频谱密度

At the same time, for ultraviolet, visible and near infrared range, the thickness, packing fraction and complex refractive indexes of the PZT thin films have been deduced from a transmission spectrum of the films by Envelope method.

同时，根据PZT铁电薄膜紫外、可见和近红外光区的透射光谱，采用"包络法"计算出了PZT薄膜的厚度、填充密度以及紫外、可见和近红外光区的复折射率及其射散频谱。

The results show that the frequency characteristic corresponds with vortex structures; the detail and approximate characteristics of signal are reflected by wavelet coefficient at different scales; the coefficient map of continuous wavelet transformation reveals the self-similarity of the signal.

采用傅里叶变换和小波变换技术，实现了混合层密度脉动信号的频谱与多分辨率分析，结果表明：信号的频域特性与流场的涡结构相对应，不同层面的离散小波系数反映了不同尺度下信号与图像的细节和平滑近似特征，连续小波变换系数图定性的反映了信号的自相似特征。

In the first session the fans vibration on-line monitoring system is realized with VC language, also compile auto power spectrum density function, cross power spectrum density function, autocorrelation function and cross correlation function etc spectral analysis function to carry through simple offline fault diagnosis.

首先用稳定性强、扩展性好的VC++语言开发了通风机振动在线监测系统，并编写了自功率谱密度函数、互功率谱密度函数、自相关函数和互相关函数等频谱分析函数来进行简单的离线故障诊断。

By adopting relationship in frequency domain coherence analysis method is presented on the thesis for conventional fMRI and resting-state fMRI. Otherwise I use cross spectral density function in the coherence analysis method to discuss the phase delay and phase lead.

本篇论文采用同调性分析的方法探讨频率上相关性的方法研究一般功能性影像与平静状态功能性的影像并藉由同调性分析里交互频谱密度函数来研究信号之间相位差的问题。

The laminar flamelet model in combination with joint probability density function transport equation of mixture fraction and turbulence frequency is used to simulate fluctuating behavior of radiative source term in turbulent jet diffusion flames of hydrogen.

采用κ-ε湍流模型、标量联合的概率密度函数输运方程和层流火焰面模型相结合，模拟氢气自由扩散火焰中辐射源项湍流脉动特征。给出了主燃区内辐射源项湍流脉动的频率图。辐射源项的样本点分布集中，大约95%以上的样本落在其系综的±3倍方差以内，频谱图为单峰

Besides, in the analytic process, it also utilizes power spectral density diagram, time frequency analysis diagram and modal stabilization diagram to assist the reach.

分析过程中并以时间历时图、功率频谱密度图、时谱图及模态稳定图来辅助观察分析。

Where bandwidth-expansion techniques are used the minimum spectral power density consistent with efficient spectrum utilisation shall be employed.

若使用带宽扩展技术，则必须采用符合有效率地使用频谱的最低频谱功率密度。

The spectrum analysis of periodic signals has some difference with the spectrum analysis of nonperiodic signals.The DFT result of nonperiodic signals indicates the spectrum density on frequency Ω,and is continuous.

一般信号的DFT结果表示该信号在频率Ω处的频谱密度，它是一个连续信号，周期信号的DFT仅表示它的基波及各次谐波的幅值，是一个离散信号。

The analysis of deformation series, of spectral response function and of spectral density in the frequency domain.

8在变形序列的频域分析中，主要对表征序列的频时域特性函数一频谱响应函数和频谱密度进行分析。

Estimation of spectral densities for single and multiple time series. Nonparametric estimation of spectral density, cross-spectral density, and coherency for stationary time series, real and complex spectrum techniques.

时间序列谱分析：单个和多个时间序列的谱密度估计，谱密度的非参数估计，交叉谱密度，静态时间序列的一致性，实时和复杂的谱技术，双频谱Bispectrum。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。