In order to explore the change of pseudo-density to the effect of material rigidity and set up the relation between them for density variable method, we presented FEM to deal with the problem.

为了探讨变密度法中伪密度的变化对材料刚度的影响，并建立两者之间的力学关系，本文采用有限元法研究这一问题。

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The oscillation problem for a class of the second order neutral difference equations with several variable delay arguments and variable coefficients was studied.

研究了一类具有多个变滞量的变系数的二阶中立型差分方程的解的振动性，得到了该类方程振动及其解的一阶差分振动的充分条件。

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