简介：VTA涡轮增压器是一种新型的增压器,具有燃油消耗率低和降低排放污染的优点,本文介绍了VTA控制系统,探讨了其工作原理,调整控制程序实现全工况范围内发动机与增压器的最佳匹配,使发动机性能优化以满足客户的需求.并对其运行管理及应用提出了合理的建议.

简介：Wavediffractionoftwoconcentricporouscylinderswithvaryingporositywasstudiedbyusingananalyticalmethodbasedoneigenfunctionmatching.Thefluiddomainaroundthecylindersisdividedintothreesub-domainsandineachsub-domainaneigenfunctionexpansionofthevelocitypotentialisobtainedbysatisfyingtheLaplaceequation,theboundaryconditionsonthefreesurfaceandontheseabed.Theunknowncoefficientsofeigenfunctionexpansionsaredeterminedbyboundaryconditionsontheporoushulls.Inthepaper,theboundaryconditionsarebasedupontheassumptionthattheflowintheporousmediumisgovernedbyDarcy’slaw.Twoporous-effectparametersappliedontwoporouscylindersarefunctionsoftheverticalcoordinateinsteadoftheconstant.Waveloadingontheouterandinnercylinderispresentedinthenumericalresults.

简介：2019年,我们的挑战会很多,如经济下行的压力,企业有明显的感觉.但货币方面不管是财政还是贸易,都在作快速调整,因此未来一年多时间里,总的趋势会比较稳定.