频率

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。

A method of keying a radio carrier for transmitting binary data or teletypewriter signals, which consists of shifting the carrier frequency in one direction for a marking signal and in the opposite direction for a spacing signal.

对无线载波频率进行键控用于传输二进制数据或电传打字机信号的一种方法。这种方法是在某一方向上对载波频率进行漂移用于传输标记信号，而在相反方向上对载波频率进行漂移用于传输空格信号。

Originally, higher input trigger frequency or lower input frequency for Viterbi Decoder were used to meet the transitions requirements.

因原本既有的标准，都是使用较高的输入频率来达成标准内的传输率，或者使用较低的输入频率，再用内部的PLL，提供出较高的触发频率给内部的维特比解码器来达成。

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。

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。

For FMCW radar ,the linearity of synthesizer is critical. A novel nonlinear PLL which can be used in VCO nonlinearity compensation is presented. By using the SAW delay line to delay the FMCW signal ,the IF signal can be locked on a reference frequency after mixing the delayed VCO signal frequency and the undelayed.

微波频率合成器是雷达系统很重要的一部分，对于FMCW雷达而言，VCO的频率线性度直接影响雷达测距测速的精度，本文应用微波频率合成器的原理构造了一个用于VCO线性化的非线性PLL，并首次研究了该PLL的环路相位模型，得出了用于线性校正计算的理论公式，最后应用ADS软件对该公式做了仿真验证，结果表明该理论的正确性，为VCO的线性化提供了理论指导。

2We need frequencies even hi gh er than those we call very high frequency .

我们所需要的频率，甚至比我们称作高频率的频率还要高。

Its software uses system self-detecting algorithm to assure measurement channel .It uses softening hardware technique software synchronic data sampling to trace the frequency of exterior signal, in other words , it gives sampling control signals 128 times of power net's frequency .It uses Direct Digital Frequency Synthetics algorithm to transform radical sine waveform parameter table into needed current. It uses FFT algorithm to get radical waveform altitude of current ,voltage and resistor .

整个系统在软件设计上采用系统自检验算法保证测量通道可用，采用硬件软化技术--软件锁相环技术，达到对外部信号频率的跟踪，给出频率为电网工频128倍的采样控制信号：直接数字频率合成技术将基波参数表转换成需要的电流信号，采用FFT变换及基波幅度的计算方法得到被测电流、电压基波幅度和电阻大小。

And they systematically studied the effect of the activate spleen-energy law on digestive and absorptive function, it is confirmed that the activate spleen-energy law have significant regulation effect on the action and secretion of gastrointestinal tract. Recently, we established the juvenile rat model with anorexia by imitating the major cause of children and found that the CCK-8S concentration in hypothalamus and periphery blood of the anorexy model was obviously increased .We also found the appestat that the spontaneous discharge frequency of LHA neurons was decreased and the spontaneous discharge frequency of VMH neurons was increased.

近几年，我们采用病因模拟法成功建立了幼龄大鼠厌食模型并发现该模型下丘脑和外周CCK-8S水平显著增高，食欲中枢——下丘脑外侧区神经元自发放电频率减低和下丘脑腹内侧区神经元自发放电频率增加，临床治疗小儿厌食有可靠疗效的运脾复方不仅可调节外周血中与摄食有关的肽类激素水平，如降低CCK-8S水平，而且能调节下丘脑食欲中枢神经元的自发放电频率。

BAW is used to on-line monitor the effluent from IC column.

在实际中，以SPQC-BAW技术对离子色谱流出物进行在线监测，可得到响应信号为频率的色谱图，具有很高的灵敏度；利用本室设计的频率/电压转换电路可将频率数字信号转化为模拟电压信号，从而为常用的色谱工作站或色谱数据处理设备接收、利用和处理，实现IC-BAW自动化分析。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。