Plants that were in no immediate danger gave out less than one ultrasonic sound per hour.

那些不受直接威胁的植物每小时发出的超声波不到一次。

So if you're standing in front of the ultrasonic sound wave, you can hear the sound.

所以如果你站在超音速声波的前面，你能听到声音。

If there is no ultrasonic sound in the received signal, the maximal value is not in order.

而当回波中没有超声信号时，相关值的极大值没有固定规律。

There are various ways to measure distance, including ultrasonic sound waves and infrared light.

有各类分歧的办法来丈量间隔，包罗超声波声波和红外光。

The application of ultrasonic sound system of measuring distance is also presented in this paper .

给出了超声波语音测距系统在车辆避障中的实际应用。

These high intensity ultrasonic sound waves (20 ~ 65khz) are out of the range of hearing of humans are most household pets, but pests.

这些高强度的超声波(20 ~ 65khz)不在人类和大部分家养宠物的听觉范围内，但能被害虫听到。

The repetition of the ultrasonic sound and the experiment of zero velocity in gas flowmeter are tested using this speed measurement system.

利用该测速系统，进行了超声波的重复性测试，以及在以空气为介质的零流实验。

They can hear ultrasonic sounds from small animals like mice. And they can hear the high sound of whistling something the human ear can't hear.

它们能听见老鼠之类的小动物发出的超声波，并且能听见高频的哨声，那是人类耳朵所听不见的。

In this paper, the principle and primary results of measure ultrasonic sound velocity and attenuation coefficient by ultrasonic syntonic method are introduced.

本文介绍利用超声共振法测量声速和声衰减系数的原理及自来水和乙醇的测量结果。

The bat emits these ultrasonic pulses, very high pitch sound waves that we cannot hear.

蝙蝠会发出我们听不到的非常高的超声波脉冲。

Ultrasonic sensor is an instrument which transform sound into electricity, therefore, it is also called ultrasonic wave transducer.

超声波传感器是实现声电转换的装置，所以，又称为超声波换能器。

The theory basis of ultrasonic contactless support is achieved by studying the sound radiant theory.

通过对声辐射理论的研究，获得超声无触点支承的理论依据。

Ultrasonic technology is based on high-frequency sensors to measure the sound.

超声波技术是根据高频率的声音感应来测量的。

The linchpin of undertaking high temperature ultrasonic testing is the control of the coupling, attenuation and route of the sound.

在高温状态下，超声波探伤实施的关键在于声耦合、声衰减和声路径的控制。

A novel audio beam loudspeaker which based on nonlinear propagation effects of ultrasonic in the air to generate audible sound with high directivity is presented.

提出了一种利用空气中超声波非线性传播效应制作的、可产生高指向性可听声的新型声束扬声器。

Ultrasonic flaw location in semisphere butt welds by sound path method is described.

介绍半球对接焊缝超声探伤的声程定位方法。

As a special hydrodynamic sound generator, ultrasonic siren has applicative effects on viscosity reduction, scale removal on electric pump well.

作为一种特殊的流体动力式声波发生器，超声旋笛在电泵井防垢降粘方面有着显著的使用效果。

This paper focuses on developing a digital ultrasonic phased array transducer system which can realize the focusing and scanning of sound beams.

本文是研制超声相控阵换能器动态聚焦系统，它包括数字式多通道信号发射系统和两种超声相控阵换能器。

A data processing method for the sound power of the medical ultrasonic diagnostic equipment is introduced in this paper.

介绍一种医用超声诊断设备声功率计量数据的处理方法。

The mechanism of ultrasonic bleaching is attributed to ultrasonic cavitation, mechanical effect and thermal effect of the sound wave.

超声波漂白机理基于它的空穴效应、机械运动以及热效应。

It is often misjudged the flaw echo in ultrasonic examination that the echo signals produced by sound field property and geometrical shape of the component examined according to sound field theory.

超声探伤中，由于声场特性、件几何形状的影响，所产生的各种回波信号常常被误判为缺陷信号。

This technique solves the puzzle of sound wave coupling and makes sure that the quality with ultrasonic detection is sound.

这一技术解决了声波耦合的难题，使超声波自动检测质量得到了保证。

With unique characteristics and sound cavitation, ultrasonic wave can exert effect on fiber macromolecule and finishing bath.

介绍了超声波的特点及其声空化作用。概括了超声波对纤维高分子物和整理液的作用机理。

A novel audio beam loudspeaker is fabricated by utilizing the nonlinear propagation effects of ultrasonic in the air to generate audible high directivity sound.

一种新颖的声束扬声器是捏造的利用超声波在空气中的非线性传播效应，产生声音的高指向性的声音。

The utility model relates to a two-polarity ultrasonic transducer, composed of a fastener, a reflecting plate, a piezocrystal, a sound direction output plate, and an oscillation amplifying circuit.

本实用新型涉及一种双极式超声波换能器，它由紧固件、反射板、压电晶体、单向输出板、振荡放大电路等组成。

Because the ultrasonic wave has the directivity, the audible audio frequency demodulated from the interior of the ultrasonic wave also has the directivity and forms a directional audible sound.

一声频定向换能器，以定向发射超声波给接听者，其中该超声频段部分经空气自解调而还原为原音频信号。

The ultrasonic signal which is emitted from the transducer carries the input audio signal information, does the nonlinear interaction in the air and is demodulated into audible sound.

换能器发出的超声信号携带输入的音频信号信息，在空气中发生非线性作用，解调为可听声。

This paper explores the feasibility of ultrasonic technology leading to produce fire-retardant wood and test conditions such as frequency, sound intensity and time etc.

探讨了超声波应用于木材阻燃浸渍处理过程的可行性，同时讨论了超声波试验参数频率、声强、辐射时间等的选择。

For both aluminum alloy and magnesium alloy, a sound joint can be obtained under appropriate welding conditions using the process method of ultrasonic brazing.

采用一定的钎料对铝合金、镁合金进行超声波钎焊能较好提高其接头力学性能。

The variation of sound velocity was more obvious than quality loss. It was concluded that ultrasonic techno…

声速变化比质量损失变化明显，说明超声波法是一种检测混凝土冻融损伤的简单可靠的方法。