学科分类
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43 个结果
  • 简介:Withtheadvancesof数字天气模拟和更新的减少的数据吸收骑车,表面观察数据吸收在数据吸收系统变得越来越重要。一个更好的数据吸收系统应该在表面层包含热力学的进程的限制,这广泛地被接受。在这份报纸,因此,一个新表面风观察操作员在全球、地区性的吸收预言System_3D变化(GRAPES_3D-Var)被利用,与在行星的边界层(PBL)的热力学的过程的限制。为了研究这新表面的能力,在吸收弯屈观察操作员并且预报,一系列实验被使用GRAPES模型操作。主要结果显示表面风观察操作员的这个新方法与GRAPES模型一起在预报上有积极影响。

  • 标签: 数字天气模拟 预报 表面风 数据吸收 热力学的过程的限制 葡萄
  • 简介:Pitchisoneofthemostimportantauditoryperceptioncharacteristicsofsound;however,themechanismunderlyingthepitchperceptionofsoundisunclear.Althoughtheoreticalresearcheshavesuggestedthatperceptionofvirtualpitchisconnectedwithphysicsincochleaofinnerear,thereisnodirectexperimentalobservationofvirtualpitchprocessinginthecochlea.Bylaserinterferometry,weobserveshiftphenomenaofvirtualpitchinbasilarmembranevibrationofexsomatizedcochlea,whichisconsistentwithperceptualpitchshiftobservedinpsychoacousticexperiments.Thismeansthatthecomplexmechanicalvibrationofbasilarmembraneincochleaplaysanimportantroleinpitchinformationprocessingduringhearing.

  • 标签: In PITCH SHIFT in Exsomatized COCHLEA
  • 简介:Anewmethodisproposedforidentifyingoutliersinthedirection-of-arrival(DOA)dataofasourceobservedfromalineararraysonar.Supposeasourcemovesuniformlyalongastraightline.Themethodforidentifyingoutliersconsistsofthreesteps.(i)Dividethedataintogroups,eachwithfoursamplepoints,anddeletecertaintwosamplepointsfromeverygroupbymeansofarobustmethodpesentedinthispaper.Whenthepercentageoftheoutliersislessthan50%,thereexistsatleastonegroupinwhichtheremainingtwosam-plepointsare"good".(ii)EstimatetheDOAanditsChangerate,(θ0,θ0),usingtheremainingtwosimplepointsofeverygroup,andcomputetheobjectivefunctionsofM-etsimatorusingtheresultingestimatesofallgroupsrespectively.A"good"estimateof(θ0,θ0),whichminmizestheobjec-tivefunctionisthenobtained.(iii)IteratetheM-estimatorwiththe"good"esti-mateof(θ0,θ0)astheinitialvalue,obtainanaccurateestimateof(θ0,θ0),andidentifyoutliersintheobserveddatausi

  • 标签: identifying straight ESTIMATOR<
  • 简介:Theshrinkageofthecementpastewithlowwater-cementratioatdifferentrelativehumiditywasobservedandanalyzedwithESEManddeformationmaptechnique.ThecrackmorphologywasobservedwithdifferentmagnificationwithSEMandFESEM,andtheformationofthecrackwasobservedwithAFMbetweentwoC-S-Hnanoparticles.Theobservationbymultitechniqueatmultiscaleindicatedthattheshrinkagewasincreasewiththedecreaseofthehumidityduetotheincreaseofthepressureofthecapillarypressure,themorphologyofthecrackinsmallerscalewassimilartothatinthebiggerscale,thesmallercrackdistributedinthelatticeworkofthebiggerones,andthecrackpropagatedalongthegapbetweentwonanoparticlesofC-S-Hwithweakerbonding.

  • 标签: 硬化水泥浆体 裂纹分布 技术 扫描电镜分析 相对湿度 毛管压力
  • 简介:TheRhineseffectmayberegardedasaninteractionbetweenRossbywavesandturbulence,inwhichtheRossbywavesmayradiateawayeddyenergywhentheirfrequenciesareequalorlargerthanthoseoftheturbulence,therebydeformingandeventuallydestroyingtheexistingeddies.Throughcomparingeddy-scalevelocityandlongRossbywavephasespeedintheoceans,ageneralizedformoftheRhineseffectisexaminedonthegeographicalcharacteristicsofaltimeter-observededdies.TheresultsshowthatthegeneralizedRhineseffecthasamuchgreaterinfluenceoneddycharacteristicsthanitsclassicalform,whichonlyconsidersthesimplebetaeffectduetothemeridionalgradientofplanetaryvorticity.Thelargestamountofeddiesaredetectedinregionswhereeddy-scalevelocityislargerthanthecriticalRossby-wavephasespeedconsideringageneralizedbetaeffect.Theeddiesinthoseregionscangrowviaaninversekineticenergycascadeandhavemuchlargeramplitudesandsizes.The'eddydesert'regionsoutsideofthetropicaloceans,whichhavefarfewerdetectededdiesandmuchweakereddyamplitudes,lieinareaswheretheeddy-scalevelocityislessthanthecriticalRossby-wavephasespeed.Inthoseregions,thegeneralizedRhineseffectmaybeapossiblemechanismofsuppressingeddygrowth.

  • 标签: 涡流特性 高度计 漩涡 地理 罗斯贝波 热带海洋
  • 简介:Ourrecentstudiesconcerningthebindingofionicsurfactantsonoppositelychargedpolyelectrolytesobservedwithfluorescencetechniquesarereviewed.Thecationicsurfactantscetyltrimethylammoniumbromide(CTAB),dodecyltrimethylammoniumchloride(DTAC),andnonionicsurfactantoctaethyleneglycolmonododecylether(C12E8)wereallowedtobindonanionicpoly(2-acrylamido-2-methylpropanesulfonicacid)(PAMPS)anditspyreneand/ornaphthalenelabeledcopolymers.TherelativeexcimeremissionintensityIE/IMofacationicprobe1-pyrenemethylaminehydrochloridewerechosentomonitorthebindingprocessandtheconformationchangeofsurfactant-boundpolyelectrolytes.The1:1aggregationofpolyelectrolyte-CTABwithrespecttothechargewasfoundaslongastheCTABconcentrationwasslightlyhigherthanitscriticalaggregationconcentration(CAC).TheintermolecularNRETindicatedthattheCTAB-boundpolyelectrolytesaggregatedtogetherthroughthehydrophobicinteractionbetweentheCTABtails.However,neither1:1polyelectrolyte-DTACaggregationnorintermolecularaggregationofDTAC-boundpolyelectrolytewasobservedowingtoitsweakerhydrophobicityof12carbonatomsinthetail,whichisshorterthanthatofCTAB.Asknownfromthefluorescenceresults,nonionicsurfactantC12E8didnotbindontheanionicpolyelectrolytes,butthepresenceofPAMPSpromotedthemicelleformationforC12E8attheCACslightlybelowitscriticalmicelleconcentration(CMC).ThesolidcomplexofdansyllabeledAMPScopolymer-surfactantexhibitedadecreaseinlocalpolaritywithincreasingchargedensityofthepolyelectrolyteorwithalkanetaillengthofthesurfactant.SAXSsuggestedalamellastructurefortheAMPScopolymersurfactantsolidcomplexeswithalongperiodof3.87nmforCTABand3.04nmforDTAC,respectively.

  • 标签: 离子表面活性剂 聚合电解质 荧光分析 粘合性
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  • 简介:Inthispaperastochasticvolatilitymodelisconsidered.Thatis,alogpriceprocessYwhichisgivenintermsofavolatilityprocessVisstudied.ThelatterisdefinedsuchthatthelogpricepossessessomeofthepropertiesempiricallyobservedbyBarndorff-Nielsen&Jiang[6].Inthemodeltherearetwosetsofunknownparameters,onesetcorrespondingtothemarginaldistributionofVandonetoautocorrelationofV.Basedondiscretetimeobservationsofthelogpricetheauthorsdiscusshowtoestimatetheparametersappearinginthemarginaldistributionandfindtheasymptoticproperties.

  • 标签: 参数估计 随机挥发模型 中心极限定理 大数定律 LEVY过程 NIG分布
  • 简介:AstudyoftheKunlunshanearthquakeofMS=8.1basedonobservedcoseismicstrainstepsfromtheboreholestrainmonitoringnetworkoverChinahasbeencarriedoutwithsomeinterestingresults.Firstly,manyrecordingsdisagreewiththeoreticcalculationusingstaticdislocationmodel.Secondly,abnormallylargestrainstepsareobservedatquiteafewstationsinthetectonicallyactiveeast-northernChina,whileintherelativelyinactiveeast-southernChinanoobviousstepsarerecorded.Itisinferredthatseismicstresstriggeringmaysignificantlyaffectremoteseismicstrainfield.Inotherwords,whetherremotefaultingbeseismicallytriggeredornotmaydeterminethepatternoflocalseismicstrainchanges.FurthercomparisonstudyresultsofMarch11,1999ZhangbeiearthquakeandNovember1,1999Datongearthquakeshowthatthespecificpatternofseismiczoneshasobviousinfluenceonseismicstrainchangesintheregion.Thissupportstheideathatobservedabnormalstrainstepsmightbeproducedbycoseismiclystress-triggeredlocalfaulting.

  • 标签: STRESS TRIGGERING STRAIN observation SEISMIC STRESS
  • 简介:Themeasurementoflow-fieldsusceptibilityXasafunctionoftemperatureTforLa2/3Ca1/3MnO3showsasignificantdownturnin1/X(T)abovetheCurietemperatureTc,abehaviourgenerallyobservedinperovskitemanganites.Suchadownturnisarguedtobeduetothesegregationofferromagneticclusterswithlargerspinsintheparamagneticmatrix.Basedonthisconsideration,aphenomenologicalexpressionforX(T)isproposed,inwhichthetotalsusceptibilityisassumedtobeasumoftwosusceptibilitiesarisingfrommagneticentitiesinthePMbackgroundandtheFMclusterswithT-dependenteffectivespins,respectively.TheresultisingoodagreementwiththeexperimentaldataobtainedinLa2/3Ca1/3MnO3.

  • 标签: 抗磁化系数 居里温度 钙钛矿 亚锰酸盐
  • 简介:Thetriangulationofredspriteswasobtained,basedonconcurrentobservationsoveramesoscaleconvectivesystem(MCS)inNorthChinafromtwostationsseparatedbyabout450km.Inaddition,broadbandsfericsfromthesprite-producinglightningweremeasuredatfivegroundstations,makingitpossibletolocateandidentifytheindividualcausativelightningdischargesfordifferentelementsinthisdancingspriteevent.TheresultsofouranalysesindicatethatthespriteswereproducedabovethetrailingstratiformregionoftheMCS,andtheirparentstrokeswerelocatedmainlyintheperipheralareaofthestratiform.Thelateraloffsetbetweenspritesandcausativestrokesrangesfromafewkmtomorethan50km.Inaparticularlybrightsprite,withadistincthalofeatureandstreamersdescendingdowntoanaltitudeofapproximately48km,thespritecurrentsignalidentifiedintheelectricsferic,measuredatarangeofabout1,110km,peakedatapproximately1msafterthereturnstroke.

  • 标签: SPRITE TRIANGULATION PEAK current hybrid location
  • 简介:喷雾器粒子清除的降水是在能改变物理的喷雾器和光性质的空气的一个重要移动过程。这份报纸在在集体集中的situ观察使用的四个雨事件前后在物理的喷雾器和光性质分析变化,数字集中,粒子尺寸分发,散布并且在在Xianghe全面大气的观察的6月和2013年7月的喷雾器的吸收系数在中国驻扎。清除的雨的效果与雨紧张和持续时间,风速度和方向有关的结果表演。在雨事件期间,喷雾器数字集中的时间的变化与在集体集中的变化一致,但是他们的解决尺寸的清除比率是不同的。在雨事件以后,喷雾器团集中的增加与直径以粒子的增加开始了<0.8m[使用空气动力学的粒子sizer(APS)测量],并且有直径的好粒子<0.1m[使用扫描活动性粒子sizer(SMPS)测量]。降雨在与直径~移开粒子是很有效的0.6m并且比3.5m大。在粒子数字分发的山峰价值的变化(使用SMPS测量)在雨事件在100-120nm以内在粒子上反映强壮的清除效果前后,缩放范围。喷雾器在雨事件前后散布和吸收系数的变化模式是类似的,但是他们的清除比率不同它可能与喷雾器粒子尺寸分发和化学作文有关。

  • 标签: 气溶胶粒子 降水事件 光学性质 物理 降雨过程 气溶胶散射
  • 简介:基于卫星检索方法论,光谱特征和云微物理性质被分析那包括了隧道的亮度温度第4a5,并且他们的亮度温度差别(BTD),播种的云轨道的有效半径由播种的运作的云和云播种的微物理效果引起了的粒子被他们的差别的比较揭示在内并且在播种轨道外面。云轨道实际上是到达深的1.5-km和14-km的一条云隧道为超过80min的宽持续。周围的云的有效半径是10-15μm,当那从15~26μm在云轨道以内时。周围的云在播种轨道以内由云的supercooled微滴,和作文组成是冰。关于在轨道附近的二个周围的方面的相当稳定的反射,可见光谱在云轨道的反射在least10%变化了,并且到达了35%的最大值,在播种轨道的3.7μm的反射相对减少了至少10%。当云播种进展了,宽度和深度逐渐地被增加。同时,在轨道以内的云顶温度关于周围的云变得日益增多地更温暖,并且最高温度差别为隧道在首先播种的位置到达了4.2和3.9℃4和5。另外,在轨道的BTD也稳定地增加了到1.4℃的最大值,与周围的云的0.2-0.4℃相比。播种的云变得的证据更薄来自显示出一条隧道的可见图象,温暖在播种轨道的BTD的云顶,和增加。因为云顶在整个它的深度下了,它输了水到降水,播种的云主要变得更薄。为播种大小写的这云,冻结成冰在云顶变得明显在播种以后的大约22min。在supercooled层状云的一个云磁道的形成主要是因为进猛抛的冰水疗院流星并且那么的播种的云卷glaciated降低了云顶高度。在播种以后在在38和63min之间的播种轨道的中间形成的新水云的一根细线,可能,由于升起,运动由结冰的释放的潜伏的热导致了。这些云消失在播种轨道的更早的片断,它建议这些eding轨道的成熟与它从方面由于周围的云的顶的扩大变窄和最终的驱散被联系里面。

  • 标签: 云雾 播种 轨道 卫星观察 微视物理学
  • 简介:Polewardatmosphericmoisturetransport(AMT)intotheArcticOceancanchangeatmosphericmoistureorwatervaporcontentandcausecloudformationandredistribution,whichmaychangedownwardlongwaveradiationand,inturn,surfaceenergybudgets,airtemperatures,andsea-iceproductionandmelt.Inthisstudy,wefoundaconsistentlyenhancedpolewardAMTacross60°Nsince1959basedontheNCAR-NCEPreanalysis.RegionalanalysisdemonstratesthatthepolewardAMTpredominantlyoccursovertheNorthAtlanticandNorthPacificregions,contributingabout57%and32%,respectively,tothetotaltransport.ToimproveourunderstandingofthedrivingforceforthisenhancedpolewardAMT,weexploredtherolethatextratropicalcycloneactivitymayplay.Climatologically,about207extratropicalcyclonesmoveacross60°NintotheArcticOceaneachyear,amongwhichabout66(32%ofthetotal)and47(23%)originatefromtheNorthAtlanticandNorthPacificOcean,respectively.Whenanalyzingthelineartrendsofthetimeseriesconstructedbyusinga20-yearrunningwindow,wefoundapositivecorrelationof0.70betweenpolewardyearlyAMTandtheintegratedcycloneactivityindex(measurementofcycloneintensity,number,andduration).ThisshowstheconsistentmultidecadalchangesbetweenthesetwoparametersandmaysuggestcycloneactivityplaysadrivingroleintheenhancedpolewardAMT.Furthermore,acompositeanalysisindicatesthatintensificationandpolewardextensionoftheIcelandiclowandaccompanyingstrengthenedcycloneactivityplayanimportantroleinenhancingpolewardAMTovertheNorthAtlanticregion.

  • 标签: ATMOSPHERIC moisture transport CYCLONE activity ATMOSPHERIC
  • 简介:IonosphereicfoF2variationsareverysensitivetotheseismiceffectandresultsofionosphericperturbationsassociatedwithearthquakesseemtoveryhopefulforshort-termearthquakeprediction.OnJanuary18,2011at20:23UTagreatearthquake(M=7.2)occurredinDalbandin(28.73°N,63.92°E),Pakistan.Inthisstudy,wehavetriedtofindoutthefeaturesofpre-earthquakeionosphericanomaliesbyusingthehourlydaytime(08.00a.m.-05.00p.m.)dataofcriticalfrequency(foF2)obtainedbythreeverticalsoundingstationsinstalledinIslamabad(33.78°N,73.06°E),Multan(32.26°N,71.51°E)andKarachi(24.89°N,67.02°E),Pakistan.TheresultsshowthesignificantanomaliesoffoF2intheearthquakepreparationzoneseveraldayspriortotheDalbandinearthquake.ItisalsoobservedthattheamplitudeandfrequencyoffoF2anomaliesaremoreprominentattheneareststationtotheepicenterascomparedtothosestationsneartheoutermarginoftheearthquakepreparationzone.TheconfidencelevelforionosphericanomaliesregardingtheseismicsignaturescanbeenhancedbyaddingtheanalysisofsomeotherionospheicparametersalongwithcriticalfrequencyofthelayerF2.

  • 标签: 电离层异常 电离层扰动 临界频率 巴基斯坦 地震前 地震效应