查询词典 first approximation

We first present a 0.73-approximation algorithm, which can take the advantage of the special structure of the bipartite graph, for disjoint bisection 2Catalog Segmentation problem.

我们先讨论无交的平分二目录分割问题，利用图的特殊结构设计了巧妙的随机舍入方法得到0.73-近似算法。

The band gaps of ternary zinc blende BxIn1-xP and BxGa1-xP alloys are calculated using first principles in the generalized gradient approximation,and their bowing parameters are obtained.

利用第一性原理计算方法，用广义梯度近似处理电子之间的交换关联能，计算了BxIn1-xP，BxGa1-xP的带隙结构。

Moreover, all analysis here is based on the first-order Distorted Wave Born Approximation theoretical model that has been quite successful in engineering application.

并且，这里所有的分析都是根据在工程应用中最成熟的一阶畸变波Born近似理论模型。

ABSTRACT In the first Born approximation, the laser assisted ion-and positron-atom charge exchange collisions are studied.

本文在Born近似下，系统地研究了强激光场中裸离子与正电子对原子的电荷转移过程，在偶极近似下。

Antihydrogen formation in the laser-assisted positronium- an tiproton collision is investigated in the first Born approximation.

在一级玻恩近似下，研究了在激光辅助的电子偶素反质子碰撞中的反氢合成。

But the singularity location inversed by Born approximation inversion is false except the first interface.

本文第二章对Born近似反演算法进行了深入研究和分析，指出了Born近似反演存在的问题。

Because of taking only advantage of the first item in scattering series, method of Born approximation inversion is only suitable to little disturbance imaging. And it will produce great error in condition of great perturbation.

考虑到上述问题，本文在Bleistein和Cohen等人对Born近似的深入研究基础上，运用地震逆散射理论进行深度成像，反演地层奇性界面的位置。

According to the theory of first-order Born approximation,a Fourier Domain Optical Coherence Tomography model of single scattering infinite narrow beam is established,and the reason why it is hard to obtain the exact solution of integrated scattering equation is analyzed.

选择多层介质作为样品，根据波恩一阶近似理论建立了单次散射的无限细直光束频域OCT模型，并分析了散射积分方程很难得到精确解的原因。

Based on this thought, in this thesis, the alternation theorem is first extended to the Chebyshev approximation problems with inequality constraints, and then two algorithms are devised for designing linear phase FIR filters with inequality constraints in Chebyshev sense according to the extended theorem.

L.J.Karam和McClellan在文献[20]中把交错点组定理扩展到复数域，并提出了求解复系数FIR滤波器的复Remez算法，但由于此扩展定理只是一个充分条件，所以此算法不能保证得到最优解。在文献[23]中，他们对复Remez算法进行了完善，使其收敛到最优解。

The stochastic Bonhoeffer-Van der Pol system is first transformed into an equivalent deterministic system using the Chebyshev polynomial approximation, so that the problem of controlling stochastic chaos is reduced to the problem of controlling deterministic chaos in the equivalent system.

首先运用Chebyshev多项式逼近的方法，将随机Bonhoeffer-Van der Pol系统转化为等价的确定性系统，使原系统的随机混沌控制问题转换为等价的确定性系统的确定性混沌控制问题，继而可用Lyapunov指数指标来研究等价确定性系统的确定性混沌现象和控制问题。数值结果表明，随机Bonhoeffer-Van der Pol系统的随机混沌现象与相应的确定性Bonhoeffer-Van der Pol系统极为相似。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。