There are good definitions of science, but none that are used across numerous different sciences. Each science defines its own boundaries. The Karl Popper slogan is one of the more popular attempts to universalize science: "A theory in the empirical sciences can never be proven, but it can be falsified, meaning that it can and should be scrutinized by decisive experiments." But how often do scientists live up to that ideal?
China has had a lot of difficulty with science. It did not develop organically in China, it was imported with a political agenda. More importantly it has been twisted together with Nationalism. Authoritarianism, Modernism, and Religion. That is true in other places too, to some extent, but in China it is a bit extreme. I am certain that there are superb scientists working in China. But I'm also certain that Chinese culture has a data falsification problem that holds it back. And then there is the massive problem of science as the religion of the state. To get a picture of this, read the short article linked below from Supchina (which is itself a weird site worth digging around in a bit):
"...The Chinese Academy of Sciences (CAS), the country’s most established scientific institution, apologized (in Chinese) on Monday, April 30, for hosting a Taoist ritual at the foundation ceremony for a nuclear power station in Wuwei, Gansu Province. CAS also announced the suspension of two employees who were in attendance but failed to terminate the religious ceremony..."