截面

Using the method we calculate the 〓 elasticdifferential scattering cross section, excitation differential scattering crosssection, and excitation cross section of electron collision with 〓 We transform the electron and molecule problem into electron problemby Born-Oppenheimer approximate. Mr Rossi, Dr. the Flinders University ofSouth Australia, calculated electron collision with molecule, but theexchange term he used become bigger and bigger as incident energyincreases, it is unreasonable, besides, the potential of electron and nucleus heused is somewhat rough. At present we correct these two terms. The potentialconsists of static potential, exchange potential, polarization potential.

电子与分子的碰撞过程的相互作用势主要是由静态势、交换势和极化势三部分决定的，这里对这三部分在动量空间中进行分波展开，推导出易于计算的表达形式，根据这些公式，并参考Rossi的弹性碰撞程序编写了计算电子与分子碰撞激发截面的程序，利用程序计算出势能矩阵元，通过求解Lippmann-Schwinger方程求得T矩阵元，便可求得散射截面。

In this paper a systematic analysis is made about the principle and characteristic of the round fiber dispersiveness based on the dispersive principle of the little drips which can produce rainbow .

以产生虹现象小水珠的色散原理为基础，分析了透明圆形截面纤维在平行光照条件下，一次内表面反射光中笛卡尔线的色散机理与特征；证明了透明圆形截面纤维与水珠在产生虹现象时的色散机理与特征是相似的；揭示了透明圆形纤维内部反射光的特征。

The numerical algorithm based on division lines method which is originally used in calculating section geometry properties.

在钢筋混凝土或预应力混凝土构件中，正截面承载力计算是桥梁设计的重要组成部分，许多类型的构件如受弯、偏压、偏拉构件都存在正截面承载力的计算问题。

A series of flexible U sections,changed in its sections,was separately simulated and analyzed by edger roll forming and flat roll forming.

本文对变截面辊弯成型仿真采用轧辊轴向加工技术，对角度连续变化的变截面U型材分别进行立辊加工和平辊加工成型模拟分析。

The study on effective gain cross section shows that there is a flat gain shape between 1530～1580 nm, which proves that the wide-band property of the glass is much better than that of phosphate glasses.

对反映宽带性能的有效增益截面的研究表明，该镱铒共掺氟磷酸盐玻璃在1530～1580 nm之间有一平坦的有效增益截面谱线，证明其宽带特性明显优于掺铒磷酸盐玻璃。

The experimental results show that the naphthalocyanine lead owns good optical limiting performance, and the ratio of effective excited-state absorption cross section to ground-state absorption cross section of naphthalocyanine lead is approximately to 15.21, which is larger than that of naphthalocyanine copper.

实验表明，萘酞菁铅具有良好的光限幅特性，它的有效激发态吸收截面与基态吸收截面的比值约为15.21，大于萘酞菁铜。

In order to deal with the irregular cross section of the milling cutter, the cutter effective cross section coefficient and effective radius coefficient are introduced to determine the inherent frequency of cutters for various cantilever lengths and radii.

针对铣刀刀杆截面形状不规则的特点，引入截面系数和有效半径系数的概念，提出了不同悬臂长度和半径的铣刀刀杆固有频率计算方法。

The influences of the isotope helium atoms on the PCSs are discussed in detail. The results show that the excitation PCSs converge faster than the elastic PCSs for the given collision energy and system.

结果表明：对确定的碰撞体系和给定的碰撞能量，激发分波截面比弹性分波截面收敛快。

In Chapter 2, resonance properties of stepped-impedance resonator are analyzed with transmission line theory. Resonance conditions and electrical lengthes of two-section and tri-section stepped-impedance resonators are mainly analyzed, which provide the theory foundation for filter design.

第二章运用传输线理论分析了阶梯阻抗谐振器的谐振特性，主要分析了两个截面和三个截面阶梯阻抗谐振器的谐振条件和电长度，为滤波器的设计提供了理论依据。

Its benefit is that different structural sizes can be controlled by single design variable, such as the thickness of plate element and the area of bar element can be controlled by single dimensionless design variable.

采用无量纲设计变量为了适合工程实际的设计变量连接，利用无量纲设计变量，其好处是可以跨单元、跨截面的用同一个设计变量控制不同类型的结构尺寸(如板单元的厚度、杆单元的截面面积等)。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷