查询词典 periodic

" Alkali metal:Any of the six chemical elements in the leftmost group of the periodic table (lithium, sodium, potassium, rubidium, cesium, and francium)."

碱金属：碱金属是元素周期表中的Ia族元素，按原子序数增加的顺序排列为︰锂、钠、钾、铷、铯和。

For free oscillation of various nonlinear conservative systems, the analytical approximate periods and the corresponding periodic solutions were established and they are valid for small as well as large amplitude of oscillation.

提出了结构参数发生较大变化时，计算结构的静力响应，固有频率与固有振型的高效的、适用范围广的方法；对非线性保守系统的自由振动，建立了既适用于小振幅又适用于大振幅的近似解析解法。

The first prob-lem is rotating tubro impeller,and by introducing the periodic free surface variable we obtainall complementary variational principles.

其一是旋转叶轮问题，通过引进周期性自由面变量，揭示了隐含的一类对偶变分原理，从而给出了可能存在的全部互补原理。

Two kinds of freestanding waveguide-array dichroics with a 2D-periodic internal structure are designed and analyzed in this paper.

介绍了两种二维周期结构的准光滤波器的设计及其仿真结果。

In order to develop this local property,this paper presents a method,which uses Fourier Series to approximate the boundary shapes of the shafts with periodic boundary of cross section,and uses the conformal mapping in Theory of Function of a Complex Variable to make the complicated boundary shapes of the shafts map a unit circle.Thus elastic theory can analyze...

本文提出一种方法，其实质是：采用富里埃级数来逼近横截面呈周期性变化边界的轴类零件的边界形状；并应用复变函数论中保角映射原理，将零件复杂的边界形状映像成单位圆，从而使弹性理论可以分析和计算复杂边界轴类零件的应力场；再通过留数的求解实现保角映射的反变换。

Generally,for a abstract functional differential equation,if it satisfies some conditions, then we can get a periodic solution.

一般地，对于一个抽象的泛函微分方程，只要系统满足一定的条件，就可以得到其周期解的存在性。

The last chapter talks about the positive solution\'s existence of periodic boundary value problem of functional differential equation.

最后一章通过锥上不动点定理讨论了泛函微分方程周期边值问题正解的存在性问题。

In this paper,we study the asympotic stability for impulsive functional differential equation and periodic solutions of population models influenced by impulses.

本文研究脉冲泛函微分方程的渐近稳定性及脉冲作用下种群模型的周期解。

Using Mawhin s theroy and Liapunov funtional we discuss the existence and global weak attractivity of periodic solutions for a class of functional differential equation.

利用Mawhin的迭合度理论和Liapunov泛函，讨论了一类泛函微分方程的周期解的存在性和全局弱吸引性。

In chapter 4, sufficient conditions of at least one, two and multiple positive periodic solutions to a scalar functional differential equation with muti-finite delays are obtained by using a fixed point theorem introduced in [27] and [85] which is different from the one of a cone compression and expansion of norm type. It generalizes and improves some related results in the literature.

第四章利用文献[27]和[85]中所给出的不同于范数型锥压缩和拉伸的不动(来源：bc1cbcABC论文网www.abclunwen.com)点定理得到了具有有限时滞纯量泛函微分方程至少存在一个、两个和多个正周期解的充分条件，推广并改进了已有的相关结果。

The United Kingdom has pledged to provide technical assistance to the peacekeeping effort in Darfur, including airlifting supplies and equipment to assist the African peacekeepers.

英国承诺为达佛的維和努力提供技术帮助，包括提供非洲的維和部队空运补給和裝备。

Results: The level of ET-1mRNA in placental villus was significantly higher in pre-eclamptic women than that in control group.

结果：妊高征组患者胎盘绒毛组织ET-1 mRNA的表达较正常妊娠组明显增高。