简介：Thisreportdescribesanewmethod,theself-searchingmethod,tofindeigenraysinanoceanwherethereisathree-dimensionalsoundspeedperturbationblobonauniformsoundspeedbackground.Comparedwiththetraditionalshootingmethod,thismethodcanreducethenumberofraycalcula-tionsbyabouttwoordersofmagnitude,andaneigenraycanbefoundbycom-puterprogramwithoutmanualintervention.

简介：在这篇论文，一个转变模型说出SARC(有限制状况的静态过滤器的调整)被介绍，它在理论和试穿更实际、更严密任何旋转角参数。转变过程被划分成4步：①t他原版和目标坐标能与错误被认为是观察；②严密公式第一被推出以便由四个普通的点的使用计算转变参数的第一近似，转变方程被线性化；③由SARC模型④计算七个转变参数的最可能的值和变化表明SARC的有效性，一个例子被给。

简介：Inthispaperareviewoncurrentresearchon3DCMispresented,andanalternativeapproachbyintegratingtheconceptsandtechniquesofobject-orientedmethodandComputerAidedDesign(CAD)issuggested.Throughtheapproachurbanspatialentitiesasobjectsareextracted,whicharerepresentedwithprimary3Delements(node,edge,faceandbody)andtheircombinations.Inthelightoftheconceptofobject,themethodsupportsthemultiplerepresentationofLevelofDetails(LOD).Moreimportantly,topologicalrelationshipsbetweenobjectsaredescribedsothat3Dtopologicaloperationscanbeimplemented.

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简介：在这份报纸，我们与不可压缩的条件为3DMHD方程的答案考虑整齐标准。由使用一些古典不平等，我们分别地以速度地和磁场的一个部件在某些足够的条件下面获得三维的MHD方程的强壮的答案的整齐。

简介：Afinite-ratemethodisusedtosimulatethethree-dimensionalcombustionprocessinaplasmageneratorwithCH4asthefuel.ThesimulationwasrunwithRNGk-εmodeltosimulateturbulence,witheddy-dissipation-concept(EDC)modeltosimulatethecombustionandwithdiscreteordinatesmodeltosimulateradiation.Thenumericalresultsshowthattheflowfieldcharacteristicsandtheparameterdistributionsareundertheconditionofrichfuels,andtheseresultsprovidevaluableinformationwhenoptimizingtheplasmageneratordesignandorganizingitsflowfields.

简介：Considerathree-dimensionalsystemhavinganinvariantsurface.Byusingbifurcationtechniquesandanalyzingthesolutionsofbifurcationequations,theauthorsstudythespacialbifurcationphenomenaofakmultipleclosedorbitintheinvariantsurface.Thesufficientconditionsoftheexistenceofmanyclosedorbitsbifurcatefromthekmultipleclosedorbitareobtained.

简介：AbstractBackground:Hemifacial microsomia (HFM), which involves multiple sites with different levels of severity, is the second most common congenital craniofacial deformity after cleft lip and palate. However, three-dimensional (3D) measurements of mandibular deformities have not yet been studied in detail. The objective of this study is to investigate the method of 3D measurements of mandibular deformities in HFM patients.Methods:A total of 48 HFM patients were included in this study. All clinical treatment for patients was performed in the Plastic Surgery Hospital of the Chinese Academy of Medical Sciences at Peking Union Medical College from June 2006 to June 2020. The patients’ 3D computerized tomography scan data were processed using medical imaging software, following four iterative steps: 3D reconstruction, mirroring, differential analysis, and partition.Results:The characteristics of the mandibular bone in HFM patients are mainly presented as follows: (1) compared to the normal side, the part of the bone body that extends from the ascending ramus to the pogonion (Po-NB) is analyzed using a dynamic process: less fullness-fullness-more fullness; (2) absences were frequently observed among the angular zones, that is, the height of the ascending ramus is deficient.Conclusions:HFM is a complicated condition with numerous variations in clinical presentation. We employed both 3D image reconstruction and computerization image processing techniques to investigate asymmetrical mandibular deformity in HFM patients in detail and with great accuracy. This will be of great use to clinicians for disease management.

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简介：Thedynamicstressintensityfactorofathree-dimensionalellipticcrackunderimpactloadingisdeterminedwiththefiniteelementmethod.Thecomputationresultscantakeintoaccounttheinfluenceoftimeandtheratioofthewavespeedsonthestressintensityfactor.Thepresentmethodissuitablenotonlyforthree-dimensionaldynamiccrack,butalsoforthree-dimensionaldynamiccontact.

简介：Thispaperinvestigatestheproblemofmodelingandcontrollingpursuerconvoyinthree-dimensionalspace.Theguidancelawsappliedforconvoy,thevelocitypursuit,thedeviatedpursuitandtheproportionalnavigation,steerthepursuerusingtherateofline-of-sight（LOS）betweensuccessivepursuers.Onthebasisofthedifferentialequationsfortherange,thepitchangleofLOSandtheyawangleofLOSbetweensuccessivepursuers,theguidancelawsareproposedtoderivedecentralizedcontrolstrategyforpursuerconvoy.Theresultsconcerningthepursuerconvoyarerigorouslyproven.Simulationsareconductedtodemonstratethefeasibilityandeffectivenessoftheproposedcontrolstrategy.

简介：TheauthorsdefinetheGaussmapofsurfacesinthethree-dimensionalHeisenberggroupandgivearepresentationformulaforsurfacesofprescribedmeancurvature.Furthermore,asecondorderpartialdifferentialequationfortheGaussmapisobtained,anditisshownthatthisequationisthecompleteintegrabilityconditionoftherepresentation.

简介：ＴＨＲＥＥ－ＤＩＭＥＮＳＩＯＮＡＬＭＯＤＥＬＬＩＮＧＦＯＲＬＵＢＲＩＣＡＴＩＯＮＷＩＴＨＲＥＦＥＲＥＮＣＥＴＯＨＵＭＡＮＪＯＩＮＴＳＺｈａｎＪｉｅ－ｍｉｎ（ＤｅｐａｒｔｍｅｎｔｏｆＡｐｐｌｉｅｄＭｅｃｈａｎｉｃｓａｎｄＥｎｇｉｎｅｅｒｉｎｇ，Ｚｈｏｎ...

简介：新奇木柴堆格子结构被建议。把方法基于飞机波浪扩大(PWE)，新奇木柴堆的完全的photonic乐队差距(PBG)三维(3D)有减少的对称相对的兆兆赫(THz)photonic水晶(PC)一，face-centred-tetragonal(fct)对称被改变一些结构的参数优化，thehighest乐队差距比率能到达27.61%。比作传统的木柴堆格子，novelwoodpile格子有大量充满获得高质量的PBG的比率，哪个为生产过程的providesgreater便利。新奇木柴堆3DPC将是很THz功能的部件的promisingfor材料。

简介：AbstractPurpose:Secondary displacement represents a frequent complication of conservative treatment of fractures, particularly of the distal radius. The gap space between skin and cast may lead to a certain degree movements and this increased mobility might favor redisplacement. The aim of this study was to develop a new 3D method, to measure the gap space in all 3 geometrical planes, and to validate this new technique in a clinical setting of distal radius fractures.Methods:This study applies 3D imaging to measure the space between plaster and skin as a potential factor of secondary displacement and therefore the failure of conservative treatment. We developed and validated a new methodology to analyze and compare different forearm casts made of plaster of Paris and fiberglass. An unpaired t-test was performed to document differences between the investigated parameters between plaster of Paris and fiberglass casts. The significance level was set at p< 0.05.Results:In a series of 15 cases, we found the width of the gap space to average 4 mm, being slightly inferior on the radial side. Comparing the two different casting materials, plaster of Paris and fiberglass, we found a significantly larger variance of space under casts made of the first material (p=0.39). A roughness analysis showed also a markedly significantly higher irregularity of the undersurface of plaster of Paris as compared with fiberglass.Conclusion:This study allows for a better understanding of the nature of the "gap space" between cast and skin and will contribute to develop and improve new immobilization techniques and materials.

简介：Anewmethodformeasuring3-Drigidbodydisplacementsisproposed,inwhichtwoperpendicularbeamsareemittedontotwosensitiveplanesofPSDsleingperpendiculartoeachother.Themethodcanbeusedtomeasure1-Dor2-Ddisplacementswhenrequired.Moreover,theexperimentalresultsarepresented,whichdemonstratethatthenewmethodhashighaccuracy,fastprocessingspeed,highreliability,andeasilybeingrealized.

简介：Avortexringimpingingonathree-dimensionalbumpisstudiedusinglargeeddysimulationforaReynoldsnumberRe=4×104basedontheinitialtranslationspeedanddiameterofthevortexring.Theeffectsofbumpheightonthevorticalflowphenomenaandtheunderlyingphysicalmechanismsareinvestigated.Basedontheanalysisoftheevolutionofvorticalstructures,twotypicalkindsofvorticalstructures,i.e.,thewrappingvorticesandthehair-pinvortices,areidentifiedandplayanimportantroleintheflowstateevolution.Thecirculationoftheprimaryvortexringreasonablyelucidatessometypicalphasesofflowevolution.Furthermore,themechanismofflowtransitionfromlaminartoturbulentstatehasbeenrevealedbasedonanalysisofturbulentkineticenergy.

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简介：我们调查了之间的差别同温层(S类型)并且在intraseasonal时间的tropospheric(T类型)北极摆动(AO)事件可伸缩，以他们对表面空气温度的影响(坐)在北半球和与他们的空间结构联系的动态特征上。S类型AO事件证明一个平流层对流层联合了结构，当T类型事件展出了一个平流层对流层时解开的结构。在北半球上的环形的容纳的异例被发现与S类型AO事件被联系，而如此的一个环形的特征是实质地在T类型AO事件的destructed。在二种类型的对流层的不同水平结构能主要被归因于强迫的短暂旋涡反馈。至于Ttype事件的垂直地解开的结构，把他们区分开来与S类型事件的内在的动态特征在地带地限制的Rossby波浪的垂直繁殖躺着。在T类型事件，在一垂直波导存在的地方，地带地限制的Rossby波浪包能在东北亚洲上从重要高度异例发出，然后向上宣传进平流层。相反，如此的垂直繁殖不为S类型事件是明显的。在T类型事件从对流层与地带地限制的Rossby波浪的向上的注射联系的同温层的异例能进一步通过在climatological想PW和异常PW之间的干扰导致行星的波浪(PW)的异常垂直繁殖，导致最后的平流层对流层T类型事件的解开的结构。

简介：3-DS-waveQstructureinJiashiearthquakeregionisinvertedbasedontheattenuationofseismicwavesrecordedfromearthquakesinthisregionin1998bytheResearchCenterofExplorationGeophysics(RCEG),CSB,andaroughconfigurationofdeepcrustalfaultsintheearthquakeregionispresented.First,amplitudespectraofS-wavesareextractedfrom450carefully-chosenearthquakerecords,calledobservedamplitudespectra.Then,afterinstru-mentalandsiteeffectcorrection,theoreticalamplitudespectraaremadetofitobservedamplitudespectrawithnonlineardampedleast-squaresmethodtogettheobservedtraveltimeoverQ,providedthatearthquakesourcesconformtoBrune￠sdiskdislocationmodel.Finally,by3-Draytracingmethod,theoreticaltraveltimeoverQismadetofitobservedtraveltimeoverQwithnonlineardampedleast-squaresmethod.Inthecourseoffitting,thevelocitymodel,whichisobtainedby3-Dtraveltimetomography,remainsunchanged,whileonlyQmodelismodified.Whenfittingcametothegivenaccuracy,theultimateQmodelisobtained.TheresultshowsthatanNE-trendinglowQzoneexistsatthedepthsof10~18km,andanNW-trendinglowQzoneexistsatthedepthsof12~18km.TheseroughlycoincidewiththeNE-trendingandtheNW-trendinglowvelocityzonesrevealedbyotherscientists.ThedifferenceisthatthelowQzoneshaveawiderrangethanthelowvelocityzones.