âIdealâ means that the feed has symmetrical properties and each port has an axial ratio of 0 dB, so each port responds only to signals with the appropriate sense of polarization and signals with the opposite sense are infinitely attenuated. The feed is mounted at the dishâs focal point.
Leizu(å«ç¥) was a legendary Chinese empress and wife of the Yellow Emperor. According to tradition, she discovered silk and invented the silk loom in the 27th century BC.Leizu discovered silkworms while on a walk investigating damage to the emperor's mulberry trees.However there are different accounts of exactly how she discovered that silkworms made silk. One account says that she used her finger to touch a piece of the silk worm causing a strand of silk come out.eizu discovered silkworms while on a walk investigating damage to the emperor's mulberry trees. However there are different accounts of exactly how she discovered that silkworms made silk. One account says that she used her finger to touch a piece of the silk worm causing a strand of silk come out.
For centuries the West knew very little about silk and the people who made it. Pliny, the Roman historian, wrote in his Natural History in 70 BC Silk was obtained by removing the down from the leaves with the help of water.