纯数

利用数字序列可奇偶分解及DFT的对称性质，把纯数对称序列FFT蝶式运算的实乘法减为一次，并通过只存贮正频率分量来节省存贮空间。

By means of the property of a digital sequence which can be decomposed into even and odd compoments , the real multiplications are further reduced .

物质的比重指的是物质的密度与水的密度的比值，所以是纯数。

The specific gravity of a material is the ratio of its density to that of water and is therefore a pure number .

本文倡议一种新的体系，其中真空的εo和μo是纯数1；

In this paper a new system is presented , which ε _0 and μ _0 in vacuum condition are the pure number 1 ;

你们将注意到，比重总是两个重量之比，因而它是一个纯数，譬如3或5。

You will notice that specific gravity is always the ratio of two weights , and so it is a pure number , such as3 or5 .

再结合植物抗性评价常用的隶属函数值法得到不同茶树品种抗寒性综合评价值D，D值这一无量纲的纯数使得各茶树品种之间的抗寒性差异具可比性。

Combined with the membership function values method , the common method in plant resistance , we obtained the D value , which is a dimensionless pure number that makes it comparable among different tea varieties .