查询词典 echolocation

Echolocation calls are usually ultrasonic ranging in frequency from 20 to 200 kilohertz Hz , whereas human hearing normally tops out at around 20 Hz .

用于回声定位的叫声一般是20－200千赫之间的超声波，而人所能听到的最高频率在20千赫左右。

Thus, the neurons with sharp frequency tuning and high Q 10 -dB values showed that there was certain relationship between echolocation call and frequency tuning of IC neurons in the leaf-nosed bats.

结果表明，大蹄蝠回声定位信号与下丘神经元频率调谐存在相关性，表现为最佳频率在回声定位信号主频附近的神经元频率调谐曲线的Q10-dB值较大，具有很强的频率分析能力。

The results showed that the echolocation calls of the leaf-nosed bats were constant frequency-frequency modulation signals with 2-3 harmonics and the second one among these three harmonics was its dominant frequency. The constant frequency components of three harmonics (Mean±SD, n=18 ) were 33.3±0.2 kHz, 66.5±0.3 kHz, and 99.4±0.5 kHz, respectively. In examined FTCs of 72 IC neurons, their Q 10 -dB values ranged from 0.5 to 95.4 (9.2±14.6) and the neurons whose best frequency around the dominant frequency had sharp frequency tuning.

结果发现，大蹄蝠回声定位叫声为恒频-调频(constant frequency-frequency modulated，CF-FM)信号，一般含有2~3个谐波，第二谐波为其主频，CF成分频率(Mean±SD，n=18)依次为：(33.3±0.2)、(66.5±0.3)、(99.4±0.5)kHz；电生理实验共获得72个神经元的频率调谐曲线，Q10-dB值的范围是0.5~95.4(9.2±14.6， n=72)，最佳频率(best frequency，BF)在回声定位主频附近的神经元具有尖锐的频率调谐特性。

Diving behavior and echolocation pulse rate of three captive porpoises in Wuhan Baiji Dolphinarium were observed continuously using both behavioral and acoustic data loggers on 23?25 November 2002. A total of 38 hr of behavioral data and 40 hr of acoustic data were recorded for each porpoise.

同时使用行为和声学微型生物跟踪记录仪，于2002 年11 月23-25日，跟踪记录了白鱀豚馆3 头江豚的行为和发声，每头江豚行为记录时间38 hr，声学记录时间40hr。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。