抛物线

The law of the influence of contractive angle of taper nozzles and curvature radius of convergence nozzles' convergent section on jet structure parameters is revealed, and it can provide a basis for optimization selection and design about laser cutting nozzles.

揭示锥型喷嘴收缩段收缩角、收敛型喷嘴收敛段抛物线曲率半径对射流的流场结构参数的影响规律，为激光切割喷嘴的优化选择和设计提供有效依据。标签激光技术激光切割会聚型喷嘴流场结构流体动力学 laser technigue laser cutting assemble nozzle jet structure hydrokinetics

A surface having parabolic sections parallel to a single coordinate axis and elliptic sections perpendicular to that axis.

具有平行于一个坐标轴的抛物线部分且垂直于同一个轴的椭圆形部分的表面。

And this paper assumes that resisting power is accordwith parabola, gets all arch as basic configuration, gets formulation from the condition that therelative corner , horizontal displacement and vertical displacement of vault section iszero,adds deformation condition of maximum resisting power and zero resisting power, solvesequation group to get the internal force of lining . And lining internal force computing methodunder bias load based on assumed resisting power method is formulized.

本文假定弹性抗力按二次抛物线分布，取全拱为基本结构，由拱顶截面的相对转角、相对水平位移和相对垂直位移为零的条件列出变形协调方程，再增加最大弹性抗力处的变形协调条件和弹性抗力为零处径向位移为零的变形协调条件，解方程组求解得出衬砌结构的弹性抗力分布及内力。

Results show that parabola is the most suitable one for the displacement-based method, following with cosine curve being the second and then circle the third,while hyperbola is unfit for the method.

认为抛物线最适合在位移法中使用，正弦曲线次之，圆曲线要有所限制，而双曲线则不宜采用。

With the change of cross section ratio of stepped transformer, the parabola regulation of resonance frequency is found.

发现随着阶梯形变幅杆粗细端截面比的改变，谐振频率具有抛物线状变化规律，呈现先下降后上升的趋势。

When aiming for a distant target, the crossbowman can estimate using the Wang Shan on how high he should elevate his crossbow. The crossbow bolts fired would thus follow a parabolic path and hit the enemies accurately.

当瞄准远处的目标时，射手参照望山估算弩抬高的角度，弩箭沿抛物线轨迹就可以准确命中敌人。

Based on the one to one correspondence of the points on the tooth trace of plunge shaving cutter and the shaved gear, a method used to calculate the axial modification of the plunge shaving cutter when processing a crown gear is proposed.

用抛物线近似表示被剃齿轮的齿向鼓形量，采用一一对应映射方式将被剃齿轮的齿向鼓形量加到径向剃齿刀理论齿向线上各对应点的修形量上，得到加工鼓形齿轮的径向剃齿刀最终齿向修形量。

Further simplification can be achieved near the classical stability threshold, where the effective potential can be replaced by a cubic parabola (1) with a .

在经典的稳定性阈值附近可以获得进一步简化，那里有效势可以用三次抛物线（1）代替。

With the help of the chart of "Unit Cubic Parabola"presented in this paper, clvil engineers may findit more convenient to acquire the routs uf the cubic-equation.

借助本文建立的"单位三次抛物线"图线，工程设计人员可以快速图解出三次方程的根，从而进行相关的应力计算或其它分析。

Starting with properties of cubic parabola, it is demonstrated elementarily that solving elliptic equations using Jacobian elliptic functions, analytic solutions for a class of nonlinear wave equations and properties of nonlinear waves can be obtained, especially for solitary waves.

从立方抛物线的特性谈起，用较初浅的方法，借助于雅可比椭圆函数求椭圆方程的解，说明一类非线性波方程可用行波法求解析解。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。