母羊3种应激行为下叫声信号的对比分析

为研究母羊在不同应激行为下叫声信号所具有的特征,选择体重相近、年龄在2~3岁的小尾寒羊母羊20只,分别录取其在3种应激行为(产羔、寻羔、饥饿)下的叫声信号。利用LabVIEW软件设计母羊发声信号特征提取与识别系统,对母羊发声信号进行时域分析、频域分析(Yule-Walker法估计功率谱、Welch法估计功率谱、线性坐标功率谱和倒谱分析)和时频域分析,提取发声信号的时间间隔、持续时间、主峰频率、能量集中范围和基音周期等特征参数。结果表明:母羊3种不同类型声音的持续时间以及主峰频率均存在显著差异(P0.05)。母羊在寻羔和饥饿时发声的持续时间是产羔时的1.93和1.82倍,饥饿叫声的主频分别为产羔和寻羔时的34.77和38.81倍,母羊叫声信号Yule-Walker法功率谱在饥饿出现1个峰值,寻羔时出现2个峰值,而产羔时无明显峰值。叫声信号能量在产羔时集中在400~600Hz,寻羔和饥饿时集中在0~900Hz,3种叫声基音周期接近为0.1ms。证明母羊叫声信号在3种应激行为下有明显的不同,因此可以作为评价其健康状况及福利化养殖水平的重要指标之一。     

褐菖鲉发声系统形态结构及其发声特征研究

分别采用形态学和模拟领地入侵的方法研究了褐菖鲉发声系统和发声特征。结果表明,褐菖鲉发声系统由鱼鳔肌和鱼鳔组成。鱼鳔肌前方附着于颅骨的翼耳骨,后经第1～7肋骨,与鱼鳔背后侧部相连。在领地入侵模拟实验中,褐菖鲉发出了连续脉冲的“咕噜噜”声音,其平均脉冲周期为(32.6±2.6) ms,平均脉冲间隔为(51.8±81.4) ms, 主频为68～175 Hz。对单个声音脉冲中包涵的正弦波型的能量周期分析发现：其声音主频与最大能量周期的倒数一致,表明褐菖鲉是采用鱼鳔肌收缩的发声机制。     

宁夏地区斑衣蜡蝉交配产卵习性研究

通过野外调查和饲养观测,对斑衣蜡蝉在宁夏地区的交配产卵习性进行了研究。结果表明斑衣蜡蝉在宁夏地区于8月中下旬开始交配产卵直至10月中旬,成虫多集中在早晨7:00-9:00开始交配,产卵历期3~5d;不同林分条件下,斑衣蜡蝉产卵存在一定的寄主选择性;卵多产于寄主3m高度以下树干的阳面,大多数卵块集中在林缘处。     

扎龙自然保护区丹顶鹤繁殖期的个体行为

采用目标取样法和所有事件取样法研究了4对野生丹顶鹤在繁殖期的各种行为。结果表明：丹顶鹤的行为类型主要有觅食、静栖、警戒、游走、修饰、繁殖（包括求偶、交配、筑巢、产卵、孵化、育雏）。丹顶鹤为保证繁殖成功而建立领域，在繁殖期的不同阶段，其行为存在一定的变化：在产卵前期，觅食行为显示的强度最高；在孵化期，繁殖行为显示的强度最高，静栖行为显示的强度下降，警戒行为显示的强度则显著升高。     

1PJ-3.0型水田激光平地机高程系统动态特性试验研究

水田激光平地机的高程系统主要接收激光信号并用以控制平地铲处于设定平面,其动态特性是平地机平整作业质量的重要保证。为分析水田激光平地机的高程系统动态特性,进一步提高平地机的工作性能,以与插秧机配套的1PJ-3.0型水田激光平地机为平台,采用电流检测电路检测电磁阀线圈电流,直线位移传感器测量油缸和平地铲的运动行程,USB高速数据采集模块同时采集电磁阀线圈电压和直线位移传感器信号,从而获得油缸和平地铲的响应时间和运动速度。在平地机高程机械液压系统处于不同油门、不同初始高度,平地铲上升过程和下降过程的条件下进行试验。试验结果表明:在上升过程中,油缸的平均响应时间48.2ms,平地铲的平均响应时间59.4ms;而在下降时,油缸的平均响应时间73.6ms,平地铲的平均响应时间62.3ms;在平地铲上升或下降时,不同初始高度和不同油门开度等级下的,油缸和平地铲的响应时间基本稳定;油门等级越大,平地铲上升速度越快,上升速度在109.0~305.0mm·s-1之间;单向节流阀能保证平地铲下降速度稳定,不受油门开度等因素影响,油缸缩回速度为35.8mm·s-1,平地铲下降速度为126.1mm·s-1。     

基于声发射信号信息熵的木材损伤断裂过程研究

为获得木材在弯曲破坏过程中的声发射（acoustic emission,AE）信号特征,从AE信号的随机性出发,利用AE信号信息熵辨识木材的损伤过程,并研究木材在不同损伤断裂水平下的AE信号分布特性。首先,对气干状态的榉木和樟子松试件进行三点弯曲试验,并通过谐振频率为150 kHz的AE传感器采集原始AE信号,采样频率设置为500 kHz。然后,采用小波变换重构AE信号波形,依据无AE发生时的信号幅值确定AE阈值,统计每秒内超过阈值的次数并作为AE活动计数,再以活动计数为随机变量定义AE信息熵。最后,依据信息熵值确定应变能释放的转折点,并结合三点弯曲试验的载荷-时间曲线,将木材损伤断裂过程划分为线性变形、非线性变形、宏观断裂3个阶段。以10 ms为间隔分析并统计AE信号的频率,获得木材弯曲破坏过程的AE信号频率分布情况,从而揭示不同损伤阶段的AE信号特征。结果表明,线性变形阶段,AE信号表现为低幅值、低频率,主要集中在30~55 kHz频段内;非线性变形和宏观断裂阶段,AE信号中既存在大量的30~55 kHz低频信号成分,又存在100~110 kHz和115~130 kHz的高频信号。研究提出的基于AE活动数信息熵能够准确反映应变能释放的集中程度,为木材损伤断裂水平评价提供了客观依据。     

2种天牛幼虫的4类声行为特征

应用声音侦听技术监测隐蔽性害虫是一种较有前景的方法,明确害虫各类声行为的特征有利于排除不同声行为混合叠加的干扰,从而有效地识别害虫种类及其活动方式。利用红外监控下的声音侦听系统对光肩星天牛Anoplophora glabripennis幼虫和星天牛A.chinensis幼虫的声行为进行了分类和分析。2种天牛幼虫的声行为主要分为取食、爬行、清理蛀道和自卫4类,取食声占比最高,可达34%。4类声行为在时域图的最大振幅、波形和脉冲持续时间以及频谱图的能量分布和频段均表现出了不同的特征。此外,对声行为进行时域和频域的定量分析发现,脉冲持续时间和脉冲主频均体现出较大差异,取食声脉冲持续时间短,分别为25.96 ms和24.28 ms,主频最高,超过7.00 k Hz。对天牛幼虫不同声行为的信号特征进行了探索,尝试通过排除各类声行为的干扰以提高侦听效果,同时发现取食声脉冲时间短、振幅大且频率高,在实际侦听时可以进行较快的辨别。     

室内饲养草间钻头蛛的生物学特性

[目的]研究室内饲养草间钻头蛛的主要生物学特性,探讨草间钻头蛛在室内饲养的可行性。[方法]在室内饲养条件下,观察不同温度下草间钻头蛛F1代的发育历期,2龄蜘蛛耐饥、耐旱能力,喂食不同食物的亚成蛛的捕食量和体重增长,F1代产卵数量、孵化率等指标。[结果]草间钻头蛛的发育历期随温度增加而缩短;2龄草间钻头蛛的饥饿历期平均为(8.94±2.79)d,耐旱历期平均为(1.30±0.57)d,耐饥、耐旱能力较亚成蛛、成蛛弱;喂食不同食物的的捕食量在2头左右,体重增长不同,饲喂果蝇和棉铃虫的亚成蛛较饲喂人工饲料增长快;草间钻头蛛F1代平均产卵4.85次,第1次产卵间隔平均为(6.62±1.56)d,以后产卵间隔缩短;F1代室内饲养孵化率为96.9%,较室外蜘蛛的自然孵化率高。[结论]室内饲养草间钻头蛛有一定的可行性。     

泥浆脉冲信号的小波检测方法研究及应用

在目前采用钻井液脉冲方式传输信号的无线随钻测量系统中,由于泥浆压力、井深、泵压力等信道传输特性的影响,测量系统中在井口采集的泥浆脉冲信号往往包含了各种噪声,直接影响到有用信号检测结果的正确性。对泥浆脉冲信号的传输特性及信号中噪声的特性进行了深入的分析,提出以小波分析为基础的泥浆脉冲信号检测方法。现场数据应用结果表明,该方法能够有效去除信号中的噪声并在不引起明显失真的情况下检测出井下有用信号,在泥浆脉冲信号处理中有广阔的应用前景。     

植食性昆虫产卵寄主选择影响因素 及机制的研究进展

昆虫产卵行为在昆虫与寄主的协同进化中起着重要作用,而母代产卵偏好性和子代生长发育情况的关系是植食性昆虫与寄主植物协同进化研究的核心.文章综述了寄主种类、环境丰富度、寄主生长发育状况和寄主被同种其他个体的利用程度等对植食性昆虫产卵寄主选择的影响,以及嗅觉、视觉和触觉在植食性昆虫产卵寄主选择过程中的作用机制.提出今后应从昆虫视觉生态学和听觉生态学两个角度深入研究植食性昆虫的产卵行为,尤其是加强植食性昆虫与环境中光信号间的联系及如何利用光信号进行寄主定位、 植食性昆虫产卵行为过程中是否利用听器进行声波测探定位产卵寄主及不同波段声音对植食性昆虫产卵行为的影响等研究,为研究害虫行为调控措施开拓新思路.     

Auditory sense in certain sphingid moths

Moths of the genus Celerio, hovering and feeding from blossoms, have been observed to react vigorously to high-pitched sounds. The acoustic receptor appears to involve the labial palps. Its characteristics have been determined from responses made, when the moth is exposed to artificial sound pulses, by an interneuron originating in its head. These responses have been found only in 4 out of 19 sphingid species tested.     

1Localization effects with steady thermal noise in one ear and pulsed thermal noise in the other

When the duration or repetition rate of pulses in the left ear is increased, while steady, in-phase, thermal noise sounds in the right ear, the pulses are heard to move toward the median plane. At still longer durations (for a given repetition rate) the loudness of noise on the right diminishes, until finally all sound is localized at the median plane.     

Neural attenuation of responses to emitted sounds in echolocating rats

Bats of the family Vespertilionidae enmit strong ultrasonic pulses for echolocation. If such sounds directly stimulate their ears, the detection of echoes from short distances would be impaired. The responses of lateral lemniscal neurons to emitted sounds were found to be much smaller than those to playback sounds, even when the response of the auditory nerve was the same to both types of sounds. Thus, responses to self-vocalized sounds were attenuated between the cochlear nerve and the inferior colliculus. The mean attenuation was 25 decibels. This neural attenuating mechanism is probably a part of the mechanisms for effective echo detection.     

Communicative Mandible-Snapping in Acrididae (Orthoptera)

Paratylotropidia brunneri Scudder is the first insect known to possess a long-range mandibular sound signal. This signal probably evolved through a stage in which feeding noises were significant; it is believed to be a functional analog of other insect calling sounds.     

人工神经网络对果蝇鸣声的分类识别

为了利用昆虫鸣声对昆虫进行种间或种下分类,对实验室环境下同种2个不同品系黑腹果蝇的飞行翅振鸣声进行了采集、分析,提取鸣声信号特征参数,并利用人工神经网络对采集的果蝇鸣声信号进行分类识别。结果表明,2个品系果蝇鸣声的基频均为236.86 Hz,有多个谐频,频率范围为0~4000 Hz,重叠较大;所建立的人工神经网络对种内不同品系果蝇鸣声的正确识别率均在75%以上,识别效果很好。研究结果为果蝇种下分类提供了新的方法和依据。     

Speech perception in infants

Discriminiationi of synthetic speech sounds was studied in 1- and 4-month-old infants. The speech sounds varied along an acoustic dimension previously shown to cue phonemic distinctions among the voiced and voiceless stop consonants in adults. Discriminability was measured by an increase in conditioned response rate to a second speech sound after habituation to the first speech sound. Recovery from habituation was greater for a given acoustic difference when the two stimuli were from different adult phonemic categories than when they were from the same category. The discontinuity in discrimination at the region of the adult phonemic boundary was taken as evidence for categorical perception.     

Wing movements of calling katydids: fiddling finesse

Stridulating Uhler's katydids produce the most complex song known for insects. Series of four types of sounds are made in stereotyped sequence. Sound-synchronized high-speed photography reveals that each type of sound is produced by a distinctively different wing-movement cycle. The most complex of these cycles includes a two-step closure and a nearly silent close-open movement.     

The influence of respiratory disease on the energy envelope dynamics of pig cough sounds

The objective of this paper is to assess if the dynamics in the energy envelope of pig cough sounds are related to pathological conditions of the respiratory system. Two groups of pigs are compared. The first group, the sick pigs, is suffering from pneumonia by infection of Pasteurella Multocida. The second group, the control group, consists of healthy pigs which produced induced coughs by nebulisation of citric acid. The cough sounds of both groups were used to calculate the energy envelope, after which two signals are derived for further modelling. The first signal is an artificial step input, the second signal is part of the energy envelope of the cough signal that starts at the maximum level and decays in time. Using an autoregressive model estimation technique, the decay of the energy envelope is modelled as an input–output system. Based on the Young Identification Criterion (YIC) and R², the optimal model is proven to be a first order model with a first order denominator. Using this first order transfer function structure to model all cough sounds, the time constant of the simulated output is estimated based on the model parameters. The time constant shows significant higher values for the decay of the cough signals from pigs which are infected with Pasteurella Multocida compared to non-infected pigs (P < 0.0001). The results are in accordance with previous work in which pathological conditions have shown to influence cough sound duration. This modelling technique gives more insight in the effect of changes in lung condition on cough sound generation and might be incorporated in techniques for automatic cough evaluation.     

柑桔实蝇幼虫振动信号的初步研究

对柑桔果实内两种实蝇幼虫的振动信号研究表明,蜜柑大实蝇(Te-tradacus tsunenonis Miyake)以单头幼虫为害,幼虫取食的振动信号频率较高,持续时间较长,容易辨识;桔大实蝇(T.citri Chen)以多头幼虫为害,不同个体的活动导致振动信号的混合和迭加,信号波型变化很大,采用常规示波技术难以进行定性定量分析。作者还讨论了本研究所用仪器的灵敏度和利用幼虫振动信号检测果实的可能性。