查询词典 periodic function

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。

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。

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。

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。

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。

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。

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。

By using theories of almost type functions,the theorem about relation of asymptotically periodic functions and asymptotically periodic sequences ,as well as the equipollence of vector-valued asymptotically periodic functions and almost periodic functions on R+ are obtained.

利用概周期型函数的理论，得出了渐近周期函数和渐近周期序列二者的关系定理，以及R+上的向量值渐近周期函数与概周期函数的等价关系。研究了渐近强周期函数空间、渐近周期序列空间的可分性质

We calculated the main effective second order nonlinear optical coefficients of the 〓 quasperiodic superlattice, analyzed the relationship between them and the quasi-periodic structure parameters, studied the extinction phenomenon and the extinction rules in quasi-periodic structure, standardized the expression of frequency conversion in homogenous crystal, periodic and quasi periodic superlattice crystal.

计算了〓准周期超晶格的有效二阶非线性系数，研究了它与准周期各结构参数之间的关系，分析了准周期结构中的消光规律，统一了频率转移效应在均匀材料、周期超晶格和准周期超晶格中的表述。

Putt your way through 36 fun-filled holes of minigolf on 3D designed courses with elevated greens, bunkers, bridges and water hazards, among other crazy obstacles.

您的推杆方式，通过36个有趣的填孔迷你的三维设计的课程，以提升绿党，掩体，桥梁和水的危害，除其他疯狂的障碍。

Some participles can be used either as attributes or as predicatives.

有些分词既可当定语用，也可当表语用。