简介：

简介：

简介：

简介：TheaimofthisstudyistoinvestigateexperimentallytheeffectofsurfaceroughnessoncloudcavitationaroundClark-Yhydrofoils.High-speedvideoandparticleimagevelocimetry(PIV)wereusedtoobtaincavitationpatternsimages(Prog.Aerosp.Sci.37:551–581,2001),aswellasvelocityandvorticityfields.ResultsarepresentedforcloudcavitatingconditionsaroundaClark-Yhydrofoilfixedatangleofattackofα=8?formoderateReynoldsnumberofRe=5.6×105.Theresultsshowthatroughnesshadagreatinfluenceonthepattern,velocityandvorticitydistributionofcloudcavitation.Forcavitatingflowaroundasmoothhydrofoil(A)andaroughhydrofoil(B),cloudcavitationoccurredintheformoffinger-likecavitiesandattachedsubulatecavities,respectively.TheperiodofcloudcavitationaroundhydrofoilAwasshorterthanforhydrofoilB.Surfaceroughnesshadagreatinfluenceontheprocessofcloudcavitation.ThedevelopmentofcloudcavitationaroundhydrofoilAconsistedoftwostages:(1)Attachedcavitiesdevelopedalongthesurfacetothetrailingedge;(2)Areentrantjetdeveloped,resultinginsheddingandcollapseofclusterbubblesorvortexstructure.Meanwhile,itsdevelopmentforhydrofoilBincludedthreestages:(1)Attachedcavitiesdevelopedalongthesurfacetothetrailingedge,withaccumulationandrotationofbubblesatthetrailingedgeofthehydrofoilaffectingtheflowfield;(2)Developmentofareentrantjetresultedinthefirstsheddingofcavities.Interactionandmovementofflowsfromthepressuresideandsuctionsidebroughtliquidwaterfromthepressuresidetothesuctionsideofthehydrofoil,finallyformingareentrantjet.Thejetkeptmovingalongthesurfacetotheleadingedgeofthehydrofoil,resultinginlarge-scalesheddingofcloudbubbles.Severalvorticesappearedanddissipatedduringtheprocess;(3)Cavitiesgrewandshedagain.

简介：

简介：ThecharacteristicofEDFAinWDMsystemisanalyzed.ThesimulationsystembasedonthearchitectureoftheChinaInformationNetwork(CAINONET)isintroduced,andtheinfluenceofnoisefigure,gainunflatnessandoutputpowerofEDFAontheBERperformanceandscaleofnetworkisinvestigated.Moreover,theinfluenceofnoisefigureisstudiedwithdifferentcrosstalk.Meanwhile,itisindicatedthatitisimportanttoapplythe"nodeisolationprinciple"intheopticalnetwork.Theresearchresultscanprovidethevaluablereferenceforthepracticalconstructionofallopticalnetwork.

简介：Toimproveseparateeffectofbinaryheterogeneousazeotropeinthemagneticfieldwithdifferentmagneticinductionintensity,theinfluenceofmagneticfieldontherectificationprocessofbinaryheterogeneousazeotropewasinvestigatedwith1-butanol-watersystem.Theresultsshowthatthecompositionofliquid-liquidphaseequilibriumof1-butanol-watersystemhasdefinitelychanged,thecompositionof1-butanolinlightphase(1-butanollayer)increasesby1.17%-1.63%andthecompositionofwaterinheavyphase(waterlayer)increasesby1.21%-1.58%undertheinfluenceofmagneticfield.Byseparationofmagnetization,thecompositionof1-butanolincreasesby0.8%-1.2%andtherecoveryratioof1-butanolincreasesby1.6%-2.5%.Magneticfieldhaspositiveeffect,however,themagnetizedeffectisnotinproportiontomagneticinductionintensityandhasanoptimumcondition,intherangeof0.25T-0.3T.

简介：

简介：Theepoxynanocompositeswithsimilaramines(CH_3(CH_2)_(17)NH_2andCH_3(CH_2)_(17)N(CH_3)_3CI)treatedmontmorilloniteclayshavebeeninvestigatedbywide-angleX-rayscattering,transmissionelectronmicroscopy(TEM),differentialscanningcalorimetry(DSC)andthermalgravimetricanalysis(TGA).Differentnanocompositestructures,intercalationandexfoliationwereformedbythereactionofoctadecyltrimethylammoniumchloride-exchangedandoctadecylamine-exchangedclayswithepoxyresinandphenalkamineasthecuringagent,respectively.Resultsshowedthattheexfoliatednanocompositecanbeobtainedwhenoctadecylaminewiththelowerpolaritywasusedasamodifier.However,theintercalatednanocompositecanbeobtainedwhenoctadecyltrimethylammoniumchloridewithhigherpolaritywasusedasamodifier.

简介：学习试图在3-year-forestage比较沼泽地的macrofauna社区的差别，5-year-forest-ageSonneratiaapetala人工的红树属植物，5-year-forest-ageKandeliacandel有一样的恢复背景的人工的红树属植物，和在珠海的Qiao岛红树属植物自然保护区的裸体潮汐的公寓，广东省。结果证明在在四种产地之中的macrofauna社区有重要结构的差别。生物资源和在3-year-forest-ageS的macrofauna的种类差异的增加。apetala人工的红树属植物在5-year-forest-ageK显然是比那快的。candel树高度其一般水准接近了3-year-forest-ageS的人工的红树属植物。apetala人工的红树属植物。BIOENV分析证明它与S的快速的生长有关。apetala，它很快在森林里改变了轻水平和shading条件。5-year-forest-ageS。人工的红树属植物有的apetala降低macrofauna种类差异但是更高的密度和生物资源比K。有一样的森林的人工的红树属植物变老的candel。这由于由S的生态的恢复的产地土壤的物理、化学的性质的快速的变化。人工的红树属植物以及改变的食物来源可能由如此的非土生土长的红树属植物种类S的叶崽引起了的apetala。apetala。然而，进一步的调查应该在是否有S的大规模耕作的任何否定生态的影响上被进行。macrofauna社区上的apetala，以便正确地评估S。在沿海的红树属植物生态系统的恢复的apetalas角色。

简介：ＩＮＦＬＵＥＮＣＥＯＦ２００ｈＰａＤＩＶＥＲＧＥＮＣＥＣＩＲＣＵＬＡＴＩＯＮＯＮＴＨＥＴＲＡＣＫＳＯＦＴＲＯＰＩＣＡＬＣＹＣＬＯＮＥＳ￥ＺｈｏｕＸｕｅｑｕｎａｎｄＺｈａｎｇＸｉａｎｇ周学群，张翔（ＭｅｔｅｏｒｏｌｏｇｉｃａｌＯｂｓｅｒｖａｔｏｒｙｏｆ...

简介：

简介：-Thevariationoftheamplitudeofwaveswithvaryingincidentangleswhenwavespropagatethroughatypicalapproachchannelisdiscussedbyanumericalcalculationmethod,theresultofwhichshowsthattheinfluenceofthechannelonwavepropagationisobvious.Whenthewavepropagationdirectionisincoincidencewiththechannelaxis,thewaveamplituderatiowilldecreasewiththeincreaseofpropagationdistance.Whentheincidentangleis15-30,thereappearsanareaoflargerwaveamplituderatioonthesideslopefacingthewaves,butattheanotherside,thewaveamplituderatioisgenerallysmall,indicatingthatthechannelhasashieldingeffect.Whenwavespropagateacrossthechannelperpendicularly,thewaveamplituderatiocanbecalculatedwiththeshallowwatercoefficient.

简介：Thispaperexplains,withconcreteexamples,thatthenon-verbalbarriersalsoobstructstudents’correctunderstandingoflisteningmaterials,andana-lyzestheproblemsresultingfromstudentslackofcul-turalknowledgeofthetargetlanguage.Suggestionsareofferedtohelpstudentshaveabetterunderstand-ingbyintroducingtheoriginofEnglishwords,intro-ducingtheculturaltraitsofnativespeakers,theircustomsandintroducetherelativeculturalknowledgetopromotestudents’comprehensionofthetargetlan-guage.

简介：Theinfluenceofexternallowfrequency(0-100Hz)vibrationonthetip-sampleinteractioninSPMisthemainconcernofthispaper.Aconcept,vibrationrejectionratio(VRR)proposedbyThompsonetal,wasinvestigatedtheoreticallyandexperimentally.Aconcisetheoreticalbackgroundwasintroduced,avibrationstimulatingandmeasuringsystemforSPMwasbuiltup,andanexperimentalresearchoftheinfluenceonSPMVRRwascarriedoutwithdifferentSPMprobes,samples,tippre-loadsandopen/closeloopsoftip-sampleinteraction.ItwasprovedbothintheoryandexperimentthatSPMVRRhadcorrelationswiththespringconstant,theairdampingconstant,theeffectivemassofthecantilever,thecontactspringconstantandthecontactdampingconstantbetweentipandsample.SPM'svibrationrejectingabilitycanbeimprovedbylongercantileverprobe,softersamplesurface,greatertippre-load,andclose-loopcontrolfortip-sampleinteraction.Moreattentionshouldbepaidtoapropercombinationoftheaboveparameters.

简介：Theartificialecologicalfloatingbediswidelyusedinriversandlakestorepairandpurifypollutedwater.However,thewaterflowpatternandthewaterleveldistributionaresignificantlychangedbythefloatingbeds,andtheinfluenceonthewaterflowisdifferentfromthatofaquaticplants.Inthispaper,basedonthecontinuousporousmediamodel,amoveabletwo-layercombinationmodelisbuilttodescribethefloatingbed.Theinfluencesofthefloatingbedsonthewaterflowcharacteristicsarestudiedbynumericalsimulationsandexperimentsusinganexperimentalwaterchannel.Thevariationsofthewaterleveldistributionarediscussedunderconditionsofdifferentflowvelocities(v=0.1m/s,0.2m/s,0.30m/s,0.4m/s),floatingbedcoveragerates(20%,40%,60%)andarrangementpositionsawayfromthechannelwall(D=0m,0.1m,0.2m).Theresultsindicatethattheflowvelocityincreasesunderthefloatingbeds,andthewaterlevelrisessignificantlyunderhighflowvelocityconditionsintheupstreamregionandthefloatingbedregion.Inaddition,theaveragerisingwaterlevelvalue(ARWLV)increasessignificantlywiththeincreaseofthefloatingbedcoveragerate,andthearrangementpositionoffloatingbedsintherivercanalsogreatlyinfluencethewaterleveldistributionunderahigh-flowvelocitycondition(v?0.2m/s).

简介：Thestudyoffrictionalpropertiesofhumanskinisimportantformedicalresearch,skincareproductsandtextileexploi-tation.Inordertoinvestigatetheinfluenceofnormalloadandslidingspeedonthefrictionalpropertiesofskinanditspossiblemechanism,testswerecarriedoutonamulti-specimenfrictiontester.Whenthenormalloadincreasesfrom0.1Nto0.9N,normaldisplacementandthefrictioncoefficientofskinincrease.Thefrictioncoefficientisdependentontheload,indicatingthatbothadhesionanddeformationcontributetothefrictionbehaviour.Thedeformationfrictionwasinterpretedusingtheploughmodeloffriction.Whenslidingspeedincreasesfrom0.5mm·s?1to4mm·s?1,thefrictioncoefficientincreasesand'stick-slip'phenomenaincrease,indicatingthathystereticfrictioncontributestothefriction.Thehystereticfrictionwasin-terpretedusingschematicofenergytranslationduringtherigidsphericalprobeslidingonthesoftskinsurface,whichprovidesanexplanationfortheinfluenceoftheslidingspeedonthefrictionalcharacteristicsoftheskin.

简介：

简介：

简介：