查询词典 ultrasonic frequency

This paper investigates the effects of high temperature on ultrasonic velocity, refraction angle of inclined probe, ultrasonic attenuation, emitting strength of ultrasonic probe and defect detectable ratio, and provides practical methods of high temperature ultrasonic inspection for vessels and equipment, as well as concrete inspection procedure and key operational points.

文章通过研究高温对超声波声速、斜探头折射角、超声波衰减、探头发射超声波强度以及缺陷检出率的影响，提出了对容器设备进行高温超声波检测的方法、具体检测步骤和操作要点等。

In the extracting process using ultrasonic wave, the preferable technical parameters of extracting polyphenols from the root and stalk of sanguisorba were acquired by changing the particle size of raw material, the ratio of sample weight to solvent volume, ultrasonic time, ultrasonic power, ultrasonic times.

在超声波法浸提过程中，通过调节料液比、原料粒度、超声时间、超声功率、超声次数因素的影响，确定了地榆根和茎中多酚较佳超声浸提工艺参数。

Our products can be widely used in home appliances, communication facilities, alarm systems, parking sensors, ultrasonic measuring instruments, ultrasonic atomizers, ultrasonic cleaners, ultrasonic welding and drilling machines.

公司技术力量雄厚，以自主研发的压电陶瓷材料为基础，所生产的压电陶瓷产品广泛应用于家用电器、医疗美容、通讯设备、报警器材、倒车雷达、测距仪器、流量计量、超声波雾化、清洗、焊接、加工以及人机交互、自动化控制、智能玩具等领域。

This study choose Changle Gaoya reservoir irrigation areas as the study sites, through the installation of different ultrasonic equipment on open channel of non-uniform flow to study the flow gauging of non-uniform flow in open channel:(1)5 tracks ultrasonic open channel flow meter used to real-time monitoring the flow of velocity ,water depth and discharge;(2)Ultrasonic liquid level gauge used to real-time measure the upper level and tail level of the two sections ,then the computer calculated average water level, gradient of water table and discharge;(3)Change the open channel water conveyance into pipeline full flow water conveyance, installed the ultrasonic liquid level gauge and pipe flow gauge on the inflow point and surface of pipe, water level and discharge would detect in real time.

本研究以山东省昌乐县高崖水库灌区为研究地点，通过安装在灌溉明渠上的不同超声波设备对明渠非均匀流的测流进行了研究：(1)用五声波超声波明渠流量计对测流渠段的流速、水深及流量进行了实时监测；(2)用超声波液位计将测流渠段的上下游两断面水位实时测出，再用计算机分时段算出平均水位、水面坡降及流量；(3)将测流渠段明渠输水改造成管道满流输水，分别在管道进口前及管管上安装超声波液位计和管道式流量计，将水位和流量实时测出。

I Division specializes in ultrasonic metal welding head welding machine and steel manufacturing, used in refrigerators; freezer; air conditioners cut brass closures, automotive wiring harness ultrasonic welding , solar heat-absorbing plate rolling ultrasonic welding, aluminum-plastic composite pipe rolling ultrasonic welding, spot welding, such as lithium-ion battery.

我司专长于超声波金属焊接机及钢焊头的制造，应用于冰箱；冷柜；空调等铜管封切，汽车线束超声波焊接，太阳能吸热板超声波滚焊，铝塑复合管超声波滚焊，锂离子电池点焊等。

In the process of building and using the mass concrete structures, because of the effect of out-side condition and themselves, some faults will form in the structure, these faults will effect the bearing capability and endurance Using nondestructive testing method to test the concrete"s quality and diagnose its healthy, which has the significant sense in assessing the safety stability and research of the administering diseasesThis dissertation mostly researched the testing methods in the mass concrete structure, discussed the principles, methods, features, sphere of application of the ultrasonic testing in the mass concrete structure with faults, used dynamic FEM to simulate the testing process, discussed when the concrete structure with cracks is under the effect of the pulse, how the elastic waves propagate and what are their changing feature, Researched the principles of the first-arriving waves" phase when the cracks" depths are not same, obtained the relation between the inversion point and the cracks" depth, which has the direction sense in the application of projects,The second part of this dissertation is CT , which used the ultrasonic wave running through the tested-substance to get arriving-time of the ultrasonic wave, then inverse the image This dissertation drawed one CT program which can well present the different little cells ultrasonic wave velocity profiles of the substance, thereby to diagnose the quality of the part of the tested-substance, CT has the better using foreground..

在混凝土结构的施工及使用过程中，由于受其自身及外界各种因素的影响，常常会产生一些缺陷，对结构物的承载能力和耐久性造成严重影响，采用无损检测技术进行质量检测和健康诊断，这对混凝土结构开展安全、稳定性评估以及病害隐患治理研究具有重要意义。本论文主要针对大体积混凝土结构缺陷的检测方法展开研究工作，重点讨论了超声波法检测混凝土结构裂缝的基本原理和方法及其特点、适用范围，运用动力有限元数值模拟其检测过程，探讨了有裂缝缺陷的混凝土结构在脉冲荷载作用下弹性波的传播及其变化特征，研究了不同裂缝深度下首波相位变化规律，得出了反转临界点与裂缝深度之间的关系，这对实际工程应用具有指导意义。声波CT是一种新的无损检测技术，它是利用声波穿透被检测体获取声波接收时间，来进行计算机反演成像的技术。本文利用直射线法编制了层析成像程序，能较好地呈现被检测物体各微小单元的声波速度分布图像，从而对检测体的质量状况作出诊断评估，具有较好的应用发展前景。

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。

In this paper,the necessity of frequency tracking in ultrasonic cleaning equipmens is discussed.Based on introduction on the principle of the mian circuit of the ultrasonic power supply for cleaning equipmens and the principle of PLL,the output frequency of 74HC4046 is changed by a single chip measuring the phase difference between volage and current.The software of adaptive tracking technique with varied frequency steps is completed.

讨论了超声波清洗机中自动频率跟踪的必要性，在介绍超声波清洗机的主电路原理、PLL锁相环原理的基础上，利用单片机检测超声电源负载的电流、电压的相位差，从而改变74HC4046 的输出频率，完成了变步长频率跟踪软件设计。

This thesis has discussed the theory of measuring distance in ultrasonic, which include ultrasonic shaking transmit velocity, central frequency, angle of launch control, measure distance, dynamic measure and so on. According to character of wave shape output by circuit, this thesis has designed an efficient way to diminish noise that enables precision of the ultrasonic sensor to 0.2%.

论文详细论述了超声波测距的基本理论，包括超声波震动传播速度、中心频率、发射角控制、发射能量、检测距离、动态检测等；并根据电路输出波形特征设计了有效的降噪方法，使超声波传感器的精度达到了0.2%，然后对降噪后的信号进行了标定。

Characteristic data have been worked out, including the maximum Lyapunov index λ, fractional dimension D, lacunarity Λ and eight energies of various frequency bands. After being normalized, they can function as the characteristic vectors. Then, they are transmitted into an artificial neural network to perform pattern recognition.Starting from the mechanism of ultrasonic generating, initial ultrasonic pulses are calibrated. A stylish discharge source is directly coupled with the ultrasonic sensors, and work out actual discharge magnitude.

利用非线性和非平稳的方法对超声波信号进行了分析处理，对于局部放电模型得到的信号，计算了超声波信号的Lyapunov指数、分维数D、空缺率、小波包分解的8个频带能量，得到了11个特征数据，归一化处理后形成特征向量，由人工神经网络进行识别，实现了对局部放电典型模型的模式识别，显著提高了模式识别的正确率，并分析了传播途径对识别的影响。

This immediately brings us to the next part of this article: creating an output "replace function".

下面进入文章的第二部分：建立一个"缓存处理函数"。

He was elected as an International Ornithological Committee member in 2002 during the 24th IOC held in Beijing.

现为中国鸟类学会理事和WPA 专家组成员。2002年被推选为国际鸟类委员会委员。