1. Let the function $f(x)=x^{3}+x$, if $0 \leqslant \theta \leqslant \frac{\pi}{2}$, $f(m \cos \theta)+f(1-m)>0$ always holds, then the range of the real number $m$ is $\qquad$ .
$$
f(m \cos \theta)>f(m-1) \Rightarrow m(1-\cos \theta)<1 \Rightarrow m<\frac{1}{1-\cos \theta} \Rightarrow m<1 \text {. }
$$
$\cos \theta=1$ also holds, so the range of $m$ is $(-\infty, 1)$.
