本文研究了社会选择理论中最小决定集的唯一存在性条件，分析了最小决定集与选择函数之间的相互联系。
In this paper, the unique existence condition of minimal determining set in social choice theory is researched, and the relation between minimal determining set and choice function is analyzed.
最后讨论了概周期解现象，得出了概周期正解的唯一存在性和全局渐进稳定性的充分条件。
Finally, we discuss almost periodic phenomena, and obtain some sufficient conditions which assure the unique existence and globally asymptotic stability of almost positive periodic solution.
证明了最佳逼近元的唯一存在性，并给出了最佳逼近元的计算公式。
The unique existence of the best element of approximation is proved and the formula of the best element of approximation is given.
证明了在某种紧性条件下拟桶式空间的强对偶空间值的向量测度的唯一存在性。
In some tightness condition, the existence and uniqueness of a vector measure with values in the strong dual of a quasi-barreled space is proved.
应用积分恒等式方法，证明了源项解的唯一存在性。
A unique solvability of the source term solution is obtained by applying integral identity methods.
讨论了一般异面直线的相交直线存在及唯一存在的充要条件，证明了两者的等价性，并在唯一存在时给出了一般的表达式。
The full and necessary conditions that the intersection line with general straight lines in different planes existed and existed solely was discussed.
讨论了一般异面直线的相交直线存在及唯一存在的充要条件，证明了两者的等价性，并在唯一存在时给出了一般的表达式。
The full and necessary conditions that the intersection line with general straight lines in different planes existed and existed solely was discussed.
应用推荐