简介:监督分类法在遥感影像分类中应用广泛,结合已有地质资料和实测地质剖面信息,将研究区岩性分为苏维依组泥岩和粗砂岩,库姆格列木群泥岩、砾岩和含砾粗砂岩,巴什基奇克组粗砂岩和砾岩,巴西改组细砂岩等8个类型,运用ENVI提供的常用监督分类方法——最大似然法,对研究区的遥感影像进行岩性分类研究。并利用混淆矩阵分别对不同影像的分类结果进行精度评价,结果表明ZY-3影像的分类总体精度达到了78.65%,Kappa系数为0.7606,能够较好地进行岩性信息提取,具有较高的可靠性,可在地质调查工作中推广,能够有效地减少面积性地质测量工作,特别适用于岩石裸露程度较高的艰苦工作区。
简介:土壤体积密度的测量为理解土壤的物理、化学、生物的性质是重要的。精确、快速的土壤体积密度测量技术在农业试验性的研究起一个重要作用。这评论是存在测量方法的一篇全面摘要并且为未来开发评估他们的优点,劣势,错误的潜在的来源,和方向。这些技术能广泛地作为直接、间接的方法被分类。直接方法包括核心,土块,和挖掘采样,而间接方法包括放射和回归途径。核心方法最广泛地被使用,但是为采样使用多重土壤深度耗时、困难。coring柱体的尺寸使用了,操作员经验,采样深度,并且在原处显著地玷污潮湿内容影响它的精确性。土块方法是合适的因为有重黏土的使用,和它的精确性依赖于设备刻度,弄干时间,和操作员经验,但是这个过程复杂、耗时。挖掘技术最通常被用来评估森林土壤的体积密度,但是把他们不能与大毛孔在土壤被使用,他们的测量精确性被土壤质地和分析的类型强烈影响的主要限制选择。间接方法看起来比直接途径有更大的精确性,但是有更高的费用,是更复杂的,并且要求更大的操作员经验。一如此的途径使用gamma放射,和它的精确性被土壤深度强烈影响。当他们能做间接大小,回归方法是节俭的,但是这些取决于土壤质地和有机物内容和地理、气候的性质的好、优秀数据。另外,它的精确性象大多数另外的途径一样,与采样深度减少。
简介:Thestudyofstructure,thermodynamicstate,equationofstate(EOS)andtransportpropertiesofwarmdensematter(WDM)hasbecomeoneofthekeyaspectsoflaboratoryastrophysics.Thisfieldhasdemonstrateditsimportancenotonlyconcerningtheinternalstructureofplanets,butalsootherastrophysicalbodiessuchasbrowndwarfs,crustsofoldstarsorwhitedwarfstars.Therehasbeenarapidincreaseininterestandactivityinthisfieldoverthelasttwodecadesowingtomanytechnologicaladvancesincludingnotonlythecommissioningofhighenergyopticallasersystems,zpinchesandX-rayfreeelectronlasers,butalsoshort-pulselaserfacilitiescapableofgenerationofnovelparticleandX-raysources.ManynewdiagnosticmethodshavebeendevelopedrecentlytostudyWDMinitsfullcomplexity.Evenultrafastnonequilibriumdynamicshasbeenaccessedforthefirsttimethankstosubpicosecondlaserpulsesachievedatnewfacilities.RecentyearssawanumberofmajordiscoverieswithdirectimplicationstoastrophysicssuchastheformationofdiamondatpressuresrelevanttointeriorsoffrozengiantplanetslikeNeptune,metallichydrogenunderconditionssuchasthosefoundinsideJupiter’sdynamoorformationoflonsdaleitecrystalsunderextremepressuresduringasteroidimpactsoncelestialbodies.Thispaperprovidesabroadreviewofthemostrecentexperimentalworkcarriedoutinthisfieldwithaspecialfocusonthemethodsused.AlltypicalschemesusedtoproduceWDMarediscussedindetail.MostofthediagnostictechniquesrecentlyestablishedtoprobeWDMarealsodescribed.Thispaperalsoprovidesanoverviewofthemostprominentexamplesofthesemethodsusedinexperiments.Eventhoughthemainemphasisofthepublicationisexperimentalworkfocusedonlaboratoryastrophysicsprimarilyatlaserfacilities,abriefoutlineofothermethodssuchasdynamiccompressionwithz-pinchesandstaticcompressionusingdiamondanvilcells(DAC)isalsoincluded.Somerelevanttheoretic
简介:Thequantumtheoryapplicationisahotresearchareainrecentyears,especiallythetheoryofquantummechanics.Inthispaper,wefocusontheresearchofimagesegmentationbasedonquantummechanics.Firstly,thetheoryofquantummechanicsisintroduced;afterwards,areviewofimagesegmentationmethodsbasedonquantummechanicsispresented;andfinally,thecharacteristicsaboutthequantummechanicsappliedtoimageprocessingareconcluded.Twomainresearchtopicsarediscussedinthispaper.Oneistoemphasizethatquantummechanicscanbeappliedindifferentresearchareas,suchasimagesegmentation,andthesecondistoconcludesomemethodsinimagesegmentationandgivesomesuggestionsforpossiblenovelmethodsbyapplyingquantummechanicstheory.Asasummary,thisisareviewpaperwhichpresentssomemethodsbasedonthefeasibletheoryinquantummechanicsaimingatachievingabetterperformanceinimagesegmentation.
简介:Thisstudytestedfivemethodswidelyusedinestimatingthecompletemagnitudes(MC)ofearthquakecatalogs.Usingcatalogsofobservedearthquakeproperties,wetesttheperformanceofthesefivealgorithmsunderseveralchallengingconditions,suchassmallvolumeofeventsandspatial-temporalheterogeneity,inordertoseewhetherthealgorithmsarestableandinagreementwithknowndata.Wefindthatthemaximumcurvaturemethod(MAXC)hasperfectstability,butwillsignificantlyunderestimateMCunlessheterogeneityisabsent.MCestimatedbytheb-valuestabilitymethod(MBS)requiresmanyeventstoreachastableresult.Resultsfromthegoodnessoffitmethod(GFT)wereunstablewhenheterogeneityloweredthefitnesslevel.Theentiremagnituderangemethod(EMR)isrelativelystableinmostconditions,andcanreflectthechangeinMCwhenheterogeneityexists,butwhentheincompletepartoftheearthquakecatalogisdismissed,thismethodfails.Themedian-basedanalysisofthesegmentslopemethod(MBASS)cantoleratesmallsamplesize,butisincapableofreflectingthemissingdegreeofsmalleventsinaftershocksequences.InconditionswhereMCchangesrapidly,suchasinaftershocksequences,observingthetimesequencedirectlycangiveapreciseestimationofthecompletesub-catalog,butonlywhenthenumberofeventsavailableforstudyislargeenoughcantheMAXC,GFT,andMBSmethodsgiveasimilarlyreliableestimation.
简介:ThispaperprovidesanoverviewofthedevelopmentsinanalyticalandtestingmethodsandexperimentalsimulationsongashydrateinChina.Inthelaboratory,theanalysesandexperimentsofgashydratecanprovideusefulparametersforhydrateexplorationandexploitation.Inrecentyears,modemanalyticalinstrumentsandtechniques,includingLaserRamanspectroscopy(Raman),X-raydiffraction(XRD),X-raycomputedtomography(X-CT),scanningelectronmicroscope(SEM),nuclearmagneticresonance(NMR)andhighpressuredifferentialscanningcalorimetry(DSC),wereappliedinthestudyofstructure,formationmechanisms,phaseequilibrium,thermalphysicalpropertiesandsoforthofgashydrates.Thedetectiontechnologyandtime-domainreflectometry(TDR)techniqueareintegratedtotheexperimentaldevicestostudythephysicalparametersofgashydrates,suchastheacoustics,resistivity,thermal,andmechanicalproperties.Itisbelievedthatthevariousanalyticaltechniquestogetherwiththeexperimentalsimulationsfromlarge-scaletomicro-scaleongashydratewillplayasignificantroleandprovideapowerfulsupportforfuturegashydrateresearches.
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简介:学校变革是教育改革的突破口与落脚点。大学与中小学在政府的支持保障或促成下进行合作的U-G-S模式具有重要意义,然而其局限也很明显:投入多、见效慢,理论研究者与实践者交流不畅。U-G-S-S模式承继了U-G-S模式的优势,并进行了突破:强调参与学校变革行动的中小学的数量为两所及以上,且学校教育质量是异质的,既有城市优质学校,也有城郊薄弱学校或乡村学校;U-G-S-S四方主体平等互动、各司其职。个案研究表明,U-G-S-S模式可以通过制度建构、任务驱动和文化营造促进各参与学校的整体发展,促进城乡义务教育均衡发展。U-G-S-S模式成功的三个主要要素:文化异质交融、知识多维共享、理论实践有机结合。
简介:Inthiswork,dynamiccompositeanalysistruncatedsandwichconicalshells(STCS)withdifferentboundaryconditionsunderlowvelocityimpactwasinvestigatedanalytically,accordinghigherordersandwichpaneltheory.ImpactoccurredatthetopfacesheetandthecontactforcehistoryispredictedusingtwosolutionmodelscalculatedapplyingprincipalofHamiltonbyconsideringthedisplacementcontinuityconditionsbetweenthelayers.Forobtainingthedisplacementandcontactforcehistories,thedifferentialquadraturemethod(DQM)isutilised.Inthisinvestigation,theeffectsoflayerlaminanumber,conesemivertexangle,boundaryconditionsandimpactvelocityontheimpactresponsearestudied.
简介:Appliedstatisticiansareoftenconfrontedwithstatisticalinferenceproblemsdealingwithsituationsinwhichthereappeartobenodata,ordataofonlylimitedusefulness.Forexample,whenattemptingtofindaconfidenceintervalforabinomialproportion,thesamplemaycontainnosuccesses.Suchascenariocouldbeencounteredwhenattemptingtoestimatetheincidenceofanextremelyraresideeffectassociatedwiththeadministrationofanewlydevelopeddrug.Inthisarticle,weuseexamplesforourexperiencesworkingwithscientificinvestigatorsanddescribeseveralscenariosinwhichthereappearedtobenousefuldata,ordataofonlylimitedusefulness.Wedescribethemethodswepreferforanalyzingthedatainthesesituationsandillustratetheirapplicationusingtheactualdatafromtheinvestigationsweparticipatedin.
简介:Inthiswork,dynamiccompositeanalysistruncatedsandwichconicalshells(STCS)withdifferentboundaryconditionsunderlowvelocityimpactwasinvestigatedanalytically,accordinghigherordersandwichpaneltheory.ImpactoccurredatthetopfacesheetandthecontactforcehistoryispredictedusingtwosolutionmodelscalculatedapplyingprincipalofHamiltonbyconsideringthedisplacementcontinuityconditionsbetweenthelayers.Forobtainingthedisplacementandcontactforcehistories,thedifferentialquadraturemethod(DQM)isutilised.Inthisinvestigation,theeffectsoflayerlaminanumber,conesemivertexangle,boundaryconditionsandimpactvelocityontheimpactresponsearestudied.