The Bethe ansatz equations are obtained from the periodic boundary conditions.

由周期边界条件推出贝特假设方程。

The basic idea of DFT is an ansatz, which assumes that any properties of many-body system can be determined by the ground state density.

密度泛函的基础是一个假定：假定一个多粒子体系的任何性质都是基态电子密度的函数。

Then, based on the fundamental equation, we present the chirped femtosecond soliton-like solution by ansatz method and discuss the transmission property of the soliton-like solution in optical fiber.

随后，我们利用拟解方法给出飞秒啁啾类孤波解的解析表达式，并讨论该解在光纤系统中的传输特性。