胸鳍或中间鳍推进模式(medianand or paired fin propulsion,MPF)鲼类以其游动高效且稳定而成为越来越多仿生学者的研究对象.研究选取胸鳍为类三角形的鲼类进行仿生建模,针对其游动姿态与推进模式,改进波动方程建立双鳍对称运动模型,并...胸鳍或中间鳍推进模式(medianand or paired fin propulsion,MPF)鲼类以其游动高效且稳定而成为越来越多仿生学者的研究对象.研究选取胸鳍为类三角形的鲼类进行仿生建模,针对其游动姿态与推进模式,改进波动方程建立双鳍对称运动模型,并运用计算流体力学(computational fluid dynamics,CFD)的方法结合动网格技术对其进行数值模拟,研究其推进机理与游动特点,在此基础上,通过改变胸鳍波动频率、波动幅值和体波波长等生物学特征探究不同参数对MPF推进模式鲼类游动能力的影响规律.研究结果表明:在胸鳍向上波动或向下波动阶段,胸鳍末端均存在明显的低压中心,大部分推进力主要由胸鳍末端的涡量差产生;向上和向下波动双鳍的过程中鱼体会产生周期性的升力,频率与摆幅更大时升力系数峰值更高.在相同初速度与相同鱼体初始运动状态下,鱼体在3 Hz与A=0.125L时垂向位移分别可达2.32和1.81 m,可获得最大垂向提升涨幅.体波波长决定鱼体胸鳍波动主要位置,当λ=0.6L即胸鳍波动主要位置靠近中性纵剖面时鱼体推进力系数均值仅有0.02,而当λ=1.05L即胸鳍波动主要位置靠近胸鳍末梢时鱼体具有较高的推进力,推进力系数均值可达0.14.本研究结果可以为基于MPF推进模式的仿生水下机器鱼提供设计与制作基础.展开更多
The spindle behavior and MPF activity changes in the progression of oocyte maturation were investigated and compared with cytological observation and kinase assay between gynogenetic silver crucian carp and amphimicti...The spindle behavior and MPF activity changes in the progression of oocyte maturation were investigated and compared with cytological observation and kinase assay between gynogenetic silver crucian carp and amphimictic colored crucian carp. MPF activity was measured by using histone H1 as phosphorylation substrate. There were two similar oscillatory MPF kinase activity changes during oocyte maturation in two kinds of fishes with different reproductive modes, but there existed some subtle difference between them. The subtle difference was that the first peak of MPF kinase activity was kept to a longerlasting time in the gynogenetic silver crucian carp than in the amphimictic colored crucian carp. It was suggested that the difference may be related to the spindle behavior changes, such as tripolar spindle formation and spindle rearrangement in the gynogenetic crucian carp.展开更多
文摘胸鳍或中间鳍推进模式(medianand or paired fin propulsion,MPF)鲼类以其游动高效且稳定而成为越来越多仿生学者的研究对象.研究选取胸鳍为类三角形的鲼类进行仿生建模,针对其游动姿态与推进模式,改进波动方程建立双鳍对称运动模型,并运用计算流体力学(computational fluid dynamics,CFD)的方法结合动网格技术对其进行数值模拟,研究其推进机理与游动特点,在此基础上,通过改变胸鳍波动频率、波动幅值和体波波长等生物学特征探究不同参数对MPF推进模式鲼类游动能力的影响规律.研究结果表明:在胸鳍向上波动或向下波动阶段,胸鳍末端均存在明显的低压中心,大部分推进力主要由胸鳍末端的涡量差产生;向上和向下波动双鳍的过程中鱼体会产生周期性的升力,频率与摆幅更大时升力系数峰值更高.在相同初速度与相同鱼体初始运动状态下,鱼体在3 Hz与A=0.125L时垂向位移分别可达2.32和1.81 m,可获得最大垂向提升涨幅.体波波长决定鱼体胸鳍波动主要位置,当λ=0.6L即胸鳍波动主要位置靠近中性纵剖面时鱼体推进力系数均值仅有0.02,而当λ=1.05L即胸鳍波动主要位置靠近胸鳍末梢时鱼体具有较高的推进力,推进力系数均值可达0.14.本研究结果可以为基于MPF推进模式的仿生水下机器鱼提供设计与制作基础.
文摘The spindle behavior and MPF activity changes in the progression of oocyte maturation were investigated and compared with cytological observation and kinase assay between gynogenetic silver crucian carp and amphimictic colored crucian carp. MPF activity was measured by using histone H1 as phosphorylation substrate. There were two similar oscillatory MPF kinase activity changes during oocyte maturation in two kinds of fishes with different reproductive modes, but there existed some subtle difference between them. The subtle difference was that the first peak of MPF kinase activity was kept to a longerlasting time in the gynogenetic silver crucian carp than in the amphimictic colored crucian carp. It was suggested that the difference may be related to the spindle behavior changes, such as tripolar spindle formation and spindle rearrangement in the gynogenetic crucian carp.
