简介:theAlternatingSegmentCrank-Nicolsonschemeforone-dimensionaldiffusionequationhasbeendevelopedin[1],andtheAlternatingBlockCrank-Nicolsonmethodfortwo-dimensionalproblemin[2].Themethodshavetheadvantagesofparallelcomputing,stabilityandgoodaccuracy.Inthispaperforthetwo-dimensionaldiffusionequation,thenetregionisdividedintobands,aspecialkindofblock.ThismethodiscalledthealternatingBandCrank-Nicolsonmethod.
简介:阐述了桥式起重机主卷扬行星减速机在运行中存在的问题,介绍了改造后的棘轮减速机工作原理及安全运行效果。
简介:摘要:某特大桥在钢桁拱预拼场里程方向配置2台MQ150t/10t-40.5m门式起重机配合施工,门式起重机起吊重量为150t/10t,跨度40.5m,高度30m。门吊拆除采用在中线上搭设支架,支架上布置千斤顶,松开大梁螺栓,在采用吊机将大梁下放至指定地点,而后依次拆除。本文以大里程侧龙门吊为例详细介绍了龙门吊支架法拆除的施工方法和质量控制要点。
简介:<正>Foranoddfunctionf(x)definedonlyonafiniteinterval,thispaperdealswiththeexistenceofperiodicsolutionsandthenumberofsimpleperiodicsolutionsofthedifferentialdelayequation(DDE)(?)(t)=-f(x(t-1)).Byuseofthemethodofqualitativeanalysiscombinedwiththeconstructingofspecialsolutionsaseriesofinterestingresultsareobtainedontheseproblems.