arXiv - PHYS - Soft Condensed Matter最新文献_第10页

Three-phase equilibria of hydrates from computer simulation. II. Finite-size effects in the carbon dioxide hydrate 计算机模拟的水合物三相平衡。II.二氧化碳水合物中的有限尺寸效应

arXiv - PHYS - Soft Condensed Matter Pub Date : 2024-08-04 DOI: arxiv-2408.02069

J. Algaba, S. Blazquez, E. Feria, J. M. Míguez, M. M. Conde, F. J. Blas

{"title":"Three-phase equilibria of hydrates from computer simulation. II. Finite-size effects in the carbon dioxide hydrate","authors":"J. Algaba, S. Blazquez, E. Feria, J. M. Míguez, M. M. Conde, F. J. Blas","doi":"arxiv-2408.02069","DOIUrl":"https://doi.org/arxiv-2408.02069","url":null,"abstract":"In this work, the effects of finite size on the determination of the\u0000three-phase coexistence temperature ($T_3$) of carbon dioxide (CO$_2$) hydrate\u0000have been studied by molecular dynamic simulations and using the direct\u0000coexistence technique. According to this technique, the three phases involved\u0000are placed together in the same simulation box. By varying the number of\u0000molecules of each phase it is possible to analyze the effect of simulation size\u0000and stoichiometry on the $T_3$ determination. In this work, we have determined\u0000the $T_3$ value at 8 different pressures and using 6 different simulation boxes\u0000with different numbers of molecules and sizes. In 2 of these configurations,\u0000the ratio of the number of water and CO$_2$ molecules in the aqueous solution\u0000and the liquid CO$_2$ phase is the same as in the hydrate (stoichiometric\u0000configuration). In both stoichiometric configurations, the formation of a\u0000liquid drop of CO$_2$ in the aqueous phase is observed. This drop, which has a\u0000cylindrical geometry, increases the amount of CO$_2$ available in the aqueous\u0000solution and can in some cases lead to the crystallization of the hydrate at\u0000temperatures above $T_3$, overestimating the $T_3$ value obtained from direct\u0000coexistence simulations. The simulation results obtained for the CO$_{2}$\u0000hydrate confirm the sensitivity of $T_{3}$ depending on the size and\u0000composition of the system, explaining the discrepancies observed in the\u0000original work by M'iguez emph{et al.} Non-stoichiometric configurations with\u0000larger unit cells show convergence of $T_{3}$ values, suggesting that\u0000finite-size effects for these system sizes, regardless of drop formation, can\u0000be safely neglected. The results obtained in this work highlight that the\u0000choice of a correct initial configuration is essential to accurately estimate\u0000the three-phase coexistence temperature of hydrates by direct coexistence\u0000simulations.","PeriodicalId":501146,"journal":{"name":"arXiv - PHYS - Soft Condensed Matter","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Three-phase equilibria of hydrates from computer simulation. III. Effect of dispersive interactions in the methane and carbon dioxide hydrates 计算机模拟水合物的三相平衡。III.甲烷和二氧化碳水合物中分散相互作用的影响

arXiv - PHYS - Soft Condensed Matter Pub Date : 2024-08-03 DOI: arxiv-2408.01819

J. Algaba, S. Blazquez, J. M. Míguez, M. M. Conde, F. J. Blas

{"title":"Three-phase equilibria of hydrates from computer simulation. III. Effect of dispersive interactions in the methane and carbon dioxide hydrates","authors":"J. Algaba, S. Blazquez, J. M. Míguez, M. M. Conde, F. J. Blas","doi":"arxiv-2408.01819","DOIUrl":"https://doi.org/arxiv-2408.01819","url":null,"abstract":"In this work, the effect of the range of the dispersive interactions in the\u0000determination of the three-phase coexistence line of the CO$_2$ and CH$_4$\u0000hydrates has been studied. In particular, the temperature ($T_3$) at which\u0000solid hydrate, water, and liquid CO$_2$/gas CH$_4$ coexist has been determined\u0000through molecular dynamics simulations using different cut-off values (from 0.9\u0000to 1.6 nm) for the dispersive interactions. The $T_3$ of both hydrates has been\u0000determined using the direct coexistence simulation technique. Following this\u0000method, the three phases in equilibrium are put together in the same simulation\u0000box, the pressure is fixed, and simulations are performed at different\u0000temperatures $T$. If the hydrate melts, then $T>T_3$. Contrary, if the hydrate\u0000grows, then $T<T_3$. The effect of the cut-off distance on the dissociation\u0000temperature has been analyzed at three different pressures for CO$_{2}$\u0000hydrate, namely, $100$, $400$, and $1000,text{bar}$. Then, we have changed\u0000the guest and studied the effect of the cut-off distance on the dissociation\u0000temperature of the CH$_{4}$ hydrate at $400,text{bar}$. Also, the effect of\u0000long-range corrections for dispersive interactions has been analyzed by running\u0000simulations with homo- and inhomogeneous corrections and a cut-off value of 0.9\u0000nm. The results obtained in this work highlight that the cut-off distance for\u0000the dispersive interactions affects the stability conditions of these hydrates.\u0000This effect is enhanced when the pressure is decreased, displacing the $T_{3}$\u0000about $2-4,text{K}$ depending on the system and the pressure.","PeriodicalId":501146,"journal":{"name":"arXiv - PHYS - Soft Condensed Matter","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141937376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Kinetics of vapor-liquid transition of active matter system under quasi one-dimensional confinement 准一维约束下活性物质体系的汽液转变动力学

arXiv - PHYS - Soft Condensed Matter Pub Date : 2024-08-02 DOI: arxiv-2408.01195

Parameshwaran A, Bhaskar Sen Gupta

引用次数: 0

Tailoring anisotropy in kirigami metamaterial skins with pop-up folding hinges 利用弹出式折叠铰链调整叽里胶超材料表皮的各向异性

arXiv - PHYS - Soft Condensed Matter Pub Date : 2024-08-02 DOI: arxiv-2408.01338

Hamid Reza Tohidvand, Alexis White, Ali Khosravi, Paolo Celli

{"title":"Tailoring anisotropy in kirigami metamaterial skins with pop-up folding hinges","authors":"Hamid Reza Tohidvand, Alexis White, Ali Khosravi, Paolo Celli","doi":"arxiv-2408.01338","DOIUrl":"https://doi.org/arxiv-2408.01338","url":null,"abstract":"Kirigami metamaterial sheets and tubes, owing to their capacity to undergo\u0000large elastic deformations while developing three-dimensional surface textures,\u0000have enormous potential as skins for soft robots. Here, we propose to use\u0000kirigami skins with folding hinges in this same context. These\u0000recently-introduced kirigami feature counter-rotating panels connected by\u0000pop-up folding hinges. So far, researchers have only explored auxetic and\u0000highly-symmetric versions of such patterns. Yet, some of these attributes have\u0000to be relaxed in order to explore their full potential as robotic skins. Thus,\u0000we parameterize these patterns and relax symmetry constraints, with the goal of\u0000using this same platform to obtain a wide range of shape-morphing behaviors. We\u0000use a combination of: matrix analysis tools and analytical kinematic formulas\u0000to thoroughly explore the vast design space that ensues; experiments for\u0000validation purposes; and numerical simulations to explore the mechanics of\u0000selected planar and tubular patterns. We demonstrate that it is possible to\u0000tailor parameters to obtain skins that globally expand or contract due to axial\u0000elongation, and that present asymmetric pop-ups that can yield anisotropic\u0000friction -- the most desired attribute for one-way locomotion of soft robots.","PeriodicalId":501146,"journal":{"name":"arXiv - PHYS - Soft Condensed Matter","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141937377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Thermodynamics of random walking vortex loops in counterflowing superfluids 逆流超流体中随机行走涡旋环的热力学

arXiv - PHYS - Soft Condensed Matter Pub Date : 2024-08-01 DOI: arxiv-2408.00680

Sergey K. Nemirovskii

引用次数: 0

Induced smectic ordering and blue phase formation in mixtures of cyanobiphenyls and cholesterol esters 氰联苯和胆固醇酯混合物中的诱导胶凝有序和蓝相形成

arXiv - PHYS - Soft Condensed Matter Pub Date : 2024-08-01 DOI: arxiv-2408.00650

Natalia A. Kasian, Longin N. Lisetski, Serhii E. Ivanchenko, Vitalii O. Chornous, Halyna V. Bogatyryova, Igor A. Gvozdovskyy

{"title":"Induced smectic ordering and blue phase formation in mixtures of cyanobiphenyls and cholesterol esters","authors":"Natalia A. Kasian, Longin N. Lisetski, Serhii E. Ivanchenko, Vitalii O. Chornous, Halyna V. Bogatyryova, Igor A. Gvozdovskyy","doi":"arxiv-2408.00650","DOIUrl":"https://doi.org/arxiv-2408.00650","url":null,"abstract":"It has been found that in mixtures of nematic E7 and smectogenic cholesteryl\u0000oleyl carbonate (COC) the S$_A$-N* transition temperature is substantially (by\u0000~20 K) increased, as compared with pure COC, at E7 concentrations around ~40%.\u0000Within the same concentration range, the isotropic transition is preceded by\u0000formation of blue phase, with its maximum width of ~3.5 K clearly correlated to\u0000the increased thermal stability of the S$_A$ phase. With other cholesterol\u0000esters or cyanobiphenyls (cholesteryl nonanoate, 5CB), this effect was either\u0000much weaker or not observed. No enhancement of smectic phase was noted when E7\u0000was replaced by N$_{tb}$-forming nematic mixture based on CB7CB with two\u0000cyanobiphenyl moieties. Selective Bragg reflection of light (BRL) spectra were\u0000measured in all three temperature regions, including the unwinding of the\u0000cholesteric helix on cooling towards S$_A$ phase and characteristic selective\u0000BRL changes in the blue phase. In the latter case, the measured\u0000{lambda}$_{max}$ values were dependent both on the helical twisting power in\u0000the cholesteric phase and on the lattice size and orientation in the blue\u0000phase. Also considered were the effects of ferroelectric BaTiO$_3$\u0000nanoparticles accumulated at disclination lines upon the blue phase thermal\u0000stability.","PeriodicalId":501146,"journal":{"name":"arXiv - PHYS - Soft Condensed Matter","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141882441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Spatio-temporal patterns in Growing Bacterial Suspensions: Impact of Growth dynamics 生长细菌悬浮液中的时空模式：生长动力学的影响

arXiv - PHYS - Soft Condensed Matter Pub Date : 2024-08-01 DOI: arxiv-2408.00403

Pratikshya Jena, Shradha Mishra

引用次数: 0

Effect of particle shape on the flow of an hourglass 颗粒形状对沙漏流动的影响

arXiv - PHYS - Soft Condensed Matter Pub Date : 2024-07-31 DOI: arxiv-2407.21685

Bo Fan, Tivadar Pongó, Raúl Cruz Hidalgo, Tamás Börzsönyi

{"title":"Effect of particle shape on the flow of an hourglass","authors":"Bo Fan, Tivadar Pongó, Raúl Cruz Hidalgo, Tamás Börzsönyi","doi":"arxiv-2407.21685","DOIUrl":"https://doi.org/arxiv-2407.21685","url":null,"abstract":"The flow rate of a granulate out of a cylindrical container is studied as a\u0000function of particle shape for flat and elongated ellipsoids experimentally and\u0000numerically. We find a nonmonotonic dependence of the flow rate on the grain\u0000aspect ratio a/b. Starting from spheres the flow rate grows and has two maxima\u0000around the aspect ratios of a/b = 0.6 (lentil-like ellipsoids) and a/b = 1.5\u0000(rice-like ellipsoids) reaching a flow rate increase of about 15% for lentils\u0000compared to spheres. For even more anisometric shapes (a/b = 0.25 and a/b = 4)\u0000the flow rate drops. Our results reveal two contributing factors to the\u0000nonmonotonic nature of the flow rate: both the packing fraction and the\u0000particle velocity through the orifice are nonmonotonic functions of the grain\u0000shape. Thus, particles with slightly non-spherical shapes not only form a\u0000better packing in the silo but also move faster through the orifice than\u0000spheres. We also show that the resistance of the granulate against shearing\u0000increases with aspect ratio for both elongated and flat particles, thus change\u0000in the effective friction of the granulate due to changing particle shape does\u0000not coincide with the trend in the flow rate.","PeriodicalId":501146,"journal":{"name":"arXiv - PHYS - Soft Condensed Matter","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141862660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Flow regimes and repose angle in a rotating drum filled with highly concave particles 装满高凹颗粒的旋转滚筒中的流态和重置角

arXiv - PHYS - Soft Condensed Matter Pub Date : 2024-07-31 DOI: arxiv-2407.21464

Weiyi Wang, Jonathan Barés, Jonathan Barés, Emilien Azéma

引用次数: 0

Molecular Simulations of Quantized Lamellar Thickening in Polyethylenes with Regularly Spaced Brominated Groups 具有规则间距溴化基团的聚乙烯中定量层状增厚的分子模拟

arXiv - PHYS - Soft Condensed Matter Pub Date : 2024-07-31 DOI: arxiv-2407.21728

Kutlwano Gabana, Gillian A. Gehring, Hendrik Meyer, Goran Ungar, Xiangbing Zeng, William S. Fall

{"title":"Molecular Simulations of Quantized Lamellar Thickening in Polyethylenes with Regularly Spaced Brominated Groups","authors":"Kutlwano Gabana, Gillian A. Gehring, Hendrik Meyer, Goran Ungar, Xiangbing Zeng, William S. Fall","doi":"arxiv-2407.21728","DOIUrl":"https://doi.org/arxiv-2407.21728","url":null,"abstract":"Polyethylene (PE) chains, with CH2 groups replaced by CBr2 at regular\u0000intervals (\"precision PE\"), have been observed to exhibit competing polymorphs\u0000driven by a preference for quantized fold lengths by Tasaki et al. Motivated by\u0000this recent discovery, the crystallisation behaviour of such precision PE\u0000chains, 400 carbons long with CBr2 groups placed regularly at every 21st\u0000carbon, is investigated using molecular dynamics simulations. The\u0000united-monomer model of PE is extended to include dibromo groups, with steric\u0000clashes at the bromines reflected in a triple-well bending potential,\u0000demonstrating its function as a preferred fold site. Different crystallisation\u0000protocols, continuous-cooling and self-seeding, reveal remarkably different\u0000crystals. Using self-seeding, the crystalline lamellar thickness increases\u0000monotonically with temperature, in quantized multiples of the distance between\u0000dibromo units. Polymer chains are observed to fold preferentially at the\u0000dibromo groups and such groups appear to be tolerated within the crystal\u0000lamellae. On quenching the bromos assemble to form registered layers, not\u0000unlike Smectic phases observed in liquid crystals, which confirms the\u0000experimental observation of competing Form I and Form I' polymorphs.","PeriodicalId":501146,"journal":{"name":"arXiv - PHYS - Soft Condensed Matter","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141862747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0