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.
Extending 4,000 miles (6,437 kilometres), the Silk Road derives its name from the lucrative trade in Chinese silk carried out along its length, beginning during the Han Dynasty (206 BC Ã° 220 AD) following the establishment by Alexander the Great of a system of Hellenistic kingdoms (323 BC - 63 BC) and trade networks extending from the Mediterranean ...