近似计算

The variational method and the effective mass approximation are used to calculate the phonon effects on the hydrogenic impurity states in a cylindrical quantum wire with finite deep potential by taking both the couplings of the electron-confined bulk longitudinal optical phonons and the impurity-ion–LO phonons into account.

采用有效质量近似和变分方法，同时考虑电子-约束型体纵光学声子及杂质离子-LO声子耦合，计算了有限深柱形量子线中杂质的极化效应。

In order to know irradiant dynamic process we must have excitation crosssection of electron collision with molecule. Incident electron energy is inintermediate range. At low energy, there are several good methods thatcalculate electron collision with molecule for example Variation, R-matrix.

此时入射电子的能量已经达到中能，在低能范围内的电子与分子散射有许多好的方法如变分法、R-矩阵方法，在高能范围内利用Born近似等方法也能得到满意的结果，在中等能量范围的电子与分子碰撞则没有相应的成熟的方法，使用比较多的是密耦(Closing-Couple)方法，这种方法将相互作用势分为静态势、交换势、极化势，在耦合态的选取上比较自由，可以根据实际的问题及分子的特性选取耦合作用比较强的通道，这样既能保证精度又能减少计算量。

In this dissertation, the moderately thick plate which works as transfer layer in" JinChao Mansion"in Hangzhou is analyzed by 3 dimensional solid finite element and the 9node mixed plate bending element. Several computation models for the transfer plate and the axial deformations of the columns and ahear walls which support the plate are considered in the analysis.

文中用三维实体单元和九节点混合板弯曲单元对杭州&金潮大厦&厚板结构转换层进行了分析，分析中考虑了多种计算模型，并用弹性支承近似地考虑了支承转换板的柱和剪力墙的轴向变形，文中给出了大量的图表。

Calculations show that effects of film evaporation can be neglectable and the temperature field of liquid film can not be approximated to linear distribution.

数值计算结果确认了液膜蒸发量对换热系数的影响可以忽略，液膜内温度分布不能近似为线性分布。

Approximate theoretical calculation model was determined for quantum wires on nonplanar substrates, with which the lateral effective width of quantum wires was estimated.Ⅵ.

五、确立了适用于非平面衬底上的量子线的理论计算近似模型，并用之估算量子线的横向有效限制尺寸。

In a 1997 interview, Plass told me,"all sorts of things came together" that placed him at the scientific forefront: new detailed laboratory measurements of the absorption bands of water vapor, carbon dioxide and ozone; theoretical developments involving the influence of temperature and pressure on infrared absorption; new information about the carbon cycle and industrial emissions; and access to a new high-speed electronic computer to facilitate complex calculations of radiative transfer that replaced the older, graphical approximations.

在1997年的一次采访中，普拉斯告诉我：&所有的事情都赶在一块儿&，把他推到了研究的最前沿：测量水蒸气、二氧化碳和臭氧的吸收光谱带有了新的实验方法；温度和压强对红外吸收的影响理论有了新的发展；碳循环和工业废气排放有了新的资料；新的高速电子计算机代替了老式的图解近似法，让辐射传热的复杂计算变得简单了。

The band-structure and partial density-of-states reveal that pseudocubic and defect cubic phases are semi-conducting, while β,γ and cubic phases are metallic.

能带结构和分波态密度计算表明，在两种近似下，膺立方和缺损立方是半导体，而β，γ和立方相是金属。

We calculate its radialization correction and make the correlative discussion,obtain the cross section of electron-antielectron collision under chain approximation,and compare the tree-level cross section with the cross section under chain approximation.

对其辐射修正作了相关的计算和讨论，从而得到了电子-正电子碰撞在链近似下的散射截面，并与最低阶的散射截面作了比较

In order to select optimal grid and good computation efficiency to recover the entire signal, aiming at the Ricker wavelet commonly used in forward modeling, we analyzed the alias and signal restoration problem in finite-difference method based on spatial sampling theorem and seismic wave traveling regulation in media with different velocity, to derive quantitative relationship among the modeling grid size, minimum velocity of model layer, and recovered main frequency of wavelet.

为了选择最佳的网格尺寸以及以最小的计算量完整地恢复出信号，针对地震波场正演模拟中经常使用的Ricker子波，根据空间采样定理和地震波在不同速度介质中的传播规律，分析了有限差分算法中的假频和信号恢复问题，推导出模拟网格尺寸、模型地层的最小速度和能够恢复的子波主频之间的近似定量关系，并用数值算例验证了这一关系。

Based on density functional theory with the generalized gradient approximation and a full-potential linearized augmented plane wave method, the calculation of the electronic structures and the magnetic properties on [Cuμ-1,3-N3](ClO4), where L is the tridentate Shiff base, has been performed.

基于广义梯度近似密度泛函和全势能线性缀加平面波方法，本文对聚铜络合物[Cuμ1，3-N3](ClO4)（其中L=tridentate Schiff base为三齿席夫基）的态密度和磁矩进行了计算。

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。