The Experts below are selected from a list of 110190 Experts worldwide ranked by ideXlab platform
Jeff Z. Y. Chen - One of the best experts on this subject based on the ideXlab platform.
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Solution of the Onsager model for the structure of rigid rods confined on a Spherical Surface.
Physical review. E Statistical nonlinear and soft matter physics, 2012Co-Authors: Wu-yang Zhang, Ying Jiang, Jeff Z. Y. ChenAbstract:We consider a free energy, within the framework of the Onsager approximation, for a spatially and orientationally inhomogeneous distribution of hard rods confined on a Spherical Surface. These rods interact with each other though the excluded-volume interaction, forming a textured nematic structure on the Spherical Surface at high Surface coverage. Our numerical solution to the model shows that the splay state, where on average rods line up in parallel to the longitudes on the Spherical Surface, is the only stable state. Other types of textures that have recently been suggested were also tested and all yield higher free energy than that of a ground splay state. We also provide a study of the disorder-splay transition, which is shown to have first-order characteristics.
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Onsager model for the structure of rigid rods confined on a Spherical Surface.
Physical review letters, 2012Co-Authors: Wu-yang Zhang, Ying Jiang, Jeff Z. Y. ChenAbstract:Recent studies have suggested that a monolayer of self-avoiding hard rods confined on a Spherical Surface may display a distribution texture corresponding to splay, tennis-ball, rectangle, or cut-and-rotate splay symmetries. We investigate the system on the basis of a generalized Onsager model which includes both excluded-volume and entropic effects. The numerical solution indicates that the splay state, where on average rods line up in parallel to the longitudinal lines on the Spherical Surface, is the only stable state.
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Tennis-ball state of a self-avoiding wormlike polymer on a Spherical Surface
EPL (Europhysics Letters), 2011Co-Authors: Wu-yang Zhang, Jeff Z. Y. ChenAbstract:Using Monte Carlo simulations of a wormlike chain that contains the excluded-volume interaction, we demonstrate that a directionally anisotropic state exists at high Surface coverage, when the chain is confined to a Spherical Surface. The isotropic-anisotropic transition has first-order characteristics and can be compared with the isotropic-nematic transition observed in lyotropic polymer systems, both driven by the excluded-volume interaction. Unlike a nematic state, the anisotropic state observed here displays the so-called tennis-ball conformation, coupling the polymer-segment orientation preference with positional order.
Wu-yang Zhang - One of the best experts on this subject based on the ideXlab platform.
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Solution of the Onsager model for the structure of rigid rods confined on a Spherical Surface.
Physical review. E Statistical nonlinear and soft matter physics, 2012Co-Authors: Wu-yang Zhang, Ying Jiang, Jeff Z. Y. ChenAbstract:We consider a free energy, within the framework of the Onsager approximation, for a spatially and orientationally inhomogeneous distribution of hard rods confined on a Spherical Surface. These rods interact with each other though the excluded-volume interaction, forming a textured nematic structure on the Spherical Surface at high Surface coverage. Our numerical solution to the model shows that the splay state, where on average rods line up in parallel to the longitudes on the Spherical Surface, is the only stable state. Other types of textures that have recently been suggested were also tested and all yield higher free energy than that of a ground splay state. We also provide a study of the disorder-splay transition, which is shown to have first-order characteristics.
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Onsager model for the structure of rigid rods confined on a Spherical Surface.
Physical review letters, 2012Co-Authors: Wu-yang Zhang, Ying Jiang, Jeff Z. Y. ChenAbstract:Recent studies have suggested that a monolayer of self-avoiding hard rods confined on a Spherical Surface may display a distribution texture corresponding to splay, tennis-ball, rectangle, or cut-and-rotate splay symmetries. We investigate the system on the basis of a generalized Onsager model which includes both excluded-volume and entropic effects. The numerical solution indicates that the splay state, where on average rods line up in parallel to the longitudinal lines on the Spherical Surface, is the only stable state.
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Tennis-ball state of a self-avoiding wormlike polymer on a Spherical Surface
EPL (Europhysics Letters), 2011Co-Authors: Wu-yang Zhang, Jeff Z. Y. ChenAbstract:Using Monte Carlo simulations of a wormlike chain that contains the excluded-volume interaction, we demonstrate that a directionally anisotropic state exists at high Surface coverage, when the chain is confined to a Spherical Surface. The isotropic-anisotropic transition has first-order characteristics and can be compared with the isotropic-nematic transition observed in lyotropic polymer systems, both driven by the excluded-volume interaction. Unlike a nematic state, the anisotropic state observed here displays the so-called tennis-ball conformation, coupling the polymer-segment orientation preference with positional order.
Ying Jiang - One of the best experts on this subject based on the ideXlab platform.
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Solution of the Onsager model for the structure of rigid rods confined on a Spherical Surface.
Physical review. E Statistical nonlinear and soft matter physics, 2012Co-Authors: Wu-yang Zhang, Ying Jiang, Jeff Z. Y. ChenAbstract:We consider a free energy, within the framework of the Onsager approximation, for a spatially and orientationally inhomogeneous distribution of hard rods confined on a Spherical Surface. These rods interact with each other though the excluded-volume interaction, forming a textured nematic structure on the Spherical Surface at high Surface coverage. Our numerical solution to the model shows that the splay state, where on average rods line up in parallel to the longitudes on the Spherical Surface, is the only stable state. Other types of textures that have recently been suggested were also tested and all yield higher free energy than that of a ground splay state. We also provide a study of the disorder-splay transition, which is shown to have first-order characteristics.
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Onsager model for the structure of rigid rods confined on a Spherical Surface.
Physical review letters, 2012Co-Authors: Wu-yang Zhang, Ying Jiang, Jeff Z. Y. ChenAbstract:Recent studies have suggested that a monolayer of self-avoiding hard rods confined on a Spherical Surface may display a distribution texture corresponding to splay, tennis-ball, rectangle, or cut-and-rotate splay symmetries. We investigate the system on the basis of a generalized Onsager model which includes both excluded-volume and entropic effects. The numerical solution indicates that the splay state, where on average rods line up in parallel to the longitudinal lines on the Spherical Surface, is the only stable state.
Natsuhiko Yoshinaga - One of the best experts on this subject based on the ideXlab platform.
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Topological defects of dipole patchy particles on a Spherical Surface
Soft matter, 2020Co-Authors: Uyen Tu Lieu, Natsuhiko YoshinagaAbstract:We investigate the assembly of dipole-like patchy particles confined to a Spherical Surface by Brownian dynamics simulations. The Surface property of the Spherical particle is described by the Spherical harmonic Y10, and the orientation of the particle is defined as the uniaxial axis. On a flat space, we observe a defect-free square lattice with nematic order. On a Spherical Surface, defects appear due to the topological constraint. As for the director field, four defects of winding number +1/2 are observed, satisfying the Euler characteristic. We have found many configurations of the four defects lying near a great circle. Regarding the positional order for the square lattice, eight grain boundary scars proliferate linearly with the sphere size. The positions and orientations of the eight grain boundary scars are strongly related to the four +1/2 defect cores.
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Topological defects of dipole patchy particles on a Spherical Surface.
arXiv: Soft Condensed Matter, 2020Co-Authors: Uyen Tu Lieu, Natsuhiko YoshinagaAbstract:We investigate the assembly of the dipole-like patchy particles confined to a Spherical Surface by Brownian dynamics simulations. The Surface property of the Spherical particle is described by the Spherical harmonic $Y_{10}$, and the orientation of the particle is defined as the uniaxial axis. On a flat space, we observe a defect-free square lattice with nematic order. On a Spherical Surface, defects appear due to the topological constraint. As for the director field, four defects of winding number $+1/2$ are observed, satisfying the Euler characteristic. We have found many configurations of the four defects lying near a great circle. Regarding the positional order for the square lattice, eight grain boundary scars proliferate linearly with the sphere size. The positions and orientations of the eight grain boundary scars are strongly related to the four $+1/2$ defect cores.
Yongjian Wan - One of the best experts on this subject based on the ideXlab platform.
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comparative experimental study on absolute measurement of Spherical Surface with two sphere method
Optics and Lasers in Engineering, 2011Co-Authors: Xi Hou, Peng Yang, Yongjian WanAbstract:Abstract The two-sphere method with multiple confocal measurements and a “cat's-eye” measurement is used widely in high accuracy interferometry, which can obtain the absolute Surface data of the tested Spherical Surface. We provide a comparative experimental study on absolute testing procedures for Spherical Surface with two-sphere method, which include the classical Jensen method with three position measurements, the Zygo method with five position measurements and a variant of the Jensen method. The variant of the Jensen method can combine the multiple “three-position” measurements based on the fiducial method and averaging method. The repeatability of the involved absolute measurement methods is also studied by the five set experiments, and the corresponding Zernike fitting coefficients are compared in detail. The experimental results are meaningful for implementation of two-sphere method with higher repeatability in practice.
