1. For any real number $x$, the quadratic trinomial $x^{2}+3 m x+m^{2}-$ $m+\frac{1}{4}$ is a perfect square, then $m=$ $\qquad$.
二、1. $\Delta=9 m^{2}-4\left(m^{2}-m+\frac{1}{4}\right)=0$. Solving it yields $m=\frac{1}{5}$ or -1.