标题： 非平衡功涨落在短B-DNA受力熔化中的研究 显示英文标题

标题： Nonequilibrium Work Fluctuations in Force-induced Melting of a Short B-DNA

摘要： 一个包含12个碱基对的溶剂化规范B-DNA系统，具有指定序列，在没有外部力 $f$ 作用的情况下首先被平衡。 平衡之后，通过拉伸DNA的一端同时限制其另一端，对该系统进行切换实验。 在施加力的恒定速率下进行有限时间的拉伸，直到最大值400 pN。 在此过程中，由施加力作为函数的力-延伸曲线数值积分确定相关的非平衡功 $(W)$。 通过多次重复拉伸实验获得一组功值， $P(W)$。 我们通过采用Jarzynski等式来确定DNA的平衡态和力诱导熔融态之间的自由能差 $(\Delta F)$。 发现 $\Delta F$的值与传统平衡方法非常一致。 显示英文摘要

摘要： A system of a solvated canonical B-DNA of 12 base pairs with the specified sequence is initially equilibrated in a state of zero external force $f$ acting on it. After equilibration, a switching experiment is performed over the system by pulling one end of the DNA while restraining its other end. The finite time pulling process is performed at a constant rate of the applied force until a maximum value of 400 pN. The associated nonequilibrium work done $(W)$ during this process is determined by numerically integrating the force-extension curve as a function of the applied force. An ensemble of the work values, $P(W)$, is obtained by repeating the pulling experiment a large number of times. We determine the free energy difference $(\Delta F)$ between the equilibrium and force-induced melted states of the DNA by employing the Jarzynski equality. The value of $\Delta F$ is found to be in close agreement with the conventional equilibrium methods.