查询词典 frequency curve

In order to avoid the inaccurate measure of the positions of the CTF zero blurred by attenuation at high frequency, we used a Gaussian curve to compensate the attenuation of Fourier transform of image at high frequency in such way that the amplitudes of two CTF zeros at the curve were compensated to the same value.

由于冷冻电子显微图像通常信噪比很低，衬度函数曲线的零点的位置不容易分辨。

The maxima of low-temperature internal friction peaks plot a symmetrical peak-like curve at logarithmic frequency spectrum and the peak-like curve shifts toward high frequencies with the increase of heating rate, indicating that phase transition relaxation time decreases; the maxima of high-temperature internal friction peaks exhibit a linear relation to the reciprocal frequencies, and as the heating rate increases its slope rises, which implies that the heating rate drives the normal movement of phase interface further in low-frequency measurements.

低温内耗峰峰值与对数频率呈现峰形函数关系，随升温速率的增加，频率峰向高频方向移动，相变弛豫时间减小；高温内耗峰峰值与倒数频率成直线关系，随升温速率的增加，直线斜率变大，表明低频测量时升温速率对相界面法向运动的驱动作用更强。

And we by the NDR curve of the IV curve can be observed, NDR device has a very special non-linear phenomenon, Usually composed of a non-linear circuit components are usually chaotic phenomenon, so we raise our six different structure in addition to the new frequency, and to explore the phenomenon of chaos, and the use of the cycle of chaotic phenomena in addition to the frequency multiplier effect achieved .

而我们由NDR的I-V curve曲线可以观察到，NDR元件具有非常特别的非线性现象，而通常一个非线性元件所组成的电路通常会有混沌现象，因此我们提出六种不同架构的新型除频器，并且探讨其中的混沌现象，而利用混沌现象中的周期倍增所实现除频效果。

Furthermore, a frequency distribution table can be developed to form a cumulative frequency distribution table which is then used to construct a cumulative frequency polygon or curve.

利用频数分布表亦可再制作出累积频数表，利用累积频数表便可制作累积频数多边形和累积频数曲线。

In this chapter, three kinds of target recognition methods are performed, which are:①Target recognition method based on the description of polarization parameter plane. The echo polarization states of target are projected onto the polarization state plane described by the ellipticity ε and the tilt angle τ of the polarization ellipse, the change of parameter following ferquency becomes the chart. According to the changing trait of the chart, the multidimensional polarization feature space of target has been contructed. Furthermore, a series of polarization feature parameters used in designing the structure of target recognition device are extracted, and they are insensible to the posture of target.②Target recognition method based on the description of Poincare polarization sphere. The echo polarization states of target expressed by Stokes vector are projected onto the Poincare polarization sphere. The conception of polarization ferquency stability, which is used in describing the dynamic distribution characteristics of the target echo polarization states on Poincare polarization sphere, has been defined. A group of polarization feature parameters used in designing the structure of target recognition device are extracted, and they are insensible to the posture of target.③Target recognition method based on the description of frequency sensitivity. In accordance with the conception of the polarization state distance defined on Poincare polarization sphere, the frequency sensibility of the physical structure property of target has been investigated, the frequency distribution feature curves in PSD domain are obtained, and targets'features are extracted by means of the curve-fitting method with Least Square Criterion.

这章具体研究了基于三种极化散射特性描述的相应的目标识别方法：①基于极化参数平面描述的目标识别方法，将目标回波极化状态投影到以极化椭圆参数，即椭圆率角ε和倾角τ表征的极化状态平面上，参数随观测频率的变化就形成了图，根据图的变化特点构造了目标的多维极化特征空间，并提取了不敏感目标姿态变化的极化特征参数组来设计目标的识别器结构；②基于Poincare极化球面描述的目标识别方法，采用Stokes矢量表征目标回波的极化状态，并将其投影到描述极化状态的Poincare极化球面上，定义了极化频率稳定度的概念用以刻画目标回波极化状态在Poincare极化球面上的动态分布信息，提取了准方位不变性的目标极化特征，最后设计了目标的识别器结构；③基于频率敏感性描述的目标识别方法，通过在Poincare极化球面上所定义的极化状态距离的概念，研究的是复杂目标物理结构特性对探测信号频率的敏感程度问题，获得了在极化状态距离下的频率分布特性曲线，采用最小二乘估计曲线拟合方法，它既用于极化特征的降维，同时又直接将拟合参数作为目标的分类特征。

This paper introduces eight methods of tlme-frequency analysis, such as Hilbert transform, Hilbert-Huang transform, sine curve fitting, Ricker wavelet matching, short time Fourier transform, wavelet transform, S transform and Cohen methods, This paper explains the merits and defects of those methods from the time resolution, frequency resolution and the adaptive ability of multi-frequency signals.

本文介绍了Hilbert变换、Hilbert—Huang变换、正弦曲线拟合、雷克子波匹配、短时傅立叶变换、小波变换、S变换以及Cohen娄这八种方法，并从时间分辨率、频率分辨率，以及对多频率成份信号适应能力等各方面阐述了各种方法的优缺点，对其中的一些方法结合了理论记录进行了试算，进一步阐述了这些方法的长处和不足之处。

The excellent agreements between simulated and measured results prove the accuracy of the established circuit model. Moreover, the varactor was added to the resonator to adjust its resonant frequency. As expected, the reactance introduced by the varactor indeed affects the net inductance and capacitance obviously. It is noted that, not only the shift with the center frequency, the inductive or capacitive of the reactance can also provide a parameter to switch its frequency toward the two directions away from the one without varactor. As a consequence, a wideband tunable band-pass filter is achieved. Although the bad quality factor with the diode strongly increases the insertion loss, this concept was proved to be available for effectively tuning the center frequency of such a class of band-pass filter.

另外，在共振器上的varactor是用来调整共振器的共振频率，如预期的，由varactor所造成的电抗确实的影响到共振器的总电感和电容值，值得一提的是，不仅滤波器的中心频率可以被改变，这电抗是电感性或是电容性也将决定滤波器的中心频率将大於或小於未加varactor时滤波器的中心频率，利用这个结果，我们也实现了一个宽的可调频率带通滤波器，虽然不理想之二极体的Q值增加了滤波器的介入损失，但这原理是被证明可有效的用於调变带通滤波器的中心频率。

Experiments shows that it can detect the carrier frequency and the low frequency of modulation signal as expected, the resolution of the carrier frequency is 0.3Hz,the detecting error is within ±0.5Hz, and the resolution of the low modulation frequency is 0.07Hz, the detecting error is within ±0.05Hz.

实验结果表明该检测仪能很好地检测出信号的载频和信号的低频调制信息，其中信号载频的分辨率为0.3Hz，误差范围在±0.5Hz 以内，低频信息的分辨率可达0.07Hz，信号的误差在±0.05Hz。

A new frequency estimation algorithm for Time Domain Synchronization OEDM system is proposed, which utilizes the time domain circular characteristic of PN sequences to adjust frequency offset and then uses a variable step frequency scan scheme to estimate large frequency offset.

提出一种新的适用于TDS-OFDM系统的频偏估计算法，利用PN序列的时域循环特性进行预频偏调整，然后用变步长扫频进行大频偏的估计，定时同步之后再利用PN的时域循环特性进行细偏估计。

Below us Divider VHDL description of the source code for the completion of the clock signal CLK frequency of 2 hours, 4 frequency, frequency of 8 hours, 16 minutes frequency.

下面我们介绍分频器的 VHDL 描述，在源代码中完成对时钟信号 CLK 的 2 分频， 4 分频， 8 分频， 16 分频。

Dixie itself is a nickname for the American South.

Dixie 本身是美国南部的别称。

I think John Terry epitomises that and a big reaction is what we will be looking for.

而我认为特里就是这样一个典型，他正是我们期望看到的那个领秀。