所以越来越受人们关注,而且已经在实际生活、生产和学习当中实现了广泛应用。聚合物材料是3D打印材料的一种,而且其应用更加广泛,无论是房屋内部装饰品还是微小电子零部件都可以应用该材料来打印。但是3D打印聚合物材料也存在一些缺陷,如,打印出来的成品强度比较低、打印层之间界面连接性比较差等,为此就要积极寻找提高该材料强度的方法。将纳米材料和该材料进行混合能够有效解决这一问题,基于此,本文对3D打印技术进行了概括总结,对3D打印聚合物纳米复合材料研究现状进行了探究,希望可以为聚合物纳米复合材料3D打印技术的发展提供助力。