学科分类
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6 个结果
  • 简介:Inthispaper,thecycle’sstructureofembeddedgraphsinsurfacesarestudied.Accordingtothemethodoffundamentalcycles,thesetC(Ccontainsallshortest)isfound.AundirectedgraphGwithnverticeshasatmostO(n5)manyshortestcycles;IftheshortestcycleofGisoddcycle,thenGhasatmostO(n3)manyshortestcycles;IfGhasbeenembeddedinasurfaceSg(Ng,gisaconstant),thenithasatmostO(n3)shortestcycles,moreover,iftheshortestcycleofGisoddcycle,then,GhasatmostO(n2)manyshortestcycles.WecanfindacyclebaseofG,thenumberofoddcyclesofG,thenumberofevencyclesofG,thenumberofcontractiblecyclesofG,thenumberofnon-contractiblecyclesofG,arealldecided.IftheΠ-embeddedgraphGhasΠ-twosidedcycles,then,CcontainsashortestΠ-twosidedcycleofG,thereisapolynomiallyboundedalgorithmthatfindsashortestΠ-twosidedcycleofaΠ-embeddedgraphG,thenewandsimplesolutionsabouttheopenproblemofBojanMoharandCarstenThomassenareobtained.

  • 标签: 曲面嵌入 循环结构 基本周期 短周期 周期数 嵌入式
  • 简介:Inthispaperbothexperimentalandanalyticalapproachestoprovidetheinputsforcreepmodelingofrefractoriesincludinganewlydevelopedhightemperaturecompressivecreepmachineandaninverseestimationprocedureofcreeplawparametersarebrieflyintroduced.Besides,amodifiedsheartestisappliedtodeterminethecohesionandfrictionangleofrefractoriesundershearstate.ARHsnorkelequippedwithmagnesia-chromitebricksischosenforacasestudyofthermomechanicalsimulationapplyingtheclassicalcreepmodelandDrucker-PragercreepmodelavailableinthefiniteelementcodeABAQUS,respectively.Afterwards,thermalstressesandjointopeningofmagnesia-chromitebricksduringaprocesscyclearecomparedtodistinguishtheimpactofthesetwocreepmodels.

  • 标签: 蠕变模型 镁铬砖 浸渍 RH 周期 ABAQUS
  • 简介:InordertodiscussthecontentdistributionsandfluxesofheavymetalsinsuspendedmattersduringatidalcycleintheturbiditymaximumaroundtheChangjiang(Yangtze)Estuary,thecontentsofheavymetals(Zn,Pb,Cd,CoandNi)havebeenanalyzed.Duringatidalcycle,theaveragecontentsofheavymetalsareintheorderofZn>Ni>Pb>CoàCd.Theaveragecontentsinebbtidearegenerallyhigherthanthatinfloodtide.However,attheinshoreSta.11,influencedbythecontaminationfromthenearbywastetreatmentplant,theaveragecontentsofZnandNiinfloodtidearehigherthanthoseinebbtideandattheoffshoreSta.10,thecontentofCdinfloodtidehigherthanthatinebbtideduetomarine-derivedmaterials.Thefiveheavymetals,mainlyterrigenous,aretransportedtowardseast-northeast,andsettledownwithsuspendedmattersintheareabetweenSta.11andSta.10.Influencedbymarine-derivedmaterials,thefluxvalueofCddoesnotaltersignificantlywithobviouslychanginginfluxdirectiontowardsnorthwest.Thesourceofheavymetals,thesalinityofwaterandtheconcentrationofsuspendedmattersarethemainfactorscontrollingthecontentdistributionsofheavymetalsduringatidalcycle.Thereisapositivecorrelationbetweenthecontentsofheavymetals(Zn,Pb,CoandNi)andthesalinityofwater,whiletheoppositecorrelationbetweenthecontentsandtheconcentrationsofsuspendedmatters.Becauseofmarine-derivedmaterials,thecontentofCdisnotcorrelatedwiththeconcentrationofsuspendedmattersandthesalinityofwater.

  • 标签: 重金属含量 悬浮物浓度 最大浑浊带 潮汐周期 长江 平均含量
  • 简介:Low-duty-cyclemechanismscanreducetheenergyconsumptionsignificantlyinwirelesssensornetworks(WSNs).Sensorsstaydormantmostofthetimetosavetheirenergyandwakeupbasedontheirneeds.However,suchatechnique,whileprolongingthenetworklifetime,setsexcessivechallengesforreducingtheend-to-end(E2E)delaywithinthenetwork.Inthispaper,thecentralizedcluster-basedlocationfinding(CCLF)algorithmisproposedtoreducethehighlatencyinlow-duty-cycleWSNsbyfindingasuitablepositionforthesink.Thealgorithmismainlycomposedofthreesteps:a)theclusterconstruction,b)thefastlook-uptable(FLU-table)construction,andc)thesinklocationdecision.ThesimulationresultsshowthattheperformanceoftheCCLFalgorithmissignificantlysimilartothatoftheoptimalalgorithm.Moreover,theCCLFalgorithmrequireslessoperationtimecomparedwiththeoptimalalgorithm.

  • 标签: 无线传感器网络 占空比 位置 延迟 终端 优化算法
  • 简介:热泵周期广泛地为他们的高效率被用于干衣机。然而,自从一个标准热泵周期不能在低温度操作,电的加热器经常是的lowefficiency在早为冻结的食物或冬季弄干舞台期间使用了。这研究介绍了代替电的加热器在低温度改进干衣机性能的串联热泵。实验被执行在与周围的温度,低阶段的周期团流动率,和高阶段的周期团流动的关系在串联热泵干衣机的性能检验变化率。结果与串联热泵周期的介绍在低温度的干衣机性能显示出重要改进。

  • 标签: 低温干燥机 热泵循环 热泵干燥装置 R134A R404A 电加热器