查询词典 acoustic wave

Ferroelectric material is a kind of functional material, besides its ferroelectricity, it has many special properties such as high dielectric permittivity, piezoelectricity, pyroelectricity, electrooptics and so on, and can be utilized in various devices such as High-K material in capacitors, acoustic wave devices, piezoelectric sensors, MEMs, thermal detector and electroopic devices. Therefore research and development effort in ferroelectric materials and devices have now hit a feverish pitch.

铁电材料是一种功能材料，它不仅具备铁电特性，而且具有高介电常数、压电效应、热释电效应、电光效应等特殊性质，可以应用于High-K介质材料、声学探测器、压电传感器件、微机械系统领域、热电探测器、铁电光阀显示器等等；因此，铁电体以其独特的物理、化学性质越来越引起人们对其技术应用的重视。

Investigation of the ballistic propagation of acoustic wave through two almost same sintered samples with face - centered cubic lattices indicates that there is a band gap range respectively in two order quasi - homogeneous media.

研究超声波经过两个烧结样品的行为。两个烧结样品为有序的面心立方结构，它们的结构几乎相同。研究表明：在两个有序的准均匀的介质中分别有一个禁带区域。

The design of a surface acoustic wave filter with a center frequency of 44?MHz, a 1?dB bandwidth of 8?MHz, an out-of-band rejection of more than 60?

采用数字傅里叶变换技术设计并制作了一个中心频率为44MHz，1dB带宽为8MHz，带外抑制大于60dB，插损小于28dB的带通滤波器。

The less the finger pairsNof surface acoustic wave element,the larger its bandwidthΔf/f,andthe largerits insertionloss,so the fingerpairsNis appropriately taken,and is nottoo small.

1引言现在小波分析的算法复杂，其算法运算目前绝大部分是在计算机中完成的，因而编程工作量大；也有一些人正在研究利用大规模集成电路进行小波变换计算，但还不成熟。

At first, basing on the boundary value problem concerned with fluid-composite structure interaction and characteristic of acoustic wave radiation, a generalized Hamilton variational principle is derived, and the equations of motion based on the finite element method is also derived.

首先，从复合结构与流体相互作用问题的有关混合边值问题出发，针对声波辐射特点，推导了一种广义形式的Hamilton原理及有限元形式的运动方程。

The refraction, reflection and propagation of the acoustic wave in a rod are studied quantitatively when a line-focused probe is employed in an axial scanning in immersion testing. The shape and position of the first and second focal line of the probe in the cylinder are calculated.

定量研究了采用线聚焦探头、液浸法、轴向扫描探伤时，棒材中声波的折射、反射和传播规律，计算得到了工件中的一次焦线和二次焦线的形状和位置。

In this thesis, the AlN thin films were deposited on SiO2/Si and GaN/Sapphire substrates respectively for layered structure SAW devices by Helicon sputtering system. Laser ultrasound system was used to measure the acoustic wave velocity of AlN/SiO2/Si layered structure. Frequency response and insertion loss were measured by an HP8510C vector network analyzer to analysis insertion loss, sidelobe and quality factor. The results showed the possibility of incorporating thin films SAW devices with other semiconductor devices.

本研究使用回旋溅镀系统分别在SiO2/Si、GaN/Sapphire两种基板上沉积AlN并制作层状表面声波元件，并利用雷射超音波系统量测AlN/SiO2/Si结构之表面波速及机电耦合系数，再利用网路分析仪量测其频率响应，分析其插入耗损、 sidelobe、品质因子Q，以比较不同基材所制作之层状表面声波元件之特性，此研究成果初步验证AlN层状表面声波元件与半导体元件整合之可行性。

But ISE has some drawbacks:(1) general ISE is too large;(2) with its high output impedance(about 109 Q), only devices with high inputimpedence and low input offset current can be used to match the ionometer;(3) it is difficult to measure weakly direct current or voltage.

针对以上问题，本课题探索研究了一种基于声表面波(Surface Acoustic Wave，SAW)传感器的液相金属离子在线实时检测技术，在实验平台上实现了液相中多种金属离子现场的同步测试和分析。

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。

It is necessary to find an optimal threshold level of delay-line type surface acoustic wave based identification-tag, because each bit code suffers from the influence of multiple reflection and propagation losses and is not uniform in amplitude.

由于受到多次反射和传播损耗的影响，延迟线型声表面波辨识标签的每一位编码幅度的判决电平需要合理确定。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。