Poisson-Nernst-Planck systems are basic models for electrodiffusion process,particularly,for ionic flows through ion channels embedded in cell membranes.In this article,we present a brief review on a geometric singula...Poisson-Nernst-Planck systems are basic models for electrodiffusion process,particularly,for ionic flows through ion channels embedded in cell membranes.In this article,we present a brief review on a geometric singular perturbation framework for analyzing the steady-state of a quasi-one-dimensional Poisson-Nernst-Planck model.The framework is based on the general geometric singular perturbed theory from nonlinear dynamical system theory and,most crucially,on the reveal of two specific structures of Poisson-Nernst-Planck systems.As a result of the geometric framework,one obtains a governing system-an algebraic system of equations that involves all physical quantities such as protein structures of membrane channels as well as boundary conditions,and hence,provides a complete platform for studying the interplay between protein structure and boundary conditions and effects on ionic flow properties.As an illustration,we will present concrete applications of the theory to several topics of biologically significant based on collaboration works with many excellent researchers.展开更多
The electrical and mechanical characteristics of the wire-to-plate surface dielectric barrier discharge and the induced ionic wind are investigated experimentally.The different temporal behaviors in positive and negat...The electrical and mechanical characteristics of the wire-to-plate surface dielectric barrier discharge and the induced ionic wind are investigated experimentally.The different temporal behaviors in positive and negative half-cycles are studied by time-resolved images.It is shown that the discharge and the light emission are generally stronger in the positive half cycle.The discharge is inhomogeneous and propagates in streamer mode;however,in the negative half-cycle,the discharge appears visually uniformly and operates in the diffuse mode.The surface discharge can produce ionic wind about several m/s above the dielectric surface.There exists an optimal width of the grounded electrode to produce a larger plasma area or active wind region.Increasing of the applied voltage or normalized dielectric constant leads to a larger wind velocity.The performance of ionic wind on flow control is visualized by employing a smoke stream.展开更多
PNP models with an arbitrary number of positively charged ion species and one negatively charged ion species are studied in this paper under the assumption that positively charged ion species have the same valence and...PNP models with an arbitrary number of positively charged ion species and one negatively charged ion species are studied in this paper under the assumption that positively charged ion species have the same valence and the permanent charge is a piecewise constant function. The permanent charge plays the key role in many functions of an ion channel, such as selectivity and gating. In this paper, using the geometric singular perturbation theory, a flux ratio independent of the permanent charge is proved.展开更多
基金supported by Simons Foundation Mathematics and Physical Sciences-Collaboration Grants for Mathematicians 581822。
文摘Poisson-Nernst-Planck systems are basic models for electrodiffusion process,particularly,for ionic flows through ion channels embedded in cell membranes.In this article,we present a brief review on a geometric singular perturbation framework for analyzing the steady-state of a quasi-one-dimensional Poisson-Nernst-Planck model.The framework is based on the general geometric singular perturbed theory from nonlinear dynamical system theory and,most crucially,on the reveal of two specific structures of Poisson-Nernst-Planck systems.As a result of the geometric framework,one obtains a governing system-an algebraic system of equations that involves all physical quantities such as protein structures of membrane channels as well as boundary conditions,and hence,provides a complete platform for studying the interplay between protein structure and boundary conditions and effects on ionic flow properties.As an illustration,we will present concrete applications of the theory to several topics of biologically significant based on collaboration works with many excellent researchers.
基金supported by National Natural Science Foundation of China(Nos.11175017 and 11475019)
文摘The electrical and mechanical characteristics of the wire-to-plate surface dielectric barrier discharge and the induced ionic wind are investigated experimentally.The different temporal behaviors in positive and negative half-cycles are studied by time-resolved images.It is shown that the discharge and the light emission are generally stronger in the positive half cycle.The discharge is inhomogeneous and propagates in streamer mode;however,in the negative half-cycle,the discharge appears visually uniformly and operates in the diffuse mode.The surface discharge can produce ionic wind about several m/s above the dielectric surface.There exists an optimal width of the grounded electrode to produce a larger plasma area or active wind region.Increasing of the applied voltage or normalized dielectric constant leads to a larger wind velocity.The performance of ionic wind on flow control is visualized by employing a smoke stream.
文摘PNP models with an arbitrary number of positively charged ion species and one negatively charged ion species are studied in this paper under the assumption that positively charged ion species have the same valence and the permanent charge is a piecewise constant function. The permanent charge plays the key role in many functions of an ion channel, such as selectivity and gating. In this paper, using the geometric singular perturbation theory, a flux ratio independent of the permanent charge is proved.
