Strongly nonlinear waves in capillary electrophoresis.
Strongly nonlinear waves in capillary electrophoresis.
复制标题
毛细管电泳中的强非线性波。
DOI：
10.1103/physreve.85.051918
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Ghosal,Sandip
中科院分区：
文献类型：
--
作者：
Chen,Zhen;Ghosal,Sandip
在毛细管电泳中，样品离子在外加电场的影响下沿沿着填充有背景电解质的微毛细管迁移。如果样品浓度足够高，则样品区中的电导率可能与背景显著不同。在这样的条件下，样品离子的局部迁移速度变得依赖于浓度，从而导致表现出冲击特征的非线性波。如果非线性较弱，则在某些简化假设下，样品浓度曲线可以显示为服从Burgers方程[Ghosal和Chen，Bull.Math.Biol.72，2047（2010）BMTBAP 0092 -824010.1007/s11538-010-9527-2]，其对于任意初始条件具有精确的分析解。在本文中，我们使用一种数值方法来研究在更一般的情况下，样品浓度不小的背景离子的浓度相比的问题。在低浓度的情况下，数值结果与弱非线性理论之前提出的，但在高浓度，波的演变方式是定性不同。
In capillary electrophoresis, sample ions migrate along a microcapillary filled with a background electrolyte under the influence of an applied electric field. If the sample concentration is sufficiently high, the electrical conductivity in the sample zone could differ significantly from the background. Under such conditions, the local migration velocity of sample ions becomes concentration-dependent, resulting in a nonlinear wave that exhibits shocklike features. If the nonlinearity is weak, the sample concentration profile, under certain simplifying assumptions, can be shown to obey Burgers’ equation [Ghosal and Chen, Bull. Math. Biol. 72, 2047 (2010)BMTBAP0092-824010.1007/s11538-010-9527-2], which has an exact analytical solution for arbitrary initial condition. In this paper, we use a numerical method to study the problem in the more general case where the sample concentration is not small in comparison to the concentration of background ions. In the case of low concentrations, the numerical results agree with the weakly nonlinear theory presented earlier, but at high concentrations, the wave evolves in a way that is qualitatively different.