换能器

Seafaring Ministry of Science and Technology has developed products: fisheries exploration transducer depth transducer temperature range, wind speed anemoscope , electric gyrocompass repeater.

航海科技部自主开发产品有：渔探换能器，水深水温系列换能器，风速风向仪，电罗经复示器。

To thoroughly solve this problem, this paper built a 3-D finite element model of an surface wave EMAT used for the surface inspection of aluminum plates. Simulation analysis of the model revealed that transduction efficiency of the EMAT was greatly affected by EMAT parameters.

为了从根本上解决该问题，对用于铝板表面检测的电磁超声表面波换能器进行了三维有限元建模和仿真分析，发现换能器的几何参数对EMAT的换能效率具有重要影响。

The surface acoustic wave filter includes interdigital transducers and reflectors arranged on both sides of the transducer.

声表面波滤波器包括叉指型换能器以及位于该换能器两侧的反射器。

Projectors and monitoring hydrophones are placed n a chamber along its length. The projectors are driven By the required drives that are calculated aceording to a measured transfer matrix, and amplitude, frequency and incident of the predicted plane wave. Then the acoustic pressure field distribution which is equivalent to the predicted plane wave of any incidence is set up in the chamber. A prototype calilbration system has been developed.

在管中沿管轴方向布置一系列发射换能器和监测水听器，根据实测得到的传递函数矩阵和所要模拟的平而波频率、幅度和入射角计算得到一组发射换能器驱动信号的幅度和相位，然后以此信号激励每个发射换能器，就能在管中形成一个等同于任意角度入射的自由场平面波声场的声压分布。

The results show that the ladder-shaped IDT can overcome shortcomings of adding reflection grating or reflector to simulate the internal reflection of IDT in traditional design and simulation,greatly reduce complexity of the simulation with δ function model,imitate its internal reflection with evolutionary structure and then simulate with Matlab.

结果表明，该结构克服了传统设计仿真时需加入反射栅或反射器来模拟叉指换能器内反射的缺点，大大缩减了δ函数模型仿真的繁杂性，通过自身结构的优化来模拟叉指换能器内反射，并运用δ函数对其建模，然后通过Matlab对其仿真。

On the basis of investigating the sound field of a plane piston transducer and the relations between sound field and radiation force, by settling four plane piston transducers driven at the same frequency at each corner of a regular triangular pyramid with their sound-beam axes crossing at the center of the pyramid, this technique uses ultrasonic wave synthetic theory to acquire a three-dimensional ultrasonic standing wave field. The micro-component can be captured, transported, released in the range of space by adjusting the phase of the transducers.

在研究单个圆形平面活塞换能器声场分布以及声场和辐射力关系的基础上，将以相同频率驱动的4个平面活塞换能器呈正四面体放置，利用声波合成原理获得三维超声驻波场，通过调整各个换能器发射信号相位之间的关系实现对微构件在空间范围内的俘获、移动、释放等操纵。

A new-type design, slotted cymbal, was presented to decrease the loss of output energy through releasing the tangential stress in the working original cymbal transducer.

为了解决传统钹形压电复合换能器在用作传感器和驱动器时，由于存在的环向应力，导致部分输出机械能损耗及换能效率不高的问题，提出一种新型高性能钹形压电复合换能器。

The computation analysis indicates that increasing the aperture of the concave focusing transducer, decreasing it's geometric focal length or raising it's central working frequency can improve the transverse and axial resolutions of the system simultaneously, but changing the dividing proportion of the transducer affects the two kinds of resolution differently. On compromisingly considering several factors including the exciting mode, the focusing ability and the radiation force effect, the concave focusing transducer should be divided into two equal-area parts.

计算研究表明：增大凹球面换能器的口径、减小几何焦距和提高中心频率均可以提高系统的侧向分辨率和轴向分辨率；但改变凹球面换能器的分割比例对两种分辨率影响不尽相同综合考虑超声换能器激励、聚焦性能以及产生的辐射力效果等因素，则换能器应按等辐射面积原则分割为宜。

Round and rectangular piston transducers are the common sound source in ultrasonic nondestructive testing, and combination plane arrays of line and rectangular array are the foundation of investigating phased array technology, so simulating these sound field is significant for studying ultrasonic field simulation.

圆形活塞换能器、矩形活塞换能器是超声无损检测中常用的声源，而线列阵组合平面阵和矩形阵组合平面阵是相控阵换能器研究的基础，因而其声场的模拟在超声场模拟的研究中具有重要意义。

The intensity of the ultrasonic wave will increase when the ultrasonic wave is focused by the sound lens in rock stratum.

然而 ，这种方法要受到两个因素的制约：一是增大超声换能器的功率，必然要增大超声换能器的尺寸，这在本身尺寸就很小的油井中是有一定限度的；二是当超声换能器辐射出的超声波的强度过大时，在超声换能器的周围要发生强烈的空化现象，产生大量的气泡，这些气泡将对超声波产生强烈的散射作用，导致超声波的衰减，反而降低超声波在岩层中的传播距离[1] 。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。