次极限

Firstly part of quadratic term of Taylor series is chosen; a low-dimension surface is used to approximate limit state surface ; and the modified reliability formula is derived.

首次选取泰勒级数的部分二次项，用一个距原点最近点处拟合的超低维曲面近似极限状态面。

The relationship between transient response and shape design variables is highly non-linear, and the behavior of feasible domains is often not good, which may cause convergence difficulties. In order to improve convergence speed of iteration process, some algorithms the feasible domains adjusting, the adaptive move limit, the approximate line search and the approximate reanalysis, are adopted.

采用基于Newmark积分的直接求导法计算瞬态响应灵敏度，在序列二次规划算法中采用了可行域调整、近似—维搜索、自适应运动极限等改进技术，提高求解效率和收敛稳定性，以解决结构动态响应与设计变量的关系复杂、高度非线性，优化可行区域的性态不良等问题。

By virtue of method of continuum approximate limit, we obtained the solitons of the vibration of lattice in one-dimensional harmonic and inharmonic chains of polarized molecule, under the conditions considering and inconsidering the interaction of exciton with phonon, through solving moving equations of exciton and phonon.

运用连续极限近似方法，通过求解声子和激子的运动方程，得到了在不考虑激子与声子的相互作用和考虑激子与声子相互作用两种情况下的极性分子简谐链和非简谐链中晶格振动的孤子解，并得出了激子与声子的相互作用的非线性效应类似于晶格三次势的非线性效应，以及相同的非线性效应不论是同时作用还是单独作用都具有相同的非线性效应的结论。

In the term of unloading and opposite side loading, let the stress-strain curve have the same form of skeleton curve, the curve uses the last unloading point as its starting point, and uses soil's ultimate stress level as its asymptote. Then the hysteretic curve is constructed.

在卸载和反向加载时，采用与骨架曲线相同的函数形式，并以前一次卸载开始点作为起点，以土体的极限应力水平作为渐近线，构造出土体动力本构模型的滞回曲线。

In this paper,the author discusses the multi-layer solution with two special limits in boundary layer of the singularly perturly boundary value problem and obtains uniformly valid zero order asymptotic expansion by using the matching asymptotic expanding method.

利用匹配渐近展开法，讨论了奇摄动边值问题中边界层内存在有两个特异极限的多层解，得出了奇摄动边值问题的一致有效的零次渐近展开

A recursive formula is derived to compute singular point values at infinity.

摘 要：研究了一类三次系统无穷远点的极限环分支问题。

This number is closely related to the number of limit cycles which are bifurcated from the generic perturbed Hamiltonian systems 〓.

这个数目与n次通有的Hamilton扰动系统〓分岔出的极限环数目密切相关，其中〓。

In chapter 3, the stability and bifurcation of the equator of a cubic system are investigated.

在第三章中，我们研究一类三次系统的赤道环的稳定性和极限环分支问题。

Prior the Nanga Parbat ascent, Buhl had only once before pushed himself to his very limit, being totally exhausted.

在攀登南迦帕尔巴特之前，布尔只有一次将自己的体力推到了极限，弄得自己完全筋疲力尽。

" Keefer replied,"I believe the central limit theorem is like a stop clock, which is right twice a day.

"科夫回答："我想中心极限定理就像是一个停止的钟，每天有 2 次时间是对的。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。