金沙集团1862cc(中国)成色有限公司-企业百科

Metallurgy refers to the process and process of extracting metals or metal compounds from minerals and making metals into metal materials with certain properties by various processing methods. Metallurgy has a long history of development, from the Stone Age to the subsequent Bronze Age, and then to the large-scale development of modern steel smelting. The history of human development is fused with the history of metallurgy.

Electricity is an energy source powered by electrical energy. Discovered in the 1870s, the discovery and application of electricity set off a second wave of industrialization. It has become one of the three scientific and technological revolutions in the world since the 18th century in human history, and science and technology have changed people''s lives since then. The emergence of large-scale power systems in the 20th century is one of the most important achievements in the history of human engineering science.

Papermaking is one of the four great inventions of China. In the Western Han Dynasty, people already understood the basic method of making paper. In the Eastern Han Dynasty, the eunuch CAI Lun summed up the experience of his predecessors, improved the papermaking process, and used plant fibers such as bark, hemp heads, rags, and old fish nets as raw materials to make paper, which greatly improved the quality of paper.