Solitons: Differential equations, symmetries, and infinite-dimensional algebras
《Solitons: Differential equations, symmetries, and infinite-dimensional algebras》 · 第 60 页 · Definition 2.34
A locally ringed space $(X,\mathcal O_X)$ is called affine scheme, if there exists a ring $A$ such that $(X,\mathcal O_X)$ is isomorphic to $(\operatorname{Spec}A,\mathcal O_{\operatorname{Spec}A})$.