失稳

Having analyzed the sliding of gravity dam foundation with a weak intercalation for failure process and destabilization mechanism by the non-linear finite technique ,it proved to be true that the second sliding surface in tail rock resistance block would be inclined to the downstream side but not simply vertical.

通过非线性有限元分析了具有软弱夹层的重力坝坝基滑动破坏过程和失稳机理，论证了尾岩抗力体第二滑裂面应向下游倾斜，而不宜简单地取为直立。

The linear threshold speeds of both the rigid symmetrical and single-disk symmetrical viscous-elastic rotor-bearing systems are studied respectively.

研究了刚性对称转子-轴承系统、单圆盘对称粘弹性转子-轴承系统的线性失稳转速。

First, the intact specimens were biomechanically tested according to a seven-part loading protocol. The specimens were then destabilized, and then restabilized with the following constructs in conjunction with bilateral T1 pedicle screws and biomechanically tested again using the same seven-part biomechanical protocol as was applied to the intact specimens.

首先，完整的标本按照一项包含7部分力学负荷的实验来进行生物力学测试；标本失稳后，使用双侧的T1椎弓根螺钉稳定脊柱标本，然后再次进行与前面一样的生物力学实验。

Macroscopic instability phenomena of NiTi shape memory alloy are reported during stress-induced martensitic phase transition.The research was focused on the evolution of Lüders-like band due to microscopic phase transition in grains percolating up to macroscopic level by self-catalysis.

介绍镍钛形状记忆合金发生应力诱发马氏体相变时的宏观失稳现象，研究微观晶粒内相变因自催化效应逾渗到宏观水平所表现的类Lüders变形带演化，同步测量应力-应变响应、表面形貌和表面温度，跟踪了不同热-机械复合加载条件下构件力学行为的变化。

Assuming the angular velocity of the beam is given as a harmonic function of time, the rotating sandwich beam is regarded as a parametrically excited system.

假设电流变夹层梁绕固定轴线做随时间变化的简谐周期运动，将变速度转动梁作为一个时变参激振动系统，分析了不同结构和控制参数对失稳区域的影响。

The numerical results show system changed rapidly near the edge of the safety areas, and the initial condition far away the edge can postpones the peak time.

数值结果表明，系统状态在接近安全域边界时变化很快，而初始状态远离安全域边界时，则可将对应的失稳时刻推后。

There are two methods to evaluate the safety of arch dam, such as overload method and synthetic method.

采用三维非线性有限元，以累积自重和设计水压为基本荷载，利用超载法和部分的超载、强度降低的综合法分析了某高拱坝的失稳破坏过程，得到其整体安全系数和破坏特征。

Based on the nonlinear dynamical model of the rotor-bearing system with rub-impact and pedestal looseness, the system periodic motion and its stability were studied in unbalance-rotating speed plane and rotor/stator clearance- rotating speed plane, and the effect of parameters on the system was analyzed and tested by the experiment.

以含有松动和碰摩耦合故障的转子轴承系统为研究对象，对松动碰摩耦合故障转子的周期运动稳定性及其失稳规律进行了研究，得到了系统在不平衡量-转速、碰摩间隙-转速等参数域内的分岔集，分析了这些参数对系统周期运动稳定性的影响，并用试验加以验证。

The rub-impact between rotor and stator often occurs because the rotor shaft stiffness decreases following the occurrence of the crack in the rotor shaft, and thus the coupling fault with rub-impact and crack is hackneyed fault type. Based on the nonlinear dynamical model of the cracked rotor-bearing system with rub-impact, the stability of the periodic motion and instability way were studied in unbalance-rotating speed plane and rotor/stator clearance- rotating speed plane and crack depth- rotating speed plane, and the main results were validated by the experiment.

转子轴承系统裂纹故障的出现会引起转子系统转静件之间碰摩故障的发生，因此裂纹碰摩耦合故障也是转子系统常见的故障类型，本文在裂纹碰摩耦合故障转子轴承系统的非线性动力学模型基础上，分析了系统在不平衡量-转速、碰摩间隙-转速、裂纹深度-转速等参数域内，周期运动的稳定性及其失稳规律，并用实验验证了主要理论结果。

By one landslide, volume is some 200000 m^3, occurred in an under-construction express highway project, main-line and the left link-line and toll station are all in danger of unstable state simultaneously.

某在建高速公路发生山体滑坡灾害，使该线路主线、主线左侧联络线以及收费站同时失稳，滑坡体积近20×10^4立方公尺。

Singer Leona Lewis and former Led Zeppelin guitarist Jimmy Page emerged as the bus transformed into a grass-covered carnival float, and the pair combined for a rendition of "Whole Lotta Love".

歌手leona刘易斯和前率领的飞艇的吉他手吉米页出现巴士转化为基层所涵盖的嘉年华花车，和一双合并为一移交&整个lotta爱&。

This is Kate, and that's Erin.

这是凯特，那个是爱朗。