简介:使用one-day-arc由覆盖的轨道集成n-days-arc的算法详细被讨论。一个例子被给,它证明轨道集成方法能高效地改进轨道的精确,特别在一个本地区域的轨道的决心。IGS出版的轨道是七个IGS分析中心(代码,EMR,ESA,GFZ,JPL,NGS,和SIO)的综合结果独立结果。因为one-day-arc的末端的效果,在两个的错误轨道的终端由比较,和轨道经常是更大的每天是不连续的。改进轨道的质量,把one-day-arc集成到n-days-arc并且提供w-days-arc的中间的节让n-analysis-center的集成获得精确IGS的每分析中心需要转。通常,由轨道集成方法的轨道的中间的节比由one-day-arc方法有更高的精确性。这块研究地仍然在在中国的基本阶段。
简介:AbstractEndoscopic endonasal orbital surgery is evolving. With increasing knowledge, expertise, and technology, the historical limits of the endonasal endoscopic approach to the orbit have been redefined. This review discusses the clinical presentation and etiology, and highlights the pertinent anatomy, and discusses the diagnostic workup and surgical approach to orbital tumors and post-operative care. The role of the multidisciplinary team is not to be underestimated. The introduction of a classification system to ensure standardization of technical difficulty and outcome data will assist with international collaboration and further consolidate our attainment of knowledge in this developing field.
简介:On-orbitservicespacecraftorbitproblemhasbeenaddressedfordecades.Theresearchofon-orbitservicespacecraftorbitcanberoughlydividedintoorbitdesignandorbitoptimization.Thepapermainlyfocusesontheorbitdesignproblem.Wesimplysummarizeofthepreviousworks,andpointoutthemaincontentoftheon-orbitservicespacecraftorbitdesign.Weclassifycurrenton-orbitservicespacecraftorbitdesignproblemintoparking-orbitdesign,maneuvering-orbitdesignandservicing-orbitdesign.Then,wegiveadetaildescriptionofthethreespecificorbits,andputforwardourownideasontheexistedachievements.Thepaperwillprovideameaningfulreferencefortheon-orbitservicespacecraftorbitaldesignresearch.
简介:有轨道的一条退化homoclinic轨道的分叉在高维的系统扭动被学习。由在homoclinic轨道附近建立一个本地坐标系统和一张Poincar茅地图,1条鈥揾omoclinic轨道和1鈥損eriodic的存在和唯一转被给。另外考虑了是2鈥揾omoclinic轨道和2鈥損eriodic轨道的存在。在additon,相应分叉表面被给。关键词轨道扭动-Homoclinic分叉-Poincar茅地图先生(2000)题目分类34C23-中国的国家自然科学基础支持的37C29工程(没有:10171044),江苏省的自然科学基础(没有:BK2001024),为中国的教育部的大学关键教师的基础
简介:Thealgorithmofautonomousorbitdeterminationfortheprobearoundsmallbodyisstudied.Inthealgorithm,first,theobservedimagesofthebodyarecomparedwithitspre-computedmodelofthebodytoobtainthelocationofthelimbfeaturesofthebodyintheinertialcoordinate.Second,theinformationoftheimagesandfeaturesinutilizedtoobtainthepositionoftheprobeusingtheLevenberg-Marquardtalgorithm.ThepositionistheninputtoanextendedKalmanfilterwhichdeterminestherealtimeorbitoftheprobe.Finally,consideringtheeffectiveoftheirregularsmallbodyshapeperturbationandthesmallbodymodelparametererrorontheorbitdeterminationprecise,theprocedureofautonomousorbitdeterminationisvalidatedusingdigitalsimulation.
简介:Hamiltonianstructureofarigidbodyinacircularorbitisestablishedinthispaper.Withthereductiontechnique,theHamiltonianstructureofarigidbodyinacircularorbitisderivedfromLie-Poissonstructureofsemidirectproduct,andHamiltonianisderivedfromJacobi’sintegral.TheabovemethodcanbegeneralizedtoestablishtheHamiltonianstructureofarigidbodywithaflexibleattachmentinacircularor-bit.Atlast,anexampleofstabilityanalysisisgiven.
简介:Thehomoclinicbifurcationsinfourdimensionalvectorfieldsareinvestigatedbysettingupalocalcoordinatesnearthehomoclinicorbit.Thishomoclinicorbitisnonprincipalinthemeaningsthatitspositivesemi-orbittakesorbitflipanditsunstablefoliationtakesinclinationflip.Theexistence,nonexistence,uniquenessandcoexistenceofthe1-homoclinicorbitandthe1-periodicorbitarestudied.Theexistenceofthetwofoldperiodicorbitandthree-foldperiodicorbitarealsoobtained.
简介:Weinvestigatetheorbitlossofalphaparticlesunderhelicalmagneticperturbationinatokamak.Theresultsshowthatlow-frequencyandlow-modenumbermagneticperturbationcancausestochasticlossofalphaparticles.Thiseffectissignificantforthoseparticlesclosetotheboundarybetweenthetransitzoneandthetrappedzone.Theparticlelossissensitivetothephaseofthemagneticperturbation,indicatingthemodulationoftheparticlelosswithrespecttomagneticperturbation.Itisalsofoundthattheprecessionoftheparticlebananaorbitcanevenfurtherenhancetheparticleloss.
简介:Thestructure,functionandrecognitionmethodofanaxisorbitauto-recognizingsystemarepresentedinthispaper.Inordertomakethebestuseofinformationofformatanddynamiccharacteristicsofmarinesteamturbineaxisorbit,thestructureandfunctionsorneuralnetworkareappliedtothissystem,whichcanbeusedtoauto-recognizeaxisorbitofthesystemturbinerotorusingBPneuralnetwork.
简介:我们理论上学习准确diagonalization方法与纺纱轨道相互作用(SOI)在联合的量点的InAs平行(CQD)限制的二交往电子的旋转性质。通过汗衫和三位字节混合的导致的纺纱说的SOI,我们为弱、强壮的SOI显示出不同旋转性质。我们在SOI下面调查二个电子的协调汗衫三位字节旋转摆动,并且表明取决于SOI力量,内部点的分离和外部磁场的旋转摆动的详细行为。为了更好理解旋转动力学的内在的物理,我们为弱、强壮的SOI介绍四水平的模型Hamiltonian,并且发现SOI在飞机导致了,有效磁场能是从二电子的刺激精力系列提取的份量上。
简介:Thelifetimeofanartificialsatellitemovinginthecircularorbitundertheactionofnonuniformrotatingatmosphericdragisstudiedfromanenergypointofviewinthispaper.Theangularvelocityofatmosphericrotationdecreaseswithheightaccordingtohydrodynamics.Theatmosphericdensitydecreaseswithheightaccordingtotheexponentialformula.Theexpressionforthelifetimeofasatelliteintheinstantaneouscircularorbitintheabove-mentionedrotatingatmosphericmodelisderived,andthenumericalestimationforthelifetimeofaconcretesatellitehasbeenmade.Theresultshowsclearlythatthesatellitelifetimecalculatedbythispaperisshorterthanthatcalculatedbytheuniformrotatingatmosphericmodel.
简介:36从柱子被恢复了的度和顺序的地球重力场模型CDS01S处理了科学轨道和GFZ的机载的加速表数据“sCHAMPsatellite。模型与精确性解决大地水准面比在700km一半波长的一个决定的4厘米好。由使用重力势系数的学位差别变化把模型CDS01S与EIGEN3P,EIGEN1S和EGM96作比较,结果显示系数ofCDS01S离EIGEN3P的那些很靠近。在在上面的精确性ofgeopotential系数之间的比较的结果当模特儿,显示在在EGM96的比那高的CDS01Sis的系数的精确性。直到30个学位的CDS01S和GGM01C的大地水准面波动被计算,标准差是在他们之间的4.7厘米。