A lustrous, blackish - brown rare earth mineral consisting primarily of cerium , erbium , titanium , uranium, and yttrium.一种红褐色矿物, 含稀土金属, 是钍和铈的主要来源.The titanium ascorbate was the substance of low toxicity to fish, shellf...
Zinc base die castings are always copper plated in cyanide baths.锌基合金的压铸件总是在氰化镀液中镀铜.It's used for the production of large castings.它用于大型铸件的制备.All lead castings were produced at first by hand in many cases from singl...
There are different meanings is different angles in explaining technology leapfrogging.从不同角度界定的“技术跨越”有著不同的内涵.The Chinese intend to accelerate modernization through technological leapfrogging.中国人通过技术上的跨越,旨在加速现代化进程.Under t...