evanescent mode meaning in English

雕落模式
渐消失模
衰减模式

we have to distinguish between the propagating modes with real valued β, and the evanescent modes with imaginary β.
我们必须分别考虑具有实数的导模和具有虚数的消失模。
< uk > we have to distinguish between the propagating modes with real valued , and the evanescent modes with imaginary . < / uk >
< uk >我们必须分别考虑具有实数的导模和具有虚数的消失模。 < / uk >
Considering the influence of high evanescent modes , we have obtained the common theory . by the comparing between theoretical calculation and experimental data , we found the theory can accurately describe the high - frequency characteristic of this kind of slow - wave helical groove structure . then , five representative shapes are chosen and researched particularly ( triangle shape , cosine shape , trapezoid shape , rectangular shape and swallow - tailed shape )
主要工作成果和创新之处在于: 1 .通过考虑高次模式的影响,获得了一种更为精确分析任意槽形螺旋槽结构的普遍理论,经与实验测量值比较,发现它更能准确可靠地描述此类螺旋慢波结构的高频特性,然后详细研究了五种槽形状(三角形槽、余弦形槽、梯形槽、矩形槽和燕尾形槽)对螺旋槽慢波系统导波特性的影响。