Recently the Association of Tantalum-niobium Metallurgical Enterprises has been establishedin the Ningxia Hui Autonomous Region. This Association belongs to Chi
Semi-insulating(SI)GaAs doped with indium has been grown and characterized.The relationship between the dislocationdensity and dopant concentration has been dis
Application of rare earths as manure in an agricultural engineering was adopted firstly inChina. In 7<sup>th</sup> Five-year-plan period this practice has sprea