A geometic proof of the Jordan normal form is given by the Euclidean algorithm and the fundamental theorem of algebra, and its works in the algebraic geometry are also given. 摘要文章利用辗转相除法和代数学基本定理得到了若当标准型的几何法证明，并指出了其在代数几何上的作用。
The absolute stability of a class of indirect control systems by applying the theory of Hermitian quadratic form and Jordan normal form was studied. 利用厄米特二次型和若当标准形理论研究了一般间接控制系统的绝对稳定性问题，给出了绝对稳定性的代数形式的判别准则。
