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 extraction kinetics of La(III) from aqueous chloride solutions into n-heptane solutions of bifunctional ionic liquid extractant [A336][CA-12](tricaprylmethylammonium sec-octylphenoxy acetic acid) was investigated ...The extraction kinetics of La(III) from aqueous chloride solutions into n-heptane solutions of bifunctional ionic liquid extractant [A336][CA-12](tricaprylmethylammonium sec-octylphenoxy acetic acid) was investigated using a constant interfacial cell with laminar flow. The effects of stirring speed, temperature and specific interfacial area on the extraction rate were examined. The results indicate that mass transfer kinetics of La(III) is a mixed-controlled process influenced by interfacial reaction. On the basis of mass transfer kinetic results in the extraction of La(III) by [A336][CA-12], the extraction rate equation of La(III) is proposed in terms of pseudo-firstorder constants, which is supported by the measured thermodynamic equations. The mass-transfer kinetic model deduced from the rate controlling step is adequate to interpret the experimental data qualitatively.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
This study demonstrated the potential of single chamber up-flow membrane-less microbial fuel cell（UFML-MFC） in wastewater treatment and power generation. The purpose of this study was to evaluate and enhance the per...This study demonstrated the potential of single chamber up-flow membrane-less microbial fuel cell（UFML-MFC） in wastewater treatment and power generation. The purpose of this study was to evaluate and enhance the performance under different operational conditions which affect the chemical oxygen demand（COD） reduction and power generation,including the increase of KCl concentration（MFC1） and COD concentration（MFC2）. The results showed that the increase of KCl concentration is an important factor in up-flow membrane-less MFC to enhance the ease of electron transfer from anode to cathode. The increase of COD concentration in MFC2 could led to the drop of voltage output due to the prompt of biofilm growth in MFC2 cathode which could increase the internal resistance. It also showed that the COD concentration is a vital issue in up-flow membrane-less MFC.Despite the COD reduction was up to 96%, the power output remained constrained.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 the National Natural Science Foundation of China(51174184)National Basic Research Program of China(2012CBA01202)+3 种基金the Key Research Programof the Chinese Academy of Sciences(KGZD-EW-201-1)the Science and Technology Planof Nantong City(BK2013030)the University Science Research Project of Jiangsu Province(14KJB150019)Open Subject of Changchun Institute of Applied Chemistry,Chinese Academy of Sciences(RERU2014016)
文摘The extraction kinetics of La(III) from aqueous chloride solutions into n-heptane solutions of bifunctional ionic liquid extractant [A336][CA-12](tricaprylmethylammonium sec-octylphenoxy acetic acid) was investigated using a constant interfacial cell with laminar flow. The effects of stirring speed, temperature and specific interfacial area on the extraction rate were examined. The results indicate that mass transfer kinetics of La(III) is a mixed-controlled process influenced by interfacial reaction. On the basis of mass transfer kinetic results in the extraction of La(III) by [A336][CA-12], the extraction rate equation of La(III) is proposed in terms of pseudo-firstorder constants, which is supported by the measured thermodynamic equations. The mass-transfer kinetic model deduced from the rate controlling step is adequate to interpret the experimental data qualitatively.
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.
基金the Science Fund MOSTI Grant (02-01-15-SF0201) for their support on this study
文摘This study demonstrated the potential of single chamber up-flow membrane-less microbial fuel cell（UFML-MFC） in wastewater treatment and power generation. The purpose of this study was to evaluate and enhance the performance under different operational conditions which affect the chemical oxygen demand（COD） reduction and power generation,including the increase of KCl concentration（MFC1） and COD concentration（MFC2）. The results showed that the increase of KCl concentration is an important factor in up-flow membrane-less MFC to enhance the ease of electron transfer from anode to cathode. The increase of COD concentration in MFC2 could led to the drop of voltage output due to the prompt of biofilm growth in MFC2 cathode which could increase the internal resistance. It also showed that the COD concentration is a vital issue in up-flow membrane-less MFC.Despite the COD reduction was up to 96%, the power output remained constrained.
