English  |  正體中文  |  简体中文  |  Items with full text/Total items : 43312/67235
Visitors : 2076995      Online Users : 2
RC Version 5.0 © Powered By DSPACE, MIT. Enhanced by NTU/NCHU Library IR team.

Please use this identifier to cite or link to this item: http://nchuir.lib.nchu.edu.tw/handle/309270000/97734

標題: 翅痣對蜻蜓振翅時翅膀形變之影響
Effects of pterostigma on deformation of flapping wings in dragonflies
作者: 張家慈
Chung, Chia-Tzu
Contributors: 楊恩誠;施明智
紀凱容
Kai-Jung Chi
中興大學
關鍵字: dragonfly;wing bending;high-speed videography;pterostigma;inertial effect;biomechanics
薄翅蜻蜓 (dragonfly Pantala flavescens);翅膀形變 (wing bending);高速攝影術 (high-speed videography);翅痣 (pterostigma);慣性效應 (inertial effect);生物力學 (biomechanics)
日期: 2011
Issue Date: 2012-09-04 09:16:53 (UTC+8)
Publisher: 生物物理學研究所
摘要: 翅痣為昆蟲翅上增厚的特殊構造,通常位於翅前緣接近末端的部分,因其大小、形態、和相對位置具有種間差異,故通常作為分類依據。時值今日,唯一以翅痣為主題,探討其力學功能的研究指出,以蜻蜓為例,翅痣改變了翅的質量分佈,故可能影響翅的振動特性及昆蟲飛行;然而此說仍無直接數據支持並描述影響機制。本研究以台灣常見的薄翅蜻蜓(Pantala flavescens)為材料,比較不同振翅條件下,移除翅痣是否改變翅膀在翼展方向上的彎曲程度,以探討翅痣對振動或拍動中蜻蜓翅膀形變的影響。經量測,翅痣的質量佔翅膀的8.0 ± 3.4% (N = 26),估計每單位面積所承載的質量約為翅膀平均值的十倍之多,故此結構將影響翅膀質量的分佈。為比較翅痣是否影響翅膀的振動特性,我首先將取下的翅膀膠著於振盪器上,以固定的頻率和振幅上下振動翅膀,並用高速攝影機以每秒2000張影像 (2000 fps) 的速度拍攝翅的振動行為,進而量化其翅膀的彎曲形變量。這部份的數據顯示,移除翅痣後的蜻蜓翅膀在上下振動時,形變量顯著下降了14.2 ± 6% (paired t-test;p = 0.0389;N = 7)。同時我發現,蜻蜓翅膀前緣的形變具上下不對稱性。然而,當運用同樣的方法來分析活體蜻蜓拍翅時翅膀的彎曲形變量,卻發現翅痣有無並不影響活體蜻蜓振翅時翅膀彎曲的程度(具有翅痣的蜻蜓翅膀彎曲程度為13.98 ± 4.58度,翅痣移除後則為13.35 ± 4.64度:p = 0.0562;N = 10)。但實驗觀察發現,翅痣移除後,蜻蜓振動翅膀的振幅顯著增加(具有翅痣的蜻蜓拍翅振幅為33.0 ± 9.38度,翅痣移除後則為42.3 ± 9.72度:p = 0.0005;N = 10),而速度則略為增加 (具有翅痣的蜻蜓拍翅速度為1.55 ± 0.63 m/s,翅痣移除後則為1.70 ± 0.49 m/s:p = 0.2864;N = 10),顯示移除翅痣會改變蜻蜓拍翅的行為。經由分析顯示翅膀彎曲形變隨拍翅振幅增加而增加。為消除拍翅振幅對翅膀形變的影響,我比較拍翅振幅歸一化後的結果,發現翅痣有無顯著影響翅膀彎曲形變(具有翅痣的蜻蜓歸一化翅膀彎曲程度為0.26 ± 0.06,翅痣移除後則減少為0.16 ± 0.04:p = 0.0006;N = 10)。因此蜻蜓可藉由增加拍翅振幅及速度,使其失去翅痣後仍能維持相同的翅膀形變量。本研究提出實驗數據,來證實翅痣可藉由調控慣性力來增加翅膀的彎曲程度;此外,生物可主動調控自身拍翅振幅與速度,來補償失去翅痣後所可能減少的翅膀形變量。近年的研究指出,翅膀形變有助於提升昆蟲飛行時的升力;因此,翅痣所造成的翅膀彎曲形變,有可能會影響蜻蜓的飛行。


關鍵詞:薄翅蜻蜓 (dragonfly Pantala flavescens)、翅膀形變 (wing bending)、高速攝影術 (high-speed videography)、翅痣 (pterostigma)、慣性效應 (inertial effect)、生物力學 (biomechanics)
Pterostigma, a darken region of the leading edge on an insect wing, accounts for 8.03.4% of the wing mass (N=26), leading to an area density 10X that of the wing. Therefore, this heavy structure may change mass distribution in the wing. To date, the roles of the pterostigma in wing functioning remain unclear. In this study, I changed the mass of pterostigma to examine its effects on span-wise wing deformation in dragonfly Pantala flavescens. Wing deformation was analyzed from images recorded using high-speed video camera (2000 fps). I first examined isolated wings on a shaker vibrating at fixed frequency and amplitude, and compared bending deformation of the leading edge of the wings with or without pterostigma intact. An intact wing had 14.2 6% greater deformation than a wing without pterostigma (paired t-test; p = 0.0389; N = 7). The wings bend asymmetrically between up- and down-strokes. These results provided the first evidence that pterostigma can enhance wing deformation under forced vibration through its inertial effect. In fixed living dragonflies, however, the deformation of flapping wings only slightly decreased after the pterostigma was removed (13.98 4.58 degree with pterostigma vs. 13.35 4.64 degree without pterostigma; p = 0.0562; N = 10) After the dragonflies lost their pterostigma, they significantly increased the flapping amplitude (33.0 9.38 degree with pterostigma vs. 42.3 9.72 degree without pterostigma; p = 0.0005; N = 10) and slightly increased flapping velocity (1.55 0.63 m/s with pterostigma vs. 1.70 0.49 m/s without pterostigma; p = 0.2864; N = 10) of the wing, presumably to maintain similar wing deformation. To compare wing deformation among subjects of different flapping amplitudes, I normalized flapping amplitude by dividing the values with bending deformation. Comparison of bending per flapping amplitude reveals that without pterostigma, the wing bends less: 0.26 0.06 in intact wings with pterostigma vs. 0.16 0.04 without pterostigma (p = 0.0006; N = 10). Furthermore, wing deformation can be modulated by actively changing flapping kinematics. The fact that dragonflies increase flapping amplitudes and velocities of the wing to compensate for the lost of pterostigma, assuming at greater energy expenditure, suggests functional importance of wing deformation. Recent literature provides evidence that wing deformation can facilitate lift production; therefore, wing deformation enhanced by the pterostigma may be important to flight performance of dragonflies.

Keywords: dragonfly Pantala flavescens, wing bending, high-speed videography, pterostigma, inertial effect, biomechanics.
Appears in Collections:[依資料類型分類] 碩博士論文

Files in This Item:

File SizeFormat
index.html0KbHTML573View/Open


 


學術資源

著作權聲明

本網站為收錄中興大學學術著作及學術產出,已積極向著作權人取得全文授權,並盡力防止侵害著作權人之權益。如仍發現本網站之數位內容有侵害著作權人權益情事者,請權利人通知本網站維護人員,將盡速為您處理。

本網站之數位內容為國立中興大學所收錄之機構典藏,無償提供學術研究與公眾教育等公益性使用。

聯絡網站維護人員:wyhuang@nchu.edu.tw,04-22840290 # 412。

DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU/NCHU Library IR team Copyright ©   - Feedback