简介:WhilenegativetransferofthenativelinguisticknowledgeinSLAiscloselystudied,otheraspectsofthelearner’snativeknowledgehavebeenignored.Thefollowingisaninvestigationandstudyinthisrespect,revealingthatnegativetransfernoton-lyhappensintheaspectofthelearner’snativelinguisticknowl-edgesuchasthatofthenativegrammaticalrulesandlexicalcon-ception,butalsohappensinaspectsofculturalconventionsandthinkingpatterns.Itisalsofoundthatnegativetransferoflin-guisticknowledgedecreaseswiththelearner’sprogressinstudywhiletheothertwoaspectshavenoobviousdecrease.WithLevel3asacontrolgroup,thispaperconfirmedtheeffectivenessandnecessityinofferingclassesdealingwiththeothertwoaspectsofnegativetransfer.
简介:Inthispaperweconsidersomerelatednegativehypergeometricdistributionsarisingfromtheproblemofsamplingwithoutreplacementfromanurncontainingballsofdifferentcoloursandindifferentproportionsbutstoppingonlyaftersomespecificnumberofballsofdifferentcolourshavebeenobtained.Withtheaidofsomesimplerecurrencerelationsandidentitiesweobtaininthecaseoftwocoloursthemomentsforthemaximumnegativehypergeometricdistribution,theminimumnegativehypergeometricdistribution,thelikelihoodrationegativehypergeometricdistributionandconsequentlythelikelihoodproportionalnegativehypergeometricdistributiuon.TotheextentthatthesamplingschemeisapplicabletomodellingdataasillustratedwithabiologicalexampleandinfactmanysituationsofestimatingBernoulliparametersforbinarytraitswithinafinitepopulation,theseareimportantfirst-stepresults.
简介:Inthispaperweconsidertheclass∑[p,α,β,k,c]consistingofanalyticfunctionswithnegativecoefficientsandfixedsecondcoefficient.Theobjectofthepresentpaperistogivecoefficientestimates,convexlinearcombinations,somedistortiontheoremsandradiiofstarlikenessandconvexityforf(z)intheclass∑[p,α,β,k,c].
简介:Small-angleX-rayscattering(SAXS)usingsynchrotronradiationasX-raysourcehasbeenemployedtocharactcizcthemicroscopicstructrureoforgano-modifiedmesoporousmolecularsieves(organo-MSU-X)preparedbyaone-pottemplate-directedsynthesis.ItisshownthattheSAXSprofileishardlyconstantwithPorod’slawshowinganegativeslope,i.e.,negativedeviation.Thissuggeststhatthereisdiffuseinterfaciallayerlocatedbetweentheporesandthematrix.Thissuggeststhattheorganicgroupsremaincovalentlylinkedtothematrix,asindicatedby^29SiCPMASNMRandFT-IR.Theaveragethicknessoftheinterfaciallayerwasfoundtobeabout1nmforeachofthethreesampleswithdifferentkindsandthesameamounts(20?oforganicgroups.Thiskindofmaterialhasalsobeenprovedtopossessbothsurfaceandmassfractalstructureoftheamophousporoussilicamaterials.2001ElsevierScienceB.V.Allrightsreserved.
简介:AccumulatingevidencehasdemonstratedthatregulatoryT(Treg)cellsplayanimportantroleinthemaintenanceofimmunologicself-toleranceandindown-regulatingvariousimmuneresponses.Thus,therehasrecentlybeenanincreasinginterestinstudyingthebiologyofTregcellsaswellastheirpotentialapplicationintreatingimmunediseases.ManytypesofTregcellsubsetshavebeenreportedinavarietyofdiseasemodels.Amongthesesubsets,αβ-TCR+CD3+CD4-CD8-doublenegative(DN)TregcellsaredefinedbytheircapabilityofinhibitingimmuneresponsesviadirectlykillingeffectorTcellsinanantigenspecificfashion.Furthermore,DNTregcellshavebeenshowntodevelopregulatoryactivityafterencounteringspecificantigens,partiallymediatedbytheacquisitionofMHC-peptidecomplexesfromantigenpresentingcells(APCs).ThepresentationofacquiredalloantigensonDNTcellsallowsforthespecificinteractionbetweenDNTregcellsandalloantigenreactiveeffectorTcells.OncetheDNTregandtargetcellshavecomeintocontact,killingisthenmediatedbyFas/Fas-ligandinteractions,andperhapsthroughotherunidentifiedpathways.Furthercharacterizationofthefunctions,molecularexpressionandmechanismsofactivationofDNTregcellswillhelpinthedevelopmentofnoveltherapiestoinduceantigenspecifictolerancetoselfandforeignantigens.Cellular&MolecularImmunology.2004;1(5):328-335.
简介:INTRODUCTIONItiscommonknowledgethatthedevelopmentandoccurrenceofanearthquakeisaverycomplicatedgeophysicalprocess.Anearthquakeiscausedbythelocalfailureoftheearthcrustmedium,andearthquakesaredistributedinhomogeneouslyinspace.Seismicactivities,however,arearealreflectionoftheinteractionofthefaults,whichprovidesussomeinformationconcerningtheearthcrustmediumandmayhelpuspredicttheearthquake.Therefore,thestudyoftheseismicitypatterncanbecomeameansofearthquakeprediction.Inordertoreflectdirectlythespacialdistributionofseismicactivities,thesketchofepicentraldistributionhasbeenwidetyusedinthestudy
简介:Mostpatientswithtrauma-hemorragicshock,priortoICUadmission,havebeenresuscitatedandstabilizedintheemergencyroom(ER)and/oroperationroom(OR).Manyofthemsufferfromsystemicedema.Thisextra-vascularfluidiscausedbymassiveinfusionoffluidandbloodforthemaintenanceofbloodpressure.Duringtherecoverystage,thepatientsexhibitspontaneousdiuresisfollowedbynegativefluidbalance.Urinevolumesofsomepatientsaremorethan10000ml/d.Doweneedtomaintainabalancebetweendailyinputandoutputofwateratthissituation?
简介:Thecut-offnegativepressuremethodisoneofeffectiveapproachestosolvetheseepageflowwithfreesurface.Accordingtothecharacteristicsofthismethod,however,ithasbeenfoundoutthatthedeficiencyofthealgorithmsistoeasilycauseinaccuratesimulationinthevicinityoffreesurfaceowingtothepenaltyfunctionwithonlyonecontrollingpenaltyparameter.Therefore,animprovedcut-offpressuremethodwaspresentedbyconstructingpenaltyfunctionwithtwocontrollingpenaltyparameters.Theimprovedalgorithmswereillustratedtobeabletoimprovethesimulationaccuracyandraisetheconvergencespeedthroughconsideringtheeffectsofthepartiallysaturatedorunsaturatedelementsmorereasonablyandcalculatingthenodalexternalforcesmoreaccurately.Finally,theimprovedcut-offnegativepressuremethodwasappliedtothesimulationofunsteadyseepageflowwithfreesurface,andthecorrespondingprogramcodesweredevelopedwithvalidationofsomecases.
简介:Weintroduceanewmodelofone-dimensional(1D)photoniccrystalcomposedofalternatelyarrangedRHMandLHMlayerswithpositiveandnegativerefractiveindicesrespectively,forwhichthetransmissionspectraofthemodelarecalculatednumericallywiththetransfermatrixmethod,andtheband-gapstructureandthepolarizationpropertiesareanalyzed.Wefoundthattheintroductionofnegativerefractiveindexlayers(i.e.LHMmediumlayers)givesrisetosomepeculiarband-gapstructureandpolarizationpropertiesasfollows.Firstly,theforbiddenbandsareextremelywideandthetransmissionbandsareverysharpwithoutoscillation;andsecondly,thechangeofincidentanglehasdifferentinfluencesontheforbiddenbandsofTEandTMmodes.FortheTMmode,theforbiddenbandwidthdecreasessubstantiallyandfinallyvanishes,andfortheTEmodewithcentralwavelength,thetotalreflectionhappensatanyincidentangle.
简介:Thetargetofthelargenegativeionsourcebasedonneutralbeaminjection(N-NBI)istoproduceneutralbeamcurrentof22Aandbeampowerof10MWat500keVwithdurationtimeof10s.Sinceitwassuccessfullyoperatedin1996,the5.3MWneutralbeampowerat380keVwithdurationtimeof3shasbeenachieved.Inrecentyearsimprovingandenhancingthebeampoweraregoingon.Severalreasonssuchasplasmanon-uniformity,higherbeamdensityattheupperregioninthebeamprofile,
简介:Thebandgappropertiesofone-dimensionalphotoniccrystalswithadefectlayerofnegativerefractiveindexmaterialsarestudied.Thedefectmodewidthisbiggerthanthatofconventionalone-dimensionalphotoniccrystalswithadefectlayerofpositiverefractiveindexmaterials.Thedefectmodeoftheformerisdifferentfromthatofthelatter,shiftstowardsthedirectionofhighfrequency(shortwavelength),andhasabiggershiftingvelocity.Furthermoretheeffectsonthetransmissionpropertiesoftheformerphotoniccrystalscausedbychangeinthepositionofthedefectlayerofnegativerefractiveindexareinvestigated.Finallytheopticalenhancementoftheformerphotoniccrystalsisalsoinvestigated.