简介:Ingasturbineengines,laminar-turbulenttransitionoccurs.However,generally,theturbulencemodelstodescribesuchtransitionresultsintooearlyandtooshorttransition.Combiningaturbulencemodelwithadescriptionofintermittency,i.e.thefractionoftimetheflowisturbulentduringthetransitionphase,canimproveit.Bylettinggrowtheintermittencyfromzerotounity,startandevolutionoftransitioncanbeimposed.Inthispaper,amethodwhereadynamicequationofintermittencycombiningwithatwo-equationk-ωturbulencemodelisdescribed.Thisintermittencyfactorisapremultiplicatoroftheturbulentviscositycomputedbytheturbulencemodel.FollowingasuggestionbyMenteretal.[1],thestartoftransitioniscomputedbasedonlocalvariables.
简介:<正>2007年2月7日,索尼爱立信在北京发动了春季攻势,一举发布了8款新机,这其中包括两款Cyber-shot拍摄手机K550c和K818c、四款低端产品K200c、K220c、J110c和J120c和两款Walkman音乐新机W888c和W610c。近日,索爱K200c也以超低价正式登陆市场,上市的价格仅仅是898元。索尼爱立信K200c是一款直板机型,其在设计上摆脱了索尼爱立信一贯的设计。小巧的机身和适宜的重量,适合各类人群使用。并且K200c还将索爱旗下在国内上市的第一款集成挂机键和通话键的手机,按键的变化必将涉及到操作方式的改变。到底索爱K200c有何独到之处呢?
简介:Letbethecollectionofm-timescontinuouslydifferentiableprobabilitydensitiesfonRdsuchthat丨Daf(x1)-Daf(x2)丨≤M‖x1-x2‖βforx1,x2∈Rd,[a]=m,whereDadenotesthedifferentialoperatordefinedbyDa=([a])/(x1a…xdad).UnderratherweakconditionsonK(x),thenecessaryandsufficientconditionsforsup丨n(x)-f(x)丨=0(((logn/n)λ/(d+3λ),λ=m+β,f∈arethat∫xaK(xi)dx=0for0<[a]≤m.Finallytheconvergencorateatapointisgiven.
简介:摘要本文首先从轨道交通和常规交通的衔接规划的视角,阐述了求解K最短路径问题在公交线网优化中的意义。然后在Dijkstra最短路算法的基础上,创造性地引入了多个P标和多个T标来记录起点到该节点的K短路径及其上界,使改进后的算法成功求解K最短路径。最后用C语言对算法进行实现,并随机产生测试数据进行算法测试,测试结果表明了该算法的计算效率和应用前景。
简介:TheXRPD(X-raypowderdiffractometry)patternsofsiliconpowderwithaunitcellstructureofdiamondweredeterminedfrom298to1473K.LatticeparametersofSilinearlyincreasewithtemperature.Thethermalshiftsofthepositionsofallreflectionpeaksarelinearlycorrelatedwiththetemperature.Thecoefficientsoftheintrinsiclinearthermalexpansionandvolumetricthermalexpansionweredeterminedas3.87×10-6/Kand1.16×10-5/Krespectively.ItindicatesthatSiisstillasuitablestandardintheXRPDmethodathightemperatures.