查询词典 spectral analysis

The program is used for a variety of mixtures of substances absorption spectral data analysis, curve fitting, and by their spectral location of each peak.

详细说明：该程序用来对多种物质混合物吸收光谱数据进行分析，拟合出光谱曲线并且得到其各个峰值位置所在。

Two technologies, spectral channelization and spectral analysis with zero crossing that could be both applied to multi-signals, are also introduced.

前面提到的插值算法也能用于多信号测频，但算法的基础是先进行谱峰的搜索，如果多信号同时到达，言普峰搜索存在的问题是有可能出现信号的错峰不能被正确判别的问题。

A method of cross power spectral density between responses is derived and a poly reference modal analysis method using cross power spectral density method in frequency domain is presented in this paper.

对各测点响应的互功率谱密度函数进行了详细推导，提出了一种基于互功率谱密度的频域多参点辨识法，这意味着许多原本利用频响函数的传统频域识别法可以很容易地用于工作状态下的模态识别，大大开阔了未知激励下模态识别的视野。

A method of time delay estimation by two times spectral analysis, where the time delay is the time interval between peaks of spectrum of the cross power spectral density, is proposed in the paper. It can be used to estimate time delay of not only single target but also multi-target without unwrap.

本文提出了两次谱分析时延估计方法，即将互功率谱函数再次进行谱估计，二次谱峰值位置间距即为时延估计，这种方法既能够估计单目标时延，又能够估计多目标时延，并且不用相位解绕。

Firstly, a quantitative relation about finite deformation and geometrical parameters which exhibit variation of laser spectral image was introduced. And then, particular emphasis was put on some important computer processing steps related to the analysis of spectral image, such as digitizing, segmentation, feature extraction and analytical algorithms. Lastly, some examples about an experiment of a ring subject to large diametral compression were given.

文中首先给出了有限应变和平均整旋角与反映频谱图像变化的几何参数之间的定量关系，然后着重介绍了与频谱图像分析有关的数字化、分割、特征提取和分析算法等重要的图像处理过程，最后给出圆环受径向荷载大变形实验的分析实例。

The stability and convergence for spectral methods and spectral element methods are presented, with the aid of the knowledge of functional analysis and calculus and with the help of the theorem of Lax-Milagram, the stability and convergence for steady problems, evolution equations and Navier-Stokes Equations are analyzed in detail.

利用泛函分析和微积分的基本知识，运用Lax-Milagram定理等，从理论上比较详细地分析了谱方法和谱元方法在定常问题、非定常问题以及求解Navier-Stokes方程方面的稳定性和收敛性问题，得出了Navier-Stokes方程谱近似的稳定性条件和收敛性准则。

This retrospective study included three medical institutes and fifty-nine patients of Alzheimer's disease. Based on spectral analysis, we calculated and presented spectral profile、power ratio、interhemispheric alpha coherence and intrahemispheric alpha coherence of individual EEG.

本研究收集三个专科医疗机构、59 位阿兹海默病患的数位脑波资料，利用频谱分析计算并呈现 spectral profile、power ratio、interhemispheric alpha coherence 和 intrahemispheric alpha coherence 等指标。

The main contents include: Some preliminary theory (introduction to Sobolev spaces and variational formulations for differential equations); finite element methods for one-dimensional elliptic problems; the construction methods for general finite elements; error estimates for interpolation operators and inverse inequalities for finite element spaces; a priori and a posteriori error estimates for the finite element method for high-dimensional elliptic problems; some typical spectral methods for partial differential equations; error analysis for the spectral approximation for some linear and nonlinear partial differential equations.

主要内容有：准备知识（Sobolev空间的基本概念和主要结果，微分方程的变分描述）；一维椭圆型方程有限元方法；一般有限元的构造；插值算子误差估计和逆不等式；高维椭圆型方程的先验、后验误差估计；求解偏微分方程的几类谱方法；线性与非线性问题谱逼近的误差分析等。

In order to find a powerful assistant computation tool for further analysis and design of multilayer optical coatings,an analytical model is mathematically established for accurate calculation of the first and second derivatives of the spectral coefficients of multilayer optical coatings with respect to layer parameters like thickness,real refractive index and extinction coefficient. It is based on the matrix theory of calculating the spectral coefficients of multilayer optical coatings and is achieved by perfectly using the trace operation of matrix.

为了寻找一种膜系深入分析与设计的有力辅助计算工具，从光学薄膜光谱系数的矩阵计算理论出发，基于对矩阵求迹运算的巧妙运用，从数学上建立了准确计算膜系光谱系数关于膜层几何厚度、实际折射率和消光系数等膜层参数的一阶和二阶偏导数的解析模型。

Missirlis in article [1]. At the same time, a sufficient condition for convergence of the PSD method is given to be compared when the coefficient matrix A of the linear system Ax = b is a symmetric, positively defective matrix. In §3.2, an example is given to state that the range of our sufficient condition is wider than theorem 3.3 of article [1]. On the other hand, following a.n analogous approach of [14] and starting the functional relationshipwe have a perfect analysis for the PSD method to converge and optimum valves for the involved parameters under different conditions.Under the assumptions that A is a consistent ordered matrix with nonvanishing diagonal elements and the eigenvalues of the Jacobi matrix of A are real,we get necessary and sufficient conditions for the PSD method to convergence.The result is equal to theorem 1 of article [9].Under the same condition, we can see the optimal parameter and of corresponding spectral radius of thePSD method in [8]:(2)When A is a consistent ordered matrix with nonvanishing diagonal elements and the eigenvalues of the Jacobi matrix of A are imaginary or zero,we get necessary and sufficient conditions for the PSD method to convergence.In chapter 3, the optimal parameter and of corresponding spectral radius of the PSD method are given by table 3.3. Moreover, under the assumption 0

Missirlis在文献[1]中定理3.3的不准确，同时给出了当线性方程组Ax=b的系数矩阵A为对称正定阵时，PSD迭代法收敛的一个充分条件与之比较，并且在§2.3中用实例说明了对于一部分矩阵而言本文得到的充分条件广于[1]中定理3.3的充分条件；另一方面，按照文献[14]的方法，我们从PSD迭代法的特征值λ与其Jacobi迭代矩阵B的特征值μ的关系式：出发，在不同条件下对PSD迭代法的收敛性和最优参数以及最优谱半径进行了完整的分析：(1)在系数矩阵A为(1，1)相容次序矩阵且对角元全不为零，其Jacobi迭代矩阵B的特征值全为实数的条件下，给出了PSD迭代法收敛的充分必要条件，此结果与[9]中的定理1等价，此时最优参数及最优谱半径由[8]得：(2)第三章表3.3中给出了，当系数矩阵A为(1，1)相容次序矩阵且对角元全不为零，其Jacobi迭代矩阵B的特征值全为纯虚数或零时的PSD迭代法的收敛范围和最优参数，并且我们可以得到当0

The receding calculations and experiment analyses in this subject are built on the blood cast of pig tongue.

本研究课题的前期工作是采用猪舌血管铸型模拟人舌而进行的数值计算与实验分析。

"Each human infection constitutes an opportunity for genetic modification of the virus through reassortment, mutation, or both...."

&每一次人类的感染都暗藏着一次基因修改的机会，无论是通过病毒的整合、突变或者兼而有之。。。。&