Self-organized criticality of liquefaction in saturated granules

Utilizing the dissipative structure theory, the evolutionary process of vibrating liquefaction in saturated granules was analyzed. When the irreversible force increases to some degree, the system will be in a state far from equilibrium, and the new structure probably occurs. According to synergetics, the equation of liquefaction evolution was deduced, and the evolutionary process was analyzed by dynamics. The evolutionary process of vibrating liquefaction is a process in which the period doubling accesses to chaos, and the fluctuation is the original driving force of system evolution. The liquefaction process was also analyzed by fractal geometry. The steady process of vibrating liquefaction obeys the scaling form, and shows self-organized criticality in the course of vibration. With the increment of the recurrence number, the stress of saturated granules will decrease rapidly or lose completely, and the strain will increase rapidly, so that the granules can not sustain load and the "avalanche" phenomenon takes place.

Complexity and Self-Organized Criticality of Solid Earth System(Ⅰ)

The author puts forward the proposition of Complexity and Self Organized Criticality of Solid Earth System in the light of: (1) the science of complexity studies the mechanisms of emergence of complexity and is the science of the 21st century, (2) the study of complexity of the earth system would be one of the growing points occupying a strategic position in the development of geosciences in the 21st century. By the proposition we try to cogitate from a new viewpoint the ancient yet ever new solid earth system. The author abstracts the fundamental problem of the solid earth system from the essence of the generalized geological systems and processes which reads: the complexity and self organized criticality of the global nature, structure and dynamical behavior of the whole solid earth system emerging from the multiple coupling and superposition of non linear interactions among the multicomponents of the earths material and the multiple generalized geological (geological, geophysical, and geochemical) processes . Starting from this cognizance the author proposes eight major themes and the methodology of researches on the complexity and self organized criticality of the solid earth system.

The Research of Transmission Network Planning Based on System’s Self-organized Criticality

This paper presents a new line importance degree evaluation index for the propagation of cascading failures, which is used to quantify transmission lines for cascade spread. And propose an improved capital matching model, according to the results of the evaluation, to enhanced robustness of the power system. The simulation results proved that in the case of the same system, the new model can inhibit cascade spread, reduce the probability of large-scale blackouts.

Lévy Flights, 1/<i>f </i>Noise and Self Organized Criticality

A new analysis of a previously studied traveling agent model, showed that there is a relation between the degree of homogeneity of the medium where the agents move, agent motion patterns, and the noise generated from their displacements. We proved that for a particular value of homogeneity, the system self organizes in a state where the agents carry out Lévy walks and the displacement signal corresponds to 1/f noise. Using probabilistic arguments, we conjectured that 1/f noise is a fingerprint of a statistical phase transition, from randomness (disorder) to predictability (order), and that it emerges from the contextuality nature of the system which generates it.

Electrical Tree Simulation Based on the Self-Organization Criticality

So far much effort has been made to understand the development of electrical treeing. For the simulation based study of electrical treeing, the most common method is to apply DBM stochastic model to simulate the growing of electrical treeing patterns. Previous simulation results showed that this stochastic model is capable of simulating the real electrical treeing patterns in a point-to-plane electrode system. However, this model only allows the tree channels to propagate on equipotential lines proportional to local electrical field. Therefore, it is necessary to develop a novel stochastic model to simulate the electrical patterns in order to get a good agreement with experimental results.

Self-organized criticality of forest fires in China

Self-organized criticality(SOC) of forest fires in China from 1950 to 1989 is studied. The stability, scale-invariant character of SOC and external effects on SOC of forest fires in China are analyzed in detail. Forest-fire cellular automata model is a typical model for the research of SOC. Based on the traditional forest-fire model, an improved model, in which effects of tree species, meteorological conditions and human efforts on forest fires are considered, is introduced. Actual forest fire data in China are compared with simulation results of the two models. It is shown that forest fire data in China have SOC behavior and simulation results of the improved model accord better with actual forest fire data than those of the traditional model.

On power system blackout modeling and analysis based on self-organized criticality

This paper makes a comprehensive survey on power system blackout modeling and analysis based on SOC (self-organized criticality). Firstly,a generalized SOC theory from the viewpoint of cybernetics is introduced. Then the evolution model of power system and its relative mathematical description,which serves as a concrete example of the proposed generalized SOC,are given. Secondly,five blackout models capturing various critical properties of power systems in different time-scales are listed. Finally,this paper analyzes SOC in power systems,such as,the revelation of criticalities of proposed models in both micro-scale and macro-scale which can be used to assess the security of power system,and cas-cading failures process.

Self-organized criticality judgment and extreme statistics analysis of major urban fires

The spatial (economic loss) and temporal characteristics of urban fires were analyzed employing relevant statistical methods. A fractal structure in terms of the power-law relation between fire frequency and economic loss was found on a spatial scale, and an exponential relation between frequency and time interval was found on a temporal scale. Thus, urban fire does not meet the rigorous criteria of self-organized criticality. In addition, based on the spatial power-law distribution characteristics, a correlation model of the frequency and scale of loss due to urban fire was established using the extremum statistical method. This model was then applied to the case analysis of Hefei and the probability of major fire incidents in the future was predicted.

Self-organized criticality of power system faults and its application in adaptation to extreme climate

This paper analyzes the statistics of faults in a transmission and distribution networks in central China, unveils long-term autocorrelation and power law distribution of power system faults, which indicates that power system fault has self-organized criticality (SOC) feature. The conclusion is consistent with the power systems data in 2008 with ice storm present. Since power systems cover large areas, climate is the key factor to its safety and stability. In-depth analysis shows that the SOC of atmosphere system contributes much to that of power system faults. Extreme climate will be more intense and frequent with global warming, it will have more and more impact upon power systems. The SOC feature of power system faults is utilized to develop approaches to facilitate power systems adaptation to climate variation in an economical and efficient way.

POWER LAW DISTRIBUTION AND SELF-ORGANIZED CRITICALITY OF DISPERSED PARTICLES

Research on particulate characteristics has been an important frontier in physics and chemistry during the past decades. It has however been mostly focused on granular materials with short-range interactions. In this work, it was found that the power law of particle size distribution applied to the long-range interacting system of floating dust in air, from which we deduced that self-organized criticality might hold for floating dust just as granular materials with short-range interactions. This feature may reveal underlying kinetic mechanisms, important in dispersed particle systems. In industry, power law of size distribution of dispersed particles can be used to investigate the change of dust size, and the power law parameter could be taken as an important index for dust separation.

基于EEMD-MFDFA的镇江港PM_(2.5)演化特征分析

为定量分析镇江港PM_(2.5)浓度时间序列的内在演化特征,以镇江港2019—2020年的205667组PM_(2.5)时均浓度数据为基础,采用基于集合经验模态分解(EEMD)的多重分形去趋势波动分析(MFDFA)算法进行研究.结果表明:各监测点PM_(2.5)日均浓度演化均具有显著的长期持续性特征,现阶段PM_(2.5)浓度升高可能会导致未来一段时间内PM_(2.5)浓度的持续升高,不同监测点PM_(2.5)浓度的多重分形谱参数存在差异性,多重分形特征强的区域应侧重即时性防治,反之则应注重长期性监管;运用自组织临界性理论,发现15个监测点PM_(2.5)浓度波动呈现幂律分布特征,符合自组织临界性特征,港口系统存在发生大气高污染的风险.

Self-organized Criticality Behavior in Bulk Metallic Glasses

Serrated flows are known as repeated yielding of bulk metallic glasses（BMGs）during plastic deformation under different loading conditions,which are associated with the operation of shear banding.According to the statistics of some parameters,the shear avalanches can display a self-organized critical state,suggesting a large ductility of BMGs.The emergence of the self-organized criticality（SOC）behavior in different BMGs is due to the temperature,strain rate,and chemical compositions.The SOC behavior is accompanied with the following phenomena：the interactions occur in the shear bands;the incubation time is longer than the relaxation time;the time interval is lacking of typical time scale;and the spatial or temporal parameters should display apower-law distribution.

四川省重点城市PM_(2.5)-O_(3)复合污染的非线性相互作用

为探究四川省PM_(2.5)和O_(3)相互作用演化的多尺度效应,并阐释PM_(2.5)-O_(3)复合污染事件发生及演化的动力机制,应用去趋势互相关分析(DCCA)对2015—2021年四川省15个重点城市高浓度的PM_(2.5)和O_(3)质量浓度数据进行分析。首先,PM_(2.5)和O_(3)质量浓度及超标天数年际变化的分析结果表明,PM_(2.5)总体呈下降趋势,O_(3)总体在2015—2018年呈上升趋势,但二者的超标天数均呈现不稳定的波动趋势。其次,应用DCCA对2015—2021年各城市高浓度PM_(2.5)和O_(3)的相关性分析结果表明,二者相互作用的演化呈现出较强的长期持续性非线性特征,且各年份之间无较大差异。最后,进一步应用DCCA对各城市高浓度PM_(2.5)和O_(3)相关性随时间尺度的演化趋势进行分析,结果表明,DCCA指数的变化趋势在各年份表现为良好一致性,均在1~12 h显著上升,在12~28 h逐渐趋于平稳。本文结合自组织临界(SOC)理论讨论了PM_(2.5)、O_(3)时空演化的内在动力规律,认为四川省PM_(2.5)-O_(3)复合污染事件的发生受到大气系统非线性SOC理论的控制,四川省独特的气象条件为SOC状态的维持提供了稳定的外部环境。

Self-organization criticality of debris flow rheology

Based on the viewpoint of stress and strain self-organization criticality of debris flow mass, this paper probes into inter-nonlinear action between different factors in the thixotropic liquefaction system of loose clastic soil on slope to make clastic soil in slope develop naturally towards critical stress status, and slope debris flow finally occurs under trigging by rainstorm. Also according to observation and analysis of self-organization criticality of sediment run-off system of viscous debris flow surges in ravines and power relation between magnitude and frequency of debris flows, this paper expounds similarity of the self-organized structure of debris flow mass. The self-organized critical system is a weak chaotic system. Debris flow occurrences can be pre-dicted accordingly by means of observation at certain time scale and analysis of self-organization criticality of magni-tude, frequency and time interval of debris flows.

Influences of finite-size effects on the self-organized critical-ity of forest-fire model

The influences of finite-size effects on the self-organized criticality (SOC) of the traditional forest-fire model are investigated by means of a new method. The forest size is originally set to a value much greater than the correla-tion length of the forest. Finite-size effects are then studied by equally dividing the forest into more and more separate subsystems on condition that the forest size, igniting prob-ability and planting probability are invariant. A new phe-nomenon, i.e. the finite-size effects with one-side frequency peak, is observed. The boundary between two neighboring subsystems can be regarded as a firebreak. The concept of ’separation ability’ is introduced to represent the probability for the firebreak to block off the fire successfully. Restrain-ing effects of separation ability on finite-size effects are ana-lyzed. Finite-size effects and separation ability, as well as their relations are found to have practical importance to the actual forest-fire protection.

Al-4％Cu多晶合金中锯齿形屈服现象的初步时序分析

对Al-4％Cu合金试样拉伸实验的锯齿形应力曲线进行了系统的统计分析,研究了锯齿应力跌幅、跌落时间以及再加载时间等特征物理量随应变、试样厚度和加载应变率的时序演化规律．结果表明,跌落时间对应变不敏感; 1和2 mm厚试样的平均应力跌幅和平均再加载时间均随应变线性增加, 3 mm厚试样的统计结果比较复杂．展示了PLC效应中自组织临界性存在的证据,并通过与经典沙堆模型的对比,结合动态应变时效原理和位错理论,解释了PLC变形带形成的非线性机制．

输电网-配电网-微电网三级电网规划的若干基础问题

根据国内外电力系统发展趋势及电力工业面临的实际问题,明确提出输电网-配电网-微电网三网合一的未来电网规划设计重大基础问题,进一步提出将复杂网络理论的概念和方法加以发展从而应用于新一代三级电网的规划设计的研究思路.研究涉及三类基础课题:一是三级电网的宏观形态及概念设计;二是三级电网结构理论基本框架;三是基于自组织临界理论(Self-Organized Criticality,SOC)的三级电网规划方法.全面阐述了规划和建设三级电网的必要性和迫切性,明确指出三级电网是未来电网的主要发展方向之一.

真三轴单面临空花岗岩岩爆自组织临界特征研究

为探究不同应力状态下花岗岩岩爆失稳特征,开展真三轴单面临空岩爆试验,结合声发射监测系统,根据自组织临界理论,分析岩爆过程应力变化及声发射能量序列的时间属性和定位信息的空间属性。试验结果表明:将岩爆自组织过程分解为时间线与空间线,最大程度地实现了岩爆自组织过程的可视化及岩体状态的量化,且能量时域性通过了幂律特征的验证,具有较强自相似性;岩爆孕育过程第二阶段的临界指数相对第一阶段较大,说明岩爆发生的概率随着自组织演化加剧;岩爆自组织行为存在中间主应力效应,随着中间主应力增大对岩石破裂限制作用增强,临界点出现越晚,临界指数越大,同时高中间主应力下亚临界点至临界点的平静期较长,自组织行为较弱,易诱发突发性强、破坏性大的岩爆灾变,预测难度增加。本研究结果为精确预测岩石岩爆提供了更为前沿、完善的思路。

舰船电力系统自组织临界特性分析

基于自组织临界理论,以直流潮流为基础,建立了舰船电力系统连锁停电的OPA模型。通过OPA模型模拟了舰船电力系统发生连锁故障的过程并揭示出舰船电力系统发生大停电事故的本质;研究了线路可靠性和线路容量对系统停电分布的影响,结果表明,增强线路可靠性和提高线路容量有利于系统抵御连锁故障。此外,对比环形舰船电网结构和辐射型舰船电网结构的停电规模分布,从系统自组织临界特性的角度验证环形舰船电网结构可靠性更高。

大学物理教学中的复杂性思维培养研究

文章探讨了复杂性科学理论在物理教学中的应用及其对学生思维发展的影响。通过引入非线性动力学、自组织临界性理论、复杂网络拓扑结构以及量子力学的概率诠释与不确定性原理等框架,文章阐述了这些理论如何为物理教学提供新的视角和工具,帮助学生更深入地理解物理现象的复杂性和非线性特征。文章还强调了这种教学模式在培养学生复杂性思维、科学素养和创新能力方面的重要性,指出将复杂性科学理论融入物理教学是未来教学改革的重要方向,有助于培养具备跨学科解决问题能力的人才。