What are the current high-end technologies that the Chinese have not mastered?

In terms of medical equipment, according to data released by the China Chamber of Commerce for Import and Export of Medicines and Healthcare Products in 2014, due to the fact that domestic medical equipment has not mastered the core technology, 80% of the high-end medical equipment in use in China, 80% of the CT, medium and high-grade monitors, 85% of the testing instruments, 90% of the ultrasonic instruments, magnetic **** vibration equipment, electrocardiogram machines are all foreign brands. A typical example is, in the medical equipment industry, CT, DR tube ball technology monopoly in the industry is well known. CT, DR tube ball, is to produce X-ray, scanning diagnostic core devices, is CT, DR device "heart", and the tube ball R & D and production technology has been mastered in the hands of foreign-funded enterprises in the past few decades. Domestic enterprises have tried to research and development, but because of the foreign patent technology monopoly binds the hands and feet of China's research institutions, intellectual property rights barriers to bind the CT, DR balloon technology research and development breakthroughs. At present, the country's medical units are all dependent on imports of foreign companies to obtain the tube ball, in order to use the CT and DR.