不稳定性

We have studied modulation instability not only in an anomalous dispersion regime but also in a normal dispersion regime when the angle between the polarized direction and the birefringence axes is arbitrary.

利用光脉冲在非线性双折射光纤中传播时所遵循的相干耦合非线性薛定谔方程，研究了偏振方向与双折射轴成任意角度时，在反常色散区和正常色散区所产生的调制不稳定性。

Polymers. In thin polymer films, large nanoparticles can be used to nucleate dewetting, whereas

上加入少量纳米粒子可以消除"鲨鱼皮"效应－在聚合物的挤出过程中产生的不稳定性。

In chapter 5,in the framework of local theory,we investigated the effect of background population in current sheet on the lower-hybrid drift instability.

在第五章中，我们在局域理论的框架下，研究了电流片中的背景等离子体对低杂漂移不稳定性的影响，结果表明，背景等离子体抑制低杂漂移模的增长，并使其实频降低。

Three different numerical iterative algorithms are developed and the accuracy and stabilities of them are compared. Tension and compression instabilities are studied and effects of Conservative Smoothing Approach and artificial viscosity on stabilities are discussed. Based on Taylor series expansion, Modified SPH method is proposed. The discrete forms of the function and its first derivative estimations of the kernel function are deduced in both one and two dimensional space.

讨论了三种不同的数值迭代算法对计算精度和稳定性的影响；分析了不稳定性产生的根源，包括拉伸不稳定和压缩不稳定，探讨了保守光滑算法和人为粘性对稳定性的影响；在Taylor展开的基础上提出了一种修正的SPH方法，并推导一维和二维情形下函数的核估计和函数的一阶导数核估计的离散形式，结果表明，二维情形下MSPH方法可以很好的改善边界粒子的计算精度。

In this paper,an instability problem of an unsteady oscillation flow is studied.

资助： 本文分析了一种非定常振荡的不稳定性问题。

According to the investigation results, the measures to prevent the oscillation are proposed.

根据试验研究和理论分析，提出了消除系统两相流不稳定性的一系列措施。

The performance of magnetic suspension is determined mainly by its control system. Due to the inherent nonlinearities and open-loop instability of the magnetic suspension system, as well as the problem of uncertainties caused by parameter variety and disturbance, increase the difficulty of magnetic suspension control technology.

悬浮性能的好坏主要取决于控制系统的设计；由于悬浮系统本身固有的非线性特性和开环不稳定性，以及参数摄动和外干扰引起的不确定性等问题，增加了悬浮控制技术的难度。

Methods 52 cases of unstable pelvic fractures were analysed retrospectively.

对52例不稳定性骨盆骨折临床资料进行回顾性分析。

However, it is a very difficult work to detect these periodic orbits due to their unstable properties.

然而，由于这些周期轨道本身具有的不稳定性，对它们的探测成为一件较困难的工作。

A periscope probe is used to map the combustion space and eliminate hot spots and instabilities.

一种潜望镜探针是用来测绘燃烧空间，并消除热点问题和不稳定性。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。