Laser phototypesetting technology is to decompose characters into lattice by computer, and then control the laser to scan on photosensitive film, and form characters and images by using the lattice of exposure points.
Generally speaking, it is actually the abbreviation of electronic typesetting system. The birth of electronic typesetting system has brought revolutionary changes to the publishing and printing industry. Using laser phototypesetting system can not only avoid low typesetting efficiency and harm to workers' health, but also benefit from its characteristics of easy modification, low cost and high efficiency.
Most newspapers, magazines and books in China are using this system, which is at least five times more efficient than ancient typesetting.
2. Synthesis of bovine insulin
Bovine insulin is a protein molecule, and its chemical structure was determined and clarified by British scientist Sanger in 1955. Bovine insulin molecule is a double-stranded molecule, consisting of an A chain consisting of 2 1 amino acid and another B chain consisting of 30 amino acids, which is connected by two pairs of disulfide bonds, and the A chain itself has a pair of disulfide bonds. ?
Later, scientists successively determined insulin from different biological sources and found that the chemical structure of bovine insulin was basically the same as that determined by Sanger for the first time. The same is true of human insulin, except that threonine is used instead of alanine at the 8 th position of A chain, and isoleucine is used instead of valine at the 10 position; The 30th position of B chain was replaced by threonine.
3. Continental oil generation theory
The theory of continental oil generation is a new concept founded and developed by Li Siguang and Pan Zhongxiang in 194 1 in the field of oil exploration.
China is one of the earliest countries in the world to discover and utilize oil and gas. However, since the emergence of modern oil exploration technology in China in 1878, China's oil industry has hardly developed for nearly half a century. One of the important reasons is that the concept of "China is poor in oil" has bound people's minds.
4. Online shopping
Online shopping is to retrieve commodity information through the internet, send a shopping request through an electronic order, and then fill in the number of a private checking account or credit card. Manufacturers deliver goods by mail order, or deliver them to your door through courier companies.
5. Hybrid rice
Hybrid rice refers to the selection of two rice varieties with certain genetic differences, and at the same time, their excellent characters can complement each other to produce the first generation hybrid with heterosis for production, which is hybrid rice. Heterosis is a common phenomenon in biology, and using heterosis to improve crop yield and quality is one of the main achievements of modern agricultural science.