查询词典 diffraction spectrum

The main contributions of the second part of this dissertation are focused on the cryptographic properties of logical functions over finite field, with the help of the properties of trace functions, and that of p-polynomials, as well as the permutation theory over finite field: The new definition of Chrestenson linear spectrum is given and the relation between the new Chrestenson linear spectrum and the Chrestenson cyclic spectrum is presented, followed by the inverse formula of logical function over finite field; The distribution for linear structures of the logical functions over finite field is discussed and the complete construction of logical functions taking on all vectors as linear structures is suggested, which leads to the conception of the extended affine functions over finite field, whose cryptographic properties is similar to that of the affine functions over field GF (2) and prime field F〓; The relationship between the degeneration of logical functions and the linear structures, the degeneration of logical functions and the support of Chrestenson spectrum, as well as the relation between the nonlinearity and the linear structures are discussed; Using the relation of the logical functions over finite field and the vector logical functions over its prime field, we reveal the relationship between the perfect nonlinear functions over finite field and the vector generalized Bent functions over its prime field; The existence or not of the perfect nonlinear functions with any variables over any finite fields is offered, and some methods are proposed to construct the perfect nonlinear functions by using the balanced p-polynomials over finite field.

重新定义了有限域上逻辑函数的Chrestenson线性谱，考察了新定义的Chrestenson线性谱和原来的Chrestenson循环谱的关系，并利用一组对偶基给出了有限域上逻辑函数的反演公式；给出了有限域上随机变量联合分布的分解式，并利用随机变量联合分布的分解式对有限域上逻辑函数的密码性质进行了研究；给出了有限域上逻辑函数与相应素域上向量逻辑函数的关系，探讨了它们之间密码性质的联系，如平衡性，相关免疫性，扩散性，线性结构以及非线性度等；讨论了有限域上逻辑函数各类线性结构之间的关系，并给出了任意点都是线性结构的逻辑函数的全部构造，由此引出了有限域上的"泛仿射函数"的概念；考察了有限域上逻辑函数的退化性与线性结构的关系、退化性与Chrestenson谱支集的关系；给出了有限域逻辑函数非线性度的定义，利用有限域上逻辑函数的非线性度与相应素域上向量逻辑函数非线性度的关系，考察了有限域上逻辑函数的非线性度与线性结构的关系；利用有限域上逻辑函数与相应素域上向量逻辑函数的关系，揭示了有限域上的广义Bent函数与相应素域上的广义Bent函数的关系，以及有限域上的完全非线性函数与相应素域上向量广义Bent函数之间的关系；给出了任意有限域上任意n元完全非线性函数存在性与否的完整证明，并利用有限域上平衡的p-多项式的性质给出了有限域上完全非线性函数的一些基本构造方法。

A real signal can be fitted by a harmonic signal series to calculate the amplitude spectrum and phase spectrum.The relationship between the coefficient,phase angle of the harmonic signal and the amplitude spectrum,phase spectrum of the bispectrum is calculated by Fourier transform.

一个实信号可以用一个谐波信号序列来拟合，计算实信号的双谱，通过Fourier变换推算出谐波信号的系数和相位角与实信号双谱振幅谱和相位谱之间的关系，可以实现信号重构。

It gives an amplitude spectrum as the inverse of a biased amplitude spectrum of the CHF, and a phase spectrum as the phase spectrum of the CHF.

该滤波器的振幅是圆谐滤波器的振幅谱加偏移量后的逆函数，位相是圆谐滤波器的位相谱。

First, experimental datum is analyzed and it is found that the shallow water ocean internal wave spectrum is different from that of the deep ocean GM spectrum. Then, the theory of weak turbulence is systematically summarized, and Lvov and Tabak's method of obtaining the deep ocean internal wave spectrum is introduced. They applied the theory of weak turbulence to internal waves of long wave length and found that GM spectrum maybe obtained theoretically.

首先，基于海洋实验数据分析了浅海内波谱特性，指出它与深海GM谱不同；接着，系统地总结了Zakharov等人发展的基于波-波相互作用的弱湍流理论，对文献中没有给出推导的一些关键性公式进行了细致的推导，并讨论了Kolmogorov-Zakharov谱在海洋内波研究方面可能的应用；最后，总结了Lvov和Tabak对于深海GM谱的弱湍流理论解释；介绍并细致推导了Madja、Mclaughlin和Tabak(1997)提出的一维MMT模型及其特性。

The spectrum analysis of the air-ultrasonic waveform indicates that when the matcher thickness is calculated at the highest spectrum and the subsequent higher spectrum of the pulse waveform, it can obtain a better result. But all the highest spectrum of the air-ultrasonic waveform moves to the high frequency zone in the experiment, which is a possible important reason that the testing extent of the air-ultrasonic transducer is limited.

经对空气超声波形进行频谱分析后发现用脉冲波形的最高谱线及次高潜线对应的频率计算匹配层厚度，可得到较好的匹配结果，但是空气超声波形的最高谱线均移向高频段，这可能是造成脉冲空气超声换能器可检测的范围有限的一个重要原因。

The spectrum resource of WiMAX system is very scarce. How to improve the spectrum utilization and reduce interference with other systems to achieve co-existence needs to be resolved. The performance and spectrum utilization improvement of WiMAX system is studied by using periodogram detection and spectrum pool technology.

为提高WiMAX系统频谱利用率，减小与其他系统之间的干扰，实现共存，利用感知无线电的周期图频谱检测和频谱池技术，对WiMAX性能加以改进。

We first introduce the positive real spectrum function and bounded spectrum function then establish the parametrization of the power spectrum by the Levinson polynomials associated with the autocorrelation matrix of the output and bounded spectrum function.

首先引入正实谱函数的和有界谱函数的概念，利用正实函数和有界实函数理论，通过和过程自相关矩阵相关联的Levinson多项式和有界谱函数，建立了功率谱参数化的表达式。

Meanwhile, 2-D spectrum and the corresponding parameters of irregular wave transformation (predominant wave direction and mean wave direction, peak frequency and peak spectrum density, spectrum width, mean period, mean wave length, mean wave crest length and 3-D index and so on)、 1-D frequency spectrum and the corresponding parameters and numerical results of wave height、 wave direction of regular wave transformation are offered.

提供不规则波传播变形二维谱及其谱参数(主波向及平均波向、峰频及谱峰值、谱宽度、平均周期、平均波长、平均波峰长度及三维性指标等等)，不规则波一维频率谱及其谱参数和规则波变形的波高、波向模拟值。

A series of bulkily substituted ferrocenium triiodides with general formula (RC5H4)2FeI3 have been synthesized and characterized by elementary analysis, IR spectrum, mass spectrum, ESR spectrum, Mossbauer spectrum and conductivity.

通过元素分析，红外光谱，质谱，顺磁共振谱，穆斯堡尔谱和电导率对这些化合物进行了表征。

At first, setting up the arith relation between the signal input and the signal output of the generalized multi-carrier system of the Discrete Fourier Test spread-spectrum; then setting equilibria parameters of the frequency field equilibria subcarrier of the generalized multi-carrier system of the DFT spread-spectrum according to channel frequency response, channel noise variance and equilibria method; then calculating average power of useful signal, interferential average power between signals as well as noise variance of the generalized multi-carrier system receiving terminal of the DFT spread-spectrum according to the arith relation as well as the frequency field equilibria parameter, and recomputing available signal information noise ratio, so as to calculate the available signal information noise ratio of the generalized multi-carrier transmission system accurately, the method for estimating the available signal information noise ratio can be used for link self-adapting transmission solution of the generalized multi-carrier system based on Discrete Fourier Test spread-spectrum and radio material management.

一种DFT扩频的广义多载波系统的SINR估计方法，其通过首先建立所述离散傅立叶变换扩频的广义多载波传输系统的信号输入输出之间的数学关系，然后根据信道频率响应、信道噪声方差和均衡方法，设定所述DFT扩频的广义多载波传输系统的频域均衡子载波的均衡系数，再根据所述数学关系及所述频域均衡系数分别计算所述DFT扩频的广义多载波传输系统接收端有用信号的平均功率、信号间干扰的平均功率以及噪声方差，再计算有效信干噪比，如此以实现对广义多载波传输系统的有效信干噪比的准确计算，该有效信干噪比估计方法可用于基于离散傅立叶变换扩频的广义多载波传输系统的链路自适应传输方案和无线资源管理方面。

Continuously improve the production mechanism, to provide customers with better quality products and services.

不断的完善生产机制，给客户提供更优质的产品及服务。

B:Yes, he was the very prize-winner in the court tennis ten years ago?

是的，他是十年前的世界网球冠军。