查询词典 periodic

This paper compares periodic set with almost periodic set, and properties of periodic function with that of almost periodic function through analysing the definitions of periodic function and almost perodic function, and then draws some important conclusions.

利用周期函数与概周期函数的定义，把周期函数的周期集与概周期函数的概周期集进行了比较，把周期函数与概周期函数的性质进行了比较，并得出一些重要结论。

We consider Lienard equation X + fx'+ g =e and obtain that if and for any periodic function or almost periodic function e it has a periodic solution or almost periodic solution.

本文考虑Lienard方程x十fx'＋g＝e，我们得到：当且时，对于任意周期或概周期。数e，它有周期或概周期解。

For Lienard equation X +fx'+ ex = e, we obtain that if and for any periodic function or almost periodic function e it has a periodic solution or an almost periodic solution.

而对于Lienard方程x＋fx'＋cx＝e，我们得到：当c＞0且时，对于任意周期、或概周期函数e，它有周期或概周期解。

A main feature in developing the theory is that the scope is expanding: from almost periodic function, asymptotically almost periodic function, weakly almost periodic function to pseudo almost periodic function which was introduced by Professor Zhang in 1992. Every extension consumedly enlarges the theory and their applications.

从概周期函数、渐进概周期函数、弱概周期函数，一直到张传义教授在上世纪九十年代初提出的伪概周期函数，每一次函数范围的扩展都大大地丰富了概周期函数的理论和其应用前景。

For some special cases, the paper gives some important identical theorems, and then establishes a valuable relation between the uniformly almost periodic functions and the trigonometric polynomials.Secondly, on the basis of the identical theorem, the paper investigates the Fourier series of the uniformly B2 almost periodic functions, and further proves that the series is unique.Thirdly, the paper discusses the Parseval equation of the uniformly B2 almost periodic functions, which establishes the relation between these functions and the coefficients of their Fourier series; and next investigates an important approximation theorem-Riesc-Fischer theorem, about the uniformly B2 almost periodic functions and the trigonometric polynomials.

并给出了特殊情况下的几个重要的恒同定理，将一致概周期函数与有限三角多项式联系起来；第二，在恒同定理的基础上，给出了一致B~2概周期函数的Fourier级数，并且级数是唯一的；第三，讨论了一致B~2概周期函数的Parseval方程，建立了函数与其Fourier级数的系数之间的联系；接着给出了关于一致B~2概周期函数和三角多项式之间的一个重要近似定理—Riesc-Fischer定理。

On the applications of the uniformly Besicovitch almost periodic functions to differential equations, the main works are as follows:First, the paper proves that the space of the uniformly B2 almost periodic functions, with a special norm, is a Banach space, and then the Fixed Point Methods could be used in this function space.Second, since the space of the uniformly B2 almost periodic functions is per-fect, the paper investigates the existence and uniqueness of uniformly B2 almost periodic solution of a wave equation involving reflection of the argument by the principle of contraction mapping.

关于一致Besicovitch概周期函数在微分方程中的应用，本文主要做了以下工作：第一，证明了一致B~2概周期函数空间在其特定范数下构成Banach空间，从而可以在此函数空间上应用不动点定理；第二，由一致B~2概周期函数空间的完备性，应用压缩映像原理，讨论了一类满足一定初始条件的带反射变量的波方程一致B~2概周期解的存在唯一性。

The instability originated in the upper R_B-like convection zone develops to larger region with the increase of Grashof number, and the number of non-axi-symmetric circulations decreases. When Grashof number exceeds another critical value, cooling air may invade the cavity and flow toward the shroud, the circulations decrease to one pair occupying the whole cavity in radial, thus these two zones are merged into one. The core structures in the cavity rotate against the disks, while the structures keep no change at the case of periodic oscillatory flow. With the Grashof number rises, the flow undergoes stable, periodic, periodic with cool air invading, quasi-periodic and ultimately to chaos.

离心浮升力是造成非等温轴向通流旋转盘腔内流动不稳定的主要因素，而哥氏力的存在加剧了流动不稳定性，导致流场失稳提前发生，而且在哥氏力的作用下流线发生偏转，盘腔内r-θ面出现了旋向相反的对涡，流动结构更加复杂化；随离心浮升力的继续增加，r-θ面的对涡减少，当其超过某一临界值后部分冷流体侵入盘腔，对涡减少至一对，而且沿径向充满整个盘腔；此后随离心浮升力的增加对涡的数量不再变化；r-θ面的对涡相对于盘面周向移动，但是形状基本保持不变。

Software Description: About Integral Scientist Periodic Table, This is a periodic table for professional chemists, educators and students.

Integral Scientist Periodic Table 这是专业的化学家，教育家和学生的元素周期表。

Our results improve the former results. For periodic Jacobi matrix, some new spectral properties of periodic Jacobi matrix are given by studying the relationship of the eigenvalues of periodic Jacobi matrix and its n—1 principal submatrix. Applying these spectral properties, we present a necessary and sufficient condition for the solvability of an inverse problem of periodic Jacobi matrices and discuss the number and the relationship of its solutions. Furthermore, we propose a new algorithm to construct its solution and compare it with the former algorithms. As this inverse problem of periodic Jacobi matrix usually has multiple solutions as many other eigenvalue inverse problems, we study the uniqueness of this problem. And a necessary and sufficient condition is given to ensure its uniqueness, under which an algorithm is presented and the stability analysis is also given. Finally, we put forward a new inverse problem for periodic Jacobi matrix which has not been solved.

对周期Jacobi矩阵特征值反问题，通过研究周期Jacobi矩阵与其n-1阶主子阵特征值的关系，给出了周期Jacobi矩阵的一些新的谱性质；利用这些谱性质，研究了一类周期Jacobi矩阵特征值反问题，用新的方法推导出了该类特征值反问题有解的充分必要条件，并讨论了解的个数以及解与解之间的关系；此外，提出了一种新的构造周期Jacobi矩阵反问题解的数值算法，并与前人的算法做了一定比较；由于周期Jacobi矩阵特征值反问题和其他很多特征值反问题一样往往存在多个解，本论文给出了周期Jacobi矩阵反问题解唯一的充要条件，并发现周期Jacobi矩阵特征值反问题的解唯一当且仅当构造的矩阵满足一定的条件；在解唯一的情况下，给出了构造唯一解的数值算法，并做了相应的稳定性分析；最后，提出了一类新的有待于解决的周期Jacobi矩阵特征值反问题。

Due to the complexity of the cell jitter, the NonSynchronous Tining Recovery methods are currently not mature With the emphasis being given to the Class A CBR traffic, this paper analyzes the performance of the queueing delay and cell jitter at the source node and intermediate nodes, and discusses the Source Timing Recovery at the destination node in ATM networks Firstly, this paper presents a description of the cell jitter of CBR traffic, and gives the definitions of two kinds of cell jitter regarding the Source Timing Recovery for CBR traffic Then, by using exact mathematical models and analysis methods, this paper analyzes the impact of the factors, such as the capacity of the queueing buffer, the randomness, the deterministic nature and the correlation in cell arrivals of the background traffic sources, on the queueing delay and cell jitter performance of the CBR traffic through Statistical Multiplexitng To obtain an insight into the power spectral distribution and look for better schemes for the depression and filtering of the cell jitter, within the analyses we succeed deriving the power spectrum of the cell jitter for CBR traffic Hence, not only the power spectral distribution of the cell jitter can in the frequency domain be qualitatively understood, but also can the rms (root-meansquare) value of the cell jitter be quantitatively obtained so as to more accurately measure the amplitude of the jitter In the end-to-end performance analysis of the queueing delay and cell jitter, we propose a kind of quasi-periodic cell stream model to characterize the jittered CBR traffic, and present an initial queueing analysis of the CBR traffic following such a model at a generic intermediate node Additionally, we briefly discuss the buildout/playout and Source Timing Recovery functions of the destination node Finally, regarding the Source Timing Recovery of CBR traffic, this paper systematically discusses several important principles of the cell jitter filtering and depression reported in the literature, introduces several implementation schemes of the Source Timing Recovery e.

由于信元抖动的复杂性，非同步定时恢复方法目前还很不成熟。本文针对A类CBR业务流在ATM网络源节点和中间节点的排队时延和信元抖动性能，以及在目的节点的源定时恢复问题作了较为全面的研究。首先，文中描述了CBR业务流的信元抖动，并具体地给出了两种与CBR业务源定时恢复有关的信元抖动的定义。然后，采用了精确的数学模型和分析方法，有针对性地分析了业务背景中信元到达的纯随机性、确定性和相关性以及排队缓存器容量等因素对CBR业务流经过统计复用后的排队时延和信元抖动性能的影响。为了了解信元抖动的功率频谱分布和寻求更好的抑制和滤除抖动的方法，在性能分析中，我们成功地完成了CBR业务流信元抖动的功率谱分析，使得不但可以从频域定性地认识信元抖动的能量分布特性，而且还可以定量地求出信元抖动的均方根值(rms：root-mean-square)，以更为准确地衡量抖动的大小。在CBR业务流的多节点端-端排队时延和信元抖动性能分析中，我们提出了一种准周期性(quasi-periodic)信元流模型来描述感染了信元抖动的CBR业务流，并基于这一模型进行了CBR业务流中间节点的初步排队分析。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了