简介：语言习得是指一个人习得语言的过程。儿童与成人之间的区别导致第一语言和第二语言习得的差异。本文从语言认知和情感因素两方面做深入分析，对第一语言和第二语言习得的差异进行比较和对照。

简介：Inordertoidentifythelocationsofirreversiblelosswithinthetranscriticalcarbondioxiderefrigerationcyclewithanexpansionturbine,amethodwithrespecttothesecondlawofthermodynamicsbasedonexergyanalysismodelisapplied.Theeffectsofheatrejectionpressures,outlettemperaturesofgascoolerandevaporatingtemperaturesontheexergyloss,exergyefficiencyandthecoefficientofperformance(COP)oftheexpansionturbinecycleareanalyzed.Itisfoundthatthegreatpercentagesofexergylossestakeplaceinthegascoolerandcompressor.Moreover,heatrejectionpressures,outlettemperaturesofgascoolerandevaporatingtemperatureshavestronginfluenceontheexergyefficiency,COPandtheexergylossofeachcomponent.TheanalysisshowsthatthereexistsanoptimalheatrejectionpressurecorrespondingtothemaximumexergyefficiencyandCOP,respectively.Theresultsareofsignificanceinprovidingtheoreticalbasisforoptimaldesignandthecontrolofthetranscriticalcarbondioxidesystemwithanexpansionturbine.

简介：本文提出一种新的盲均衡和通道辨识方法．该方法基于过采样技术和独立分量分析神经网络进行信道均衡，利用均衡输出序列和高阶累积量，辨识信道参数．与通常的方法相比，该方法网络结构简单，不必利用训练序列．计算机仿真结果表明算法的良好性能

简介：Code-switchingisasocio-linguisticterm,whichreferstotheswitchingfromonelanguagetoanother.Thispaperattemptstoshowthatcode-switchingcanbeusedasateachingstrategyforsecondlanguageteachingbyillustratingthepossiblereasonsfortheswitching.Italsoexploresthepossibilityofviewingcode-switchingaslanguageinterferenvefromateachingperspective.Inaccordancewiththeseanalysisthispapermakesaconclusionthatwhencode-switchingistocompensateforalanguagecifficultyitmaybeviewedasinterfernceandwhenitisusedasasocio-linguistictoolitbecomesastrategy.

简介：本文对依赖于过去的死亡率和出生率的年龄结构人口动力学模型建立了一个三层特征差分格式，证明了这一差分格式在离散无穷范数下是二阶收敛的

简介：常规差错分析方法基于对称的部件假定未调换的传播线的三阶段的参数在差错的情况下是对称的。方法与对称的分布式的参数电路引起的误差作为未调换的极端高电压(UHV)的相等的电路当模特儿传动线在正常操作和差错下面被学习，并且产生的相应问题被指出。由对比与电磁短暂并且有不均匀的分布式的参数电路的力量电子学(EMTPE)模拟结果未调换的线当模特儿，常规方法不能显示出存在，这被显示出否定并且零在差错发生前定序，在差错发生以后电压和电流上有许多错误哪个与差错类型是不同的。电压和电流的错误范围是2.13%81.13%并且−7.82%−86.15%分别地。

简介：Basedonthesteady-statesolutionoffinite-statebirthanddeathprocess,theprincipleoflineconfigurationforsharedmulti-channelsystemisanalyzed.Callcongestionratioequationandchannelutilizationratioequationarededuced,andvisualizeddataanalysisispresented.Theanaly-sisindicatesthat,calculatedwiththeproposedequations,theoverestimateforcallcongestionratioandchannelutilizationratiocanberectified,andtherebythecostofchannelscanbesavedby20%inasmallsystem.WithMATLABprogramming,lineconfigurationmethodsareprovided.Inordertogenerallyandintuitivelyshowthedynamicrunningofthesystem,andtoanalyze,promoteandimproveit,thesystemissimulatedusingM/M/n/n/mqueuingmodelandMonte-Carlomethod.Inaddition,thesimulationvalidatesthecorrectnessofthetheoreticalanalysisandoptimizingconfigurationmethod.

简介：Givenarealfinite-dimensionalorinfinite-dimensionalHilbertspaceHwithaJordanproduct,thesecond-orderconelinearcomplementarityproblem（SOCLCP）isconsidered.Someconditionsareinvestigated,forwhichtheSOCLCPisfeasibleandsolvableforanyelementq？H.ThesolutionsetofamonotoneSOCLCPisalsocharacterized.Itisshownthatthesecond-orderconeandJordanproductareinterconnected.

简介：文章以SecondLife为参照，描述和分析了虚拟世界中的教育活动，从交互空间、信息表征等方面探讨了虚拟世界的教育功用及属性，同时通过实例和数据展开分析。文章最后提出在虚拟世界中开展教育实践将面临的问题和挑战。

简介：Inthispaper,theeffectsofsecond-orderdifference-frequencywaveforcesontheglobalmotionofanoffshorewindturbinesystemwithalargedisplacementunderthesurvivalconditionarestudied.Inthiscase,thehydrodynamicforceisthemainforcebecausethebladesarefeatheredtoreducetheliftingforce.Thefirst-orderhydrodynamicforcesarecalculatedbyWADAM,whilethesecond-orderwaveforcesarecalculatedbyacustomizedMATLABmodule.ThenthehydrodynamiccoefficientsaretransferredtothewindturbineanalyticalcodeFAST.Throughthecomparisonsofdynamicresponsesbetweenthefirst-andsecond-ordernumericalmodels,itisfoundthatthesecond-orderwaveforcessignificantlyinfluencethemotionoffloatingwindturbineunderthesurvivalcondition.Moreover,neglectingthesecond-orderforcesignificantlyunderestimatesthetensionforcesinthemooringlines.