paper filter element

The dry-type air filter is made of a paper element.

干式空气滤清器由纸制造而成。

The sample preparation by the filter paper method and the direct determination of major (thulium)and five neighbouring micro-rare earth element impurities in pure thulium oxide by XRF are described.

本文拟定了一种采用滤纸片法制样，X射线荧光直接测定纯氧化铥中氧化铥主量以及氧化钬、氧化铒、氧化镱、氧化镥和氧化钇等稀土杂质含量的分析方法。

In this paper, wavelet is used to erase speckle noise in radar PPI, and the principle of morphology is used for building structure element to filter off the speckle noise and clutter.

提出了利用小波来去除雷达平面位置图像(PPI)的散点噪声，然后利用形态学原理构造目标结构元来滤除斑点噪声和杂波。