简介:3D技术是虚拟现实、实时仿真和交互三维设计结合产生的关键技术,包括3D显示技术、3D虚拟现实技术和3D打印技术。目前3D技术已成为桌面技术(3D显示技术和3D虚拟现实技术为桌面显示技术,3D打印技术为桌面制造技术),正逐渐在知识创新、深度学习、虚拟实验、技能训练等方面彰显优势,为教育应用创新提供新环境、新平台、新资源、新工具和新范式。然而由于产品价格较为昂贵,后续的保养、管理及维修等费用也较高,3D技术教育应用在顶层设计、技术支持、教育资源、测评标准、应用领域、人才培养等方面仍面临较多困难。3D技术教育应用是一个教育生态系统,是依托3D技术、资源、工具、平台、产品、人才和课程,构建教学资源、教学媒体和教学产品的设计、开发、运用、管理和评价的教育系统,需要进行理论、技术与应用的协同推进,从生态发展、产业推进、深度融合视角开展研究。在落实《教育信息化十年发展规划(2011-2020年)》之际,应将"3D技术教育应用创新"作为技术与教育"深度融合"的重要途径,构建3D教育应用生态系统环境,促进教学方式与学习方式变革,以此应对第三次工业革命带来的机遇和挑战。
简介:摘要:细胞3D打印技术是在3D打印的基础上, 以活细胞为原料结合生物材料、生命体材料的拓展延伸, 打印活体组织与器官的一种技术。这种技术以计算机三维模型为基础, 通过离散堆积的方法, 将生物材料或细胞按仿生形态、生物体功能、细胞特定微环境等要求, 用增材制造法打印出同时具有复杂结构与功能的生物三维结构、体外三维生物功能体等生物医学产品, 在骨骼、皮肤、血管、心脏、肾脏、肝脏等组织等再生与重建、药物筛选等领域具有广阔的应用前景。下面将对于现阶段3D细胞打印技术做一综述。
简介:Thebovinehydroxyapatite(BHA)wasappliedtopreparebiologicaltissueengineeringscaffoldsbythemethodofextrusionfreeforming.Toachievethisgoal,BHAwereaddedtosodiumalginate(SA)solutiontoformaslurrysysteminappropriateproportion.Theresultingmixtureswerefabricatedtobeakindofcontrollableandporousscaffoldsfollowedwithcross-linkingin5%calciumchloride(CaCl2)solutionfor24h.Afterthat,thescaffoldsweresinteredinairat1000,1100,1200and1300℃for5h.Scanningelectronmicroscopy(SEM)andX-raydiffraction(XRD)studieswereperformedonthescaffoldstoanalyzeitsmicrostructureandconstituent.Toexploretheeffectofsinteringtemperatureonscaffolds,thecompressivestrength,volumeshrinkageandwaterabsorptivityofBHA-SAcompositescaffoldsaftersinteringwereinvestigated.TheresearchtestsindicatedthefeasibilityofapplyingBHApowderto3Dprinting.Besides,thescaffoldssinteredinarespectivelylowertemperaturepossessmuchmoreporesandperformedhigherwaterabsorptivity,whichmeansbettercellularaffinity.Andscaffoldssinteredbetween1100and1200℃presentshighercompressivestrength.
简介:Theconventionalpseudo-staticapproachoftenneglectstheeffectoftheverticalseismicaccelerationonthestabilityofaslope,butsomeanalysesunderplane-strain(2D)conditionsshowasignificanteffectontheslopestability.Thepurposeofthisstudyistoinvestigatetheeffectoftheverticalaccelerationonthesafetyofthree-dimensional(3D)slopes.Inthestrictframeworkoflimitanalysis,a3Dkinematicallyadmissiblerotationalfailuremechanismisadoptedherefor3Dhomogeneousslopesinfrictional/cohesivesoils.Asetofstabilitychartsispresentedinawiderangeofparametersfor3Dslopesundercombinedhorizontalandverticalseismicloadingconditions.Accountingfortheeffectsoftheverticalseismicacceleration,thedifferenceinsafetyfactorsfor3Dslopescanexceed10%,whichwillsignificantlyoverestimatethesafetyofthe3Dslopes.
简介:Amathematicalmodelforthethree-dimensionalsimulationoffreedendriticgrowthandmicrostructureevolutionwasdevelopedbasedonthegrowthmechanismofcrystalgrainsandbasictransferequationssuchasheat,massandmomentumtransferequations.Manyfactorsincludingconstitutionalundercooling,curvatureundercoolingandanisotropy,whichhadvitalinfluencesonthemicrostructureevolution,wereconsideredinthemodel.SimulatedresultsshowedthatfinalmicrostructuralpatternsandfreedendriticgrowthcouldbepredictedreasonablyandcalculatedresultswerecoincidentwithexperimentalThesimulatedresultsoffreedendriticgrowthindicatedthatthestrengthofanisotropyhassignificanteffectsonfreedendriticgrowth,dendriteprofile,microsoluteandtemperaturedistribution.Thedendriticgrainprofileswithfully-grownparallelsecondaryarmtendtobeformedattheintensiveanisotropy,whilenearoctahedralgrainprofileswithsmallprotuberancesofsurfaceatlowstrengthofanisotropy.Thesimulatedresultsoffreedendriticgrowthalsoindicatedthattherearesmallmoltenpoolsleftininterdendriticareas.Thisishelpfultounderstandthefundamentaloftheformationofmicrostructurerelateddefectssuchasmicrosegregationandmicroporosity.
简介:摘要3D打印技术是当前新兴的一种比较前沿的科学技术,即增材制造。传统制造复杂繁琐、原料的利用率低,并且许多产品的内部复杂工艺无法加工,区别于传统的减削材料的制造方式,增材制造较为简单而高效,不需要繁重、庞大的机床,仅通过三维设计出结构轮廓,堆积叠加即可实现产品的制造,它完全不具有传统制造的这些缺点。3D打印的关键技术在于新材料、计算机辅助与制造。目前该技术受到世界各国、各学术界的高度重视,未来将会大放光彩。