Elastic pinch biomechanisms can yield consistent launch speeds regardless of projectile mass
Elastic pinch biomechanisms can yield consistent launch speeds regardless of projectile mass
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弹夹生物力学可以产生一致的发射速度，而与弹丸质量无关
DOI：
10.1098/rsif.2023.0234
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发表时间：
2023-08
影响因子：
3.9
通讯作者：
J. Jorge;S. Patek
中科院分区：
文献类型：
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作者：
J. Jorge;S. Patek
能量权衡尤其与生物弹道系统有关，生物弹道系统仅在发射期间向炮弹提供能量。我们研究了中国金缕梅、金缕梅和中国金缕梅春播种子的这种权衡。利用类似的种子萌发机制，这些同科植物(金缕梅科)的果实在春季和种子质量中跨度一个数量级。我们预计，随着种子质量的增加，发射速度会降低。相反，发射速度相对恒定，与种子质量无关。我们测试了水果是否通过储存更多的弹性势能(PE)来萌发更大的种子。春季质量和PE随种子质量的增加而增加(按种子质量大小顺序为羊草>华山羊草>华山羊草)。随着种子质量与春季质量比的增大(南方红豆杉=0.50，华山松=0.65，羊草=0.84)，种子比贮藏量增加。PE向种子动能的转化效率(KE)随果实质量的增加而降低。因此，由于(I)较大的水果存储了更多的PE和(Ii)较小的水果具有更高的质量比PE存储和提高了PE到KE的转化率，所以发生了跨尺度的相似的发射速度。通过在我们的焦点物种中研究集成的弹簧和弹丸力学，我们揭示了与弹簧推进系统在能量权衡中导航相关的各种能量缩放策略。
Energetic trade-offs are particularly pertinent to bio-ballistic systems which impart energy to projectiles exclusively during launch. We investigated such trade-offs in the spring-propelled seeds of Loropetalum chinense, Hamamelis virginiana and Fortunearia sinensis. Using similar seed-shooting mechanisms, fruits of these confamilial plants (Hamamelidaceae) span an order of magnitude in spring and seed mass. We expected that as seed mass increases, launch speed decreases. Instead, launch speed was relatively constant regardless of seed mass. We tested if fruits shoot larger seeds by storing more elastic potential energy (PE). Spring mass and PE increased as seed mass increased (in order of increasing seed mass: L. chinense, H. virginiana, F. sinensis). As seed mass to spring mass ratio increased (ratios: H. virginiana = 0.50, F. sinensis = 0.65, L. chinense = 0.84), mass-specific PE storage increased. The conversion efficiency of PE to seed kinetic energy (KE) decreased with increasing fruit mass. Therefore, similar launch speeds across scales occurred because (i) larger fruits stored more PE and (ii) smaller fruits had higher mass-specific PE storage and improved PE to KE conversion. By examining integrated spring and projectile mechanics in our focal species, we revealed diverse, energetic scaling strategies relevant to spring-propelled systems navigating energetic trade-offs.