查询词典 fractional

Two special cases are discussed: flow due to a constant pressure gradient and flow due to a periodic one; In chapter 4, on the basis of the method of fractional element proposed by Schiessel et al and of the generalized fractional element networks proposed by Xu and Tan and by the use of discretization method for solving the inverse Laplace transform, we obtain the creep compliance of Zener and Poynting-Thomson models which are composed of the generalized fractional element networks.

并讨论了如下两种特殊情形：常压力梯度下的流动和周期性压力梯度下的流动；第四章在Schiessel等提出的分数阶单元法和徐明瑜等提出的广义分数阶单元网络的基础上，应用离散求逆Laplace变换的方法，给出并讨论了广义分数阶单元网络Zener和Poynting-Thomson模型的蠕变柔量。

The results demonstrated that the fractional conversion and reaction rate were rapidly increased in the initial curing reaction. The higher the curing temperature, the higher the fractional conversion and reaction rate was. With increasing of the curing temperature and time, the fractional conversion and reaction rate decreased and became constantly. The initial curing reaction was a first order reaction. The apparent activation energy and frequency factor of curing reaction used G- capryl ester was bigger than that of used G-oligomer.

结果表明：固化体系在研究的固化温度下，转化率和反应速率在固化反应初期增加快速，温度越高增加越快，随着固化时间的延长，这种变化逐渐变慢，并最终趋于恒定；初期固化反应为一级反应，反应初期的表观活化能和指前因子大小顺序为G-预聚体＞G-辛酯。

Based on this, aim at the disadvantage on Wigner Distribution and Fractional Fourier Transform that can't restrain noise interference effectively when be used to detect Linear Frequency Modulated signals interfered by heavy noises, we proposed a improved WD. Simulation results show that this method can restrain noise interference effectively and improve the ability of LFM signals detection. On the other hand, in multi-component cases, WD suffers from the cross-terms, which may impair some of the auto-terms. In order to separate original multi-component signals into components and reconstruct them separately, we can use the method of optimal filtering in fractional Fourier domain. But this method also has a problem that if signals have aliasing in the fractional Fourier optimal domain as well, the reconstructed signals will be distorted. In this thesis, a novel method of quasi Fourier transform is proposed in order to solve the problem of multi-component signal reconstruction, and have good results.

在此基础上，针对Wigner分布和分数维傅里叶变换在处理高噪声背景下线性调频信号检测的问题时存在不能有效抑制噪声干扰的缺点，提出了改进Wigner分布的办法，该方法能够抑制噪声，提高信号的检测能力；针对Wigner分布在处理多分量非线性调频信号时存在干扰项的缺点，以及分数域最优滤波方法在处理多分量非线性调频信号分离重构问题时存在的局限性，该局限性表现为在对最优分数域上也有信号分量重叠的情况进行处理时重构信号发生畸变，提出了新颖的类傅里叶变换的方法，该方法对在最优分数域上也有信号分量重叠的情况也能处理，得到的重构信号失真很小。

Based on the theory of fractional Fourier transform and one of its very important parameter, fractional order, the relationship between FRT and Fresnel diffraction are deduced and analyzed. The fractional Fourier transform hologram reconstructed with the Lohmann Ⅰ FRT system is presented and its computer simulation and digital reconstruction are realized. It is shown that FRT is an ideal tool to describe Fresnel diffraction,and the FRTH can record information on the object and the system at the same time,which extends the application areas of FRT and holography.

基于分数傅里叶变换理论并以分数阶这一重要参量为纽带，推导和分析了分数傅里叶变换与菲涅耳衍射之间的关系；提出了基于罗曼I型分数傅里叶变换系统的分数傅里叶变换全息图，并实现了其计算机生成及数字重现；研究表明，分数傅里叶变换是描述菲涅耳衍射的理想工具，分数傅里叶变换全息图可以同时记录物体和系统的信息，开拓了分数傅里叶变换和全息术的应用领域。

In order to let Apparent Hurst exponent be greater than 1, an accelerated fractional Brownian motion is introduced based on the fractional Brownian motion. A new particle tracking technique is established to model the non-Fickian dispersion in coastal waters.

因此本研究在分数型布朗运动的基础上，引进加速分数型布朗运动来模拟non-Fickian扩散，使表面Hurst指数可以大于1，从而建立了一种新型的粒子追踪技术，由此来模拟沿海水域中的non-Fickian传播。

Based on major and trace elements and isotope geochemical data, it is inferred that Sandouding suite is formed by magma melting of Late Archeozoic continent tholeiite source, and its geochemical variation is controlled by hornblende fractional crystallization. Besides fractional crystallization, the geochemical variation of Huanglingmiao suite is related to the mixing between dacitic magma and felsic magma. Dalaoling suite is probably derived from early Precambrian volcanics.

根据岩石化学和同位素组成推断，三斗坪岩套的源岩主要是晚太古代大陆拉斑玄武岩，母岩浆相当于英安质，岩套内的成分变化主要受角闪石分离结晶作用控制；黄陵庙岩套除受分离结晶作用影响外，成分变化主要与英安质母岩浆和某种长英质岩浆的混合有关；大老岭岩套的源岩亦为早前寒武纪火山岩。

With the concept, the fractional lower array power is formulated and it is theoretically proved that the power is finite and reasonable for beamforming, provided thatthe fractional order does not exceed the half of the noise characteristic exponent.

根据分数低阶统计量和零阶统计量，这部分提出强冲击噪声环境下表现出稳健的波束形成性能的三种新的波束形成算法：分数低阶最小方差无畸变响应波束形成算法、线性约束最小几何功率波束形成算法和最小几何误差波束形成算法。

The first section is to introduce some corresponding basic definiens and properties on the fractional calculous. The rest of the chapter is to present solving methods for the approximation solutions of the nonlinear fractional differential equations and their application.

首先介绍了本章涉及到的分数微积分的定义及其性质，然后介绍了非线性分数阶微分方程近似求解的方法及其应用。

The performance of traditional particle filter would be degenerate in alpha stable distribution noise.A new fractional lower order particle filter based on fractional lower order model was presented in this paper,and the detailed operation algorithm was proposed.

在alpha稳定分布噪声下，传统的基于二阶模型的粒子滤波器性能会出现退化，文章提出了一种基于分数低阶模型的分数低阶粒子滤波器，并给出了具体的运算公式。

In Chapter 2, starting from the basic fractional ordinary differential equations,weapply a high order approximation of fractional derivative advanced by Lubich to frac-tional differential equation, construct a high numerical difference scheme to solve thefractional differential equation, present error analysis of the algorithms theoretically,and prove the consistency ,convergency and stability.

接下来的第二章中，首先从基本的分数阶常微分方程出发，对Lubich提出的一个关于分数阶导数的高阶近似，将其应用于分数阶微分方程，构造高阶数值差分格式来进行分数阶微分方程的数值求解，并在理论上给出这一算法的误差分析，证明了它的相容性，收敛性和稳定性。

Finally it offers the analysis of the fault-tolerance system as well as its test verification.

这样，运行于空间环境中的系统的设计目标就是在保证系统实时性

However, it is still difficult to find out the real reason of the increase of the keratinized gingiva during the orthodontic extrusion whether it is due to the proliferation of the gingival tissue or to its elastic nature, that is because the proliferation of the fibroblasts as well as the connective tissue changes in volume and the intra-fibers spaces were all immeasurable in most of the studies.

然而，仍然难以找到真正的原因增加的角化牙龈在正畸挤压它是否是由于扩散的牙龈组织或其弹性性质，这是因为增殖的成纤维细胞以及作为结缔组织的变化量和内部纤维空格都是不可估量的，大多数的研究。