简介:日本松下电器产业(股份)公司同NATIONAL自行车工业(股份)公司通力合作,共同打造了一款取名为“WlLLBIKEA”的折叠式电动自行车新品。据介绍,该折叠式电动自行车(车架表面色彩;黑色;整车重量:9.7千克:整车规格:长1175mm×宽555mm;整车折叠后尺寸:长1250mm×高590mm×宽280mm)以“德
简介:Theplowofthesubmarineplowingtrencherisoneofthemainfunctionalmechanisms,anditsoptimizationisveryimportant.Thedesignparametersplayaverysignificantroleindeterminingtherequirementsofthetowingforceofavessel.Amulti-objectivegeneticalgorithmbasedonanalyticalmodelsoftheplowsurfacehasbeenexaminedandappliedineffortstoobtainoptimaldesignoftheplow.Foraspecificsoilcondition,thedraftforceandmoldboardsurfaceareawhicharethekeyparametersintheworkingprocessoftheplowareoptimizedbyfindingthecorrespondingoptimalvaluesoftheplowbladepenetrationangleandtwosurfaceanglesofthemaincuttingbladeoftheplow.Parameterssuchasthemoldboardsideangleofdeviation,moldboardliftangle,angularvariationofthetangentline,andthespanninglengtharealsoanalyzedwithrespecttotheforceofthemoldboardsurfacealongsoilflowdirection.Resultsshowthattheoptimizedplowhasanimprovedplowperformance.Thedraftforcesofthemaincuttingbladeandthemoldboardare10.6%and7%,respectively,lessthantheoriginaldesign.ThestandarddeviationofGaussiancurvatureofmoldboardisloweredby64.5%,whichimpliesthatthesmoothnessoftheoptimizedmoldboardsurfaceismuchgreaterthantheoriginal.
简介:以港珠澳大桥钢桥面铺装为研究背景,采用3种沥青含量,分析沥青含量变化对GMA浇注式沥青混凝土的施工和易性、高温稳定性、疲劳性能的影响。研究表明:流动度随沥青含量的增加而减小;沥青含量对其路用性能影响显著。研究成果可为其它类似桥面铺装质量控制提供较好的借鉴。