Early in the tang dynasty a scientific experiment to create what?

The popularization of woodblock printing during the Tang dynasty made the written word available to greater audiences. As a result of the much wider distribution and circulation of reading materials, the general populace were for the first time able to purchase affordable copies of texts, which correspondingly led to greater literacy.[1] While the immediate effects of woodblock printing did not create a drastic change in Chinese society, in the long term, the accumulated effects of increased literacy enlarged the talent pool to encompass civilians of broader social-economic circumstances and backgrounds, who would be seen entering the imperial examinations and passing them by the later Song dynasty.

They weaken the south vietnamese army.