简介：Ｔｈｒｅｅ　ｄｉｍｅｎｓｉｏｎａｌ　ｖｅｌｏｃｉｔｙ　ｓｔｒｕｃｔｕｒｅ　ｂｅｎｅａｔｈ　ｔｈｅ　Ｋｕｎｍｉｎｇ　Ｔｅｌｅｍｅｔｅｒｅｄ　Ｓｅｉｓｍｉｃ　Ｎｅｔｗｏｒｋ（王椿镛）（王溪莉）（颜其中）Ｔｈｒｅｅｄｉｍｅｎｓｉｏｎａｌｖｅｌｏｃｉｔｙｓｔ...

简介：Focusingonobstacleavoidanceinthree-dimensionalspaceforunmannedaerialvehicle(UAV),thedirectobstacleavoidancemethodindynamicspacebasedonthree-dimensionalvelocityobstaclesphericalcapisproposed,whichquantifiestheinfluenceofthreateningobstaclesthroughvelocityobstaclesphericalcapparameters.Inaddition,theobstacleavoidanceschemesofanypointonthecriticalcurveduringthemulti-obstaclesavoidancearegiven.Throughprediction,theinsertionpointfortheobstacleavoidancecanbeobtainedandtheflightpathcanbereplanned.TakingthePythagoreanHodograph(PH)curvetrajectoryre-planningasanexample,thethree-dimensionaldirectobstacleavoidancemethodindynamicspaceistested.Simulationresultsshowthattheproposedmethodcanrealizetheonlineobstacleavoidancetrajectoryre-planning,whichincreasestheflexibilityofobstacleavoidancegreatly.

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简介：这份报纸处理坡度关于一个可变度量标准在被拿的一个抽象周期的坡度系统。我们经由一条全球反的定理的申请获得存在和唯一结果。

简介：作为在许多设计应用程序的一个基本问题，到骚乱的从laminar的转变在计算液体动力学(CFD)仍然是一个困难的问题。一过渡流动在的数字研究二维被雷纳兹进行在这份报纸的平均数字模拟(RANS)。骚乱模型戏在复杂流动模拟的一个重要角色，和四个先进骚乱模型被评估。摩擦抵抗系数的数字答案与在过渡地区的测量那个相比，它显示有修正的那个威尔科克斯(2006)k-模型是最好的候选人。平均无尺寸的速度介绍的streamwise的无尺寸的速度表演的数字、分析的解决方案的比较在过渡区域很快改正形状。而且，象骚乱动能，旋涡粘性，和雷纳兹应力那样的骚乱数量也被学习，它是有用的学习转变行为。

简介：Inthispaper,weinvestigateexcitedcharacteristicoftheweaklyinteractingquasi-one-dimensional(1D)andquasi-two-dimensional(2D)Bose–Einsteincondensation(BEC)inharmonicpotentialtrap.Theenergyspectrumandtheanalyticalexpressionofthesoundvelocityareobtainedandanalyzed.Comparedwith3-DimensionalhomogeneousBose-condensedgasoccasion,thesoundvelocityof2DBose-Einsteincondensationinharmonicpotentialtrapissmaller.

简介：ExperimentsontheNationalIgnitionFacilityshowthatmulti-dimensionaleffectscurrentlydominatetheimplosionperformance.Lowmodeimplosionsymmetryandhydrodynamicinstabilitiesseededbycapsulemountingfeaturesappeartobetwokeylimitingfactorsforimplosionperformance.Onereasonthesefactorshavealargeimpactontheperformanceofinertialconfinementfusionimplosionsisthehighconvergencerequiredtoachievehighfusiongains.Totackletheseproblems,apredictableimplosionplatformisneededmeaningexperimentsmusttrade-offhighgainforperformance.LANLhasadoptedthreemainapproachestodevelopaone-dimensional(1D)implosionplatformwhere1Dmeansmeasuredyieldoverthe1Dcleancalculation.Ahighadiabat,lowconvergenceplatformisbeingdevelopedusingberylliumcapsulesenablinglargercase-to-capsuleratiostoimprovesymmetry.Thesecondapproachisliquidfuellayersusingwettedfoamtargets.Withliquidfuellayers,theimplosionconvergencecanbecontrolledviatheinitialvaporpressuresetbythetargetfieldingtemperature.Thelastmethodisdoubleshelltargets.Fordoubleshells,thesmallerinnershellhousestheDTfuelandtheconvergenceofthiscavityisrelativelysmallcomparedtohotspotignition.However,doubleshelltargetshaveadifferentsetoftrade-offversusadvantages.Detailsforeachoftheseapproachesaredescribed.

简介：Threekindsofmathematicalmodelsrepresentingweldingheatsourcesarepresented.Amongthem,Gaussianmodelanddoubleellipsoidalmodelareusedtoanalyzethethermaldistributionswithfiniteelementmethod.Atthesametime,thispaperanalyzedtheinfluencesoftheheatsourcemodels,thelatentheatandtheweldingparametersonthetemperaturedistributions.Thecomparisonsbetweenthesimulatedresultsandtheexperimentsshowdoubleellipsoidalmodelisgoodforthree-dimensionalnumericalsimulations.Furthermore,theadaptivemeshtechniqueisappliedinthethree-dimensionalmodelwhichgreatlyreducesthenumberofnodesandelementsinthesimulation.

简介：Itiswellknownthatopticaltomographycanaccuratelyandquantitativelyre-constructtherefractiveindexfieldofatransparentmediumanddisplaythethreedimensionalimageofotherthysicalquantitiesrelevanttotemperatureordensity.Inthispaper.anewmultidirectionalholographicinterferometricsystemisbuilt,andtwokindsofimagetecon-structionalgoritmaareintroducedandanautomaticimageprocessingsystemofinterfero-gramisdesigned.Athreedimentsionalasymmetricgadflowfieldaboveacombustorisexperi-mentallyinvestigatedwithholographicinterferormetry.Thereconstructedtemperaturesaresimilartothosemeasuredwithathermocouple.

简介：Three-dimensionaledgecracksareanalyzedusingtheSelf-SimilarCrackExpansion(SSCE)methodwithaboundaryintegralequationtechnique.TheboundaryintegralequationsforsurfacecracksinahalfspacearepresentedbasedonahalfspaceGreen’sfunction(Mindlin,1936).ByusingtheSSCEmethod,thestressintensityfactorsaredeterminedbythecrack-openingdisplacementoverthecracksurface.Indiscreteboundaryintegralequations,theregularandsingularintegralsonthecracksur-faceelementsareevaluatedbyananalyticalmethod,andtheclosedformexpressionsoftheintegralsaregivenforsubsurfacecracksandedgecrakcs.Thisgloballynumericalandlocallyanalyticalmethodim-provesthesolutionaccuracyandcomputationaleffort.Numericalresultsforedgecracksundertensileloadingwithvariousgeometries,suchasrectangularcracks,ellipticalcracks,andsemi-circularcracks,arepresentedusingtheSSCEmethod.Resultsforstressintensityfactorsofthosesurfacebreakingcracksareingoodagreementwithothernumericalandanalyticalsolutions.

简介：Wepresentaninexpensivetechniquetoobtainathree-dimensional(3D)millimeterwave(MMW)andterahertz(THz)imageusingupconversion.InthisworkwedescribeanddemonstrateamethodforupconversionofMMW/THzradiationtothevisualbandusingaveryinexpensiveminiatureglowdischargedetector(GDD)andasiliconphotodetector.WepresentMMW/THzupconversionimagesbasedonmeasuringthevisuallightemittingfromtheGDDratherthanitselectricalcurrent.Theresultsshowbetterresponsetimeandbettersensitivitycomparedtotheelectronicdetectionperformedpreviously.Furthermore,inthisworkweperformfrequencymodulationcontinuouswave(FMCW)radardetectionbasedonthismethodusingaGDDlamp,withaphotodetectortomeasureGDDlightemission.ByusingFMCWdetection,therangeinadditiontotheintensityateachpixelcanbeobtained,thusyieldingthe3Dimage.TheGDDactsasaheterodynemixernotonlyelectronicallybutalsooptically.Thesuggested3DupconversiontechniqueusingtheGDDissimpleandinexpensiveandhasbetterperformancecomparedtootherMMW/THzimagingsystemssuggestedintheliterature.Thismethodprovidesminimumdetectablesignalpowerthatisabout6ordersofmagnitudebetterthansimilarplasmasystemsduetotheverylargeinternalsignalgainderivingfromthemuchsmallerelectrodeseparationandresultinginmuchhigherplasmaelectricfield.

简介：ThispaperpresentsanewandsimpleschemetodescribetheconvexhullinR^d,whichonlyusesthreekindsofthefacesoftheconvexhull.i.e.,thed-1-faces,d-2-facesand0-faces.Thus,wedevelopandefficientnewalgorithmforconstructingtheconvexhullofafinitesetofpointsincrementally.Thisalgorithmemploysmuchlessstorageandtimethanthatofthepreviously-existingapproaches.Theanalysisoftherunniingtimeaswellasthestorageforthenewalgorithmisalsotheoreticallymade.Thealgorithmisoptimalintheworstcaseforevend.

简介：ＤＹＮＡＭＩＣＡＬＢＥＨＡＶＩＯＲＳＦＯＲＡＴＨＲＥＥ－ＤＩＭＥＮＳＩＯＮＡＬＤＩＦＦＥＲＥＮＴＩＡＬＥＱＵＡＴＩＯＮＩＮＣＨＥＭＩＣＡＬＳＹＳＴＥＭＬＩＮＹＩＰＩＮＧ（ＳｅｃｔｉｏｎｏｆＭａｔｈｅｍａｔｉｃｓ，ＫｕｎｍｉｎｇＩｎｓｔｉｔｕｔｅｏｆＴ...

简介：Theartificialboundarymethodisappliedtosolvethree-dimensionalexteriorproblems.Twokindofrotatingellipsoidsarechosenastheartificialboundariesandtheexactarti-ficialboundaryconditionsarederivedexplicitlyintermsofaninfiniteseries.Thenthewell-posednessofthecoupledvariationalproblemisobtained.Itisfoundthaterroresti-matesderiveddependonthemeshsize,truncationtermandthelocationoftheartificialboundary.Threenumericalexamplesarepresentedtodemonstratetheeffectivenessandaccuracyoftheproposedmethod.

简介：Apiezoelectricaccelerometerwithopticalfibertomeasurethedynamicparameterof3dimensionsispresented.TheoperationequationsonX,YandZaxesaredivided,andthetestresultsof3dimensionalsensitivitiesandfrequencyresponse,aregivenaswellasexperimentresultsofvibrationtestwiththissetup.

简介：这份报纸发源维的分析的讨论并且在有磁力地帮助的使流体化的床上可伸缩。进程变量的基本检查，合并机械、磁性的单位，允许变量的混合集合的变换直到作为贡献帮助使液化行为的领域的效果代表表面力量的统一术语。自从新变量都是由三个基本领域产生的典型压力，这转变被称为压力变换：严肃，磁性并且液体流动。这条途径以无尺寸的组而非对古典维的分析恰当的正式代数学的操作探讨物理基础。基本的无尺寸的组称为小粒的磁性的邦德数字作为严肃并且磁场的典型压力的比率被介绍。这分析也提供描绘磁场的一套命名无尺寸的数字帮助使液化象Filippov数字，Rosensweig数字，Kwauk数字和Siegell数字那样，作为典型压力的比率发源。

简介：为在调查的飘动的plateare附近的二维的流动的水动力学特征。在大雷纳兹数字近似下面，流动被假定是combinationof外部潜在的流动和薄旋涡层，它由边界层和shedfree组成砍层。为描述外部不稳定的potentialflow的非线性的数学明确的表达结合了一个不稳定的边界层方程为内部粘滞邻近thewaving板的流动被开发。有在thetrailing边强加的一个非线性的Kutta条件的一个半分析的方法被用来解决外部流动和进化的速度领域由一个大振幅的飘动盘子弄醒vortexinduced。不稳定的边界层方程是解决的byextendingPohlhausen“s方法到它的不稳定的对应物。戳并且粘滞拖系数，推进的效率，和模式醒来旋涡表被讨论。

简介：Themassflowrateofagranularflowthroughanapertureundergravityisalong-standingchallengeissueinphysicalscience.Weshowthatforsteadyflowfieldclosetolaminarflow,thedynamicalequationstogetherwiththecontinueequationandMohr-circledescriptionofthestressareclosed,andhencesolvable.Inacaseofstreamlineguidedbythetwo-dimensionalhopper,weobtainaconsistentconditionanduseittodeterminethestressandthevelocitydistribution.Ourresultindicatesthat3/2powerscalingbehaviorisrecoveredwithacoefficientC(μ,α)beingafunctionoffrictionalcoefficientandthehopperangle.ItisfoundthatthepredictedcoefficientC(μ,α)iscompatiblewithpreviousstudies.

简介：Inthepast,thepseudo-staticmethodusedtobethemostcommonforevaluatingthestabilityoflandslidesunderseismicloads,inwhichstaticforcesactingonthecenterofgravityofaslidingbodyareusedtoconsidertheeffectsofearthquake.However,seismicloadsofrockandsoildifferfromtimeandlocationtotimeandlocation.Obviously,itisirrationalforthepseudo-staticapproachtobeappliedtosolvingdynamicproblems.Inthispaper,adisplacementpseudo-dynamicmodelisproposedtoassessseismicstabilityoflandslides,inwhichthesinusoidalcosinusoidalwaveisappliedtosimulatingearthquakedisplacement,andan'amplificationfactor'ofpeakseismicdisplacementisreferredtoastheamplificationofseismicwavewhenitpropagatesfromthebottomtothetopofthelandslide.Theeffectsofphysico-mechanicalbehaviorsofaslidingbodyonseismicstabilityofsoilslopesaretakenintoaccountaswellasinertiaforcesanddampingforces.Thesensitivityanalysesonthepermanentdisplacementandthedynamicfactorofsafetyoflandslidesarestudiedindetail.Moreover,alarge-scaleTangjiashanlandslidethatoccurredinWenchuanearthquakeisinvestigatedtoverifytherobustnessandprecisionofthepresentmethod.Itisfoundthattheresultsfromthepresentmethodisingoodagreementwiththosefromthepreviousmethod.

简介：Thispaperisconcernedwiththenumericalsimulationoftheinjectionmoldfillingprocess.AmathematicalmodelbasedongeneralizedHele-Shawflowforaninelasticnon-Newtonianfluidundernonisothermalconditionsisused.Ahybridnumericalschemeisemployed.Thenumericalsimulatingre-sults,pressureandtemperatureprofile,locationofthemeltfronts,areinagoodagreementwiththeex-perimentalones.