近似计算

In this paper an attempt is made to derive a practical formula for the induced velocity distribution in the lifting rotor disk plane on the basis of the generalized vortex theory.

本文试图根据涡流理论导出的精确公式，通过简化，获得适于工程计算的近似公式。

In order to study the changing process of Barium strontium titanate Ba(subscript xSr(subscript 1-x) TiO3, BST from cubic phase to the tetragonal phase with Ba doping and the ferroelectric characteristic of BST, the total energy of BST with different mole ratio of Ba/Sr when Ba doped was calculated and the fine structure determined, based on general gradient approximation, by means of ultrasoft pseudopotentials plane wave method.

为了研究钛酸锶(SrTiO3， ST)中随Ba的掺入，其晶体从顺电相到铁电相的变化过程及四方相钛酸锶钡Ba(下标 xSr(下标 1-x)TiO3， BST的铁电性。在广义梯度近似下，利用超软赝势平面波方法计算了不同Ba/Sr摩尔比BST的总能量，确定了BST的精细结构。

The hot helium temperature follows HTR-10's nuclear power changes slowly, and there is a large coupling between them, so the RPHHT system adopts cascade control, the minor loop is fast, and the major loop is hot helium temperature control loop whose dynamic response is slow; there is also a large coupling between main helium loop and steam-water loop, and both the main steam temperature measure signal and the heating process of the once-through steam generator are delayed, therefore, the MHFMST applies cascade control, the minor is main helium flow control loop whose dynamic response is fast, and the major is the main steam temperature control loop whose dynamic response is slow.

本文运用机理建模法，建立了HTR-10系统动态控制模型，然后进行了动态性能仿真，将堆芯用集中参数表示，冷却剂按一维流动处理；直流蒸汽发生器按二回路工质不同的相分为预热段、蒸发段和过热段，建立了三环节控制模型，得到HTR-10系统控制模型；仿真结果与数值计算结果对比表明，本文所建立的控制模型，能近似地反映HTR-10的动态特性，适合设计控制系统。

The calculation method also included a stair-step representation of the shroud, staggered grid system, the k-ε turbulence model and wall function method on the shroud.

计算方法还包括涵道壁的阶梯型近似，原始变量的交错网格，k-ε湍流模型和涵道壁上的壁面函数法等措施。

We describe the GW approximation which has turned out to be a fruitful approximation to the self-energy.

通过理论的推导和计算试验将表明GW方法能很好地近似求解自能。

As same as the above-mentioned reason, because theconditions at the inside straight boundary of the binarycomposite material can not be easily satisfied, here, anelastic circular inclusion with large radius is used to replacethe upper half space of the binary composite material, so the〓mary binary composite mater ial problem can be changed〓the scattering problem of a circular elastic inclusion andto the scattering problem of a circular eastic inclusion and〓circular cavity in an infinite space to the steady incident〓wave.

与前面两个问题的理由一样，同样，由于问题中双质复合材料的内部直边界上的边界条件不易解析满足，为此，本文采用了一个半径很大的弹性实夹杂来代替问题中双质复合材料的上半空间部分，而将原来的双质复合材料问题转化成了无限大空间中一圆形弹性夹杂和一圆孔对稳态P波的共同散射问题，根据该问题的特点写出了弹性夹杂内外波场中波函数的一般形式解，利用该问题中夹杂和圆孔处的位移和应力的连续条件，并采用复数傅立叶级数展开技术将其化为一个仅包含问题波函数中未知系数的无穷线性代数方程组，在满足一定计算精度的前提下，通过有限项截断进行近似求解，进而讨论了双质复合材料中圆孔边界处的动应力集中系数随不同入射角、圆孔的不同位置、以及入射波的不同无量纲波数的变化和分布情况。

When the IAU's value for k is used to calculate these times, they must be corrected to accommodate low valleys or high mountains along the Moon's limb. The calculation of these corrections is not trivial, but is necessary, especially if one plans to observe near the path limits (Herald 1983). For observers near the central line of a total eclipse, the limb corrections can be more closely approximated by using a smaller value of k, which accounts for the valleys along the profile.

当IAU的K值被用来计算这些时刻，他们必须纠正并使其符合月球边缘的低谷和高山，这种修正并不是不重要的，相反是很必要的，特别是计划观察靠近极限路径时（Herald 1983），对于靠近全食中心线的观测者来说，在使用更小K值的情况下，边缘修正会被更准确地近似，这个K值代表山谷沿着轮廓。

The manner in which a score is calculated is a secret, but here are some approximations on how it works.

哪种方式的分数计算，是一个秘密的，但这里有一些近似对如何运作。

To check its validation, relevant program has been developed with appropriate approximations, and has been used to calculate the test problems.

为了验证该方法的有效性，在一定近似处理的前提下，开发出了相应的程序，并计算了相关的问题。

Calculation of integrated emissivities of diffuse cavities with lids "The integrated emissivities of diffuse cavities with lids have not been able to be calculated precisely up to now."

作者提出的&矩形区域近似法&与Bedford法计算精度相同，但避开了奇点处理问题，使问题得到充分简化。

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。