简介：

简介：Inthispaper,wepresenttwonewunifiedmathematicsmodelsofconicsandpolynomialcurves,calledalgebraichyperbolictrigonometric(AHT)Béziercurvesandnon-uniformalgebraichyperbolictrigonometric(NUAHT)B-splinecurvesofordern,whicharegeneratedoverthespacespan{sint,cost,sinht,cosht,1,t,...,t~(n-5)},n≥5.ThetwokindsofcurvessharemostofthepropertiesasthoseoftheBéziercurvesandB-splinecurvesinpolynomialspace.Inparticular,theycanrepresentexactlysomeremarkabletranscendentalcurvessuchasthehelix,thecycloidandthecatenary.Thesubdivisionformulaeofthesenewkindsofcurvesarealsogiven.Thegenerationsofthetensorproductsurfacesarestraightforward.Usingthenewmathematicsmodels,wepresentthecontrolmeshrepresentationsoftwoclassesofminimalsurfaces.

简介：摘 要：尼贝原油外输管道海上终端项目位于西非大西洋沿岸，项目所处区域海岸线无潮间带，且常年受长周期涌浪影响,近岸段海管登陆区域破碎浪冲击力大。针对该工程特点，分析了海底管道AHT拖管法的选取理由，较全面的介绍了AHT拖管法的主要施工工艺及相关计算过程。该工程AHT拖管法的顺利实施，为海洋管道登陆段施工提供了新思路、新方法。