Université Frères Mentouri - Constantine 1
- التفاصيل
- كتب بواسطة: Redaction Web 1
- المجموعة: Articles à Lire
- نشر بتاريخ: 09 حزيران/يونيو 2015
- الزيارات: 3357
In July 2010, the Chinese government sent a chill through the world's high-technology industries when it announced a 37% cut in export quotas for rare-earth elements — a group of 17 metallic elements that are essential ingredients in display screens, low-energy lighting, high-powered lasers and a host of other twenty-first-century products.