A nonlinear chain with sixth-order polynomial on-site potential is used to analyze the evolution of the total-to-kinetic-energy ratio during development of modulational instability of extended nonlinear vibrational modes. For the on-site potential of hard-type (soft-type) anharmonicity, the instability of \(q =\pi \) mode (\(q = 0\) mode) results in the appearance of long-living discrete breathers (DBs) that gradually radiate their energy and eventually the system approaches thermal equilibrium with spatially uniform and temporally constant temperature. In the hard-type (soft-type) anharmonicity case, the total-to-kinetic-energy ratio is minimal (maximal) in the regime of maximal energy localization by DBs. It is concluded that DBs affect specific heat of the nonlinear chain, and for the case of hard-type (soft-type) anharmonicity, they reduce (increase) the specific heat.

使用具有六阶多项式现场势能的非线性链来分析扩展非线性振动模式的调制不稳定性发展过程中总动能比的演变。对于硬型（软型）非谐性的现场潜力，\（q = \ pi \）模式的不稳定性（\（q = 0 \）模式）导致出现长寿命离散呼吸器（DBs），这些呼吸器逐渐散发其能量，最终系统在空间均匀且温度恒定的情况下达到热平衡。在硬型（软型）非谐波情况下，在通过DBs进行最大能量定位的情况下，总动能比最小（最大）。可以得出结论，DB影响非线性链的比热，对于硬型（软型）非谐波，它们会降低（增加）比热。