研究对角占优矩阵原位替换解算方法，包括矩阵行列式、矩阵方程未知数和矩阵逆阵的解算。

The calculation methods of diagonally dominant matrix in-situ replacement are researched, including the matrix determinant, the matrix equation unknown and the matrix inversion computation.

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研究具时滞的三阶非线性微分方程，利用变量替换和不动点方法，得到了此方程有界解和概周期解的存在性及唯一性结果。

This paper deals with the problems on the existence and uniqueness of bounded solutions and almost periodic solution for third order nonlinear differential equations with time lag.

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然后采用变量替换，可获得物理平面上的近似解析解。

Then with the use of the substitution of variables. the approximately analytical solution in physical plane can be obtained.

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