Pub Date : 2024-09-17DOI: 10.1103/physreve.110.034604
Federico Ghimenti, Ludovic Berthier, Grzegorz Szamel, Frédéric van Wijland
Exerting a nonequilibrium drive on an otherwise equilibrium Langevin process brings the dynamics out of equilibrium but can also speed up the approach to the Boltzmann steady state. Transverse forces are a minimal framework to achieve dynamical acceleration of the Boltzmann sampling. We consider a simple liquid in three space dimensions subjected to additional transverse pairwise forces, and quantify the extent to which transverse forces accelerate the dynamics. We first explore the dynamics of a tracer in a weak coupling regime describing high temperatures. The resulting acceleration is correlated with a monotonous increase of the magnitude of odd transport coefficients (mobility and diffusivity) with the amplitude of the transverse drive. We then develop a nonequilibrium version of the mode-coupling theory able to capture the effect of transverse forces, and more generally of forces created by additional degrees of freedom. Based on an analysis of transport coefficients, both odd and longitudinal, both for the collective modes and for a tracer particle, we find a systematic acceleration of the dynamics. Quantitatively, the gain, which is guaranteed throughout the ergodic phase, turns out to be a decreasing function of temperature beyond a temperature crossover, in particular as the glass transition is approached. Our theoretical results are in good agreement with available numerical results.
{"title":"Irreversible Boltzmann samplers in dense liquids: Weak-coupling approximation and mode-coupling theory","authors":"Federico Ghimenti, Ludovic Berthier, Grzegorz Szamel, Frédéric van Wijland","doi":"10.1103/physreve.110.034604","DOIUrl":"https://doi.org/10.1103/physreve.110.034604","url":null,"abstract":"Exerting a nonequilibrium drive on an otherwise equilibrium Langevin process brings the dynamics out of equilibrium but can also speed up the approach to the Boltzmann steady state. Transverse forces are a minimal framework to achieve dynamical acceleration of the Boltzmann sampling. We consider a simple liquid in three space dimensions subjected to additional transverse pairwise forces, and quantify the extent to which transverse forces accelerate the dynamics. We first explore the dynamics of a tracer in a weak coupling regime describing high temperatures. The resulting acceleration is correlated with a monotonous increase of the magnitude of odd transport coefficients (mobility and diffusivity) with the amplitude of the transverse drive. We then develop a nonequilibrium version of the mode-coupling theory able to capture the effect of transverse forces, and more generally of forces created by additional degrees of freedom. Based on an analysis of transport coefficients, both odd and longitudinal, both for the collective modes and for a tracer particle, we find a systematic acceleration of the dynamics. Quantitatively, the gain, which is guaranteed throughout the ergodic phase, turns out to be a decreasing function of temperature beyond a temperature crossover, in particular as the glass transition is approached. Our theoretical results are in good agreement with available numerical results.","PeriodicalId":20085,"journal":{"name":"Physical review. E","volume":"100 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142251448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-17DOI: 10.1103/physreve.110.035002
Keith A. Seffen
When a simply supported thin disk is indented by a centrally applied point force, it buckles out-of-plane to form a shape dominated by two conical portions: a uniform region indenting against the support, interrupted by a smaller elevated portion detached from the support, altogether known as a “developable cone” or d-Cone. If a central circular region of the disk is clamped instead, then the buckling complexion changes markedly: The indenting region is interspersed with several detached and elevated cones, now “truncated,” where their number depends on the clamping extent as well as the radius of the circular simple support. Studies of d-Cone kinematics often consider its shape as an analogous vertex, which forms by folding along hinge lines separating triangular facets. We extend this methodology by, first, showing that each truncated cone, or “t-Cone,” operates as a pair of connected d-Cone vertices that fold synchronously and that their number, viz. distribution, around the indented disk stems from optimal “packaging” of the folded shape in the annular space between the clamping edge and support; furthermore, because our analysis presumes a geometrically dominant character, it captures the “saturated,” i.e., final number of t-Cones, in experiments from a recent study. Our predictions agree rather well.
{"title":"Truncated cones from indenting a clamped disk","authors":"Keith A. Seffen","doi":"10.1103/physreve.110.035002","DOIUrl":"https://doi.org/10.1103/physreve.110.035002","url":null,"abstract":"When a simply supported thin disk is indented by a centrally applied point force, it buckles out-of-plane to form a shape dominated by two conical portions: a uniform region indenting against the support, interrupted by a smaller elevated portion detached from the support, altogether known as a “developable cone” or d-Cone. If a central circular region of the disk is clamped instead, then the buckling complexion changes markedly: The indenting region is interspersed with several detached and elevated cones, now “truncated,” where their number depends on the clamping extent as well as the radius of the circular simple support. Studies of d-Cone kinematics often consider its shape as an analogous vertex, which forms by folding along hinge lines separating triangular facets. We extend this methodology by, first, showing that each truncated cone, or “t-Cone,” operates as a pair of connected d-Cone vertices that fold synchronously and that their number, <i>viz.</i> distribution, around the indented disk stems from optimal “packaging” of the folded shape in the annular space between the clamping edge and support; furthermore, because our analysis presumes a geometrically dominant character, it captures the “saturated,” i.e., final number of t-Cones, in experiments from a recent study. Our predictions agree rather well.","PeriodicalId":20085,"journal":{"name":"Physical review. E","volume":"20 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-17DOI: 10.1103/physreve.110.034123
E. Can Artun, Deniz Sarman, A. Nihat Berker
A nematic phase, previously seen in the classical Heisenberg spin-glass system, occurs in the -component cubic-spin spin-glass system, between the low-temperature spin-glass phase and the high-temperature disordered phase, for number of spin components , in spatial dimension , thus constituting a liquid-crystal phase in a dirty (quenched-disordered) magnet. Furthermore, under application of a variety of uniform magnetic fields, a veritable plethora of phases is found. Under uniform magnetic fields, 17 different phases and two spin-glass phase diagram topologies (meaning the occurrences and relative positions of the many phases), qualitatively different from the conventional spin-glass phase diagram topology, are seen. The chaotic rescaling behaviors and their Lyapunov exponents are calculated in each of these spin-glass phase diagram topologies. These results are obtained from renormalization-group calculations that are exact on the hierarchical lattice and, equivalently, approximate on the cubic spatial lattice. Axial, planar-diagonal, or body-diagonal finite-strength uniform fields are applied to and 3 component cubic-spin spin-glass systems in .
{"title":"Axial, planar-diagonal, body-diagonal fields on the cubic-spin spin glass in d=3: A plethora of ordered phases under finite fields","authors":"E. Can Artun, Deniz Sarman, A. Nihat Berker","doi":"10.1103/physreve.110.034123","DOIUrl":"https://doi.org/10.1103/physreve.110.034123","url":null,"abstract":"A nematic phase, previously seen in the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>d</mi><mo>=</mo><mn>3</mn></mrow></math> classical Heisenberg spin-glass system, occurs in the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>n</mi></math>-component cubic-spin spin-glass system, between the low-temperature spin-glass phase and the high-temperature disordered phase, for number of spin components <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>n</mi><mo>≥</mo><mn>3</mn></mrow></math>, in spatial dimension <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>d</mi><mo>=</mo><mn>3</mn></mrow></math>, thus constituting a liquid-crystal phase in a dirty (quenched-disordered) magnet. Furthermore, under application of a variety of uniform magnetic fields, a veritable plethora of phases is found. Under uniform magnetic fields, 17 different phases and two spin-glass phase diagram topologies (meaning the occurrences and relative positions of the many phases), qualitatively different from the conventional spin-glass phase diagram topology, are seen. The chaotic rescaling behaviors and their Lyapunov exponents are calculated in each of these spin-glass phase diagram topologies. These results are obtained from renormalization-group calculations that are exact on the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>d</mi><mo>=</mo><mn>3</mn></mrow></math> hierarchical lattice and, equivalently, approximate on the cubic spatial lattice. Axial, planar-diagonal, or body-diagonal finite-strength uniform fields are applied to <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>n</mi><mo>=</mo><mn>2</mn></mrow></math> and 3 component cubic-spin spin-glass systems in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>d</mi><mo>=</mo><mn>3</mn></mrow></math>.","PeriodicalId":20085,"journal":{"name":"Physical review. E","volume":"75 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142251449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-16DOI: 10.1103/physreve.110.035206
G. J. Li, S. Davidovits
Ablator materials used for inertial confinement fusion, such as high-density carbon (HDC) and beryllium, have grain structure which may lead to small-scale density nonuniformity and the generation of perturbations when the materials are shocked and compressed. Here, we use a combination of a linear theory of shock interaction with density nonuniformity [Velikovich et al., Phys. Plasmas14, 072706 (2007)] and numerical simulations to study shock interaction with a model representation of HDC grains. While the shock-grain interaction is nonlinear, the linear theory shows some key features of the shock-grain interaction, which also hold for the (nonlinear) simulations. The postshock perturbations are made up of sonic reflections off of grain boundaries and vorticity deposition along them, with the latter dominating the perturbed energy content. The mean (per mass) postshock perturbed kinetic energy decreases with increasing grain size, but energy will be deposited at increasing spatial scale. From the perspective of the postshock perturbed energy, the detailed linear theory largely supports a proposed method [S. Davidovits et al., Phys. Plasmas29, 112708 (2022)] for deresolving the grains (in a similar grains model) that treats the grains statistically. Our simulation results highlight the influence of thermal conduction on the perturbation dynamics at grain scales.
{"title":"Microphysics of shock-grain interaction for inertial confinement fusion ablators in a fluid approach","authors":"G. J. Li, S. Davidovits","doi":"10.1103/physreve.110.035206","DOIUrl":"https://doi.org/10.1103/physreve.110.035206","url":null,"abstract":"Ablator materials used for inertial confinement fusion, such as high-density carbon (HDC) and beryllium, have grain structure which may lead to small-scale density nonuniformity and the generation of perturbations when the materials are shocked and compressed. Here, we use a combination of a linear theory of shock interaction with density nonuniformity [Velikovich <i>et al.</i>, <span>Phys. Plasmas</span> <b>14</b>, 072706 (2007)] and numerical simulations to study shock interaction with a model representation of HDC grains. While the shock-grain interaction is nonlinear, the linear theory shows some key features of the shock-grain interaction, which also hold for the (nonlinear) simulations. The postshock perturbations are made up of sonic reflections off of grain boundaries and vorticity deposition along them, with the latter dominating the perturbed energy content. The mean (per mass) postshock perturbed kinetic energy decreases with increasing grain size, but energy will be deposited at increasing spatial scale. From the perspective of the postshock perturbed energy, the detailed linear theory largely supports a proposed method [S. Davidovits <i>et al.</i>, <span>Phys. Plasmas</span> <b>29</b>, 112708 (2022)] for deresolving the grains (in a similar grains model) that treats the grains statistically. Our simulation results highlight the influence of thermal conduction on the perturbation dynamics at grain scales.","PeriodicalId":20085,"journal":{"name":"Physical review. E","volume":"4 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142251450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-13DOI: 10.1103/physreve.110.034122
Aaron Shih, Mathias Casiulis, Stefano Martiniani
Media with correlated disorder display unexpected transport properties, but it is still a challenge to design structures with desired spectral features at scale. In this work, we introduce an optimal formulation of this inverse problem by means of the nonuniform fast Fourier transform, thus arriving at an algorithm capable of generating systems with arbitrary spectral properties, with a computational cost that scales with system size. The method is extended to accommodate arbitrary real-space interactions, such as short-range repulsion, to simultaneously control short- and long-range correlations. We thus generate the largest-ever stealthy hyperuniform configurations in () and () and demonstrate the flexibility of the approach by generating structures with designed spectral features at scale. By an Ewald sphere construction we link the spectral and optical properties at the single-scattering level and show that stealthy hyperuniform structures generically display transmission gaps, providing a concrete example of fine-tuning of a physical property. We also show that large power-law hyperuniformity in particle packings leads to single-scattering properties nearly identical to those of simple hard spheres. Finally, we demonstrate generalizations of the approach to impose features in either continuous or discrete real space, using constraints in either continuous or discrete reciprocal space. In particular, enforcing large spectral power at peaks with the right symmetry leads to the nondeterministic generation of quasicrystalline structures in and . This technique should become an essential tool to embed, and understand the role of, long-range correlations in disordered metamaterials.
具有相关无序性的介质会显示出意想不到的传输特性，但要设计出具有所需规模光谱特征的结构仍是一项挑战。在这项工作中，我们通过非均匀快速傅立叶变换引入了这一反问题的最优表述，从而得出了一种算法，能够生成具有任意光谱特性的系统，其计算成本与系统规模成 O(NlogN)比例关系。该方法还可扩展到任意的实空间相互作用，如短程斥力，以同时控制短程和长程相关性。因此，我们在二维（N=109）和三维（N>107）中生成了有史以来最大的隐形超均匀构型，并通过生成具有设计尺度光谱特征的结构证明了该方法的灵活性。通过埃瓦尔德球结构，我们在单散射水平上将光谱和光学特性联系起来，并证明隐形超均匀结构一般会显示传输间隙，这为微调物理特性提供了一个具体实例。我们还表明，粒子填料中的大 3d 幂律超均匀性会导致与简单硬球几乎相同的单散射特性。最后，我们展示了该方法的一般化，即利用连续或离散倒易空间中的约束条件，在连续或离散实空间中施加特征。特别是，在具有正确对称性的峰值上强制施加大的谱功率，会导致在 2d 和 3d 中非确定性地生成准晶体结构。这项技术将成为嵌入无序超材料并理解其长程相关性作用的重要工具。
{"title":"Fast generation of spectrally shaped disorder","authors":"Aaron Shih, Mathias Casiulis, Stefano Martiniani","doi":"10.1103/physreve.110.034122","DOIUrl":"https://doi.org/10.1103/physreve.110.034122","url":null,"abstract":"Media with correlated disorder display unexpected transport properties, but it is still a challenge to design structures with desired spectral features at scale. In this work, we introduce an optimal formulation of this inverse problem by means of the nonuniform fast Fourier transform, thus arriving at an algorithm capable of generating systems with arbitrary spectral properties, with a computational cost that scales <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi mathvariant=\"script\">O</mi><mo>(</mo><mi>N</mi><mo form=\"prefix\">log</mo><mi>N</mi><mo>)</mo></mrow></math> with system size. The method is extended to accommodate arbitrary real-space interactions, such as short-range repulsion, to simultaneously control short- and long-range correlations. We thus generate the largest-ever stealthy hyperuniform configurations in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>2</mn><mi>d</mi></mrow></math> (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>N</mi><mo>=</mo><msup><mn>10</mn><mn>9</mn></msup></mrow></math>) and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>3</mn><mi>d</mi></mrow></math> (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>N</mi><mo>></mo><msup><mn>10</mn><mn>7</mn></msup></mrow></math>) and demonstrate the flexibility of the approach by generating structures with designed spectral features at scale. By an Ewald sphere construction we link the spectral and optical properties at the single-scattering level and show that stealthy hyperuniform structures generically display transmission gaps, providing a concrete example of fine-tuning of a physical property. We also show that large <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>3</mn><mi>d</mi></mrow></math> power-law hyperuniformity in particle packings leads to single-scattering properties nearly identical to those of simple hard spheres. Finally, we demonstrate generalizations of the approach to impose features in either continuous or discrete real space, using constraints in either continuous or discrete reciprocal space. In particular, enforcing large spectral power at peaks with the right symmetry leads to the nondeterministic generation of quasicrystalline structures in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>2</mn><mi>d</mi></mrow></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>3</mn><mi>d</mi></mrow></math>. This technique should become an essential tool to embed, and understand the role of, long-range correlations in disordered metamaterials.","PeriodicalId":20085,"journal":{"name":"Physical review. E","volume":"39 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142200999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1103/physreve.110.034121
Adrianne Zhong, Ben Kuznets-Speck, Michael R. DeWeese
The free-energy difference between two high-dimensional systems is notoriously difficult to compute but very important for many applications such as drug discovery. We demonstrate that an unconventional definition of work introduced by Vaikuntanathan and Jarzynski (2008) satisfies a microscopic fluctuation theorem that relates path ensembles that are driven by protocols unequal under time reversal. It has been shown before that counterdiabatic protocols—those having additional forcing that enforces the system to remain in instantaneous equilibrium, also known as escorted dynamics or engineered swift equilibration—yield zero-variance work measurements for this definition. We show that this time-asymmetric microscopic fluctuation theorem can be exploited for efficient free-energy estimation by developing a simple (i.e., neural-network free) and efficient adaptive time-asymmetric protocol optimization algorithm that yields estimates that are orders of magnitude lower in mean squared error than the generic linear interpolation protocol with which it is initialized.
{"title":"Time-asymmetric fluctuation theorem and efficient free-energy estimation","authors":"Adrianne Zhong, Ben Kuznets-Speck, Michael R. DeWeese","doi":"10.1103/physreve.110.034121","DOIUrl":"https://doi.org/10.1103/physreve.110.034121","url":null,"abstract":"The free-energy difference <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi mathvariant=\"normal\">Δ</mi><mi>F</mi></mrow></math> between two high-dimensional systems is notoriously difficult to compute but very important for many applications such as drug discovery. We demonstrate that an unconventional definition of work introduced by Vaikuntanathan and Jarzynski (2008) satisfies a microscopic fluctuation theorem that relates path ensembles that are driven by protocols unequal under time reversal. It has been shown before that counterdiabatic protocols—those having additional forcing that enforces the system to remain in instantaneous equilibrium, also known as escorted dynamics or engineered swift equilibration—yield zero-variance work measurements for this definition. We show that this time-asymmetric microscopic fluctuation theorem can be exploited for efficient free-energy estimation by developing a simple (i.e., neural-network free) and efficient adaptive time-asymmetric protocol optimization algorithm that yields <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi mathvariant=\"normal\">Δ</mi><mi>F</mi></mrow></math> estimates that are orders of magnitude lower in mean squared error than the generic linear interpolation protocol with which it is initialized.","PeriodicalId":20085,"journal":{"name":"Physical review. E","volume":"15 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142200998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1103/physreve.110.034802
Xiao Wang, Weidong Wang, Yingmin Zhu, Ji Zhang, Haiyan Zhang
The elimination of the scale-dependent statistical parameters is a challenge in the estimation of the van der Waals force between a particle and rough surfaces. Herein, a scale-independent parameter, the fractal dimension, was introduced into the Rabinovich model to calculate the microadhesion force. First, a Weierstrass-Mandelbrot function is proposed to generate a random 2D contour, which has a simplified form and is more reasonable for spectrum analysis. And then, the roughness scale extraction method was employed to calculate the fractal-dimension value of the real aluminum (Al) surface. And last, the proposed scale-independent Rabinovich-Fractal model was used to calculate the adhesion forces, which are consistent with the results of the atomic force microscopy adhesion test. Aside from providing a more accurate estimation of the van der Waals forces, the proposed model is not influenced by the sampling scale of the surface roughness measurement, which eliminates the related error in van der Waals force estimation.
{"title":"Scale-independent model based on fractal theory for calculating the adhesion force between a particle and rough surfaces","authors":"Xiao Wang, Weidong Wang, Yingmin Zhu, Ji Zhang, Haiyan Zhang","doi":"10.1103/physreve.110.034802","DOIUrl":"https://doi.org/10.1103/physreve.110.034802","url":null,"abstract":"The elimination of the scale-dependent statistical parameters is a challenge in the estimation of the van der Waals force between a particle and rough surfaces. Herein, a scale-independent parameter, the fractal dimension, was introduced into the Rabinovich model to calculate the microadhesion force. First, a Weierstrass-Mandelbrot function is proposed to generate a random 2D contour, which has a simplified form and is more reasonable for spectrum analysis. And then, the roughness scale extraction method was employed to calculate the fractal-dimension value of the real aluminum (Al) surface. And last, the proposed scale-independent Rabinovich-Fractal model was used to calculate the adhesion forces, which are consistent with the results of the atomic force microscopy adhesion test. Aside from providing a more accurate estimation of the van der Waals forces, the proposed model is not influenced by the sampling scale of the surface roughness measurement, which eliminates the related error in van der Waals force estimation.","PeriodicalId":20085,"journal":{"name":"Physical review. E","volume":"5 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142201000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1103/physreve.110.034120
Ramgopal Agrawal, Leticia F. Cugliandolo, Lara Faoro, Lev B. Ioffe, Marco Picco
By considering the quench dynamics of two-dimensional frustrated Ising models through numerical simulations, we investigate the dynamical critical behavior on the multicritical Nishimori point (NP). We calculate several dynamical critical exponents, namely, the relaxation exponent , the autocorrelation exponent , and the persistence exponent , after a quench from the high temperature phase to the NP. We confirm their universality with respect to the lattice geometry and bond distribution. For a quench from a power-law correlated initial state to the NP, the aging dynamics are much slower. We also look up the issue of multifractality during the critical dynamics by investigating different moments of the spatial correlation function. We observe a single growth law for all the length scales extracted from different moments, indicating that the equilibrium multifractality at the NP does not affect the dynamics.
{"title":"Dynamical critical behavior on the Nishimori point of frustrated Ising models","authors":"Ramgopal Agrawal, Leticia F. Cugliandolo, Lara Faoro, Lev B. Ioffe, Marco Picco","doi":"10.1103/physreve.110.034120","DOIUrl":"https://doi.org/10.1103/physreve.110.034120","url":null,"abstract":"By considering the <i>quench</i> dynamics of two-dimensional frustrated Ising models through numerical simulations, we investigate the dynamical critical behavior on the multicritical <i>Nishimori point</i> (NP). We calculate several dynamical critical exponents, namely, the relaxation exponent <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>z</mi><mi mathvariant=\"normal\">c</mi></msub></math>, the autocorrelation exponent <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>λ</mi><mi mathvariant=\"normal\">c</mi></msub></math>, and the persistence exponent <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>θ</mi><mi mathvariant=\"normal\">c</mi></msub></math>, after a quench from the high temperature phase to the NP. We confirm their <i>universality</i> with respect to the lattice geometry and bond distribution. For a quench from a power-law correlated initial state to the NP, the aging dynamics are much slower. We also look up the issue of <i>multifractality</i> during the critical dynamics by investigating different moments of the spatial correlation function. We observe a <i>single</i> growth law for all the length scales extracted from different moments, indicating that the equilibrium multifractality at the NP does not affect the dynamics.","PeriodicalId":20085,"journal":{"name":"Physical review. E","volume":"2 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142201012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1103/physreve.110.034310
Andrea Della Vecchia, Kibidi Neocosmos, Daniel B. Larremore, Cristopher Moore, Caterina De Bacco
We present a physics-inspired method for inferring dynamic rankings in directed temporal networks—networks in which each directed and timestamped edge reflects the outcome and timing of a pairwise interaction. The inferred ranking of each node is real-valued and varies in time as each new edge, encoding an outcome like a win or loss, raises or lowers the node's estimated strength or prestige, as is often observed in real scenarios including sequences of games, tournaments, or interactions in animal hierarchies. Our method works by solving a linear system of equations and requires only one parameter to be tuned. As a result, the corresponding algorithm is scalable and efficient. We test our method by evaluating its ability to predict interactions (edges' existence) and their outcomes (edges' directions) in a variety of applications, including both synthetic and real data. Our analysis shows that in many cases our method's performance is better than existing methods for predicting dynamic rankings and interaction outcomes.
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Pub Date : 2024-09-12DOI: 10.1103/physreve.110.034405
Ana María Zamora-Vinaroz, Pablo de Vera, Isabel Abril, Rafael Garcia-Molina
We have determined the depth-dose curve, penetration range, and water equivalent ratio for proton beams of clinical energies in cortical bone by means of a detailed and accurate simulation that combines molecular dynamics and Monte Carlo techniques. The fundamental input quantities (stopping power and energy loss straggling) for the simulation were obtained from a reliable electronic excitation spectrum of the condensed-phase target, which takes into account the organic and mineral phases that form it. Our simulations with these inputs, which are in excellent agreement with the scarce data available for a cortical bone target, deviate from simulations performed using other stopping quantities, such as those provided by the International Commission on Radiation Units and Measurements in its widely used Report No. 49 [M. J. Berger et al., Stopping powers and ranges for protons and alpha particles, International Commission on Radiation Units and Measurements, Bethesda, Maryland, 1993]. The results of this paper emphasize the importance of an accurate determination of the stopping quantities of cortical bone to advance towards the millimetric precision for the proton penetration ranges and deposited dose needed in radiotherapy.
我们通过结合分子动力学和蒙特卡洛技术的详细而精确的模拟，确定了临床能量质子束在皮质骨中的深度-剂量曲线、穿透范围和水当量比。模拟的基本输入量（停止功率和能量损失杂散）是从凝聚相靶的可靠电子激发光谱中获得的，其中考虑到了形成凝聚相靶的有机相和矿物相。我们使用这些输入数据进行的模拟与皮质骨靶的稀缺数据非常吻合，但与使用其他停止量进行的模拟有所不同，例如国际辐射单位和测量委员会在其广泛使用的第 49 号报告中提供的停止量[M. J. Berger et al.J. Berger 等人，质子和阿尔法粒子的停止功率和范围，国际辐射单位和测量委员会，马里兰州贝塞斯达，1993 年]。本文的研究结果强调了准确测定皮质骨的停止量对提高质子穿透范围和放射治疗所需的沉积剂量的毫米级精度的重要性。
{"title":"Simulation of depth-dose curves and water equivalent ratios of energetic proton beams in cortical bone","authors":"Ana María Zamora-Vinaroz, Pablo de Vera, Isabel Abril, Rafael Garcia-Molina","doi":"10.1103/physreve.110.034405","DOIUrl":"https://doi.org/10.1103/physreve.110.034405","url":null,"abstract":"We have determined the depth-dose curve, penetration range, and water equivalent ratio for proton beams of clinical energies in cortical bone by means of a detailed and accurate simulation that combines molecular dynamics and Monte Carlo techniques. The fundamental input quantities (stopping power and energy loss straggling) for the simulation were obtained from a reliable electronic excitation spectrum of the condensed-phase target, which takes into account the organic and mineral phases that form it. Our simulations with these inputs, which are in excellent agreement with the scarce data available for a cortical bone target, deviate from simulations performed using other stopping quantities, such as those provided by the International Commission on Radiation Units and Measurements in its widely used Report No. 49 [M. J. Berger <i>et al.</i>, Stopping powers and ranges for protons and alpha particles, International Commission on Radiation Units and Measurements, Bethesda, Maryland, 1993]. The results of this paper emphasize the importance of an accurate determination of the stopping quantities of cortical bone to advance towards the millimetric precision for the proton penetration ranges and deposited dose needed in radiotherapy.","PeriodicalId":20085,"journal":{"name":"Physical review. E","volume":"2 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142201001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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