论文标题
电动力学相关的敲门和仿制:电流在离子通道中的空间均匀
Electrodynamics Correlates Knock-on and Knock-off: Current is Spatially Uniform in Ion Channels
论文作者
论文摘要
很长一段时间以来,通道中的离子被认为是宏观机械模型中的硬球。硬球在此类模型中通过碰撞相互作用,在热运动中随机互相敲打和关闭“结合”位点。但是离子的电荷很大,经典模型的硬球没有。电荷的电动力学保证了离子在所有时间尺度上的运动,即使是原子尺度热运动的运动之间的强大相关性。每当麦克斯韦的方程应用时,就会存在相关性,因此它们存在于单个轨迹中,而不仅仅是平均值。实际上,在像理想化的狭窄频道这样的串联系统中,由于保存总电流(包括麦克斯韦的位移电流),这种相关性是完美的(在麦克斯韦方程式的准确性之内),这些空白$ {\ varepsilon} _0 {\ partial \ partsymbol {\ boldsymbol {防止串联系统中总电流的空间变化。在串联系统中,电流的空间热运动的随机复杂性消失了。总电流不取决于在任何时间尺度上像窄离子通道这样的串联系统中的位置。根据Maxwell方程,在任何时间尺度上的总电流描述中不需要空间变量。人们可能会想象,消除总电流的空间依赖性应大大简化理论和模拟。
Ions in channels have been imagined as hard balls in a macroscopic mechanical model, for a very long time. Hard balls interact by collisions in such models, randomly knocking each other on and off `binding' sites in thermal motion. But ions have large charge, and the hard balls of classical models do not. The electrodynamics of charge guarantee strong correlations between the movements of ions on all time scales, even those of atomic scale thermal motion. Correlations are present whenever Maxwell's equations apply, so they are present in individual trajectories, not just averages. Indeed, in a series system like an idealized narrow channel, the correlation is perfect (within the accuracy of Maxwell's equations) because of conservation of total current (that includes Maxwell's displacement current, the ethereal ${\varepsilon }_0{\partial \boldsymbol{\mathrm{E}}}/{\partial t}$).The ethereal component of current prevents spatial variation of total current in a series system. The stochastic complexity of spatial thermal motion disappears for current }in a series system. Total current does not depend on location in a series system like a narrow ion channel on any time scale. Spatial variables are not needed in the description of total current in a one dimensional channel on any time scale, according to the Maxwell equations. Removing the spatial dependence of total current should dramatically simplify theories and simulations, one might imagine.