共查询到18条相似文献,搜索用时 109 毫秒
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为研究工程陶瓷崩碎损伤演化过程中的逾渗行为,揭示其损伤机理,以氧化铝陶瓷为研究对象,构建了工程陶瓷崩碎损伤实验系统,建立了基于声发射的逾渗理论模型。通过对崩碎损伤过程中声发射信号分析可得:声发射计数率/能量释放率能实时反映陶瓷崩碎损伤过程中裂纹激活率的逾渗行为;基于声发射累积计数/累积能量的破坏比率反映了损伤累积对材料内部性能的影响,可从损伤积累的角度描述陶瓷崩碎损伤过程中的逾渗行为;声发射持续时间反映了陶瓷崩碎过程中逾渗行为的团簇变化规律。研究结果表明:基于声发射的逾渗理论模型可较好的描述陶瓷崩碎损伤演化过程的逾渗特征。 相似文献
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在一维分立时间量子行走中,通过静态和动态两种方式随机地断开连接边引入无序效应,研究了静态逾渗和动态逾渗对量子行走传输特性以及位置自由度和硬币自由之间纠缠的影响.随着演化时间的增加,静态逾渗会使得量子行走从弹道传输转变为安德森局域化,而动态逾渗则会使之转变为经典扩散.理想情况下,量子纠缠在较短的时间内就达到一个常数值E_0.静态逾渗量子行走的纠缠减小,并随着时间做无规振荡,而动态逾渗量子行走的纠缠则会随着时间光滑地增加,并在某一时间超过理想情况下的常数值,表现出动态逾渗增强量子纠缠的特性. 相似文献
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简要介绍基于孔隙逾渗和裂隙逾渗叠加的双重逾渗模型,阐述模型的原理、算法及其实现过程.初步研究模型的分形特性,认为分形维数D是能够衡量模型连通性的重要参数.最后探讨模型的蒙特卡洛数值计算方法,兼顾计算精度与计算耗时,提出可操作的计算规模. 相似文献
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研究了一类非零键渗透率满足均匀分布的随机多孔介质逾渗模型-数值计算了该模型系统渗透率在临界点处的标度指数-结果表明该指数并不能看作是普适常数,而与均匀分布的参数有关-这意味着即使非零键渗透率值的概率密度函数满足负一阶矩存在条件,系统渗透率在逾渗临界点处的标度指数仍然依赖于分布函数的具体参数,并不是常数-这一数值结果与Sahimi对此问题的结论不同-
关键词:
逾渗
随机多孔介质
标度指数
渗透率 相似文献
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We have investigated both site and bond percolation on two-dimensional lattice under the random rule and the product rule respectively. With the random rule, sites or bonds are added randomly into the lattice. From two candidates picked randomly, the site or bond with the smaller size product of two connected clusters is added when the product rule is taken. Not only the size of the largest cluster but also its size jump are studied to characterize the universality class of percolation. The finite-size scaling forms of giant cluster size and size jump are proposed and used to determine the critical exponents of percolation from Monte Carlo data. It is found that the critical exponents of both size and size jump in random site percolation are equal to that in random bond percolation. With the random rule, site and bond percolation belong to the same universality class. We obtain the critical exponents of the site percolation under the product rule, which are different from that of both random percolation and the bond percolation under the product rule. The universality class of site percolation differs different from that of bond percolation when the product rule is used. 相似文献
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We study the critical behavior of certain two-parameter families of correlated percolation models related to the Ising model on the triangular and square lattices, respectively. These percolation models can be considered as interpolating between the percolation model given by the + and – clusters and the Fortuin-Kasteleyn correlated percolation model associated to the Ising model. We find numerically on both lattices a two-dimensional critical region in which the expected cluster size diverges, yet there is no percolation. 相似文献
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The universality of the spanning fraction R(p) of percolation is confirmed by comparing bond percolation with site-bond percolation in four to six dimensions. However, different boundary conditions change the universality class, as shown also for site percolation in two dimensions. 相似文献
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We study a site analogue of directed percolation. Random trajectories are generated and their critical behavior is studied. The critical behavior corresponds to that of simple percolation in some of the parameter space, but elsewhere the exponents reveal new universality classes. As a byproduct, we use the model to make an improved estimate of the percolation hull exponents and to calculate the site percolation probability for the square lattice. 相似文献
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Recently a discontinuous percolation transition was reported in a new "explosive percolation" problem for irreversible systems [D. Achlioptas, R. M. D'Souza, and J. Spencer, Science 323, 1453 (2009)] in striking contrast to ordinary percolation. We consider a representative model which shows that the explosive percolation transition is actually a continuous, second order phase transition though with a uniquely small critical exponent of the percolation cluster size. We describe the unusual scaling properties of this transition and find its critical exponents and dimensions. 相似文献
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介绍了几种计算纳米金属颗粒镶嵌于陶瓷基体中而形成的复合纳米金属陶瓷薄膜渗透阈的理论方法,分析了理论方法中所运用模型的特点及其精度.并将Landauer有效介质理论和Priou渗透阈理论应用于Ag-MgF2复合纳米金属陶瓷薄膜的渗透阈计算,所得值分别为0.08和0.14(Ag的体积分数),按Priou渗透阈理论计算的结果与实验结果相符.最后讨论了影响复合金属陶瓷薄膜体系渗透阈的主要因素.
关键词:
2复合纳米金属陶瓷薄膜')" href="#">Ag-MgF2复合纳米金属陶瓷薄膜
渗透阈理论
渗透阈 相似文献
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The High Temperature Ising Model on the Triangular Lattice is a Critical Bernoulli Percolation Model
We define a new percolation model by generalising the FK representation of the Ising model, and show that on the triangular
lattice and at high temperatures, the critical point in the new model corresponds to the Ising model. Since the new model
can be viewed as Bernoulli percolation on a random graph, our result makes an explicit connection between Ising percolation
and critical Bernoulli percolation, and gives a new justification of the conjecture that the high temperature Ising model
on the triangular lattice is in the same universality class as Bernoulli percolation. 相似文献
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A. G. Hunt 《哲学杂志》2013,93(29):3409-3434