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.
This silk cocoon is made of one single thread of raw silk that ranges from 1,000 to more than 3,000 feet in length. The silk is produced in the salivary glands of the silkworm and it is used for protection during the silkwormâs pupal stage. Because silk is considered one of the worldâs most beautiful fabrics, it is estimated that approximately 75 million pounds of raw silk are produced each year. It takes more than 3,000 cocoons to make one pound of silk and more than 10 billion pounds of mulberry leaves to feed the silkworms that produce the silk.