strong; solid; firm; unyielding; resolute

core; nucleus; backbone

Sun Jian (155-191), famous general at end of Han dynasty, forerunner of the southern kingdom of Wu of the Three Kingdoms

to assault a fortified position; (fig.) to concentrate one's efforts on a particularly difficult part of one's mission

first Sui emperor Yang Jian (541-604), reigned 581-604

Fu Jian (338-385), emperor of Former Qin 前秦[Qian2 Qin2], reigning from 357-385

Huang Tingjian (1045–1105), Song poet and calligrapher

to become more resolute with the passing of time (idiom)

love is more solid than gold (idiom)

poor but ambitious (idiom); hard-pressed but determined; the worse one's position, the harder one must fight back