We show that the fourth order accurate finite difference implementation of continuous finite element method with tensor product of quadratic polynomial basis is monotone thus satisfies the discrete maximum principle for solving a scalar variable coefficient equation $-\nabla\cdot(a\nabla u)+cu=f$ under a suitable mesh constraint.

中文翻译：

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论$$C^0$$C0-$$Q^2$$Q2有限元法有限差分实现的单调性和离散最大值原理

我们证明，二次多项式基张量积的连续有限元法的四阶精确有限差分实现是单调的，因此满足求解标量变系数方程$-\nabla\cdot(a\nabla u)+的离散极大原则cu=f$ 在合适的网格约束下。