Estimation of biophysical properties of cell exposed to electric field

Excitable media,such as cells,can be polarized and magnetized in the presence of an external electromagnetic field.In fact,distinct geometric deformation can be induced by the external electromagnetic field,and also the capacitance of the membrane of cell can be changed to pump the field energy.Furthermore,the distribution of ion concentration inside and outside the cell can also be greatly adjusted.Based on the theory of bio-electromagnetism,the distribution of field energy and intracellular and extracellular ion concentrations in a single shell cell can be estimated in the case with or without external electric field.Also,the dependence of shape of cell on the applied electronic field is calculated.From the viewpoint of physics,the involvement of external electric field will change the gradient distribution of field energy blocked by the membrane.And the intracellular and extracellular ion concentration show a certain difference in generating timevarying membrane potential in the presence of electric field.When a constant electric field is applied to the cell,distinct geometric deformation is induced,and the cell triggers a transition from prolate to spherical and then to oblate ellipsoid shape.It is found that the critical frequency in the applied electric field for triggering the distinct transition from prolate to oblate ellipsoid shape obtains smaller value when larger dielectric constant of the cell membrane and intracellular medium,and smaller conductivity for the intracellular medium are used.Furthermore,the effect of cell deformation is estimated by analyzing the capacitance per unit area,the density of field energy,and the change of ion concentration on one side of cell membrane.The intensity of external applied electric field is further increased to detect the change of ion concentration.And the biophysical effect in the cell is discussed.So the deformation effect of cells in electric field should be considered when regulating and preventing harm to normal neural activities occurs in a nervous system.     

一种新的集群Web服务器体系结构及其数据复制算法

数据副本管理是集群Web服务器(CWS)的一个重要研究内容，它与CWS的体系结构和具体的应用密不可分。文章提出了一种架构于IJnux虚拟服务器(INS)基础之上、应用广泛、可扩展性强的集群Web服务器结构，给出了相应特定的数据复制算法，包括数据定位和数据同步。通过实验对此复制算法进行了测试与分析，并和其它复制方案进行了比较，证明了本算法具有更高的可用性和更好的性能。     

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基于粒子群算法，在环状构型下通过矩量法数值分析了二维均匀、各向同性连续介电常数实部，在无噪声、有先验约束情况下的重构。重构结果表明，该重构方法有较好的重构结果。该研究对基于电磁场理论的医学临床诊断乃至于对遥感、地球勘探、无伤探测等做了理论上的准备，也为生物体电磁波成像的实际应用提供了理论指导。     

基于单片机的金卤灯电子镇流器研制

设计了一种基于单片机控制的数控金卤灯电子镇流器.由于数字电路的可控性较强,降低了电路的复杂度,提高了系统的稳定性和可靠性,并有利于提高灯的寿命.经测试表明,该电子镇流器性能稳定,效率较高,满足了设计要求.     

掠入射法测量液体折射率实验现象分析

掠入射法是基于全反射定律,采用几何光学原理来测量液体折射率的一种方法.文中对掠入射法测量透明液体折射率实验中出现的干涉条纹进行了定量分析,认为在分光计望远镜中观察到的干涉条纹是光线进入辅助透镜和直角棱镜间被测薄液膜干涉形成的,通过定义干涉条纹疏密度,对于薄膜引起的光程差与干涉明纹(或暗纹)间距两者间的关系进行讨论,其讨论的结果与实验结果一致.