简介:S.M.LozinskiiprovedtheexactconvergencerateatthezeroofLagrangeinterpolationpolynomialsto|x|basedonequidistantnodesin[-1,1].In2000,M.RevergeneralizedS.M.Lozinskii'sresultto|x|α(0≤α≤1).Inthispaperwewillpresenttheexactrateofconvergenceatthepointzerofortheinterpolantsof|x|α(1<α<2)..
简介:Threetypesofroughsurfacewereprocessedbylaserirradiationonthe3Cr2W8Vmaterialhot-workdiesteelsurface.Thewearexperimentswithsmoothsurfaceandroughsurfacesampleswererepeatedonthepin-traywearmachine.Accordingtothewearresults,westudiedtheregularityofwearresistanceofdifferentroughsurfacesamples.Theresultsindicatedthatbionicroughsurfacecanimprovethewearresistanceofthematerialandthewearresistancecanbeincreased1-2times,comparedwiththesmoothsurface.Also,thewearresistanceoftheroughsurfacewasaffectedbylasercurrentanddurationofimpulse.Thebiggerthelasercurrentortheimpulseduration,thebetteristhewearresistance.Whenthedistancebetweenthesamekindofunitswhicharedistributedonthesurfacesischanged,thewearresistancechanges.Thewearresistanceofabionicroughsurfaceonwhichthegridunitsweredistributedatspacingof1mmwasthebest.Andwedesignedthewearmodels.
简介:摘要:电力安全稳定供电是保障社会经济稳定运行的基础,一旦因突发事件而中断供电,将对社会造成严重影响。近年来,国内外发生了一系列大面积停电事故,如2008年初冰灾导致的南方大面积停电、2016年澳大利亚的“9·28”大面积停电等。这些大面积停电导致了社会生产和生活秩序严重破坏,造成了巨大的损失。从各级电力公司应急处置经验看,在大面积停电事件应对中,快速高效恢复配电网重要负荷,保障重要民生用户供电,是灾后大面积停电事件应急处置的关键点。目前的相关研究主要集中在如何加速配电网应急抢修的处置速度、控制损失方面。伴随国家对电力应急工作的重视,大批电力应急电源车配置到供电企业,为电网保障供电提供了基础,但尚欠缺将应急电源车的调度和应急抢修相结合来系统的提升配电网复电效率的研究,制约了配电网抢修效率的进一步提升。应急电源车作为电力应急处置的重要资源,具有极大的灵活性,过去主要应用在单点的应急抢修和保电工作。对于配电网大面积停电情景,应急电源车单车容量有限,如何充分发挥应急电源车的灵活性,合理分配有限资源,使效益最大化是相关研究的方向。
简介:ForquadraticnumberfieldsF=Q(√2pl…pt-1)withprimespj≡1mod8,theauthorsstudytheclassnumberandthenormofthefundamentalunitofF.TheresultsgeneralizenicelywhathasbeenfamiliarforthefieldsQ(√2p)withaprimep≡1mod8,includingdensitystatements.Andtheresultsarestatedintermsofthequadraticformx2+32y2andillustratedintermsofgraphs.
简介:theAlternatingSegmentCrank-Nicolsonschemeforone-dimensionaldiffusionequationhasbeendevelopedin[1],andtheAlternatingBlockCrank-Nicolsonmethodfortwo-dimensionalproblemin[2].Themethodshavetheadvantagesofparallelcomputing,stabilityandgoodaccuracy.Inthispaperforthetwo-dimensionaldiffusionequation,thenetregionisdividedintobands,aspecialkindofblock.ThismethodiscalledthealternatingBandCrank-Nicolsonmethod.