The phenomenon of supercritical pseudo-boiling reveals the anomalous behavior of various physical and chemical properties of supercritical fluids near the Widom line (WL). To explore the regularity of this anomalous behavior, density fluctuations and transport properties of supercritical carbon dioxide are calculated by molecular dynamics (MD) simulation near the WL. The results show that the loci of density fluctuations extremes form ridge lines near the WL with the same trends. The average errors of the ridge lines are only 1.92% for spatial density fluctuation and 2.61% for temporal density fluctuation compared with the WL, respectively. The viscosity and self-diffusion coefficient have inflection points but no extremes near the WL. By comparing the ridge lines formed by the density fluctuations and the inflection points from the transport properties on the phase diagram, it can be found that the ridge lines and inflection points close to the critical point bunch into a straight line along the WL, and gradually diverge away from the critical point, which is similar to the loci of a series of thermodynamic response functions extremes.

超临界伪沸腾现象揭示了超临界流体在 Widom 线 (WL) 附近的各种物理和化学性质的反常行为。为了探索这种异常行为的规律性，通过 WL 附近的分子动力学 (MD) 模拟计算了超临界二氧化碳的密度波动和传输特性。结果表明，密度波动极值的轨迹在WL附近形成具有相同趋势的脊线。与 WL 相比，空间密度波动的脊线平均误差仅为 1.92%，时间密度波动的平均误差仅为 2.61%。粘度和自扩散系数在 WL 附近有拐点但没有极值。