查询词典 difference frequency

We got the simple and high accurate eigenvalue equations and cutoff frequency formulae of all propagation modes. Second, to the optical fiber with homogeneous cladding, we defined the "permittivity ratio", and we got the simple and high accurate connection of cutoff frequency to the ratio. Third, to the fiber with inhomogeneous cladding, we analyzed the dispersive and power-frequency characteristics.

第二，对于具有各向同性包层的弱渐变光纤，引入了介电比，找到了精度高且形式简洁的截止频率对折射率参数的依赖关系；第三，对于具有各向异性包层的弱渐变光纤，首次通过包层的轴向与横向的介电常数比分析了该类光纤的色散和功率特性。

Radar frequency voice hoist features choice: allow users to choose a simple warning or select the frequency on the sound frequency Gun alerts using both voice and sonorant.

雷达频率语音启闭功能选择：让用户可选择单纯频论响声警示或选择频謴语音及响音警示同时使用。

The formula for lower limit of natural frequency of tapered pier of continuous beam bridge were derived by the combination of Rayleigh and Southwell method. The natural frequency of tapered pier was composed of the sum of frequency of each subsystem consisted in inertia component and deformable component.

采用瑞利法和Southwell频率合成法，将基频表示成各惯性元与复位元所组成的子系统的频率合成，导出了变截面桥墩自振频率下限的计算公式。

In this paper, an algorithm to achieve both two dimensional high resolution and wide swath is proposed. Every small satellite work in the active state, they transmit and receive different frequency band signal simultaneity. First, the azimuth ambiguity is eliminated in each frequency sub-band, then the signal is rectified to zero Doppler frequency, after that this algorithm does the range spectral synthesis to achieve high range resolution.

该文分析了一种沿航向排列分布式小卫星宽测绘带二维高分辨率成像技术，每颗卫星同时发射接收不同频率的线性调频信号，先分别在每个子带解方位多普勒模糊，并将方位多普勒中心频率调整至零频，然后在距离向进行子带拼接得到大带宽的线性调频信号从而得到高的距离向分辨率。

In the aspect of the study of the application of HHT method, This dissertation has done three part of jobs: first, the Elcentro strong ground motion which is in common use in earhtquake engineering is analyzed by HHT method, getting its amplitude-frequency-time distribution and the comparison between the HHT marginal spectrum and Fourier spectrum is also made; second, the typical nonlinear system defined by the Duffing equation is analyzed by HHT method, getting its numerical value's amplitude-frequency-time distribution and the comparison between the HHT marginal spectrum and Fourier spectrum is also made; third, define the stationary degree of non-stationary signals making use of 3-D time-frequency spectrum and marginal spectrum, the stationary degree curve of Elcentro seismic recording is protracted according to its defining formula, the stationary degree curve of Elcentro seismic recording which change with time is protracted according to similiar definition.

在HHT方法的应用研究方面，本文做了三部分的工作：首先，利用HHT方法分析了地震工程中常用的Elcentro非平稳强震记录，得到了该记录的振幅－频率－时间分布特性，并将得到的边际谱与傅立叶谱做了比较；其次，应用HHT方法分析了典型的非线性系统－Duffing方程，得到了该方程数值解的振幅－频率－时间分布特性，并将得到的边际谱与傅立叶谱做了比较；最后，利用三维时频谱与边际谱定义了非平稳信号的平稳度，并依照其定义式绘制了Elcentro地震波记录的平稳度曲线，依照类似与依赖与频率变化的平稳度定义，初步尝试编程绘制了Elcentro地震波随时间变化的平稳度曲线。

Because of the great effect of the stray capacitance and stray inductance under the high frequency, both the analysis methods and design applications of the high frequency show different from the one of low frequency circuit.

在高频条件下，杂散电容和杂散电感对电路的影响非常大，所以射频电路无论是分析方法还是设计应用都与低频电路存在很大的不同。

After multivariable adjustment, consumption of tuna or other broiled/baked fish was associated with specific HRV components, including indices suggesting greater vagal predominance and moderated baroreceptor responses (eg, higher root mean square successive differences of normal-to-normal intervals [P=0.001]; higher normalized high-frequency power [P=0.008]; and lower low-frequency/high-frequency ratio [P=0.03]) and less erratic sinoatrial node firing (eg, lower Poincaré ratio [P=0.02] and higher short-term fractal scaling exponent [P=0.005]) but not measures of circadian fluctuations (eg, 24-hour standard deviation of normal-to-normal intervals).

经过多因素校正，鲔鱼或其他烤鱼的摄入与HRV某些特异性指标相关，包括了反映更强的迷走神经张力的指数和适当的压力感受器影响如更高的正常-正常均方根连续差[P=0.001；更大的正常化高频功率[P=0.008]；更小的低频/高频功率比［P=0.03］以及更少的窦房结电冲动游走（如，更低的Poincaré比［P=0.02］和更高的短期分形定标指数［P=0.005］），但不测量昼夜波动（如24小时正常-正常间期的标准差）。

In the mobile communication system, the intermediate frequency signal results in the characteristic value is took the appraisal signal quality one kind of standard, how this topic main research is withdraws the intermediate frequency signal the characteristic value,as well as withdraws in the method in each kind to select superiorly withdraws the intermediate frequency signal characteristic value the method.

在移动通信系统中，中频信号得特征值是作为评估信号质量的一种标准，本课题主要研究的是如何来提取中频信号的特征值，以及在各种提取方法中选出最优的提取中频信号特征值的方法。

Plasma is a dispersive medium and its equivalent refractive index is related to the frequency of the incident electromagnatic wave and the plasma frequency, so it is feasible to shift the syntonic frequency of plasma defect by changing the plasma parameters, which behaves as a tunable filter.

据等离子体的强色散特性，其等效折射率与电磁波频率及等离子体频率等参数有关，因而可以通过改变等离子参数，使一维微波光子晶体缺陷层的谐振频率发生偏移，实现微波光子晶体的可调谐滤波特性。

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。

Chimborazo and Cotopaxi, took me by the hand.

越过琴博腊索山和科托帕克西山。

This car is in a good condition.

这辆车的状况很好。