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求Helfrich方程级数解的一种新方法
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作者 贾艳伟 刘全慧 《湖南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2002年第2期10-13,共4页
利用流体膜泡的物理条件 ,引入泰勒级数解法来求解二阶非线性微分方程 - Helfrich方程 。
关键词 helfrich方程 Delaunay曲面 流体膜 级数解 Taylor级数法二阶非线性微分方程 轴对称常平均曲率曲面
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哈密顿正则方程在生物膜与胶体粒子相互作用研究中的应用
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作者 郑斌 李红 孟庆田 《大学物理》 北大核心 2012年第4期9-11,18,共4页
介绍经典分析力学中的哈密顿正则方程在生物膜与胶体粒子相互作用研究中的一个具体应用.由Helfrich理论模型得到体系的哈密顿,用正则方程给出一组常微分方程,并用打靶法对其进行求解得到体系的稳定构型随膜参数变化的规律.
关键词 哈密顿正则方程 生物膜 helfrich理论
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Symmetrical adhesion of two cylindrical colloids to a tubular membrane 被引量:1
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作者 牛余全 魏巍 +2 位作者 郑斌 张彩霞 孟庆田 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第12期542-548,共7页
With the full treatment of the Helfrich model we theoretically study the symmetrical adhesion of two cylindrical colloids to a tubular membrane. The adhesion of the rigid cylinders with different radius from the membr... With the full treatment of the Helfrich model we theoretically study the symmetrical adhesion of two cylindrical colloids to a tubular membrane. The adhesion of the rigid cylinders with different radius from the membrane tube surface can produce both shallow wrapping with relatively small wrapping angle and deep wrapping with big wrapping angle. These significant structural behaviors can be obtained by analyzing the system energy. A second order adhesion transition from the desorbed to weakly adhered states is found, and a first order phase transition where the cylindrical colloids undergo an abrupt transition from weakly adhered to strongly adhered states can be obtained as well. 展开更多
关键词 helfrich model phase transition free energy tubular membrane
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Theoretical study of interactions between striated cylindrical particles and membrane
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作者 王晶晶 冯佳伟 任春来 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第8期624-631,共8页
The interaction of nanoparticles with cell membranes is of great importance because of their potential biomedical applications. In this paper, we investigate the adhesion of stripe-patterned cylinders to a fluid membr... The interaction of nanoparticles with cell membranes is of great importance because of their potential biomedical applications. In this paper, we investigate the adhesion of stripe-patterned cylinders to a fluid membrane with a full consideration of the Helfrich free energy. Three situations are considered: one striated cylindrical particle, two pure cylindrical particles, and two Janus cylindrical particles. It is found that, with the adhesion of a single sparse striated cylinder, there are a variety of steady-states with energy barriers and the stable state is determined by the pattern of the cylinder. However,when the particle is densely striped, it has no effect on the stable state. By comparing the wrapping degree of two cylindrical particles with that of a single cylindrical particle, we find that two pure cylindrical particles can promote or suppress their interaction with the membrane under different situations. However, two Janus cylindrical particles can only inhibit their interaction with the membrane. Besides, this interaction is related to a first-order transition which is a shallow-to-deep wrapping transition for two pure cylinders while it is a shallow-to-half wrapping transition for two Janus cylinders. Furthermore, the position where the transition happens as a function of adhesion energy is given for fixed membrane tension and the precondition of the transition is presented. 展开更多
关键词 helfrich free energy striated particles MEMBRANE WRAPPING
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Bending energy of a vesicle to which a small spherical particle adhere:An analytical study
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作者 曹思勤 韦广红 Jeff Z.Y.Chen 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第9期572-580,共9页
On the basis of Helfrich's bending energy model, we show that the adsorption process of a small spherical particle to a closed vesicle can be analytically studied by retaining the leading terms in an expansion of the... On the basis of Helfrich's bending energy model, we show that the adsorption process of a small spherical particle to a closed vesicle can be analytically studied by retaining the leading terms in an expansion of the shape equation. Our general derivation predicts the optimal binding sites on a vesicle, where the local membrane shape of the binding site could be non-axisymmetric before the continuous adhesion transition takes place. Our derivation avoids directly solving the shape equation and depends on an integration of the contact-line condition. The results are verified by several examples of independent numerical solutions. 展开更多
关键词 membrane conformation helfrich model nano-particle adsorption phase transition
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管间相互作用对细胞膜包裹碳纳米管的影响
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作者 陈鸿韬 吴凯 +1 位作者 梁桃 修鹏 《医用生物力学》 CAS CSCD 北大核心 2022年第3期441-447,共7页
目的针对平行放置于细胞膜表面的两单壁碳纳米管系统,探究两碳管间相互作用对膜包裹碳管方式的影响,并给出能量最优的构象。方法建立考虑两根碳管间范德华相互作用的膜包裹碳管的力学模型,并引入反映细胞膜形态的参数以及描述碳管相对... 目的针对平行放置于细胞膜表面的两单壁碳纳米管系统,探究两碳管间相互作用对膜包裹碳管方式的影响,并给出能量最优的构象。方法建立考虑两根碳管间范德华相互作用的膜包裹碳管的力学模型,并引入反映细胞膜形态的参数以及描述碳管相对位置的参数。利用基于Helfrich自由能的连续介质力学建模,计算膜弯曲能量,并利用Lennard-Jones势描述碳管之间的相互作用。通过查表法计算系统不同位置的自由能,并给出细胞膜包裹碳管的典型结构。结果与未考虑管间相互作用的情况相比,系统自由能曲线出现了较大改变:在碳管间距约为0.3倍管半径时,能量曲线上出现深势阱;随着碳管间距增大,自由能恢复到没有管间相互作用能时的大小。结论引入碳管间相互作用能后,膜包裹碳管的方式发生变化,两碳管倾向于以触碰到一起的方式进行协同胞吞。研究结果为理解并设计基于纳米管的药物输运系统提供理论借鉴。 展开更多
关键词 细胞膜力学 碳纳米管 胞吞 helfrich模型 范德华作用
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Confinement of spherical colloid particles in a soft fluid membrane tube
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作者 郑斌 孟庆田 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第3期649-655,共7页
We investigate the structure of multiple spherical particles confined in a soft membrane tube that originally has a cylindrical shape. Assuming an attraction energy between the surface of the spherical particle and th... We investigate the structure of multiple spherical particles confined in a soft membrane tube that originally has a cylindrical shape. Assuming an attraction energy between the surface of the spherical particle and the inner wall of the membrane tube, we show that a variety of conformational structures can be stabilized on the basis of analyzing a Helfrich energy for the soft tube. Using a numerical approach, we calculate the phase diagram in terms of basic parameters in the system. Structures that prefer close contact of spheres and structures that contain well separated spheres are found in this calculation. 展开更多
关键词 MEMBRANE helfrich model
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Simulation and prediction of membrane fusion dynamics
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作者 Zhi Zheng Shouqin Lü Mian Long 《Theoretical & Applied Mechanics Letters》 CSCD 2022年第1期49-55,共7页
Membrane fusion is an important process by which biological membranes perform their life activities. Simulations show that the membrane fusion process happens mainly through three pathways, where the Stalk-Pore hypoth... Membrane fusion is an important process by which biological membranes perform their life activities. Simulations show that the membrane fusion process happens mainly through three pathways, where the Stalk-Pore hypothesis, in which two membranes come into close contact to form a stalk to a hemifusion intermediate, and then the fusion pore opens to achieve completely fusion, is widely accepted, and there exist two free energy barriers that break the current structural steady state for lipid rearrangement. Factors of lipid composition, mechanical environment, protein and ion have regulatory roles in the membrane fusion process by effecting membrane curvature structurally and the free energy barriers from energetic perspective. Meanwhile, many theoretical models, represented by the Helfrich model, have been proposed to predict the membrane fusion process. In this paper, we review the research process of membrane fusion and mainly introduce the dynamics of membrane fusion, regulation factors and typical theoretical models. 展开更多
关键词 Membrane fusion Hemifusion intermediates Fusion pathway REGULATION helfrich model
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A Structure-Preserving Numerical Method for the Fourth-Order Geometric Evolution Equations for Planar Curves
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作者 Eiji Miyazaki Tomoya Kemmochi +1 位作者 Tomohiro Sogabe Shao-Liang Zhang 《Communications in Mathematical Research》 CSCD 2023年第2期296-330,共35页
For fourth-order geometric evolution equations for planar curves with the dissipation of the bending energy,including the Willmore and the Helfrich flows,we consider a numerical approach.In this study,we construct a s... For fourth-order geometric evolution equations for planar curves with the dissipation of the bending energy,including the Willmore and the Helfrich flows,we consider a numerical approach.In this study,we construct a structure-preserving method based on a discrete variational derivative method.Furthermore,to prevent the vertex concentration that may lead to numerical instability,we discretely introduce Deckelnick’s tangential velocity.Here,a modification term is introduced in the process of adding tangential velocity.This modified term enables the method to reproduce the equations’properties while preventing vertex concentration.Numerical experiments demonstrate that the proposed approach captures the equations’properties with high accuracy and avoids the concentration of vertices. 展开更多
关键词 Geometric evolution equation Willmore flow helfrich flow numerical calculation structure-preserving discrete variational derivative method tangential velocity
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模拟囊泡形变动力学的新方法离散空间变分法 被引量:3
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作者 李剑锋 张红东 +1 位作者 邱枫 杨玉良 《物理学报》 SCIE EI CAS CSCD 北大核心 2005年第9期4000-4005,共6页
提出了全新的离散空间变分法研究二维囊泡形变动力学过程,克服了原先解析或数值解囊泡形状方程遇到的困难,结果表明动力学终态与已有理论方法的计算结果完全一致;说明这一方法正确而且解法稳定有效,这一方法可进一步推广至研究三维无对... 提出了全新的离散空间变分法研究二维囊泡形变动力学过程,克服了原先解析或数值解囊泡形状方程遇到的困难,结果表明动力学终态与已有理论方法的计算结果完全一致;说明这一方法正确而且解法稳定有效,这一方法可进一步推广至研究三维无对称性的囊泡形状以及膜与膜之间有长程相互作用的情形,这为囊泡形状的研究提供了新的理论手段. 展开更多
关键词 离散空间变分法 囊泡 动力学 helfrich方程 动力学过程 离散空间 变分法 形变 模拟 长程相互作用 计算结果 理论方法
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高分子锚定的流体膜 被引量:2
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作者 郭坤琨 邱枫 +1 位作者 张红东 杨玉良 《物理学报》 SCIE EI CAS CSCD 北大核心 2006年第1期155-161,共7页
将高分子自洽平均场理论和膜弹性理论结合起来研究高分子锚定流体膜体系,得到了高分子链热力学平衡浓度的分布和膜的形状.由于膜对高分子的不可穿透性,造成高分子可以实现的构象受到限制,导致高分子对膜施加不均匀的熵压,从而锚定点附... 将高分子自洽平均场理论和膜弹性理论结合起来研究高分子锚定流体膜体系,得到了高分子链热力学平衡浓度的分布和膜的形状.由于膜对高分子的不可穿透性,造成高分子可以实现的构象受到限制,导致高分子对膜施加不均匀的熵压,从而锚定点附近的膜弯离高分子,这些结果符合前人的理论分析和蒙特卡罗模拟的结果.此外,考察了膜和高分子链段之间的相互作用,高分子链长以及膜的弯曲刚性、张力对膜形变的影响. 展开更多
关键词 高分子 流体膜 自洽场理论 helfrich膜弹性理论
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双柱胶体粒子与管状生物膜的相互作用 被引量:1
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作者 牛余全 郑斌 +3 位作者 崔春红 魏巍 张彩霞 孟庆田 《物理学报》 SCIE EI CAS CSCD 北大核心 2014年第3期450-457,共8页
本文采用Helfrich理论模型研究双柱胶体粒子与管状生物膜的相互作用.通过对柱状粒子与不同半径的管状膜吸附时的自由能分析发现,该体系存在具有较小包络角的弱吸附相以及具有较大包络角的深度吸附相.进一步研究发现体系从解吸附相到弱... 本文采用Helfrich理论模型研究双柱胶体粒子与管状生物膜的相互作用.通过对柱状粒子与不同半径的管状膜吸附时的自由能分析发现,该体系存在具有较小包络角的弱吸附相以及具有较大包络角的深度吸附相.进一步研究发现体系从解吸附相到弱吸附相的相变是二级相变,而从弱吸附相到深度吸附相的相变是一级相变.双柱粒子与管状膜相对位置的不同会影响体系相变和结构. 展开更多
关键词 helfrich理论 相变 自由能 管状膜
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Measuring the Spontaneous Curvature of Bilayer Membranes by Molecular Dynamics Simulations
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作者 Han Wang Dan Hu Pingwen Zhang 《Communications in Computational Physics》 SCIE 2013年第4期1093-1106,共14页
We propose a mathematically rigorous method to measure the spontaneous curvature of a bilayer membrane by molecular dynamics(MD)simulation,which provides description of the molecular mechanisms that cause the spontane... We propose a mathematically rigorous method to measure the spontaneous curvature of a bilayer membrane by molecular dynamics(MD)simulation,which provides description of the molecular mechanisms that cause the spontaneous curvature.As a main result,for the membrane setup investigated,the spontaneous curvature is proved to be a constant plus twice the mean curvature of the membrane in its tensionless ground state.The spontaneous curvature due to the built-in transbilayer asymmetry of the membrane in terms of lipid shape is studied by the proposed method.A linear dependence of the spontaneous curvature with respect to the head-bead diameter difference and the lipid mixing ratio is discovered.The consistency with the theoretical results provides evidence supporting the validity of our method. 展开更多
关键词 Bilayer membrane helfrich free energy spontaneous curvature molecular dynamics simulation
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