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500 个结果
  • 简介:ThenorthernmarginoftheAlxablockisthejunctionofatectonicunits.Fourfirst-ordertectonicunitsaredistinguished:1.theYaganstructuralzonecharacteristicofanimmatureislandarc;2.theZhusileng-Hangwulastructuralzone,whichwasapassivecontinentalmarginintheEarlyPalaeozoicandwastransformedintoanactivecontinentalmarginintheLatePalaeozoic;3.theShalazhastructuralzonecharacteristicofamatureislandarc;4.theNuru-Langshanstructuralzone,whichwasaProterozoicorogenicbeltandlaterevolvedintoanextensionaltranstionalcrustinthePalaeozoic.Theabove-mentionedtectonicunitsdifferremarkablyinsedimentaryformations,magmaticrockassociations,metamorphismandgeochemistryandareboundedbyfaultsbetweenoneanother.

  • 标签: Alxa structural ZONE BOUNDARY ROCK association
  • 简介:MultistagesuperimposeddeformationhasbeendiscussedsystematicallybasedontheprogressofthestratigraphicsequencesofthenortheasternmarginofYangtzeBlock.Thenew-discoveredfirststagedeformationofthosesequencesoccurredfromthemiddleTriassictotheendofearlyJurassictogetherwithdevelopmentofregionalfolding,whichwasresultedfromthedeepdetachmentshearingtendingtowardNW-WNW.Thefoldsdiptoeastandfalldowntowardwest,andweresuperimposedbythemainstagefolding.Thereafter,aseriesoffoldsweredevelopedwithaxestrendingtowardnortheast.Consequentlynormalfoldsoccurredonthenormallimbswhileoverturnedfoldontheoverturnedlimbsduringthefirststagefolding.ThedetachmentorthrustwasformedfromlateJurassictoearlyCretaceous.DuetotheupliftingofDabieandtheWannanMountainsinthenorthandsouthsides,thebi-directionalthrustingbeltwasformedbygravityflowingfromtheMountainstowardthecenterofthebasinalongthenorthsideofXuanchengandsouthsideofGuichi.Thedeformationgeodynamicswasdiscussedsimplybasedonthenewlyrecognizedinformationaboutthetectonicevolution.

  • 标签: 中国 长江下游东北部板块 多级叠加变形 重力滑动 冲断层
  • 简介:INTRODUCTIONThepaleocontinentalmargins,characterizedbyactivein-teractionbetweenearthcrustandmantle,complicatedtecton-icmoveme...

  • 标签: paleocontinental margin METALLOGENIC SYSTEM NORTH China
  • 简介:这篇论文论述新细胞的自动机(CA)为火车控制的模型系统模拟。在建议CA模型,训练运动的司机反应被一些更新的规则捕获。交通鞠躬和火车运动的轨道的时空图被用来获得卓见进铁路交通流动的典型行为。很多模拟结果证明建议CA模型能成功地为铁路交通的模拟被使用。铁路交通鞠躬的典型行为能不仅被复制,而且模拟前进接近理论价值的最小的时间珍视。

  • 标签: 交通流 细胞自动机 列车 移动闭塞式控制系统 建模
  • 简介:Forthedirectionofarrival(DOA)estimation,traditionalsparsereconstructionmethodsforwidebandsignalsusuallyneedmanyiterationtimes.Forthisproblem,anewmethodfortwo-dimensionalwidebandsignalsbasedonblocksparsereconstructionisproposed.First,aprolatespheroidalwavefunction(PSWF)isusedtofitthewidebandsignals,thentheblocksparsereconstructiontechnologyisemployedforDOAestimation.Theproposedmethodusesorthogonalizationtochoosethematchingatoms,ensuringthattheresidualcomponentscorrespondtotheminimumabsolutevalue.Meanwhile,thevectorsobtainedbyiterationareback-disposedaccordingtothecorrespondingatomicmatchingrules,sotheextraatomsareabandonedinthecourseofiteration,andtheresidualcomponentsofcurrentiterationarereduced.Thustheoriginalsparsesignalsarereconstructed.Theproposedmethodreducesiterationtimescomparingwiththetraditionalreconstructionmethods,andtheestimationprecisionisbetterthantheclassicaltwo-sidedcorrelationtransformation(TCT)algorithmwhenthesnapshotissmallorthesignal-to-noiseratio(SNR)islow.

  • 标签: 波达方向(DOA)估计 宽带信号 稀疏 估计方法 迭代次数 传统方法
  • 简介:Anewpreparationmethodhasbeendevelopedforthermallystableporouspolyimidemicrospheres.Porouspolyimidemicrosphereswerepreparedusingtriblockcopolymersthatconsistedofathermallystablepolyimidederivedfrompyromelliticdianhydride/4,4’-oxydianilineasthecontinuousphaseandathermallylabilepolyetherasthedispersedphase.Spheresofcopolymersweregeneratedinanonaqueousemulsionandthengraduallyheatedtocompletetheimidizationtoformamicrophase-separatedstructure.Subsequently,thermaltreatmentataslightlyreducedpressureremovedthelabileblocksandproducedpores.Undersuitabledecompositionconditions,theporesizeoftheporouspolyimidewasintherangeof200-400nm.

  • 标签: 嵌段共聚物 聚酰亚胺 制备方法 多孔质 微球 热降解
  • 简介:Adifferentialmodulationschemeusingspace-timeblockcodesisputforward.Comparedwithotherschemes,ourschemehaslowercomputationalcomplexityandhasasimplerdecoder.Inthecaseofthreeorfourtransmitterantennas,ourschemehasahigherrateahighercodinggainandalowerbiterrorrateforagivenrate.Thenwemadesimulationsforspace-timeblockcodesaswellasgroupcodesinthecaseoftwo,three,fourandfivetransmitantennas.Thesimulationsprovethatusingtwotransmitantennas,onereceiveantennaandcoderateof4bits/s/Hz,thedifferentialSTBCmethodoutperformthedifferentialgroupcodesmethodby4dB.Useingthree,fourandfivetransmitantennas,onereceiveantenna,andcoderateof3bits/s/Hzareadopted,thedifferentialSTBCmethodoutperformthedifferentialgroupcodesmethodby5dB,6.5dBand7dB,respectively.Inotherwords,thedifferentialmodulationschemebasedonspace-timeblockcodeisbetterthanthecorrespondingdifferentialmodulationscheme

  • 标签: 微分调制 空时分组码 编码增益 差异调制 误码率
  • 简介:Inthispaper,ablockwiseadaptivesubcarrierallocationalgorithmformultiuserOrthogonalFrequencyDivisionMultiplexing(OFDM)systemisintroduced.Assumingtheknowledgeofchannelinformationforallusers,thealgorithmminimizesthetotaltransmitpowerwhilesatisfyingthetotalpowerandusers'rateconstraints.TheresultofsimulationshowsthattheproposedalgorithmreducestheaveragebitSignal-to-NoiseRatio(SNR)byapproximately4dBcomparedwithOFDM-FrequencyDivisionMultipleAccess(OFDM-FDMA),andsupportsmoreusersinamultiuserRayleighfadingchannel.Asassigningsubcarriersinblock,thecomputationalcomplexityofthealgorithmismuchlowerthanthatofthederivationof"water-filling"algorithm.

  • 标签: OFDM FDMA SNR 正交频分复用 频分多址 信噪比
  • 简介:块在特征0的域上介绍了Zassenhaus代数学的某些类似物。块类型的无限维的简单谎言代数学由徐构造了的nongraded能被看作块代数学的归纳。在这份报纸,我们为块的谎言代数学与复合一一般线性谎言代数学基于有限维的无法缩减的重量模块打的four-devivationnongraded在鈥減olynomials鈥?上以增加和区别操作员构造无法缩减的模块的一个家庭。我们也发现一些无法缩减的商模块从被获得的submodules的一个新系列。关键词无法缩减的模块-nongraded谎言代数学-块类型先生(2000)的nongraded谎言代数学使分类17B10遭到-17B65由中国(资助号码10701002)的国家自然科学基础支持了

  • 标签: 导子李代数 块型 线性李代数 子模块 单李代数 经营条件
  • 简介:WesimulateGPShorizontalvelocityfieldintermsofrotationsofcrustalblockstodescribedeformationbehavioroftheChinesemainlandanditsneighboringareas.31crustalblocksareboundedprimarilyby~30Quaternaryfaultswithdistinctgeometriesandvariablelong-termratesof<20mm/a,and1683GPSvelocitiesweredeterminedfromdecade-longobservationsmostlywithanaverageduncertaintyof1?2mm/a.WedefineGPSvelocityatasitebythecombinationofmotionofrigidblockandelasticstraininducedbythefaultthatislockingduringaseismiccycle.ModelvelocitiespredictedfromthepreferableblockmodelmatchwellwiththeGPSvelocitiestoanuncertaintyof~1.7mm/a.Theslipratesinferredfromthismodelisinarangeof6?18mm/aforthemajorfaultsinTibetanditsmarginsand1?4mm/aineasternChina,consistentwithgeologicalobservations.Ournumericalsimulationsuggeststhatthecrustalblocksdeforminternallyatalevelof~10×10-9/a,quitesmallincomparisonwithsignificantdeformationlocalizedalongfaultzonesof50?100kmwide.Weconcludethatthepatternofcontinentaldeformationisnotcontinuous-likebutblock-like,andthetenetofplatetectonicsmaybeapplicabletocharacterizetheactivedeformationinAsia.

  • 标签: GPS测量 大陆地壳 旋转 地壳变形 全球定位系统 不确定性
  • 简介:AclassofQuasi-SystematicBlock-CirculantLow-DensityParity-Check(QSBC-LDPC)codesisproposed.Block-circulantLDPCcodeshavebeenstudiedalotrecently,becausethesimplestructuresoftheirparity-checkmatricesareveryhelpfultoreducetheimplementationcomplexities.QSBC-LDPCcodesarespecialblock-circulantLDPCcodeswithquasi-systematicparity-checkma-trices.ThememoriesforencodersofQSBC-LDPCcodesarelimited,andtheencodingprocesscanbecarriedoutinasimplerecursivewaywithlowcomplexities.ResearchesshowthattheQSBC-LDPCcodescanprovideremarkableperformanceswithlowencodingcomplexities.

  • 标签: 通信技术 低密度奇偶校验码 回归编码 循环变化
  • 简介:<正>TheWorldTourismOrganiza-tionreckonedthatChinawouldemergeastheNo1tourismdestinationinthenextdecades,exceedingSpain,FranceandtheUS.TheRepresentativeoftheWorldTourismOrganizationsaidthattheinternationalintensitythreatenednothingtothetourismofChina.

  • 标签: tourism DESTINATION holiday exceeding TRAVELING TOURIST
  • 简介:这部电影的故事发生在未来的地球,大部分人在一个被称为“绿洲”的网络虚拟空间打发时间。

  • 标签: 中学 英语 课外阅读 阅读材料
  • 简介:小迪面对妹妹下棋的建议很不以为然,他觉得自己一定比妹妹厉害,太自以为是了,结果却输了。

  • 标签: 《Get on One's HIGH Horse》 小学生
  • 简介:代词one的用法很多,且容易误用,现将其常见的用法归纳如下:

  • 标签: 代词 ONE 用法 初中 英语