学科分类
/ 25
500 个结果
  • 简介:一个单圈G的邻接矩阵是奇异的当且仅当G含完美匹配和4m(m∈N)阶圈,或G和从G删去唯一圈的顶点及其关联边后得到的导出子均不含完美匹配.单圈的邻接矩阵的最大行列式是4.

  • 标签: 单圈图 邻接矩阵 完美匹配 最大行列式 特征多项式
  • 简介:ApplicationofFoxprotoManagementofArticles¥HuangTuanhuaThedatabasemanagementsystemofFoxpro2.5forwindowsisapopularsoftwareforda...

  • 标签:
  • 简介:<正>WeareconcernedwiththefollowingDirichletproblem:-△u(x)=f(x,u),x∈Ω.u∈H01(Ω).(P)wheref(x,t)∈C(Ω×R),f(x,t)/tisnondecreasingint∈RandtendstoanL∝-functionq(x)uniformlyinx∈Ωast→+∝(i.e.,f(x,t)isasymptoticallylinearintatinfinity).Inthiscase.anAmbrosetti-Rabinowitz-typecondition,thatis.forsomeθ>2.M>0,0<θF(x.s)≤f(x,s)s,forall|s|≥Mandx∈Ω,(AR)isnolongertrue,whereF(x,s)=integralfromn=0tosf(x,t)dt.Asiswellknown,(AR)isanimportanttechnicalconditioninapplyingMountainPassTheorem.Inthispaper,withoutassuming(AR)weprove,byusingavariantversionofMountainPassTheorem,thatproblem(P)hasapositivesolutionundersuitable,conditionsonf(x,t)andq(x).Ourmethodsalsoworkforthecasewheref(x,f)issuperlinearintatinfinity.i.e.,q(x)≡∞.

  • 标签: DIRICHLET PROBLEM MOUNTAIN Pass THEOREM ASYMPTOTICALLY
  • 简介:Inthispaper,wepresentthesimplificationofSachsformulasforthemeasurementandcalculationoftheresidualstressesoftheeylinderonlywiththeplanestresses.Furthermore,wepresentthemethodforthemeaurementandcalculationoftheresidualstressesofthecylindernotonlywiththefinitelengthbutwiththelongitudinalstress.Thesecanbeappliedtotheinvestigationontheresidualstressesoftheautofrettedguntube.

  • 标签: longitudinal CYLINDER Sachs length tangential simplified
  • 简介:在教学,经常会遇到条件不明确的问题,学生常顾此失彼,导致少解或漏解,这需要对不明确条件逐一分析讨论、做出正确的判断,这就是物理分类思想。

  • 标签: 分类思想 物理教学 中学 教学方法
  • 简介:Inthispaper,theauthorsintroduceakindofreduciblealgebroidfunctions,thatisgeneralalgebroidfunctionsandobtaintwofundamentaltheoremsofgeneralalgebroidfunctions.Atlast,asanapplication,wegeneralizedatheoremofLiGuoping’s.

  • 标签: 代数体函数 应用 定理 可约
  • 简介:Thegeodesicindifferentialgeometryiseornmonlyusedincomputer-aidedfilamentwinding(CAFW)toavoidslippageinmanufacturingprocess.Theuniquenessofthegeodesicbyitsinitialvaluesseverelyrestrictsthechoiceofthefiberpathandisanobstacletotheproductionofoptimizedstructures.Thispaperpresentsanewclassofmoreflexiblenon-sliptrajectoriesonrevolutionalsurfacesasanextensionofthewell-knownClariautequationandgivesitsapplicationinCAFW.

  • 标签: Clariaut方程 扩展性 微分几何学 唯一性
  • 简介:Inthispaper,weintroducetheapplicationofrandommatricesinmathematicalphysicsincludingRiemann-Hilbertproblem,nuclearphysics,bigdata,imageprocessing,compressedsensingandsoon.WestartwiththeRiemannHilbertproblemandstatetherelationbetweentheprobabilitydistributionofnontrivialzerosandtheeigenvaluesoftherandommatrices.Throughtherandommatricestheory,wederivethedistributionofNeutronwidthandprobabilitydensitybetweenenergylevels.Inaddition,theapplicationofrandommatricesinquantumchromodynamicsandtwodimensionalEinsteingravityequationsisalsopresentinthispaper.

  • 标签:
  • 简介:Wavelettransformisaparticularlyusefultooltocharacterizetran-sientphenomenasuchaswavebreaking.Inthispaper,weapplywavelettransformtothedetectionandquantificationofthebreakingwaves.Weuseanewmethodthatusesthelocalpropertiesofwavelettransformtodetectandquantifythebreak-ingwavesandgivesomenewbreakingcriteria.Bycomparingthismethodwiththeclassicmethod,wefindthatwavelettransformisveryeffectiveinthedetectionofbreakingwaves.Withwavelettransform,asetofmeasuredwindwavedataisinves-tigated.Theresultshaverevealedsomepreviouslyunknownphenomenaaboutwavebreaking.

  • 标签: WAVELET WAVE BREAKING CRITERIA
  • 简介:Inthispaper,fibrouschelatingexchangerswith-N(CH2COOH)2grouphavebeenpreparedforthefirsttimebyaweaklybasicanionexchangefiber(aminatedfiber)asthestartingmaterials.ThefiberswerequiteeffectivefortheadsorptionofheavymetalionsuchasCu^2+.Inaddition,IRspectrumofthestructureoffibersconfirmsthatitisfeasibletoprepareiminocarboxylicchelatingfiberthroughdirectcarboxylationreaction.

  • 标签: 合成树脂 纤维 重金属离子吸附
  • 简介:Timereversalisappliedtotheunderwaterspreadingspectrumcodingcommunication.Onthebaseofanalyzingthefocusingcharacteristicsofthetimereversalinunderwaterwaveguide,thetimereversalisstudiedtoovercomethewavedistortionoftheencodedsignalcausedbythemulti-patheffect.TheexperimentresearchforunderwatercodingcommunicationiscarriedoutinalabwatertankandthecorrespondingtheoreticalanalysisisalsoconductedbyBinaryPhaseShiftKeying(BPSK)encodingandBarkercodewith7chipsforthespreadingspectrumsignal.Theresultsshowthatthetimereversalcanimprovethefocusinggainandincreasetheratiooftheprincipaltothesecondlobeofthecodingsignal,andcandecreasethebiterrorrateandincreasethecommunicationdistance.

  • 标签: 时间反转 水下通讯 声音脉冲 多路效应 自适应调焦
  • 简介:WiththedevelopmentofWeb2.0,moreandmorepeoplechoosetousetheInternettoexpresstheiropinions.Allthisopinionstogetherintoanewformtextwhichcontainsalotofvaluableemotionalinformation,thisiswhyhowtodealwiththesetextsandanalysistheemotionalinformationissignificantforus.Wegetthreemaintasksofsentimentanalysis,includingsentimentextraction,sentimentclassification,sentimentapplicationandsummarization.Inthispaper,basedontheRsoftware,weintroducedthestepsofsentimentanalysisindetail.Finally,wecollectthemoviereviewsfromtheInternet,anduseRsoftwaretodosentimentanalysisinordertojudgetheemotionaltendencyofthetext.

  • 标签: TEXT SENTIMENT Analysis R SOFTWARE Information
  • 简介:Auditorymodelhasbeenappliedtoseveralaspectsofspeechsignalprocessingfield,andappearstobeeffectiveinperformance.Thispaperpresentstheinversetransformofeachstageofonewidelyusedauditorymodel.Firstofallitisnecessarytoinvertcorrelogramandreconstructphaseinformationbyrepetitiousiterationsinordertogetauditory-nervefiringrate.ThenextstepistoobtainthenegativepartsofthesignalviathereverseprocessoftheHWR(HalfWaveRectification).Finallythefunctionsofinnerhaircell/synapsemodelandGammatonefiltershavetobeinverted.Thusthewholeauditorymodelinversionhasbeenachieved.Anapplicationofnoisyspeechenhancementbasedonauditorymodelinversionalgorithmisproposed.Manyexperimentsshowthatthismethodiseffectiveinreducingnoise.EspeciallywhenSNRofnoisyspeechislowitismoreeffectivethanothermethods.Thusthisauditorymodelinversionmethodgiveninthispaperisapplicabletospeechenhancementfield.

  • 标签: 听觉模型 倒置 应用 语音信号处理
  • 简介:Inthispaper,theapplicationofhomotopymethodstotheloadflowmulti-solutionproblemsofpowersystemsisintroduced.BythegeneralizedBernshteintheorem,thecombinatorialnumberC2n^misshowntobetheBKKboundofthenumberofisolatedsolutionsofthepolynomialsystemtransformedfromloadflowequationswithgenericallychosencoefficients.AsaresultofthegeneralBezoutnumber,thenumberofpathsbeingfollowedisreducedsignificantlyinthepracticalloadflowcomputation.Finally,thecompleteP-Vcuresareobtainedbytrackingtheloadflowwithhomotopymethods.

  • 标签: 同伦法 电力系统 Bernshtein定理 负荷流动方程 Bezout数 非线性代数方程
  • 简介:IntroductionAlthoughtheapplicationofmicrowavetechniquehasbeenreportedasanewtypeofenergysourcechemically,itisonlyinrecentyearsthatthistechniquehasbeenusedastheenergysourcefororganicsynthesis.In1986,R.Gedye,etal.,publishedthereportofthebenzoatesynthesisfromtherespectivereactionsbetweenbenzenecarboxylicacidandmethanol,propanolorbutanolundermicrowaveheatingandthecatalysisofH2SO4.

  • 标签: MICROWAVE HEATING ESTERIFICATION