查询词典 ultrasonic

Objective To study the power spectrum density of blood flow ultrasonic Doppler signal using wavelet analysis. Method Doppler signal of blood flow in human common carotid artery was studied with wavelet scalogram analysis, an affine smoothing Wigner Ville transform with a constant "Q" character. Result Wavelet scalogram of blood flow ultrasonic signal had a higher distinguishability than STFT spectrogram in the low frequency portion, but had poorer decussation terms than spectrogram.

对于平稳信号的处理工具仍然是Fourier变换，但是，在实际应用中的绝大多数信号是非平稳的，现在看来处理非平稳信号的主要工具将是小波变换，这主要是因为传统的Fourier变换分析信号时，时间和频率分辨率精度是固定不变的，而利用小波变换分析信号，在信号高频段时间分辨率精度也较高，在信号低频段频率分辨率精度较高，这很符合非平稳信号的特点。

The design of signal processing circuit in this paper can achieve anticipative purpose in the ultrasonic detection receiver of the new rocket depth charge multifunction fuze and it offers definite reference value to farther research of ultrasonic proximity fuze.

本文对接收机信号处理电路的研究设计，能够达到预期的目的，对今后的进一步研究火箭深弹声近炸引信具有一定的参考价值。

Results revealed that the large side insulation of the stator bar in slot is available for ultrasonic pulse-echo testing; Coupling transducer on the surface of a practical stator bar could minimize the influence on the measurements of velocity, contributing no destructivity of the ultrasonic testing for stator insulation; The simultaneity of same velocity and higher attenuation can be used to detect insulation delamination from conductors; Compared with the wide sides of the bars in slot, the short sides of the bars near the exit from slot and the end bars had a same velocity and a higher attenuation; The velocity might be exactly measured on the shot sides of the bars near the exit from slot and the end bars, while the attenuation might not, which were examined though filed tests; V min decreased greatly and V av decreased slightly with the service time of the bars.

在实验室对线棒多种结构处的主绝缘和不同运行年数(未老化、16、18 和23年)线棒的主绝缘进行了低频超声反射法检测试验，并进行了现场试验，发现(参见 Hao et al， IEEE DEI， to be published)，槽部线棒的宽面绝缘不受换位绝缘的影响，比窄面绝缘更适合超声测量；线棒表面平滑的半导体层减小了耦合剂对超声测量的影响，实现了无损性；波速不变而声衰减减小可以检测线棒出现绝缘与导体脱壳缺陷；出槽口和端部线棒的窄面绝缘与槽部线棒的宽面绝缘相比，声衰减大而波速一致；现场试验验证了波速不受绝缘结构和现场测试条件的影响，而声衰减受以上因素影响很大(参见 Hao et al，中国电机工程学报， Vol.23 No.4)； V min 随运行年数明显减小， V av 随运行年数慢慢越小。

Based on the principle of ultrasonic cleaning, the working process of the ultrasonic cleaning machine was analyzed including control circuit, driver circuit, frequency tracking,impedance matching and software design.

依据超声波清洗原理，分析了超声波清洗机的工作过程，对超声波清洗机的控制电路、驱动电路、频率自动跟踪技术、阻抗匹配及系统软件设计方法进行了详细介绍。

The ultrasonic detector gives off an ultrasonic wave when it is given an electronic pulse.

1超声波液位测量的工作原理图1为脉冲回波式测量液位的工作原理图。

First of all, this paper introduces the whole design project and interrelated knowledge about Non-destructive detection, ultrasonic detection, and Phased-Array ultrasonic detection Then the paper depicts the principle of Phased-Array focus and abstracts a set of math model and feasible arithmetic on the base of the real parameter of the system. Put forward several problems that exist during the course of system development and program. Introduce some measures of distinguish that are often used in non-destructive detecting and echo wave crest. Then I depict one of the measures in detail that used in the course of non-destructive detection, which is the way of distinguishing whether defects exist or not. Then provide part core program to realize it. This paper also provides main flow chart through analyzing how main control program controls different parts to make the whole system more effective.

然后在文中以较大的篇幅，描述了相控阵聚焦的原理，并根据该系统的实际参数，抽象出一套数学模型和可行的算法，在此基础上提出了在系统开发过程及编程实现过程中存在的一些问题；介绍了在无损检测中缺陷的分类和对回波峰常用的识别方法，详述了系统开发过程中使用的其中一种识别方法，即判别是否存在缺陷的算法，并给出实现之的部分核心程序；详述主控程序如何控制各部分并协调各相关软件的工作，使整个系统发挥最高效能，并给出主要设计框图和程序。

Back a car radar uses principle of ultrasonic range finding commonly, below the control of controller, transmit ultrasonic signal by sensor, when encountering fraise, generate echo signal, controller of the classics after sensor receives echo signal undertakes data processing, judgement gives the seat of fraise, by show

倒车雷达一般采用超声波测距原理，在控制器的控制下，由传感器发射超声波信号，当碰到障碍物时，产生回波信号，传感器接收到回波信号后经控制器进行数据处理、判定出障碍物的位置，由显

The theories on pyrolysis and coking and hydrogenation of heavy oil are used to know the liquefaction and gasify and coking of coal. 3. The results of particle feeding in the hot plasma jet (1) By using the cold state of spraying the diesel oil mist transversely in the air flow at the subsonic and ultrasonic speed to imitate the stress condition and motion trace of coal powder in the plasma jet, it shows that with the speed of air flow changed from subsonic speed to ultrasonic speed, the uniformity of mixture between the coal powder with certain speed and air flow becomes worse, mixture length becomes shorter, which agrees with the law of momentum transfer.

三、热等离子体射流中颗粒注入研究的结果(1)利用柴油油雾在亚、超音速气流中横向喷射冷态模拟煤粉在等离子体射流中的受力和运动轨迹，结果表明随着气流速度由亚音速向超音速增加，一定速度的煤粉与气流混合均匀度变差，混和长度增加，符合动量传递规律。

The yield of SCP is 22.3%, and the extraction ratio of the ultrasonic method was 36.58% more than that of the traditional method. The structures of sc by ultrasonic extraction do not change judging from the analysis by FTIR. The extracts of SCP exhibit strong antioxidant activity on lard and gingili. The sc and Vc on lard and gingili have synergic antioxidative effect.

辽五味子多糖的提取率可达到22.30%，超声波法提取比传统法的提取率高出36.58%，通过红外光谱分析，超声波浸提没有使辽五味子多糖的结构发生改变；辽五味子多糖对油脂具有较强的抗氧化性能，抗坏血酸对辽五味子多糖具有协同抗氧化作用。

The hospital owns superior equipments, such as CT of whole body, automatic biochemical analyzer, automatic hemocytometer, colorful type-B ultrasonic, 800mA X-ray machine, laparoscope, imported electronic gastroscope and intestinscope, cataract ultrasonic emulsification treatment instrument, cheilopalatoschisis repair instrument,diagnostic analyzer of cardiac, cerebral and vascular diseases, first-aid and guardian system, supersonic diagnosing system, equipment of physical treatment and other advanced equipments.

医疗设备先进，拥有进口全身CT机、全自动生化分析仪、免疫化学发光仪、全自动凝血仪、全自动血球计数仪、彩色B超、800mA X光机、腹腔镜、进口电子胃肠镜，白内障超声乳化治疗仪、阴道镜、体外冲击波碎石机、前列腺汽化电切镜、输尿管肾镜、膀胱镜、前列腺汽化电切镜、气压弹道碎石机、心脑血管疾病诊断分析仪、急诊抢救监护系统、超声诊断系统及理疗康复设备等一系列大中型先进设备。临床诊断和治疗具备科学先进手段。

To be affiliated to the culture sector has structurally dissevered its operation contact with the middle and primary schools ' libraries and affected its exertion of educational functions.

城市公共少年儿童图书馆的本质属性是教育性，与中小学图书馆有更紧密的业务关系，隶属文化系统从体制上割裂了其与中小学图书馆的业务联系，影响了其教育功能的发挥。

The three types of interfaces are LANs, WANs, and console or auxiliary.

介面的三种型态为 LAN，WAN 和主控台或辅助埠。