南京大学学报（自然科学版）Issue(z1)：139-142,4.DOI:10.13232/j.cnki.jnju.2015.07.027
两种菊头蝠超声发射特性与鼻叶形态的相关性
The correlation between ultrasonic emission characteristic and noseleaf shape in two types of horseshoe bat
摘要
Abstract
Finite element method is adopted for the numerical study of the correlation between ultrasonic emission characteristic and noseleaf shape of two types of horseshoe bat.With evolution and natural selection,most bats have developed an ultrasonic echolocation system with high performance,called biosonar,The signal sender is surrounded by complicated wrinkle noseleaf whose position and structure are considered to change the direction of ultrasonic pulse.Experimental studies have suggested noseleaf really has complicated acoustic function.In this paper,the noseleaf samples of Bourret’s horseshoe bat and Rufous horseshoe bat are chosen to simulated.The first step is to acquire original biological data.In experiment,high-resolution X-ray micro CT machine is adopted to scan samples of noseleaf of two horseshoe bats to get original digital shadow images.Then the cross-section view of the noseleaves are reconstructed with the method of cone beam reconstruction.These images with 256 gray level are then processed through Gaussian filter and boolean process,and images with clear definition of air and biological tissue could be got. With three-dimensional digital image processing technique,three-dimensional digital image attributes of two horseshoe bat noseleaf are acquired.The near-field sound pressure distribution of the two noseleaves structure is simulated with finite element method,and the far-field sensitivity function is extrapolated based on Kirchhoff integral theorem from near field,to analyze the directivity at azimuth and elevation angles.Finally,the width of noseleaf ultrasonic beam in the direction of elevation angle is measured to get the ultrasonic emission characteristics of the two types of noseleaves.Thus,the correlation between the ultrasonic emission characteristics and the length of noseleaf sella of the two types of bats are gotten through contrast between the length of their noseleaf sella.The result indicates sella plays a significant role in controlling the directivity at elevation angle in the process of emitting ultrasound,and there is obvious negative correlation between the length of sella and ultrasonic frequency.关键词
菊头蝠/鼻叶形态/鞍状叶/波束形成/超声发射Key words
horseshoe bat/noseleaf characteristic/sella/beam forming/ultrasonic emission分类
数理科学引用本文复制引用
张智伟,王福勋,赵昕,庄桥..两种菊头蝠超声发射特性与鼻叶形态的相关性[J].南京大学学报（自然科学版）,2015,(z1):139-142,4.基金项目
国家自然科学基金(11104355,11374193) （11104355,11374193）
