计算时间

Simulation results show that, for the fixed sampling frequency, the error rises with the frequency increasing of periodic signal, and decreases with the attenuation time constant increasing of non-periodic signal. The sampling frequency determines the upper limit of appropriate frequency band directly. The research provides the basis for the selection of cutoff frequency in filter design.

仿真结果表明，在采样频率确定时，对于周期信号，计算误差随频率的增加而增大，而对于非周期信号，计算误差随衰减时间常数的增大而减小，采样频率大小决定了插值法用于分布参数模型的适用频带上限，该研究为滤波器设计中截止频率的选择提供了依据。

Coupled with the three-dimensional transient heat conduction equation, a heat treatment furnace is simulated. The temperature of the gas in the enclosures and the steels vary with the time of calefaction.

将辐射传热模型与三维非稳态导热模型相耦合，对一个热处理炉简化模型内传热问题进行了计算，分析了炉内气体温度分布与钢锭温度随加热时间的变化情况，炉内气体温度和钢锭温度分布合理，计算结果可信。

The center of Hartmann diaphragm image is solved by utilizing the centers of mass of all the light spots, and then the algorithm for the center superposition of the mass center distance is confirmed by the center symmetry of the diaphragm image.

其中利用所有光斑的质心求解哈特曼光阑图像的中心，再由光斑质心关于光阑图像中心的对称性确定光斑质心距离的中心重叠算法可减少计算次数，大大降低了算法的时间复杂度和计算复杂度。

During design of pile raft foundation, reacting force raft board bottom is very important,and it not only suffers the stiffness influence of upper structure,and the degree of solidifying that still suffers the constantly change of base soil along with the increase of time reaches and the influence that time efficiency of base stiffness.

桩 -筏基础设计时，筏板底部的地基反力的确定是十分关键的，它不仅受到上部结构的刚度影响，还受到地基土的固结度随着时间的增长而不断变化及地基刚度的时效性等的影响。设计时其计算模型的建立又和桩-筏的刚度有关。根据地基土在桩-筏基础的作用下的实际受力状况，结合工程实例，提出桩-筏基础设计时简化计算的 3种模型及 3种型使用时的注意事项

In this paper, we used molecule dynamics simulation technique in researching dielectric property. By analyzing the information that is provided from molecule dynamics simulation, we can got some dielectric properties like dielectric constant and chargeability. Firstly, 3D model of silicon dioxide was been built and geometric optimization was been used to make the model more correctly. Then the model was been put in calculation of molecule dynamics simulation with a definitive temperature.

本文针对氮化硼晶体在极端高温下的介电性能开展研究，首先建立六方氮化硼晶体的微观结构模型，通过几何优化对其进行进一步的结构修正，然后选择合适的力场、系综、积分时间步长和压力温度控制方法，对微观结构模型进行某一温度下的分子动力学计算，动力学计算达到平衡后得到该温度下电介质材料的微观结构模型和动力学特性。

When to get the coefficients of polynomial directly,the ill-conditioned matrix may be produced and effect the precision of result.Using orthogonal polynomial can avoid this problem.This paper introduces 4 orthogonal polynomial.In our discussion,it is proposed to use Chebyshev polynomial and Legendre polynomial,they are easier to sa...

讨论4种常用正交多项式在拟合卫星轨道与时间函数时的适用性；通过计算实例说明利用切比雪夫多项式和勒让德多项式做数据拟合时具有很高的精度；分析得出评定多项式拟合数据精度的适用阶数，实际应用中可降低工作量，提高计算效率；最后讨论同一多项式阶数下不同历元数对拟合结果的影响。

Based on the working condition of the tractor, a new type of electric tractor drive system which combines a motor and a gear, and the evaluation index and the calculation method for dynamic performance of electric tractor are suggested; taking an electric tractor drive system as design object, the balance graph of drive-resistance force, climbable gradient under different shifts, and continuous working time are calculation analyzed.

根据电动拖拉机作业特点，提出了一种电动机和变速箱相结合的电动拖拉机传动系统结构方案，并给出了电动拖拉机动力性能和经济性能评价指标以及电驱动系统主要参数的设计计算方法，以基于串励直流电动机的某型号小四轮电动拖拉机电驱动系统为设计实例，计算分析了该电动拖拉机的驱动力-行驶阻力平衡图、不同挡位下的爬坡度以及连续作业时间。

Statistic analysis result shows that the time step is the most important influence factor of simulation precision, and there is relation between simulation error and the setup value of restitution coefficient which the greater the setup value is, the less the simulation error is. Although there is no effect to the total contact time in the course of collision, the value of the time step decides the total contact step, and there is a logarithmic linear correlativity between them.

统计分析结果表明：计算时步是影响模拟精度最重要的因素；模拟误差还同恢复系数的设定值有关，设定值越大，模拟误差就越小；计算时步的大小虽然对碰撞过程的总接触时间影响不大，但是却决定了碰撞过程的总接触时步数，二者之间存在对数线性相关关系

To solve the third problem, the definition of T-revision function and RT-computation model are proposed, and it is proved that with the increase of revision time, T-revision function converges to revision function and T-revision function is computable.

作为对第3个问题的解决，作者提出了T-修正函数的定义和RT-计算模型，证明了随修正时间的增长，T-修正函数逼近修正函数，且T-修正函数是可计算的。

To solve the third problem, we present the definition of T-revision function and RT-computation model, prove that T-revision function converges to revision function with the increase of revision time and Trevision function is computable.

作为对第3个问题的解决，作者提出了T－修正函数的定义和RT－计算模型，证明了随修正时间的增长，T－修正函数逼近修正函数，且T－修正函数是可计算的。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。