Near the melting transition the bending elastic constant $\kappa$, an emergent property of double-stranded DNA (dsDNA), is shown not to follow the rodlike scaling for small-length $N$. The reduction in $\kappa$ with temperature is determined by the denatured bubbles for a continuous transition, e.g., when the two strands are Gaussian, but by the broken bonds near the open end in a Y-like configuration for a first-order transition as for strands with excluded volume interactions. In the latter case, a lever rule is operational, implying a phase coexistence although dsDNA is known to be a single phase.

中文翻译：

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DNA的软化接近融化，因为消失了新出现的特性

在熔融转变附近，弯曲弹性常数 $\kappa$，双链DNA（dsDNA）的新兴特性，对于小长度的DNA，不遵循棒状缩放 $ñ$。减少$\kappa$温度的变化取决于连续转变的变性气泡，例如，当两条链为高斯分布时，但对于一阶跃迁而言，Y形构型的开口端附近的断裂键与具有排除体积相互作用的链有关。在后一种情况下，可以使用杠杆规则，这意味着阶段共存，尽管已知dsDNA是单个阶段。