In Nanjing there are over 460 natural science research institutions with more than 320,000 technical personnel of different specialities and over 40 social science research institutions with more than 50,000 researchers. The scientific and technological strength thereof ranks third in the country. 291 major achievements have been made in the fields of science and technology throughout the city in 1 995,of which 6% are up to the international standard and 42% are up to the domestic advanced standard .