换能器

The arc array transmitter is composed of many ceramic flexural vibrators which are arranged in an annulus. Directional radiation is realized by controlling the vibrating phase of each vibrator.

声波测井圆弧阵发射换能器由多个压电振子沿着圆周排列，通过控制各个振子的激励时间可以实现向某个方位方向的声波辐射。

We obtain scattering values of the metal cylinder by utilizing the monostatic system.

我们利用单向系统获得金属圆柱体的声场散射值，即：换能器在远场发射声波照射金属圆柱并且在远场同一地点接收金属圆柱的散射值。

Electrostatic-type electro-acoustic transducer in the use of the diaphragm will gradually become the process of relaxation, so that decreased sensitivity.

静电式电声换能器的振膜在使用过程中会逐渐变得松驰，使灵敏度下降。

We analyzed the characteristic of cylindrical focused ultrasound transducer and the relation between direction ratio of transducer and its ultrasound field.

本文分析了柱面聚焦换能器的声场特点，剖析了方向比与声场的关系。

The plasma ignition threshold of metal is got through experimental and numerical study. The vapour and plasma ignition times of the target are got based on the equation of heat conduction and cascade model. We suppose that the plasma is ignited when generations of new electrons are born in vapour generation time. The influence of temperature on the thermodynamics and optics parameters of material also have been considered in the model. The resulting theory has good agreement with the experiment and overseas report. A blade method to measure the laser spot is given in this paper with validation and error analysis. The plasma threshold of metals in atmosphere and water ambients both are diagnosed with the light deflection and piezoelectric transducer. A Q-switched pulsed Nd:YAG laser operating at infrared (1064nm), visible(532nm) and ultraviolet (355nm) wavelengths has been used. Al、Fe、Cu are used as targets and get a similar results with both method. Theoretical and experimental analyses are applied on the influence of wavelength on the threshold have been done, both of which have shown that the plasma threshold of metals decrease as the laser wavelength increases; The plasma threshold of metals are higher in water than in air and the pressure of the shock wave in water is five times higher than in air .

从热传导方程和雪崩电离机制出发，假设当电子增值210倍时，考虑了温度对材料热力学和光学参数的影响时，得到了气化和等离子体点燃的时间，利用该模型进行计算得到的结果与国内外报道及自行通过实验测得的阈值基本一致；提出了利用刀刃法测量激光光斑面积的方法，并通过实验进行了验证和误差分析；利用光偏转装置和压电换能器分别对空气和水中金属等离子体点燃阈值进行了实验诊断，激光器均为调Q－YAG激光器（波长1064nm，532nm，355nm，脉宽10ns），靶材分别为Al、Fe和Cu，两种测试方法得到的等离子体点燃阈值基本一致；本文从实验和理论计算两个方面讨论了波长对等离子体点燃阈值的影响，均得到了等离子体点燃阈值随著波长的增加而减小的结论；对空气中和水中不同环境下金属等离子体的点燃阈值进行了比较研究，得到了金属在水中的等离子体点燃阈值比空气中的大，且水中产生的冲击波的压强是空气中的5倍左右的结论。

In this paper, the acoustic characteristic of bubbles and the interaction with tissue are studied by the experiments of sonoluminescence, the simulations and comparison of dynamics characteristic of gas bubbles and shell encapsulated bubbles, and the interaction between bubbles and tissue using single-frequency mode and dual-frequency mode ultrasound.

本文从空化气泡的声致发光实验、理论求解和比较带球壳微泡和空化气泡的动力学特性，和微泡在单双频超声换能器下的与生物组织的作用效果出发，研究微泡的超声特性以及微泡对生物组织的作用效果。

While performing the seismic modelling experiment , it needs to have tens to hundreds of kilohertz and well distributed orientation dependent narrow pulse acoustic wave as simulation source .

由上述理论和实验的研究，研制出了具有一定灵敏度，方向性较均匀的窄脉冲压电换能器，初步满足了地震模型实验的要求。

The parallel tangents momentum-matching condition and the design method of the piezoelectric transducer are also introduced.

介绍了非共线声光作用的切线平行动量匹配关系以及压电超声换能器的设计方法。

The response time can be shortened and high throughput and real-time detection analysis can be achieved. Although now the use of zero-dimensional nanomaterials is popular, it is still rare for the study of one-dimensional materials.

与传统的生物传感器相比，基于纳米技术的新型生物传感器已呈现出更优越的性能，具有了亚微米的尺寸、换能器、探针或者微米系统，生物传感器的化学和物理性质和其对生物分子或者细胞的检测灵敏度大幅提高，响应时间也得以缩短，并且可以实现高通量的实时检测分析。

Based on the vibro-acoustography and basic sector-array field theory, a modified and accurate velocity potential function is obtained.

在相关振动声成像和扇阵换能器的理论基础上，经过推导修正并得到了精确的速度势函数。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。