18+污漫画,亚洲国产港台日韩欧美三级电影网,办公室扒开奶罩揉吮奶明星,爱爱电影爱情影院网,斗破苍穹 小说免费阅读全集,人妻洗澡被强伦姧完整,打扑克牌又疼又叫视频软件,亚洲,日韩,aⅴ在线欧美,寂寞少妇扒开双腿猛烈进入免费看

www.cdcqgg.com 2003.10.22

               
The Difficulties Involved in the Casting Technology of the Yongle Bell and the Valuable Achievements in Science and Technology

The Yongle Bell was cast by means of China' s traditional method of pit shaping and pottery moulding. No characters cast on the bell were left out by mistake and the lines were well spaced, manifesting the effects of refinement and neatness. First of all, the special clay mould material was filtered through water over and over again, so it was finer than water-glass sand. Clay moulds were made by scraping, divided into pieces and dried in the shade. Characters were written on Xuan paper (a kind of high- quality paper for traditional Chinese painting and calligraphy) after typesetting planning. The Xuan paper was pasted on the mould and the characters were copied out and then carved by engravers. When the moulds were combined for casting, each mould had to be preheated to effect "surface pottery moulds." When the surface strength of pottery moulds was increased in the process of casting, no damage would be caused to the cast. The inscriptions on the Yongle Bell to-talled more than 230,000 characters. Not a single character was cast in a wrong way. This alone was astonishing.

· The Alloy Ingredients of the Yongle Bell
· The Acoustics and Timbre
· The Scientific Suspending Structure of the Yongle Bell
· The Rain- type Casting Technique
· The Connecting Casting Technique
· The Cooling Technique of the Yongle Bell
· The Technique of Preventing 'Leak-out'
Copyright © China Internet Information Center. All Rights Reserved
E-mail: [email protected] Tel: 86-10-68326688 (2003.10)