http://www.sciencedirect.com/science/article/pii/S1674987111000545

By applying the ’theory of synchronization’ from the science of complexity to studying the regional regularity of ore formation within the Nanling region of southern China,a characteristic target-pattern regional ore zonality has been discovered.During the early and late Yanshanian epoch(corresponding respectively to the Jurassic and Cretaceous periods),two centers of ore formation emerged successively in the Nanling region;the former is mainly for rare metals(W,Sn,Mo,Bi,Nb) and one rare-earth element (La) and was generated in the Jurassic period;whereas the latter is mainly for base metals(Cu,Pb,Zn,Sb, Hg),noble metals(Au,Ag),and one radioactive element(U) and was generated in the Cretaceous period. Centers of ore formation were brought about by interface dynamics respectively at the Qitianling and Jiuyishan districts in southern Hunan Province.The characteristic giant nonlinear target-pattern regional ore zonality was generated by spatio-temporal synchronization process of the Nanling complex metallo-genic system.It induced the collective dynamics and cooperative behavior of the system and displayed the configuration of the regional ore zonality.Then dynamical clustering transformed the configuration into rudimentary ordered coherent structures.Phase dynamics eventually defined the spatio-temporal structures of the target-pattern regional ore zonality and determined their localization and distribution.A new methodology for revealing regional ore zonality is developed,which will encourage further investigation of the formation of deep-seated ore resources and the onset of large-scale mineralization.     

Bringing resilience-thinking into water governance: Two illustrative case studies from South Africa and Cambodia

Resilience is a multidimensional concept that is increasingly used to understand environmental change in hydrological systems. Yet, the current discussion about water governance and resilience remains relatively limited, with resilience typically seen as a normative outcome for governance (i.e., to be resilient against change). Using a theoretical multiplicity approach, we explore how the theories of social-ecological systems (SES), resilience and interactive (water) governance can provide new insights for water governance studies. We propose a resilience–governance framework that captures the partly overlapping but distinct characteristics from these three theories. The framework aims to develop a more nuanced way of using resilience-thinking for water governance, viewing resilience as a function of three capacities (absorptive, adaptive and transformative capacity) and noting the simultaneous existence of three interpretations for resilience (as a property, process and outcome) across different scales. The framework also considers issues of power and equity, which are often missing from resilience framings. We illustrate the framework with two case studies – the Tonle Sap Lake in Cambodia and a small sub-catchment of the Limpopo River Basin in South Africa – to provide two distinct examples of the possibilities of resilient governance. Finally, we consider what the framework suggests more broadly for ongoing discussions around resilience and water governance, including the possibilities for governance to also ‘bounce forward’ – i.e., transform – to a new, improved state. We argue that resilience-thinking may be valuable in understanding governance characteristics and guiding governance processes, in addition to seeing resilience (just) as a normative end-goal. In this way, the article supports an epistemological shift away from focusing on institutional structure, towards capturing the dynamic processes within governing systems.     

Comment la Terre a-t-elle pu vieillir de plus de quatre milliards d’années en quatre siècles ?

The history of the determination of the Earth's age is interesting in two ways. First, it is a great school for understanding the genesis of a scientific theory. It stands at the crossroads of almost all scientific disciplines, and also philosophy or even theology. This history shows how what one may well call a “scientific truth” was established through polemics. Second, that age of 4.567 billion years is not just another figure in the series of ages that would be of concern only to astrophysicists; this scale is the only one that makes it possible to understand the genesis of the marvelous order of the solar system (that Newton attributed to God) and the fantastic complexity of Life on Earth.     

全球变化的集成研究

在论述全球变化集成研究的理论基础——复杂性科学的基础上,概述了国际全球变化集成研究的含义、现状与方向,讨论了中国全球变化集成研究的现状,并展望了中国全球变化集成研究的切入研究命题。     

五大连池老黑山火山钾质玄武岩结晶动力学研究

本文模拟了五大连池地区老黑山火山钾质响质碱玄岩熔岩在不同降温速率下从1150℃冷却到700℃橄榄石的结晶动力学过程,并从晶体粒度、晶体数量和晶体形态三方面研究了晶体结晶特征与降温速率之间的关系。结果表明:(1)晶体粒度分布(CSD)显示七组不同降温速率下的晶体粒度与布居密度均呈现较好的幂率关系,且幂律指数相近,斜率范围在3.69～4.42之间,这说明了晶体粒度分布对降温速率的依赖性并不显著。(2)随着降温速率由快变慢,晶体数量总体增长。当降温速率为0.0468℃/min时,晶体数量达到峰值。随后,结晶进入以退火合并为主的晶体粗化过程,直至结晶动力学达到平衡。(3)各降温速率下晶体形态呈现出分形特征,分形维数界于1.39～1.62之间,反映了新生晶体生长的自组织临界性。不同降温速率下的晶体边界复杂程度出现较大无规波动,显示出晶体形态对降温速率的高度敏感性。当降温速率为0.1℃/min时,晶体边界形态最复杂,当降温速率变慢到0.0468℃/min后,晶体边界形态的复杂程度趋于稳定。本项动力结晶实验对于深入了解五大连池新期火山熔岩流的运动机制以及动力结晶过程有重要的科学意义。     

Assessing the transition from deforestation to forest regrowth with an agent-based model of land cover change for south-central Indiana (USA)

The Midwest and Northeast United States has experienced a net increase in forest cover since the beginning of the 20th century. However, we lack a detailed understanding of the transition to net forest cover increase because this forest regrowth occurred prior to the use of tools like household-level surveys focused on land use decision-making and availability of remote sensing data. Agent-based modeling presents an appealing means to explore what social and biophysical dynamics may have contributed to this forest regrowth process. In this paper we employ an agent-based model to analyze the process of forest regrowth in south-central Indiana from 1939 to 1993. Simulation results are presented for assumptions regarding pre-existing forest age and the stand age at which landowners harvest timber with a goal of understanding the influence of these factors on future trajectories of land cover change. The results demonstrate both the value and the burden of having many time points to evaluate the success of the model. Is the best simulation the one with the smallest net residuals across all time points? Or is the best simulation the one that best reproduces the correct trajectory of land cover change for each time interval? Model simulations that assume a harvesting frequency of 30 years all produced landscapes within 2% of the actual forest cover in 1993, the end point of the study period. However, the trajectories of these simulations did not all mimic the gradual forest regrowth found in our observed data. The model simulation with the smallest residual values across all time points assumed a initial forest age of 5 years in 1939 and a harvesting frequency of 30 years. Ultimately, we cannot definitively conclude that one model simulation is a better representation of reality than another because we have no way of comprehensively validating the model assumptions. However, we can more plausibly conclude that the age of forest regrowth in 1939 and the frequency of timber harvesting by landowners both had an influence on the successive trajectory of land cover change in the study area.     

Evidence of non extensivity in the evolution of seismicity along the San Andreas Fault,California, USA: An approach based on Tsallis statistical physics

We examine the nature of the seismogenetic system along the San Andreas Fault (SAF), California, USA, by searching for evidence of complexity and non-extensivity in the earthquake record. We use accurate, complete and homogeneous earthquake catalogues in which aftershocks are included (raw catalogues), or have been removed by a stochastic declustering procedure (declustered catalogues). On the basis of Non-Extensive Statistical Physics (NESP), which generalizes the Boltzmann–Gibbs formalism to non-equilibrating (complex) systems, we investigate whether earthquakes are generated by an extensive self-excited Poisson process or by a non-extensive complex process. We examine bivariate cumulative frequency distributions of earthquake magnitudes and interevent times and determine the size and time dependence of the respective magnitude and temporal entropic indices, which indicate the level on non-equilibrium (correlation). It is shown that the magnitude entropic index is very stable and corresponds to proxy b-values that are remarkably consistent with the b-values computed by conventional means. The temporal entropic index computed from the raw catalogues indicate moderately to highly correlated states during the aftershock sequences of large earthquakes, progressing to quasi-uncorrelated states as these die out and before the next large event. Conversely, the analysis of the declustered catalogues shows that background seismicity exhibits moderate to high correlation that varies significantly albeit smoothly with time. This indicates a persistent sub-extensive seismogenetic system. The degree of correlation is generally higher in the southern SAF segment, which is consistent with the observation of shorter return periods for large earthquakes. A plausible explanation is that because aftershock sequences are localized in space and time, their efficient removal unveils long-range background interactions which are obscured by their presence! Our results indicate complexity in the expression of background seismicity along the San Andreas Fault, with criticality being a very likely mechanism as a consequence of the persistent non-equilibrium inferred from the temporal entropic index. However, definite conclusions cannot be drawn until the earthquake record is exhaustively studied in all its forms.     

Modes of pre-Ediacaran multicellularity

A multicellular grade of organization is widely distributed among extant organisms and widely represented in the pre-Ediacaran fossil record. A review of the pre-Ediacaran record identifies nine general categories of multicellular organization: (1) simple clonal colonies; (2) integrated coenobial colonies; (3) simple uniseriate filaments; (4) simple multiseriate filaments; (5) simple coenocytic filaments; (6) branched coenocytic filaments; (7) complex multicellular filaments; (8) complex multicellular vesicles; and (9) problematic macrofossils. A small subset of these fossils can be assigned to extant lineages based on taxonomically diagnostic patterns of cell division, including compelling evidence for chroococcacean, oscillatoriacean and pleurocapsalean cyanobacteria, bangiophycaceaen red algae and hydrodictaceaen green algae. The identification of pre-Ediacaran vaucheriaceaen xanthophyte algae and siphonocladalean green algae is almost as secure, whereas the case for early multicellular nostocalean/stigonematalean cyanobacteria and fungi requires further corroboration; a distinctively patterned acritarch is tentatively identified as an early Neoproterozoic poriferan. Despite this breadth of early multicellular experimentation, there is no evidence for organ-grade differentiation prior to the Ediacaran. Indeed, it is the absence of eumetazoans and embryophytes that distinguishes the pre-Ediacaran world from the fundamentally richer and more dynamic biosphere of the Phanerozoic.     

用算法复杂性分析地震活动演化特征

以非线性动力学理论为依据，用非线性动力学中分析时间序列的算法复杂性研究地震活动规律和构成地震活动复杂现象的动力学特征。提出了按震级计算的地震算法复杂性ＡＣ值和按发震时间计算的地震算法复杂性ＴＡＣ值。选取１９７０年以来中国东部ＭＳ≥６．０地震，西部ＭＳ≥６．５的强震，对ＡＣ值和ＴＡＣ值进行回顾性分析；利用１９７０￣１９８０年大华北地区展望性空区识别结果，对ＡＣ值和ＴＡＣ值进行展望性检验分析，并进行了     

地震复杂性前兆与强震多重分形谱异常

大量的震例和实验研究表明，在震孕育的非线性过程、大破裂发生前，近震源区不同观测点的变化是不确定的、不重复的，但从整体上看，声发射（小震）和形变场随着应力的增加而存在由无序→有序，从简单→复杂，由“白脸”变“花脸”的变化确定的、可重复的。要注意，这里的重复不是细结构的重复，而是宏观图像复杂性增中的重复。这种具有重复性的、地震宏观图像复杂性的变化，称为地震复杂性前兆。显然它不同于某一物理某种定式的变化