简介：Thispaperpresentsamethodofconstructingamixedgraphwhichcanbeusedtoanalyzethecausalityformultivariatetimeseries.Weconstructapartialcorrelationgraphatfirstwhichisanundirectedgraph.Foreveryundirectededgeinthepartialcorrelationgraph,themeasuresoflinearfeedbackbetweentwotimeseriescanhelpusdecideitsdirection,thenweobtainthemixedgraph.Usingthismethod,weconstructamixedgraphforfuturessugarpricesinZhengzhou(ZF),spotsugarpricesinZhengzhou(ZS)andfuturessugarpricesinNewYork(NF).Theresultshowsthatthereisabi-directionalcausalitybetweenZFandZS,anunidirectionalcausalityfromNFtoZF,butnocausalitybetweenNFandZS.更多还原

简介：Anultrasensitivebiosensorbasedonhybridstructureandcomposedoflong-rangesurfaceplasmonpolariton(LRSPP)anddielectricplanarwaveguide(PWG)modesisproposed.BothPWGandLRSPPmodeshavestrongresonancestoformstrongcouplingbetweenthetwomodes,andthetwomodescancoupletoenhancesensitivityofsensors.Inthehybridstructure,PWGiscomposedofcytop–Si–cytopmultilayersandtheLRSPPconfigurationiscomposedofcytop–metal–sensingmediummultilayerslabs.Thehighestimagingsensitivitiesof2264and3619RIU-1wererealizedintheproposedsensorsbasedonAuandAl-monolayergraphene,respectively,whicharenearly1.2and1.9timeslargerthanthe1910RIU-1sensitivityoftheconventionalLRSPRsensor(LRSPPsensor).Moreover,itisdemonstratedthatthePWG-coupledLRSPPbiosensorisapplicabletothesensingmedium,withrefractiveindexinthevicinityof1.34.

简介：Astudyiscarriedoutonthestructuraldesignofwood-plasticcompositefloors.Thegeometricparametersofthecavities,thestructure,andthemeanstooptimizetheperformanceoftheselightboardsareinvestigated.Variousstructuralparametersoftheboards,suchassize,shape,andthepatternofcavitiesarealsostudied.Theoptimalstructurecanbedeterminedbycalculationandanalysisofthestrength,stiffness,weightandcostofthematerial.Afiniteelementmodelforthemechanicalanalysisofwood-plasticcompositefloorsisestablished;andtheresultsareusedtoverifythestrengthcriteriaunderbendingdeformation,whichisthemostcommonloadingconditionofflooringboard.

简介：我们为把坚持、有效的抗菌剂性质合并到广泛地使用的聚合物报导灵巧的策略，poly(甲基methacrylate)(PMMA)，由异分子聚合有2-(tert-butylamino)的甲基methacrylate(MMA)在经由原子转移基聚合(ATRP)的一个壶的乙醇methacrylate(TA)。随后自己组装结果poly(甲基methacrylate)-block-poly[(2-tert-butylamino)ethylmethacrylate](PMMA20-b-PTA15)diblock共聚物负担得起明确的水可分散的泡，它能轻易地为有效抑制在医院里在墙上被喷洒并且细菌杀死。1H-NMR和胶化浸透层析(GPC)研究证实了良好共聚物的成功的合成。传播电子显微镜学(TEM)，原子力量显微镜学(AFM)和散布的动态光(DLS)学习与狭窄的尺寸分发证明了泡的形成。DLS研究在各种各样的温度揭示了泡的优秀稳定性。抗菌剂测试对克积极、克否定的细菌显示出聚合物泡的有效抗菌剂活动。而且，这策略可以为在许多领域里为灵巧的抗菌剂应用准备大量聚合材料被扩大。

简介：Phononicmaterialswithspecificband-gapcharacteristicsatdesiredfrequencyrangesareingreatdemandforvibrationandnoiseisolation,elasticwavefilters,andacousticdevices.Theattenuationcoefficientcurvedepictsboththefrequencyrangeofbandgapandtheattenuationofelasticwave,wherethefrequencyrangescorrespondingtothenone-zeroattenuationcoefficientsarebandgaps.Therefore,theband-gapcharacteristicscanbeachievedthroughmaximizingtheattenuationcoefficientatthecorrespondingfrequencyorwithinthecorrespondingfrequencyrange.Becausetheattenuationcoefficientcurveisnotsmoothinthefrequencydomain,thegradient-basedoptimizationmethodscannotbedirectlyusedinthedesignoptimizationofphononicband-gapmaterialstoachievethemaximumattenuationwithinthedesiredfrequencyrange.Toovercomethisdifficulty,theobjectiveofmaximizingtheattenuationcoefficientistransformedintomaximizingitsCosine,andinthisway,theobjectivefunctionissmoothedandbecomesdifferentiable.Basedonthisobjectivefunction,anovelgradient-basedoptimizationapproachisproposedtoopenthebandgapataprescribedfrequencyrangeandtofurthermaximizetheattenuationefficiencyoftheelasticwaveataspecificfrequencyorwithinaprescribedfrequencyrange.Numericalresultsdemonstratetheeffectivenessoftheproposedgradient-basedoptimizationmethodforenhancingthewaveattenuationproperties.

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简介：Asimplelayer-by-layerdepositiontechniquewasusedtofabricatethemultilayerthinfilmsofunmodifiedsilvertriangularnanoplates(AgTNPs).ThemultilayerofAgTNPsthinfilmswerefabricatedbyalternatedepositionofeachanionicsodiumcitratestabilizedAgTNPsandcationicpoly(diallyldimethylammoniumchloride).AllpreparedAgTNPsmultilayerthinfilmswereexhibitedastrongplasmonbandatthewavelengthof667nm,whichconfirmedtheformationofAgTNPsontothesubstrate.Thecharacteristicsofthemultilayerthinfilmswereinvestigatedusingcontactanglemeasurement,UV-visiblespectroscopy,X-raydiffractionanalysis(XRD),atomicforcemicroscope(AFM)andfieldemissionscanningelectronmicroscope(FESEM).Asthesefilmsaretobeusedasamercury(II)colorimetricsensor,thechangesinopticalpropertiesofthefilmswereevaluatedforvariousmercury(Ⅱ)concentrations.AgTNPsassembledintothinfilmsshowedastrongcolorshiftfrombluetomauveandcolorlesswhenexposedtomercury(Ⅱ).Theconstructedmultilayerthinfilmsexhibitedexcellentcolorchangesofmercury(II)withalinearrangebetween0.5and20ppm.Thelimitofdetection(LOD)andlimitofquantitation(LOQ)were0.45±0.002and1.52±0.002ppm,respectively.TherecoveryvaluesofAgTNPsmultilayerthinfilmsaresatisfactoryintherangeof100.1%-106.4%whenappliedtodeterminingmercury(Ⅱ)inwatersamples.

简介：Inthispaper,opticalpulserepetitionratemultiplicationbasedonaseries-coupleddouble-ringresonatorisproposed.First,thespectralcharacteristicoftheseries-coupleddouble-ringresonatorissimulatedandtheoptimumcouplingcoefficientstoachieveaperiodicflat-toppassbandareobtained.Then,high-qualitypulserepetitionratemultiplicationisrealizedbyperiodicallyfilteringoutspectrallinesoftheinputpulsetrain.DifferentmultiplicationfactorsN2,3,4,5canbeobtainedbyadjustingtheringradii.Inaddition,comparedwithasingle-ringresonator,themultipliedoutputpulsetrainbyaseries-coupleddouble-ringresonatorexhibitsmuchbetterpoweruniformity.

简介：WedemonstrateaQ-switchedRamanfiberlaserusingmolybdenumdisulfide(MoS_2)asasaturableabsorber(SA).TheSAisassembledbydepositingamechanicallyexfoliatedMoS_2ontoafiberferrulefacetbeforeitismatchedwithanothercleanferruleviaaconnector.ItisinsertedinaRamanfiberlasercavitywithatotalcavitylengthofabout8kmtogenerateaQ-switchingpulsetrainoperatingat1560.2nm.A7.7-km-longdispersioncompensatingfiberwith584ps·nm~(-1)km~(-1)ofdispersionisusedasanonlineargainmedium.Asthepumppowerisincreasedfrom395mWto422mW,therepetitionrateoftheQ-switchingpulsescanbeincreasedfrom132.7to137.4kHzwhilethepulsewidthisconcurrentlydecreasedfrom3.35μsto3.03μs.Themaximumpulseenergyof54.3nJisobtainedatthemaximumpumppowerof422mW.TheseresultsshowthatthemechanicallyexfoliatedMoS_2SAhasagreatpotentialtobeusedforpuisegenerationinRamanfiberlasersystems.

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简介：Anultrasensitivemagneticfieldsensorbasedonacompactin-fiberMach–Zehnderinterferometer（MZI）createdintwin-corefiber（TCF）isproposed,anditsperformanceisexperimentallydemonstrated.AsectionofTCFwassplicedbetweentwosectionsofstandardsingle-modefibers,andthenamicrochannelwasdrilledthroughonecoreoftheTCFbymeansoffemtosecondlasermicromachining.TheTCFwithonemicrochannelwasthenimmersedinawater-basedFe3O4magneticfluid（MF）,formingadirectcomponentofthelightpropagationpath,andthensealedinacapillarytube,achievingamagneticsensingelement,whichmergestheadvantagesofanMZIwithanMF.Experimentswereconductedtoinvestigatethemagneticresponseoftheproposedsensor.Thedevelopedmagneticfieldsensorexhibitsalinearresponsewithinameasurementrangefrom5to9.5mTandanultrahighsensitivityof20.8nm/mT,which,toourbestknowledge,is2ordersofmagnitudegreaterthanotherpreviouslyreportedmagneticsensors.Theproposedsensorisexpectedtooffersignificantpotentialfordetectingweakmagneticfields.

简介：新奇结合的聚合物，poly(1)，在主要的链包含thiourea一半经由联合反应的铃木被综合。亚铜的离子的增加熄灭荧光(1)而荧光在另外的金属离子的增加之上稍微变化，poly展出荧光灯向Cu+察觉到能力的几乎转弯。当氢过氧化物被加到poly包含的答案(1)和Cu+,Cu时，+被氧化进导致荧光恢复的Cu2+,。H2葡萄糖oxidase(上帝)免除葡萄糖氧化的O2也恢复了荧光poly(1)/Cu+答案。结果显示(1)poly，/Cu+答案能为氢过氧化物和葡萄糖用作一个察觉到的平台。

简介：Anewmethodforfabricatingorderedporoussiliconisreported.Atwo-dimensionalsilicananospherearrayisusedasatemplatewithahydrofluoricacid-hydrogenperoxidesolutionforetchingthenanospheres.Theinitialdiameteranddistributionoftheholesintheresultingporoussiliconlayeraredeterminedbythesizeanddistributionofthesilicananospheres.Thecorrosiontimecanbeusedtocontrolthedepthsoftheholes.ItisfoundthatthepresenceofaSiO_2layer,formedbytheoxidationoftheroughinternalsurfaceofthehole,istheprimaryreasonallowingthecorrosiontoproceed.Ultravioletreflectionandthermalconductivitymeasurementsshowthatthediameteranddistributionoftheholeshaveagreatinfluenceonpropertiesoftheporoussilicon.

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简介：Theeffectsoftwogeometricrefinementstrategieswidespreadinnaturalstructures,chiralityandself-similarhierarchy,onthein-planeelasticresponseoftwo-dimensionalhoneycombswerestudiedsystematically.Simpleclosed-formexpressionswerederivedfortheelasticmoduliofseveralchiral,antichiral,andhierarchicalhoneycombswithhexagonandsquarebasednetworks.Finiteelementanalysiswasemployedtovalidatetheanalyticalestimatesoftheelasticmoduli.Theresultswerealsocomparedwiththenumericalandexperimentaldataavailableintheliterature.WefoundthatintroducingahierarchicalrefinementincreasestheYoung'smodulusofhexagonbasedhoneycombswhiledecreasestheirshearmodulus.Forsquarebasedhoneycombs,hierarchyincreasestheshearmoduluswhiledecreasingtheirYoung'smodulus.IntroducingchiralitywasshowntoalwaysdecreasetheYoung'smodulusandPoisson'sratioofthestructure.However,chiralityremainstheonlyroutetoauxeticity.Inparticular,wefoundthatanti-tetra-chiralstructureswerecapableofsimultaneouslyexhibitinganisotropy,auxeticity,andremarkablylowshearmodulusasthemagnitudeofthechiralityoftheunitcellincreases.

简介：Bystudyingthetraditionalspectralreflectancereconstructionmethod,spectralreflectanceandtherelativespectralpowerdistributionofalightingsourcearesparselydecomposed,andtheorthogonalpropertyoftheprincipalcomponentorthogonalbasisisusedtoeliminatebasis;thenspectralreflectancedataareobtainedbysolvingasparsecoefficient.Aftertheoreticalanalysis,thespectralreflectancereconstructionbasedonsparsepriorknowledgeoftheprincipalcomponentorthogonalbasisbyasingle-pixeldetectoriscarriedoutbysoftwaresimulationandexperiment.Itcanreducethecomplexityandcostofthesystem,andhascertainsignificancefortheimprovementofmultispectralimageacquisitiontechnology.

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简介：TheZnOquantumdots(QDs)weresynthesizedwithimprovedchemicalsolutionmethod.ThesizeoftheZnOQDsisexceedinglyuniformwithadiameterofapproximately4.8nm,whicharehomogeneouslydispersedinethanol.Theopticalabsorptionedgeshiftsfrom370nmofbulkmaterialto359nmofQDmaterialsduetothequantumsizeeffect,whilethephotoluminescencepeakshiftsfrom375nmto387nmwiththeincreaseofthedensityofZnOQDs.ThestabilityofZnOQDswasstudiedwithdifferentdispersiondegreesat0?Candatroomtemperatureof25?C.Theagglomerationmechanismsandtheirrelationshipwiththeemissionspectrawereuncoveredforthefirsttime.WiththeageingofZnOQDs,theagglomerationisaggravatedandthesurfacedefectsincrease,whichleadstothedefectemission.

简介：Klapper(1994)showedthatthereexistsaclassofgeometricsequenceswiththemaximalpossiblelinearcomplexitywhenconsideredassequencesoverGF(2),butthesesequenceshaveverylowlinearcomplexitieswhenconsideredassequencesoverGF(p)(pisanoddprime).ThislinearcomplexityofabinarysequencewhenconsideredasasequenceoverGF(p)iscalledGF(p)complexity.ThisindicatesthatthebinarysequenceswithhighGF(2)linearcomplexitiesareinadequateforsecurityinthepracticalapplication,while,theirGF(p)linearcomplexitiesarealsoequallyimportant,evenwhentheonlyconcerniswithattacksusingtheBerlekamp-Masseyalgorithm[Massey,J.L.,Shift-registersynthesisandbchdecoding,IEEETransactionsonInformationTheory,15(1),1969,122–127].Fromthisperspective,inthispapertheauthorsstudytheGF(p)linearcomplexityofHall’ssexticresiduesequencesandsomeknowncyclotomic-set-basedsequences.

简介：Inthispaper,themodifiedextendedtanhmethodisusedtoconstructmoregeneralexactsolutionsofa(2+1)-dimensionalnonlinearSchr¨odingerequation.WiththeaidofMapleandMatlabsoftware,weobtainexactexplicitkinkwavesolutions,peakonwavesolutions,periodicwavesolutionsandtheir3Dimages.