学科分类
/ 1
13 个结果
  • 简介:这篇论文涉及近似可控制性的费用和热方程的空可控制性的界限,即,最小的Lp需要近似控制系统的控制或控制的标准和L∞标准需要驾驶系统的状态到零。我们使用的方法联合observability不平等,为热方程的精力估计和双理论。

  • 标签: 近似可控性 成本估算 热方程 脂蛋白 Z规范 La
  • 简介:Westudyaninventorysysteminwhichproductsareorderedfromoutsidetomeetdemands,andthecumulativedemandisgovernedbyaBrownianmotion.Excessivedemandisbacklogged.Wesupposethattheshortageandholdingcostsassociatedwiththeinventoryaregivenbyageneralconvexfunction.Theproductorderingfromoutsideincursalinearorderingcostandasetupfee.Thereisaconstantleadtimewhenplacinganorder.Theoptimalpolicyisestablishedsoastominimizethediscountedcostincludingtheinventorycostandorderingcost.

  • 标签: 库存成本 最优策略 库存模型 布朗运动 订货会 库存系统
  • 简介:在这篇论文,我们以速度在二台一致机器上调查安排问题的变体1;s。为这个问题,我们被给二台潜在的一致机器处理独立工作的一个序列。机器需要在开始到过程前被激活,;激活的每台机器招致固定机器激活费用。没有机器开始被激活,;当一个工作被揭示时,算法有选择激活新机器。目的是最小化makes平底锅的和;机器激活费用。我们与竞争比率设计最佳的联机算法(2s+1)为每s≥1的/(s+1)。

  • 标签: 同类机 在线算法 在线排序 机器激活成本 竞争分析
  • 简介:Afewclassesoforganiccompoundsarepromisingelectrode-activematerialsduetotheirhighpowerandenergydensities,lowcost,environmentalfriendliness,andfunctionality.Inthepresentwork,thepossibilityofusingKlasonligninextractedfrombuckwheathusksasacathode-activematerialforaprimarylithiumbatteryhasbeeninvestigatedforthefirsttime.Thereactionmechanisminthelithium/ligninelectrochemicalcellwassuggestedbasedonthedeepgalvanostaticdischarge(upto0.005V)dataandcyclicvoltammetryresults.ThedependenceoftheelectrochemicalbehavioroftheKlasonligninonthemillingdegreewasevaluated.Themaximumspecificcapacityoftheligninisequalto600mAhg-1atadischargecurrentdensityof75μAcm-2.BeneficialeffectofthethermaltreatmentoftheKlasonlignincathodeat250°Conthecellperformancewasestablished.Itwasfoundthatthedischargecapacityofthecellincreasedby30%intherangefrom3.3to0.9Vforthetreatedcathodematerial.TheseresultsdemonstratetheprospectsofusingKlasonlignin-basedelectrochemicalcellsaslow-rateprimarypowersources.

  • 标签: 电极活性材料 阴极材料 木质素 锂电池 电化学性能 低成本
  • 简介:Here,wereportthesynthesisofhardcarbonmaterials(RH)madefromnaturalricehuskthroughasinglepyrolysisprocessandtheirapplicationasananodeinsodium-ionbatteries.ThestudiesshowthattheelectrochemicalpropertiesofRHsareaffectedbythetreatmenttemperatures,whichdeterminethematerialsmorphology,inparticular,theirdegreeofgraphitizationandextentofcontinuouschannels(nanovoids).Thelatterareaccessibletosodiumionsandsignificantlycontributetochargestoragecapacityoftheproducedanodes.TheRHsobtainedat1600°Cdeliverthehighestreversiblecapacityof276mAhg-1mainlyduetoinsertionofsodiumionsintothenanovoids.Thisworkdeepensthebasicunderstandingoftheinfluenceofthecarbonizationtemperatureonthesodiumstoragemechanism.

  • 标签: Nanovoids in RICE husk SUSTAINABLE energy
  • 简介:Thispaperproposesanonmonotonicbacktrackingtrustregionalgorithmviabilevellinearprogrammingforsolvingthegeneralmulticommodityminimalcostflowproblems.Usingthedualitytheoryofthelinearprogrammingandconvextheory,thegeneralizeddirectionalderivativeofthegeneralmulticommodityminimalcostflowproblemsisderived.Theglobalconvergenceandsuperlinearconvergencerateoftheproposedalgorithmareestablishedundersomemildconditions.

  • 标签: 置信域算法 线性规划 多物成本 最小化问题
  • 简介:WedescribeandexperimentallydemonstrateameasuringtechniqueforMach–Zehnderinterferometer(MZI)basedintegratedphotonicbiochemicalsensors.OurtechniqueisbasedonthedirectmeasurementofphasechangesbetweenthearmsoftheMZI,achievedbysignalmodulationononeofthearmsoftheinterferometertogetherwithpseudoheterodynedetection,anditallowsustoavoidtheuseofcostlyequipmentsuchastunablelightsourcesorspectrumanalyzers.Theobtainedoutputsignalisintrinsicallyindependentofwavelength,powervariations,andglobalthermalvariations,makingitextremelyrobustandadequateforuseinrealconditions.Usingasilicon-on-insulatorMZI,wedemonstratethereal-timemonitoringofrefractiveindexvariationsandachieveadetectionlimitof4.1×10-6refractiveindexunits(RIU).

  • 标签:
  • 简介:Industrialgrademulti-walledcarbonnanotubes(IG-MWCNTs)arealow-costsubstituteforcommerciallypurifiedmulti-walledcarbonnanotubes(P-MWCNTs).Inthiswork,IG-MWCNTswerefunctionalizedwithtetraethylenepentamine(TEPA)forCO2capture.TheTEPAimpregnatedIG-MWCNTswerecharacterizedwithvariousexperimentalmethodsincludingN2adsorption/desorptionisotherms,elementalanalysis,X-raydiffraction,Fouriertransforminfraredspectroscopyandthermogravimetricanalysis.BoththeadsorptionisothermsofIGMWCNTs-nandtheisostericheatsofdifferentadsorptioncapacitieswereobtainedfromexperiments.TEPAimpregnatedIG-MWCNTswerealsoshowntohavehighCO2adsorptioncapacitycomparabletothatofTEPAimpregnatedP-MWCNTs.TheadsorptioncapacityofIG-MWCNTsbasedadsorbentswasintherangeof2.145to3.088mmol/g,dependingonadsorptiontemperatures.Havingtheadvantagesoflow-costandhighadsorptioncapacity,TEPAimpregnatedIG-MWCNTsseemtobeapromisingadsorbentforCO2capturefromfluegas.

  • 标签: CO2 ADSORPTION multi-walled carbon nanotubes(MWCNTs) tetraethylenepentamine(TEPA)
  • 简介:Weproposeapositionsensorlesscontrolschemeforafour-switch,three-phasebrushlessDCmotordrive,basedonthezerocrossingpointdetectionofphaseback-EMFvoltagesusingnewlydefinederrorfunctions(EFs).Thecommutationin-stantsare30°afterdetectedzerocrossingpointsoftheEFs.DevelopedEFshavegreatermagnituderatherthanphaseorlinevoltagessothatthesensorlesscontrolcanworkatalowerspeedrange.Moreover,EFshavesmoothtransitionsaroundzerovoltagelevelthatreducesthecommutationerrors.EFsarederivedfromthefilteredterminalvoltagesvaoandvbooftwolow-passfilters,whichareusedtoeliminatehighfrequencynoisesforcalculationoftheaverageterminalvoltages.Thefeasibilityoftheproposedsensorlesscontrolisdemonstratedbysimulationandexperimentalresults.

  • 标签: 无刷直流电动机 四开关逆变器 传感控制器 反电势 数字信号处理
  • 简介:Facileproductionofhighqualityactivatedcarbonsfrombiomassmaterialshasgreatlytriggeredmuchattentionpresently.Inthispaper,aseriesofinterconnectedporouscarbonmaterialsfromlotusrootshellsbiomassarepreparedviasimplepyrolysisandfollowedbyaKOHactivationprocess.Thepreparedcarbonsexhibithighspecificsurfaceareasofupto2961m~2/gandlargeporevolume~1.47cm3/g.Inaddition,theresultantporouscarbonsservedaselectrodematerialsinsupercapacitorexhibithighspecificcapacitanceandoutstandingrecyclingstabilityandhighenergydensity.Inparticular,theirspecificcapacitanceretentionwasalmost100%after10500cyclesatacurrentdensityof2A/g.Remarkabely,theimpactofthetailoredspecificsurfaceareasofvariouscarbonsamplesontheircapacitiveperformancesissystematicallyinvestigated.Generally,itwasbelievedthatthehighly-developedporosityfeatures(includingsurfaceareasandporevolumeandporesize-distributions),togetherwiththegoodconductivityofactivatedcarbonspecies,playakeyroleineffectivelyimprovingthestorageenergyperformancesoftheporouscarbonelectrodematerialsinsupercapacitor.

  • 标签: 超级电容器 碳电极材料 电容性能 多孔炭 绿色合成 莲藕
  • 简介:UniqueZnSnanobunsdecoratedwithreducedgrapheneoxide(RGO)wassynthesizedandfoundtoexhibitasynergeticeffectasahighlyefficientandlow-costcounterelectrode(CE)indye-sensitizedsolarcells(DSCs).UsingthisZnS-RGOCE,apowerconversionefficiency(PCE)of7.03%wasachieved.Thisvaluewas53%and41%higherthanthoseofpureZnSandRGOCEs,respectively.TheZnS-RGOnanocompositeisindeedanefficientandcost-effectivePt-likealternativeforiodinereductionreaction.

  • 标签: 染料敏化太阳能电池 还原反应 ZNS 低成本 氧化物 对电极
  • 简介:Wehavedevelopedacost-effectiveandhighlycompact100-Gb/scoarsewavelengthdivisionmultiplexing(CWDM)transmitteropticalsubassembly(TOSA)usinglens-freehybridintegration.Toachievelargealignmenttolerances,distributedfeedbacklaserdiodes(DFB-LDs)arebutt-coupledtoafour-channelsilica-basedplanarlightwavecircuit(PLC)arrayedwaveguidegrating,withthesiliconsub-mountsandPLCadhesivelybonded.Then,aflexibleprintedcircuitisemployedtoconnecttheinternalDFB-LDsandtheexterioroftheTOSApackageforradiofrequencysignaltransmission,eliminatingtheexpensiveceramicfeed-through.ThepackagedCWDMTOSA,whichis15.8mm×7.0mm×6.0mminsize,showsaside-modesuppressionratioof>40dB,a3dBbandwidthof>18GHz,anderror-freetransmissionwithanaverageopticaloutputpowerof>0dBmanddynamicextinctionratioof>4.0dBat25.78125Gb/sovera10kmsingle-modefiberforallfourlanes.

  • 标签: DFB PLC AWG Figure LOW-COST HYBRID