查询词典 radio-frequency spectrum

The main content of this dissertation includes: 1. Research on the theory of ultrasonic power supply, introduce its development process. On the basis of these, fix on the scheme of medical ultrasonic low-power supply. 2. According to the principle of modularized design, divide medical ultrasonic low-power supply into four parts. They are power amplify circuit, power control circuit, frequency automatic tracking circuit and matching circuit. Separately research on their theories and design their circuits and necessary programs, especially, effectively resolve the problem tracking the supersonic vibration system with a narrow syntony frequency bandwidth and a high swing. 3. The matching experiments gain good result, and prove that medical ultrasonic low-power supply is entirely up to the mustard on intellectualization, wide band of working frequency, steady output and high efficiency.

本文工作的主要内容包括： 1、研究了超声功率电源的原理，并回顾了它的发展过程，在此基础之上确定本文医用小功率超声电源的设计方案； 2、按照模块化的设计原则，将医用小功率超声电源的设计分解为功率放大电路、功率控制电路、频率自动跟踪电路和匹配电路等四个部分，分别研究了各部分的原理，在此基础之上进行了具体的电路设计和程序设计，尤其是有效地解决了对谐振频率带宽窄振幅高的超声振动系统的频率跟踪问题； 3、通过与超声振动系统的各项配合实验，取得了很好的实验结果，验证了医用小功率超声电源完全满足智能化、工作频带宽、输出功率稳定、输出效率高的设计要求。

The process of frequency fluctuation in the hydropower station with surge tank is impacted both by high-frequency water pressure wave and low-frequency water level fluctuation in surge tank.

在负荷变化和扰动过程中，设调压室水电站机组频率受到压力管道内水击压力波和调压室内水位波动的共同作用。

The crystal oscillator provides frequency stable accurate 32768Hz the signal. After frequency divider frequency division to 1Hz stable accurate function signal,Does for the counter pulse signal. Six counter serial connections,Uses the decimal base and the senary counting separately (when ten for ternary notation counting). Comes out through 7448 decoders and the monitor appearances,The counting cycle is 24 hours.

晶振提供一个频率稳定准确的32768Hz的信号，经过分频器分频的到1Hz稳定准确的函数信号，做为计数器的脉冲信号，六个计数器串行连接，分别采用十进制和六进制计数，通过7448译码器和显示器显现出来，计数周期为24小时。

The principle of MUSIC algorithm and theoretical analysis of the spectral separate frequency and frequency detection threshold are included. MUSIC algorithm compared with FFT based algorithm for harmonic frequency estimation using matlab simulation platform .

给出了MUSIC算法的基本原理，对MUSIC算法的频谱分辨能力和频率检测门限进行了理论分析，在Matlab仿真平台下对MUSIC算法和FFT算法的频率估计性能进行了比较。

Has been produced by 'WH' series of new, ultra-high frequency, high frequency, ultra-audio frequency induction heating equipment.

现已生产的'WH'系列新型超高频、高频、超音频感应加热设备。

At present, the Legend main customers for the provision of various types of RFID gain ratio the high efficacy of microwave paragraph (2.4G frequency) reader, as well as independent research and development Legend of international general agreement to support a variety of ultra-high frequency tags ( 860-915MHZ frequency) RFID read professional adjustable head.

目前，凌讯公司主要为RFID客户提供各类增益比的高功效微波段（2.4G频率）读写器以及凌讯自主研发的可支持多种国际通用协议标签的超高频段（860-915MHZ频率）可调的专业RFID读头。

Based on the special design requirements of high frequency circuits in communication systems, the simulations of the process flow and physical characteristics of small-scale (the base width is under 100 nm),ultra-high frequency(the characteristic frequency is upon 15 GHz) bipolar transistors were simulated.

基于通信系统中射频电路设计的特殊要求，对小尺寸(基区宽度低于100nm)、超高频(特征频率高于15GHz)双极晶体管工艺制程和器件的物理特性进行了模拟，为工艺线流片进行可行性研究。

This measurement frequency using direct comparison of the phase relation is a new important method to probe into the accurate measurement of the ultrahigh frequency like the optical frequency.

这种利用相位关系直接比对测频是探索光频等超高频率准确测量的一种重要的新方法。

Is a high-tech enterprise in Henan Province, China Heat Treatment Association, relying on university scientific research strength, the basis of modern power electronics theory, with Zhengzhou University Motorcycle Factory United attachment to the strict requirements of the production process of "X" series new frequency, high frequency, ultrahigh frequency induction heating equipment, the main circuit using IGBT, MOSFET and other new types of power devices, to integrated, modular, as the basic characteristic of independent innovation with new output transformer, equipment greatly enhance the power, energy consumption significantly reduced, the reliability of the maintenance-free development, and by domestic users widely welcomed and has been exported to Southeast Asia and the European Union and many other countries and regions.

郑州科创电子有限公司是河南省高新技术企业、中国热处理协会会员，依托高校科研实力，依据现代电力电子理论，与郑州大学摩托车附件厂联合，以严格的工艺要求生产的"X"系列新型中频、高频、超高频感应加热设备，主电路采用IGBT、MOSFET等新型功率器件，以集成化、模块化为基本特征，配以自主创新的新型输出变压器，设备功率大幅度提升，能耗大幅度降低，可靠性向免维护发展，受到国内用户的广泛欢迎，并已出口到东南亚及欧盟等众多国家和地区。

Ciliary beat frequency was measured by digital high-speed microscope. results ciliary beat frequency of cultured human nasal epithelial cells is 10.39±1.80 hz at 25℃. ciliary beat frequency of different cilia is equal on the same cell,it is also equal from uncinate process and inferior turbinate.

结果 在25℃，体外培养的人鼻腔黏膜纤毛摆动频率是10.39±1.80hz；同一细胞任意两点纤毛摆动频率是相同的；同一来源的体外培养的钩突和下鼻甲的纤毛摆动频率是相同的。

Alternatively, the con- trollers can use the synchronous rectifier itself or loss- less inductor current-sensing methods to provide overload protection with lower power dissipation.

另外，康威特罗勒斯可以使用同步整流器本身或亏损减少电感电流检测方法，以提供低功耗过载保护。

Mr. Dauber's other Schatz hangs in his home movie studio.

多伯把沙兹的另一件作品挂在家里的电影室。