极限

They have to push the envelope to see whether a newly designed plane really can meet the limits the designers planned.

他们必须让新设计的飞机挑战极限，以便测试飞机是否真能达到设计人员所设定的安全极限。

In chapter 3,we dig out two families of invariant quartic curves of a quadratic system.

第五章讨论向量场具有对称中心的二次系统，利用系统的不变双曲线及不变四次曲线，我们确定了一个对应极限环（1.1）分布的二维参数区域，其边界的构成为如下几种常见的极限环分枝：霍夫分析，庞加莱分枝，同宿分枝和异宿分枝。

At the same time, the center conditions and bifurcation of limit cycles at the origin of the quintic polynomial system are also investigated.

第二章研究了一类三次多项式系统由细焦点分支出极限环的问题，证明了该系统有12个小振幅极限环，证明过程是符号和代数的，且焦点量的表达式相对简单。

The expression of the complex equipment failure rate under the normal operating conditions were researched based on the renewal theory .

基于更新理论，研究了正常使用条件下复杂设备故障率λ的表达问题，结果表明：对任意的故障分布，复杂设备故障率λ的极限为一积分表达式，仅在指数分布时，该极限是一个常数。

The Royal Air Force pilots have reached the limit of fatigue, are still beyond the limit to continue fighting.

这些皇家空军的飞行员已经到了疲劳的极限，却还在超越极限地继续战斗。

B From One Extreme to the Other When the burning hot crust of the salt flat began to break under my boots, I knew I was approaching the lowest point in America.

Words：1，010 从极限到极限当灼热的盐田表层在我的靴子底下开始断裂时，我知道我已接近了美国的海拔最低点。

Unless otherwise stated in the design brief, the North Atlantic scatter diagram should be used in ULS and FLS for unrestricted world wide operation.

除设计概要中另有说明外，北大西洋散点图应用于非限制全球作业的极限状态和疲劳极限状态。我翻译，我存在！

In the region upstream of vortex breakdown, the sectional streamlines emanating from the leading edge spiral inward to primary vortex and in the region downstream of the breakdown, on the other hand, the streamlines separating from the leading edge are not entrained into the vortex core in the instantaneous sense. Along the axis, the topology of the primary vortex alters several times starting from stable focus near the apex to unstable focus, and lasts back to stable focus near wake edge, the stable hmit cycle and unstable limit cycle are shown in this evolution.

发现在截面流线谱中，即使奇点的类型、数目及位置相同，奇点的连接方式也有可能不同；旋涡破裂点前，主涡由来自前缘的力线卷绕而成，主涡焦点与前缘半鞍点相连，旋涡破裂后，来自前缘的力线不再卷入主涡，主涡焦点与对称面上的鞍点相连：在流体由翼尖流向后缘的过程中，截面流线谱的拓扑结构发生了多次变化，主涡焦点相继由稳定状态转变为不稳定状态，最后又转化为稳定状态，并先后出现了稳定的极限环及不稳定极限环。

In the paper we consider a wide class of slow-fa.st second order systems and give sufficient conditions for the existence of a singular limit cycle related to a homoclinic orbit.

本文研究一类正二阶快-慢系统中奇性同宿轨道和极限环，并且给出了此系统存在奇性同宿轨道和极限环的充分条件。

Based on f the stability computation theory of structures are elaborated in brevity and in consideration of material elasticity and geometrical nonlinearity, the 3-D model of finite element in studying on in-plane elastic ultimate load-carrying capacity of 工-section arches with holes in soffit is built by ANSYS software.

本文在简要阐述结构稳定计算理论的基础上，利用ANSYS计算软件，在弹性材料、几何大变形条件下建立了研究腹板开洞工形截面钢拱平面内弹性极限承载力的有限元三维模型，并把极限承载力的各种影响因子设为变量，形成了整个计算过程的MAC文件。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐