计算误差

The error analysis of asymptotic approximation of finite series expansion is also given. Our method avoids choosing the integral length of the reentrant comer, and can be used to calculate the charge on the conductor conveniently and efficiently. Numerical examples are presented to demonstrate the efficiency of the method.

本文算法克服了邓肯矫正需要选择角点积分区域的不足，有效地校正了导体角点奇异性引起的电容参数提取的计算误差，最后给出了算法的数值实验与分析结果。

The precondition of the above method is that the site relationship among the marks must be changeless at the two reference frames, but this relationship will be destroyed by the computational error.

实现上述目标位姿测量方法的前提条件是要保证该组特征点在不同坐标系下，其位置关系相同，但计算误差的存在却破坏了这种固定的位置关系。

Simulations show that when the signal to noise ratio is greater than 0dB, the inverse model algorithm converges rapidly and stably with computational error being within a minimal bound.

仿真结果表明在信噪比大于0dB时，该自适应逆模型算法收敛迅速、稳定，计算误差保持在较小的范围之内。

As an application example,numerical calculation was performed for partially coherent modified Bessel-Gaussian beams propagating in free space with hard-edge aperture,and the computation errors and application ranges of those analytical equations were discussed.

以部分相干修正贝塞尔－高斯光束在有光阑情况下自由空间的传输为例作了数值计算，对所得解析公式的计算误差和适用范围进行了讨论。

The checking results of field data shows that the calculation accuracy of THD is relatively higher and the calculation error of harmonic ratio is not more tha.

对现场实测数据的验算结果表明，所提方法对总谐波畸变率的计算精度较高，对各次谐波含有率的计算误差在4%以内。

Firstly, the principle of the iteration method is presented, the characteristic of the method is analyzed. The downward continuation computation for model and practical data with noise of different variance is performed by means of iteration method.

首先介绍了迭代法的基本原理，分析迭代法的特点；然后利用迭代法对不同噪声水平的模型数据和实测数据进行向下延拓计算，研究噪声对迭代法的计算误差影响。

He electronic excitation energies of M2X4(PMe3)4 have been studied employing the time-dependent density functional theory. The effects of metal atoms, haloid ligands, and relativistic effect on these compounds were examined.

DDFT方法对M2X4(PMe3)4δ→δ和π→δ跃迁能量的计算较为准确，对π→δ跃迁能量的计算误差较大。

In order to solve this problem, an improved algorithm is presented in the paper. Results from model data show that the method can diminish traveltime error in near surface model with great difference in slowness and describe accurately seismic sliding along the interface of the velocity layers.

提出了一种改进的地震波走时计算的逆风差分算法，通过考虑首波和散射波的走时，能有效地减小速度值差异较大的近地表地质模型的走时计算误差，准确地描述速度界面上折射波的滑行描述，特别适用于近地表层析成像及地震勘探中的静校正问题。

The flowfield and performance of a centrifugal compressor was predicted and analysed, which was composed of a Krain's impeller and two types of vaneless diffuser specially: one was constant area vaneless diffuser and the other was the straight-wall. The results show that the efficiency of the straight-wall vaneless diffuser is obviously lower than that of the constant area, and a separate flow occurs nearby the exit of the centrifugal impeller with the straight-wall diffuser. However, the type of vaneless diffuser has little influence on the aerodynamics performance of the centrifugal impeller. Finally, it is suggested that the constant-area vaneless diffuser should be selected as the downstream extended area of the centrifugal impeller during the prediction for the centrifugal impeller.

对Krain叶轮后带等面积与直壁两种形式的无叶扩压器离心压缩机内部流场进行了计算与分析，结果表明：直壁型无叶扩压器离心压缩机的效率低于等面积无叶扩压器离心压缩机的效率；直壁型无叶扩压器使得叶轮出口的流动出现分离；扩压器的形式对离心叶轮的整体气动性能影响并不大；在进行离心叶轮数值研究时，叶轮后的延伸区最好采用等面积无叶扩压器，以尽量减小无叶扩压器所引起的计算误差。

The analytic solution of plane distribution of water depth and velocity in curved open channels are also given, which is better than those only giving depth-averaged velocity in radial direction.

但有限元法作为一种域法，不适合用于无界域的计算，且有限元法及边界元法的收敛性、稳定性目前还不能从理论上加以证明，计算误差也无法精确预测。

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％。