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500 个结果
  • 简介:在为被动声纳的沿岸的区域的安静目标的察觉和本地化上的主要挑战是复杂声学的繁殖和表面上的大声的轮船干扰的流行。适应的匹配的地处理能提供能力给空表面干扰,而是失配在之间计算并且由于环境无常驾驶向量的实际数组,和目标和干扰的运动能显著地导致数组获得的损失。为了处理环境失配和目标的问题,运动,一个柔韧的运动赔偿算法和一个系统策划因为适应的匹配的地处理被开发了。试验性的数据的数字模拟和分析证明柔韧的AMFP计划能大声压制表面干扰并且改进为在水下的弱移动的性能在复杂的浅水里指向的察觉。

  • 标签: 环境不确定性 被动声纳 水声探测 水声学
  • 简介:AnexperimentalapparatustoinvestigateACMHDpumpwasestablished,whichmainlyconsistsofarotarypermanentmagnetwith4polesanannularchannel,amotor,ashaftandaplatform.Themagnetgeneratesafieldsimilartosinusoidwiththemaximumof0.9TinthechannelwhenitisrotatedupbythemotortosimulateanACmagneticfield.Thismovingmagneticfieldactsontheconductivefluidinthechannel,andproducesanelectromagneticforcetomovethefluidinthesamedirectionasthatofthemagnetrotating.Experimentswerecarriedouttoinvestigatetheperformanceofthepump.Flowvelocityintheannularchannelwasmeasuredfordifferentconductivitiesandrotatingspeedsofthemagnet.Theresultsshowthattheflowrateandpressureincreaseasthemagneticfieldstrength,fluidconductivityandfrequencyofthemagneticfieldincrease.

  • 标签: 流体动力学 水泵 实验研究 施工工程
  • 简介:Theaimofthisexpositionistoprovideadetaileddescriptionoftheuseofcombinatorialalgebrainquantumfieldtheoryintheplanarsetting.ParticularemphasisisplacedontherelationsbetweendifferenttypesofplanarGreen'sfunctions.TheprimaryobjectisaHopfalgebrathatisnaturallydefinedonvariablesrepresentingnon-commutingsources,andwhosecoproductsplitsintotwohalf-coproducts.Thelattergiverisetothenotionofanunshuffiebialgebra.ThissettingallowsadescriptionoftherelationbetweenfullandconnectedplanarGreen'sfunctionstobegivenbysolvingasimplelinearfixedpointequation.Wealsoincludeabriefoutlineoftheconsequencesofourapproachintheframeworkofordinaryquantumfieldtheory.

  • 标签: PLANAR field theory Green's functions free
  • 简介:在一系列最近的报纸[1-4]没有,免费的量地理论怎么能用机械原语被导出,被显示出(包括时空,特殊相关性,量子化规则,等等),但是仅仅考虑包含其相互作用的网络满足unitarity,同质,地区,和isotropy的简单原则的量系统的一个可计算的集合的最容易的量算法。这打开了线路到扩大抽象系统的量子论的公理的信息理论上的推导[5,6]包括量域理论。参考axiomatization的固有的分离性质导致量地理论的延期到量细胞的自动机理论,在平常的地理论在自动机的分离结构不能被探查的政体被恢复的地方。简单启发式的争论给组件的规模到普朗克常数规模的A,和组件不是可见的惯常的物理政体是相对论小wavevectors之一。

  • 标签: 元胞自动机 量子场论 自由 量子场理论 狭义相对论 CAYLEY图
  • 简介:Tostudythepossibilityofdetectingthecrossingchannelbyusingatraditionalloggingtool,acousticfieldgeneratedbyamonopolesourceinacasedwellwithacrossingchannelofvariousanglesissimulatedby2.5-DFiniteDifferenceMethod(FDM).Snapshotsofnormalstressandsynthetictime-domainwaveformsaredisplayed.Thetwo-dimensionalspectruminwave-numberandfrequencydomainsisalsocalculated,wheretheinfluenceofthechannelisclearerthanthatinthewaveforms.Numericalstudydemonstratedthatacrossingchannelcanbedetectedandsizedifitsangleisgreaterthan30degree,andlargerspacingandlowerfrequencysourcearefavorabletodetectandsizethecrossingchannel.

  • 标签: 声场 交叉管 有限微分理论 实轴积分理论 FDM 数值模拟
  • 简介:Tomeettherequirementsfortheaerodynamicperformanceandthrustforcedemandedinhypersonicmissions,theintegrationdesignoffuselageandenginemustbeconsideredforhypersonicvehiclewithascramjetengine.Theconfigurationofwaveriderisatypicalhypersonicvehicleshape,whosefore-bodycancompresstheflowinadvanceandprovideuniformflowfortheairintake,andwhoseaft-bodyisusedasanexpansionsurfaceofnozzle.Inthepresentpaper,anengineeringmethodisappliedtodefinetotalaerodynamiccharacteristicsofanapproximatewaveriderconfiguration.Afinitevolumemethodbasedonthecenterofgridisalsoemployedtonumericallyinvestigatetheoutflowpassthesameconfiguration.Theflowfielddetailsandtheaerodynamicchanacteristicsatgivenconditionsareobtained.Theevaluationforthisconfigurationmaybeusedasaguideforthehypersonicvehicleexperiment.

  • 标签: 超音速运载工具 全流场 数字模拟
  • 简介:为测试作为这个区域拿中国,新卫星严肃技术的潜力,为改进地区性的重力场模型的精确性追踪的satellite-to-satellite被学习。与是的WDM94引用,三个模型,的严肃异例剩余最近二个优雅全球重力场模型(EIGEN_GRACE02S,GGM02S)并且EGM96,被计算并且比较。为在三个模型的剩余之中的差别的原因被讨论。在剩余之间的Thecomparison证明在选择区域,EIGEN_GRACE02S或GGM02S比在更低的度部分(不到110度)的EGM96好。通过模型严肃异例剩余的分析,另外,有期刊性质的一些系统的错误在EIGEN和GGM模型,的更高的度部分存在,这被发现结果能也在SST严肃数据的确认作为引用被拿。

  • 标签: SST 重力场 中国 卫星 物理大地测量
  • 简介:Weldingtechnologyinoil-fieldconstructioninChina¥HOUXianzhong(DaqingOilField)Abstract:Thispaperintroducestheapplicationanddeve...

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  • 简介:Spatialandtemporalvariationof gravity fieldinthecapitalregionChang-CaiHUA;(华昌才)YongGUO;(果勇)Duan-FaLIU;(刘瑞法)GangXIAO;(肖钢),J.T....

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  • 简介:就时空的分数维的结构而言,在拓扑的尺寸DT=的规模相关性理论2被造。在这一conjecture,这时空的geodesics暗示量力学的水动力学模型。随后,计量器分数维的时空上的重力的地被给。然后,计量器组,gauge-covariant衍生物,计量器地的力量张肌,计量器不变的Lagrangean,计量器潜力的地方程和计量器精力动量张肌被决定。最后,使用这个模型,ReissnerNordstr?m类型度量标准被获得。

  • 标签: 分形时空 相对性理论 重力场 度量
  • 简介:Thedistributionofelectricfieldforthealignmentandattachmentofcarbonnanotubes(CNTs)wassimulated.Tobeattachedatthedesiredplace,thealignedandattractedCNTsshouldbestayedinthedesiredareacalledthestableregionorthequasi-stableregionforaninstantwherethechangeofelectricfieldisminimized.Sincetheconicalelectrodehastheverynarrowsizedquasi-stableregion,fewCNTscanbeattached.Therectangularelectrodeshaveawidestableregion,solotsofCNTscanbeattached.Theresultsindicatethattheroundelectrodewhichhasapropersizedquasi-stableregionismoreeffectiveforaligningandattachingasingleCNTthantheconicalorrectangularshapedelectrodes.

  • 标签: 碳纳米管 电场分布 数值模拟 组装 电场变化 圆锥形
  • 简介:Wehavedesignedanddemonstratedasimple,widefield-of-view(FOV=60°)foveatedimagingsystemutilizingadeformablemirror.Thedeformablemirrorisusedtodynamicallycorrecttheoff-axisaberrationsthatlimittheusefulFOVofthesystem.ThesystemmimicstheoperationofhumaneyethroughcreatinganimagewithvariablespatialresolutionandcanbemadesignificantlysmallerandmorecompactthanaconventionalwideFOVsystem.Experimentsshowthatthissystemcanbeusedinmanyareaswheresize,weight,anddatatransmissionbandwidtharecritical.

  • 标签: 孔隙成像系统 可变形镜子 自适应光学 视野
  • 简介:在旋转地效果晶体管的弹道的旋转运输被考虑联合的Rashba纺纱轨道学习,界面的散布,并且乐队失配。有半导体隧道长度的旋转传导力摆动是Rashba旋转领前和旋转干扰摆动的重迭,这被显示出。他们与k_R有不同摆动时期π/k_R和π/kRashba波浪向量和k半导体隧道的Fermiwavevector,和戏慢、快速的摆动的不同部分,取决于π/k_R和π/k的相对大小。仅仅在k=k_R,旋转传导力展出一个单个时期的摆动。掘的磁致电阻的不同行为的二种类型被讨论。

  • 标签: 自旋场效应晶体管 RASHBA自旋轨道耦合 弹道旋转运输 电导振荡
  • 简介:“恐龙之乡”——山东诸城惊爆恐龙考古大发现:在300多米长的斜坡上密布着巨大的恐龙骨骼化石,宛如一条浮雕长廊,成为目前世界范围内已发现曝露面积最大的恐龙化石群,也成为一道绝无仅有的自然地理奇观。

  • 标签: 高中 英语教学 课外阅读 阅读教材
  • 简介:Thecoalescencetimebetweentwocontactingbubbleswasmeasuredexperimentallyindifferentacousticpressuresandfrequenciesusinganimagingsystemwithahigh-speedvideocamera,andtakenananalysistotheinfluenceofthesecondaryBjerknesforceandmaximumoscillationvelocityonthecoalescencetimeoftwocontactingbubblesinthispaper.Itshowedthatundertheactionofdifferentacousticpressuresandfrequencies,thecoalescencetimeincreaseswithsecondaryforceandmaximumoscillationvelocity.TheanalysisandcomparisonofthesecondaryBjerknesforceandmaximumoscillationvelocityfortheeffectofbubblecoalescencetimeshowedthatthesecondaryBjerknesforceisthecriticalfactortoinfluencethebubblecoalescence.

  • 标签: 气泡聚并 影响因素 聚结 声场 聚并时间 振动速度
  • 简介:磁性的珍珠的使液化行为上的外部磁场的影响的试验性的研究被执行。磁性的珍珠是主要由从研磨的煤燃烧从大量的发电厂苍蝇灰被恢复的Fe2O3组成的氧化铁的一张磁性的表格。由于它的丰富,低价格和物理的详细规格和化学性质,磁性的珍珠能被用作重媒介因为矿物质或稳固的废物基于密度差别弄干分离。这份报纸介绍磁性的珍珠的性质并且把磁性的珍珠fluidised病床操作的表演与或没有一个外部磁场作比较。试验性的结果证明一个外部磁场显著地改进象一致性和稳定性那样的磁性的珍珠的使液化表演。

  • 标签: 磁珠 流化性质 磁场 重力分离
  • 简介:PoplarisoneofthedominanttreespeciesfortheestablishmentoffastgrowingplantationsinShandongProvince.EighteenpoplarclonesbelongingtoPopulusaigeirossectionwereintroducedfromItaly,Turkeyanddomesticregions.Populusdeltoidescv.'Lux'I-69/55(I-69),whichwaswidelyusedinShandongProvince,China,wastakenascontrolclone(I-69).Followingarandomizedcompleteblockdesign,seedlingtestandcontrolledafforestationtrialswerecarriedoutatJuxianCounty,CaoxianCountyandLaiyangCity.Theresultsshowedthatthepoplarclone(Populus×euramericanacv.'102/74'),namely102/74,performedwellbothintermsofadaptabilityandgrowthrate.Themeanheightof13.9m(H),diameteratbreastheightof18.0cm(DBH)andvolumegrowthof0.1445m3(V)were2.2%,21.6%and52.9%higherthanthoseofI-69(CK),respectively,attheageof5yearsatthreeexperimentalsites.Moreover,theclonecanbepropagatedeasilyandshowedhighresistancetopoplardisease,pestaswellassalinityandhadlongergrowingperiod.Furthermore,woodbasicdensityandfiberlengthofnewpoplarclone(102/74)wereassameasI-69(CK).Itwasconcludedthattheselectedclone(102/74)wasidealfortheestablishmentoffast-growingpoplarplantations,especiallyforthepulpwoodplantationsinShandongProvince.

  • 标签: 欧美杨 无性系 引种 苗期试验 造林试验 山东
  • 简介:Fieldcomputation,anemergingcomputationtechnique,hasinspiredpassionofintelligencescienceresearch.Anovelfieldcomputationmodelbasedonthemagneticfieldtheoryisconstructed.Theproposedmagneticfieldcomputation(MFC)modelconsistsofafieldsimulator,anon-derivativeoptimizationalgorithmandanauxiliarydataprocessingunit.ThemathematicalmodelisdeducedandprovedthattheMFCmodelisequivalenttoaquadraticdiscriminantfunction.Furthermore,thefiniteelementprototypeisderived,andthesimulatorisdeveloped,combiningwithparticleswarmoptimizerforthefieldconfiguration.Twobenchmarkclassificationexperimentsarestudiedinthenumericalexperiment,andonenotableadvantageisdemonstratedthatlesstrainingsamplesarerequiredandabettergeneralizationcanbeachieved.

  • 标签: 计算模型 磁场理论 模式分类 数据处理单元 二次判别函数 粒子群优化