The fast-growing economy has had one unintended consequence: Scientists must pay more if they want to get published in international journals, which no longer consider China a low-income country.

For example, US online publication PLoS One charges Chinese researchers as much as $1,350 per article, a standard fee for contributors from the United States and Europe.

In comparison, it charges nothing for papers submitted from low-income countries such as Afghanistan, Cambodia and Ethiopia, while charging $500 for lower-middle-income countries such as India, Cuba and Egypt, in accordance with a country's per capita GDP and investment in science and technology.