简介：FifteennewabsorptionlinesareobservedwhenstudyingCO2absorptionspectroscopybywavelengthmodulation(WM)techniquewithadistributedfeedbacklaser.TheovertonespectraofCO2around1.31μmandthecorrespondingspectralparameters(i.e.positions,intensities,self-broadeningcoefficients)arepresented.Theintensityoftheweakestlinedetectedis2.25163×10^-27cm^-1/(molecule·cm^-2)atthepressureof5Tort,withacorrespondingabsorptionof3.88×10^-8.

简介：Failureofbridgesduetolocalscourinthevicinityofbridgeabutmentsisacommonoccurrence.Inthisstudy,experimentsundertwodifferentchannelconditionswereconductedtoassesstheimpactsofvegetationonchannelbanksonlocalscouraroundawing-wallabutmentwithcircularedges.Someexperimentswereconductedinchannelwithvegetationonchannelbanks,andotherexperimentsinchannelwithoutvegetationonchannelbank.TheflowvelocityandReynoldsstressdistributionsinscourholesaroundawing-wallabutmentwithcircularedgeswerecomparedunderthese2differentchannelconditions.Resultsrevealthatthevegetated-bankscanreducethetimeforachievingtheequilibriumconditionfrom17hto9h.Also,vegetated-bankchannelscanresultinasignificantdecreaseinthemaximumscourdepthfrom0.084m(forbarechannelbank)to0.00032m.Additionally,aroundtheabutment,vegetated-banksplayasignificantroleindiminishingtheReynoldsstress(RS)nearthebedandremovingnegativevaluesinRSdistributionbyweakeningunfavorablepressuregradientanddown-flowintheupstreamofabutment.

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.

简介：因为它启用自由并且从而的光子旋转度的敏感控制，光的纺纱轨道相互作用(SOI)强烈地在nanophotonics被学习了光子的轨道，它为象信号编码和路由那样的应用程序是有用的。最近的研究[Phys。加快。Lett。117，166803(2016)]证明光子的SOI在光子通过宣传的媒介的介电常数面对一个坡度表明；这提高在沿着扭曲的轨道宣传的光子散布循环地极化的光和结果。这里，我们理论上预言那，因为在不同类的绝缘的媒介和在转变光学表明的一个重力的领域之间的等价，重要SOI被导致到一个黑洞的重力的透镜过去的循环地极化的光上。这导致：我)如果黑洞的尺寸比事件光子的波长小，沿着chiral轨道宣传的光子；ii)重力的透镜到的产生图象因为这些chiral轨道，表明方位角的旋转。为探查为并且用循环地极化的光发现subwavelength尺寸黑人洞的一个方法开的调查结果。

简介：Laserinsituscatteringandtransmissometry(LISST)significantlyimprovesourabilitytoassessparticlesizedistribution(PSD)inseawater,whilewide-rangingmeasurementsoftheorganic-inorganiccompositionsofsuspendedparticulatematters(SPM)arestilldifficultbyusingtraditionalmethodssuchasmicroscopy.Inthisstudy,PSDpropertiesandSPMcompositionsaroundtheBohaiStrait(China)wereinvestigatedbasedonthemeasurementsbyLISSTincombinationwithhydro-biologicalparameterscollectedfromafieldsurveyinsummer2014.FourtypicalPSDshapeswerefoundintheregion,namelyright-peak,left-peak,double-peakandnegative-skewshapes.Thedouble-peakandnegative-skewshapesmayinterconvertintoeachotheralongwithstronghydrodynamicvariation.IntheupperlayeroftheBohaiSea,organicparticleswereinthemajority,withinorganicparticlesrarelyobserved.Inthebottomlayer,SPMwerethemixtureoforganicandinorganicmatters.LISSTprovidedvaluablebaselineinformationonsize-resolvedorganic-inorganiccompositionsofSPM:thesizeoforganicparticlesmainlyrangedfrom4to20μmand40to100μm,whilemostSPMrangingfrom20to40μmwerecomposedofinorganicsediment.

简介：Inthisstudy,wesimulatedtyphoonwavesintheshallowwatersaroundtheZhoushanIslandsusingtheWaveWatch-III(WW3)modelversion5.16,thelatestversionreleasedbytheNationalOceanicandAtmosphericAdministration.Specifically,weusedin-situmeasurementstoevaluatetheperformanceofsevenpackagesofinput/dissipationsourcetermsintheWW3model.WeforcedtheWW3modelbywindfieldsderivedfromacombinationoftheparametricHollandmodelandhigh-resolutionEuropeanCenterforMedium-RangeWeatherForecasts(ECMWF)winddataina0.125°grid,hereincalledH-Ewinds.WetrainedtheH-EwindsbyfittingashapeparameterBtobuoy-measuredobservations,whichresultedinasmallestrootmeansquareerror(RMSE)of3ms?1forB,whentreatedasaconstant0.4.Then,weappliedtheseveninput/dissipationtermsofWW3,labelledST1,ST2,ST2+STAB2,ST3,ST3+STAB3,ST4,andST6,tosimulatethesignificantwaveheight(SWH)upto5mduringtyphoonsFungwongandChan-homaroundtheZhoushanIslands.WethencomparedtheSWHsofthesimulatedwaveswiththosemeasuredbythein-situbuoys.TheresultsindicatethatthesimulationusingST2performsbestwithanRMSEof0.79mfortyphoonFung-wongandanRMSEof1.12mfortyphoonChan-hom.Interestingly,wefoundthesimulatedSWHresultstoberelativelyhigherthanthoseoftheobservationsintheareabetweenHangzhouBayandtheZhoushanIslands.Thisbehaviorisworthyoffurtherinvestigationinthefuture.

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简介：AnumericalwaveflumeisconstructedbasedontheReynoldsAveragedNavier-Stokes(RANS)equationswithturbulenceclosurebyamodifiedk-εmodeltostudytheviscousinteractionsofwaveswithverticalbreakwatersfordifferentovertoppingcases.Thegoverningequations,theturbulencemodel,boundaryconditions,andsolutionmethodforthenumericalwaveflumeareintroducedbriefly.Thereliabilityofthenumericalwaveflumeisexaminedbycomparingthenumericalresultswiththeexperimentalmeasurements,andgoodagreementsbetweenthemindicatethevalidityofthepresentmodel.Thedevelopmentsofmeanvelocityfields,thecontoursofvorticity,andtheinfluencesofwavenonlinearityonturbulencefieldaswavepassingthroughverticalbreakwatersarediscussedindetailbasedonthenumericalresults.Itisnotedthatthevorticesattherearofthelowersubmergedbreakwaterareclosetothebottomandmaybeinducethescouringtotheleesidetoeofmarinestructureinpractice.Overall,aconclusioncanbeobtainedfromthisstudythattheturbulenceinwavefieldaroundstructureisinduceddirectlybythedevelopmentofboundarylayeronthesolidboundary,thenonlinearinteractionoffreesurfacewithobstacle,andtheplungingofovertoppingwaves.

简介：二层的污染物质移流散开建模的A被造在Maidao附近在海区域调查污染物质运输离开Qingdao海岸。一种伴随数据吸收技术被使用估计模型参数的最佳的价值。污染物质的起始的地上的试验性的结果显示化学需氧量(货到付款)集中的分发对水平旋涡扩散性敏感。水平旋涡扩散性的适当价值是必要的以便精确描绘起始的领域的影响，；它对污染物质的移流散开过程的模拟也必要。由模型参数的倒置；起始的货到付款集中的优化，模拟结果显著地被改进。费用函数被归结为它的第一步值中的40%个。在模型产量之间的平均不合身的衣服；在从0.46～0.25mgL的上面的层减少的观察[1]，；那从0.22～0.14mgL在底层减少[1]。

简介：Ontheconditionthatthevelocityratioofcompressivewavetoshearwaveisstableduringthepropagatingprocessofseismicwave,thispaperdevelopsanestimationmethodformediumqualityfactorbasedonsinglestation'straveltimedifferencebetweendirectSandPwavesandthefirstperiodsignalofdirectPwave.8774highSNRwavedataaltogetherrecordedby75stationsareanalyzed.Theresultsshowthat:(1)underthenormalregionalstressfield,thequalityfactorsQmSPinthestabletectonicareaarehigherthanthatintheactivetectonicareaaroundtheWeifang-JiashansectionanditssurroundingareaintheTanlufaultzone;(2)intheJuxian-Tanchengsectiontheseismicwaveattenuationisrelativelyquick,andthemediaisrelativelybroken,suggestingnotectonicstressaccumulation;(3)theXinyi-Sihongsectioniscurrentlylockingandinaccumulatingelasticstrainenergystage,whichhasthedeepenvironmentandconditionsofstrongearthquakegenerationsimilartothoseofthe1668M8.5Tanchengstrongearthquake.

简介：FlowsaroundacircularcylinderdisplayinganunsteadyvortexsheddingprocessattheReynoldsnumbersof1000,3900and1×104arestudiedusingafinite-volumeTotalVariationDiminishing(TVD)schemeforsolvingtheUnsteadyReynolds-AveragedNavier-Stokes(URANS)equations.AnElementalVelocityVectorTransformation(EVVT)approachisproposedforthelocalnormalandtangentialvelocitytransformationattheinterfacesofmainandsatelliteelements.Thepresentedmethodisvalidatedbycomparingwiththeavailableexperimentaldataandnumericalresults.Itisshownthatthetwo-dimensionalTVDfinitevolumemethodwiththeRenormalizationGroup(RNG)turbulencemodelcanbeusedtodeterminehydrodynamicforcesandcapturesvortexsheddingcharacteristicsverywell.

简介：TheunsteadycavitationevolutionaroundtheClark-Yhydrofoilisinvestigatedinthispaper,byusinganimprovedfilter-basemodel(FBM)withthedensitycorrectionmethod(DCM).Toimprovethepredictionaccuracy,thefilterscaleisadjustedbasedonthegridsize.Thenumericalresultsshowthatasmallfilterscaleiscrucialfortheunsteadysimulationsofthecavitysheddingflow.ThehybridmethodthatcombinestheFBMandtheDCMcouldhelptolimittheoverpredictionoftheturbulentviscosityinthecavitationregiononthewallofthehydrofoilandinthewake.Thelargevalueofthemaximumdensityratio?l/?v,clippromotesthemasstransferratebetweentheliquidphaseandthevaporphase,whichresultsinalargesheetcavitylengthandthevaporfractionriseinsidethecavity.Thecavitypatternspredictedbytheimprovedmethodareverifiedbytheexperimentalvisualizations.Thetime-averagelift,thedragcoefficientandtheprimaryoscillatingfrequencyStforthecavitationnumber?=0.8,theangleofattack,?=8o,ataReynoldsnumberRe=7?105are0.735,0.115and0.183,respectively,andthepredictederrorsare3.29%,3.36%and8.93%.Thetypicalthreestagesinonerevolutionarewell-captured,includingtheinitiationofthesheet/attachedcavity,thegrowthtowardthetrailingedge(TE)withthedevelopmentofthere-entrantjetflow,andthelargescalecloudcavityshedding.ItisobservedthatthecloudcavitysheddingflowinducesthevortexpairsoftheTEvorticesinthewakeandthesheddingvortices.Thepositivevorticityvortexofthere-entrantjetandtheTEvorticesinteractsandmergeswiththenegativevorticityvortexoftheleadingedge(LE)cavitytoproducethesheddingflow.

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简介：摘要：英语学科是一门以语言学习为最终目标的学科，阅读与写作都是学生进行语言学习的步骤。随着人们对英语学科本质了解的深入，阅读与写作之间的结合教学受到了越来越多人的重视，如何优化读写课堂，已经成为了高中生提升自身知识感知能力的有效方法。因此，要想提升高中英语读写教学的有效性，我们不妨充分重视阅读与写作之间的本质性联系，将阅读与写作合理的统一到同一教学过程中。

简介：Withtheincreaseofpetroleumandgasproductionindeepocean,marinerisersofcircularcylindershapearewidelyusedintheoffshoreoilandgasplatform.Inordertoresearchthehydrodynamicperformanceofmarinerisers,thedynamicmeshtechniqueandUser-DefinedFunction(UDF)areusedtosimulatethecircularcylindermotion.Themotionofatransverselyoscillatingcircularcylinderincombinationofuniformflowandoscillatingflowissimulated.Theuniformflowandoscillatingflowbothareinxdirection.SIMPLEalgorithmisusedtosolvetheNavier-Stokesequations.TheUser-DefinedFunctionisusedtocontrolthecylindertransversevibrationandtheinletflow.Theliftanddragcoefficientchangingwithtimeandthemapofvorticityisolinesatdifferentphaseangleareobtained.ForcetimehistoriesareshownforuniformflowatReynoldsnumber(Re)of200andforthecombinationofuniformandoscillatingflows.Withtheincreaseofamplitudeofoscillatingflowincombinedflow,thechangeofliftamplitudeisnotsensitivetothethechangeofcylinderoscillatingfrequency.Liftamplitudeincreaseswiththeincreaseofoscillatingflowamplitudeinthecombinedflow,butthereisnodefiniteperiodicityoftheliftcoefficient.Thedragandinertiaforcecoefficientschangewhenthemaximumvelocityoftheoscillatingflowincreasesinthecombinedflow.Thevortexsheddingnearthecircularcylindershowsdifferentcharacteristics.

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简介：Physicalmodeltestswerecounductedtopredictlocalscourandmaximumscourdeptharoundthelargediametercylinderslocatedinthe(sand)seabedundertheactionofbothwaveandcurrent.Accordingtotheresultoftests,ananalysiswasmadeonallthefactorsinfluencingthescour.Theresultsshowsthatfortheseabedwithrelativefinegrainsinshallowwater(0.07＜h/L≤0.28),whentherelativediameterD/Lofthecylinderiswithin0.3-0.7,themaineffectivescourfactorsaroundthecylinderintheseabedarediameterDofthecylinder,thewaveheightH,thewavelengthL,thevelocityVcofthecurrentandtheparametersrelatedtotheseabedsoiltexture.Themainparametersinfluecingthemaximumscourdepthwereanalyzed,andthetestdataweresyntherized,toobtaintheformulapredictingthescourdeptharoundthelargediametercylinderundertheofbothwaveandcurrent.

简介：Atime-domainmethodisappliedtosimulatenonlinearwavediffractionaroundasurfacepiercing3-Darbitrarybody.ThemethodinvolvestheapplicationofTaylorseriesexpansionsandtheuseofperturbationproceduretoestablishthecorrespondingboundaryvalueproblemswithrespecttoatime-independentfluiddomain.AboundaryelementmethodbasedonB-splineexpansionisusedtocalculatethewavefieldateachtimestep,andthefreesurfaceboundaryconditionissatisfiedtothesecondorderofwavesteepnessbyanumericalintegrationintime.Anartificialdampinglayerisadoptedonthefreesurfacefortheremovalofwavereflectionfromtheouterboundary.Asanillustration,themethodisusedtocomputethesecond-orderwaveforcesandrun-uponasurface-piercingcircularcylinder.Thepresentmethodisfoundtobeaccurate,computationallyefficient,andnumericallystable.

简介：Theheadmounteddisplay(HMD)iswidelyusedinvirtualrealitytechnology.IncommonHMD,however,thebinoculardisparityissettoanequalfixedvalueintheentirerangeofview.SuchHMDsystemshaveseveralshortcomingswhenusedforwideviews.Inthisstudy,inordertorealizeanaturalstereosensationofHMDwithwideview,wemeasurethecharacteristicsofbinocularstereoperceptionandbinocularlightperception.Resultsshowthatboththestereoacuityandlightsensitivitydecreaseastheretina'seccentricityincreasesfromfoveatoperiphery.However,thedecreaseofthestereoacuityismorerapidthanthatofthelightsensitivity.Theseresultssuggestthatthebinoculardisparityattheperipheralfieldshouldbesmall,otherwisedoubleimageswouldbeobservedinsteadofastereoview.Basedontheresultswedeveloparelativebinocularstereoacuitymodelwhichcanbeapplied{orthedesignofHMDsystemswithwideview.