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1.
湘西沃溪金锑钨矿床分形成矿动力学 总被引：8，自引：0，他引：8
随着分形理论的建立与发展 ,应用分形理论研究矿床分布及元素的分布与富集规律已经成为研究成矿作用的一个有力的新工具。文中对湘西沃溪金锑钨矿床金品位空间变化进行了分形与混沌吸引子分析 ,结果表明 ,该矿床金品位分布具有分形结构特征 ,并都呈双分形关系 ,分叉处的金品位与其平均品位相当 ,分维值可以指示成矿流体的运移方向。其金品位空间变化为混沌序列 ,在相空间维数为 8～ 1 0时 ,出现一个混沌吸引子 ,吸引子的维数变化于 1 .5 3～ 4 .72之间 ;表明其成矿流体的演化及金元素的沉淀富集成矿过程为混沌动力学过程 ,描述或控制本矿区金品位变化的独立变量至少需要 8～ 1 0个。总之 ,成矿物质的沉淀过程是一个复杂的非线性动力学过程 ,矿物在热液体系中通过构造应力、流体流动、流体岩石反应等之间的复杂非线性反馈作用 ,最终在合适部位沉淀下来 ,形成了各种具分形与混沌特征的矿床和品位分布 相似文献
2.
A constitutive law for viscoelastic behaviour of rocks is derived from irreversible thermodynamics. To this model, two specific parameters are introduced; one is an internal state variable which is a variable concerning the microstructures such as defects in crystals or microcracks, and the other is a temperature reduced time obtained by normalizing the various temperature behaviours. A large number of internal state variables have the respective relaxation times and show the respective time evolutions, while a set of the time evolutions generates temporal power-law behaviour of rocks. The time evolutions of internal states are regarded as dynamics of elements of the generalized Maxwell model, and the stress–strain relation is represented by a response function following a temporal power-law in terms of linear system theory. This relation is inversely formulated to investigate the source field from output data. This model enables us to explain experimentally-based constitutive laws for transient and steady-state behaviour of rocks (e.g., lherzolite) following a temporal power-law and for attenuation behaviour of polycrystals (e.g., olivine) represented by a relation between the quality factor and frequency. Both laws show power-laws on deformation time or frequency depending on the fractal structure in polycrystals or rocks, and the experimental high-temperature behaviours can be extrapolated to long deformation time or high frequency behaviour. 相似文献
3.
地质作用的自组织临界过程动力学——地质系统在混沌边缘分形生长(下) 总被引：1，自引：0，他引：1
笔者对复杂性科学中的自组织临界性、瞬态混沌、混沌边缘和弱混沌四大理论和研究领域就其发展现状和最近动态作系统和深入的剖析后得出结论 ,认为以上四者是对自然界中开放、远离平衡、相互作用的巨大耗散动力学系统的时空演化这个统一事物的本质的面面观。笔者进一步将四者的相互关系归纳成一个重要的命题 :自然界中开放、远离平衡、相互作用的巨大耗散动力学系统的时空演化服从“自组织临界过程动力学” ,并且系统“在混沌边缘分形生长”。地质系统是自然界中的一种既十分重要 ,又异常复杂的开放、远离平衡、相互作用的巨大耗散动力学系统。它具有自组织临界性的内禀基本属性。它的时空行为服从地质作用的自组织临界过程动力学。地质系统位于有序和混沌之间的过渡时空域 ,即混沌边缘 ,其中系统呈规则与混沌运动并存和混合的弱混沌动力学状态 ,并且地质系统在混沌边缘分形生长。将上述命题演绎和整合成一种广泛适用于地质系统的地球科学的复杂性理论 ,名之为 :“地质作用的自组织临界过程动力学———地质系统在混沌边缘分形生长” ,并将其内容归纳成 6部分 :(1)自组织临界性、瞬态混沌、混沌边缘和弱混沌 ,(2 )多组分的耦合与相互作用及其相干与协同 ,(3)演化过程的分形动力学 ,(4 )作用的时空结构 ,( 相似文献
4.
非线性铀成矿作用--以上第三系砂岩型铀矿为例 总被引：2，自引：1，他引：1
戴杰敏 《矿物岩石地球化学通报》2000,19(2):119-126
本以滇西上第三系陆相砂岩铀矿为例研究非线性铀成矿作用。与铀矿化有关的参数可分为矿化参量和控制参量,矿化参量以及矿化在控制参量中的分布均遵从对数正态分布,控制参量(温度、压力和地球化学条件)的耦合作用对铀矿化的概率和平均品位的控制作用是非线性的,铀矿化在控制参量构成的相空间中的变化轨迹是一复杂的超曲面。非线性铀成矿作用具分形特征。 相似文献
5.
大尺度断层往往控制了沉积盆地的形成和油气成藏,而小尺度断层则影响着注水开发效果和剩余油分布.大尺度断层可以通过二维或三维地震资料识别,而小尺度断层的识别则特别困难.本文提出了一种基于断层分形生长模式和三维地质力学模拟相结合来确定小尺度断层的数量、发育位置和方位的方法,并根据油田开发动态资料来确定小尺度断层对注水开发和剩余油分布的影响.将地震上识别的大尺度断层引入到三维数值力学模型中,模拟大尺度断层形成时期断裂带附近的应力扰动作用,然后结合破裂准则来建立最易发生破裂的方位和最大库伦剪切应力网格,以这两套网格和断层尺度的幂律分布确定的小尺度断层数量为约束条件来确定随机模型,对小尺度断层的密度、产状和发育位置进行定量预测.研究表明:利用分形理论和三维地质力学模拟可以对大尺度断层伴生小尺度断层进行有效预测;小尺度断层对注水开发效果和剩余油分布的影响取决于小尺度断层的规模(断距)以及小尺度断层方位和注采方向的关系. 相似文献
6.
The widely used wavelet filtering technique holds potential to approach anomaly–background separation in geophysical and geochemical data processing. Wavelet statistics provide crucial information on such filtering methods. In general, conventional (Gaussian-type) statistical modeling is insufficient to adequately describe the heavily tailed and sharply peaked (at zero) distribution of the wavelet coefficients of irregular geo-anomaly patterns. This paper demonstrates that the cumulative (frequency) number of the wavelet coefficient yields a power-law scaling relationship with the coefficient based on wavelet transform of a fractal/singular measure. This wavelet coefficient–cumulative number power-law model is proven to be more flexible and appropriate than the Gaussian model for characterizing the scaling nature of the coefficient distribution. Accordingly, a fractal-based filtering technique is developed based on the wavelet statistical model to decompose mixed patterns into components based on the distinct self-similarities identified in the wavelet domain. The decomposition scheme of the fractal-based wavelet filtering method considers not only the coefficient frequency distribution but also the fractal spectrum of singularities and the self-similarity of real-world features. Finally, a synthetic data test and real applications from two metallogenic provinces of China are used to validate the proposed fractal filtering method for anomaly–background separation and identification of geophysical or geochemical anomalies related to mineralization and other geological features. 相似文献
7.
8.
The current geodynamics and tectonophysics of the Baikal rift system (BRS) as recorded in lithospheric stress and strain are discussed in the context of self organization of nonlinear dissipative dynamic systems and nonlinear media. The regional strain field inferred from instrumental seismic moment and fault radius data for almost 70,000 MLH ⩾ 2.0 events of 1968 through 1994 shows a complex pattern with zones of high strain anisotropy in the central part and both flanks of the rift system (the South Baikal, Hovsgöl, and Muya rift basins, respectively). The three zones of local strain anisotropy highs coincide with domains of predominantly vertical stress where earthquakes of different magnitudes are mostly of normal slip geometry. Pulse-like reversals of principal stresses in the high-strain domains appear to be nonlinear responses of the system to subcrustal processes. In this respect, the BRS lithosphere is interpreted in terms of the self organization theory as a geological dissipative system. Correspondingly, the domains of high strain anisotropy and stress change, called rifting attractor structures (RAS), are the driving forces of its evolution. The location and nonlinear dynamics of the rifting attractors have controlled lithospheric stress and strain of the rift system over the period of observations, and the same scenario may have been valid also in the Mesozoic-Cenozoic rifting history. The suggested model of a positive-feedback (fire-like) evolution of nonlinear dynamical systems with rifting attractors opens a new perspective on the current geodynamics and tectonophysics of the Baikal rift system. 相似文献
9.
A Research on Fractal Dimension and Nonlinear Dynamic Model of Xintan Landslide，China 总被引：1，自引：0，他引：1
ＡＲｅｓｅａｒｃｈｏｎＦｒａｃｔａｌＤｉｍｅｎｓｉｏｎａｎｄＮｏｎｌｉｎｅａｒＤｙｎａｍｉｃＭｏｄｅｌｏｆＸｉｎｔａｎＬａｎｄｓｌｉｄｅ，ＣｈｉｎａＺｈｏｕＣｕｉｙｉｎｇ；ＴａｎｇＬｉａｎｓｈｅｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＥａｒｔｈＳｃｉｅｎｃｅ，... 相似文献
10.
天山麦兹巴赫冰川湖突发性洪水分形特征研究 总被引：6，自引：2，他引：4
冰川湖突发性洪水具有强烈的随机性和不确定性。文章以天山麦兹巴赫冰川湖突发洪水为例。应用其近４０ａ来实测的３７次冰川突发洪水的洪峰流量等实测资料,从洪水时间序列出发,应用非线性动力系统重构技术,探讨了冰川湖突发洪水的分形特征,计算得出了关联分维数Ｄ２和Ｋｏｌｏｍｏｇｏｒｏｖ熵。结果表明,冰川湖突发洪水的时序分布具有分形特征,是其内在的非线性动力系统演化的结果。 相似文献
11.
The landslide blockage length along a man-made linear structure, the Alishan railway, is analyzed herein. The Alishan railway runs from Chiayi City to the Alishan scenic area. Numerous landslide and debris flow disasters have blocked the railway since it began operations in 1911. In this study, features of landslides are interpreted from Spot 5 images along the Alishan railway. The results show that larger landslides along the railway exhibit a power-law distribution in frequency-area analysis. The railway blockage length by landslide and its frequency can be linearized by plotting it in a log scale for a blockage length over 0.02?km. The characteristics may be attributed to the fact that the landslide magnitude for its area and volume versus frequency exhibits a power-law distribution. It may thus be possible to estimate the blockage length of linear structures (e.g., railway and expressway) by landslides using the power-law distribution. 相似文献
12.
海南岛中西部金矿集中区断裂构造的分形研究 总被引：9，自引：1，他引：8
利用数盒子法对海南岛中西部金矿集中区断层分布统计表明 :断层系统在 5～ 75km尺度内符合分形分布 ,其分维值为 1 .70。根据成矿系统的差异 ,将全区分为 9个子区块 ,各子区块断层系统在 2 .5～ 2 5km尺度内均符合分形分布 ,其分维值介于 0 .6 6～ 1 .72之间。断层分维值的大小可作为判断矿化强弱的指标 :断层的分维值≥ 1 .5 ,是矿化集中区的标志 ;分维值小于 1 .4 ,不利于规模成矿 ;断层的分维值较大 ,是形成金矿化的有利条件 ,若形成超大型矿床 ,则断层系统需处于临界分维状态(Dc≈ 1 .5 )。白沙元门地区断层分维 (D =1 .4 9)接近于临界分维 ,预示该区有良好的找矿前景。基于离散元方法 (UDEC)的数值模拟显示 :随着断层分维值增大 ,则变形趋强、连通性更好、渗透率增大 ;临界状态下断层间的连通性好 ,变形及渗透率突然增加且变形及流体流动局限于骨干断层中 ,即临界状态下最有利于形成含矿流体的局域化分布 相似文献
13.
分形噪声、（多维）分形滤波及地球物理测井典型处理应用 总被引：6，自引：0，他引：6
白噪声、布郎运动以及其它满足在双对数坐标中呈一直线的信号具分形结构、自相似性或尺度无关性。地球物理信号通常表现为多个这类信号的叠加，为多维分形特征。研究、模拟在双对数坐标中成一直线的信号以及如何将多维分形中多个这种信号剖分出来，对于理解相应的地质、地球物理成因机制具有重要意义。通过对两口井的地球物理测井曲线处理，可以初步看出，在选定的地球物理测井曲线中，其具多维分形特征，不同的沉积过程相互叠加在原始测井曲线中。用滤波方法分析分解信号，可以了解不同沉积作用特征并进一步分析可能的环境变化控制机制。开发的图形界面程序使得这一过程极为容易实现。 相似文献
14.
Recent studies have shown that many natural systems display temporal fluctuations with long-range power-law correlations, suggesting a fractal geometry of the underlying dynamical system. Four geoelectrical time series, measured in a seismic area of Southern Italy, are investigated by means of spectral tools in order to evidence the existence of power-law correlations. Results show the scaling behaviour for all the signals recorded, pointing to the presence of fractal features expressing a long-term correlation with scaling exponents which indicate stabilizing mechanisms. Furthermore, our findings suggest an observational evidence of correlations between the variation of parameters describing the temporal fluctuations of geoelectrical signals and earthquakes that occurred in the area investigated. 相似文献
15.
动荷载作用下结构性软土微结构变化的分形研究 总被引：1，自引：0，他引：1
为探讨天津滨海新区典型结构性软土的动力特性,采用动三轴试验和压汞试验,对交通荷载作用下结构性软土微观结构变化进行了研究。取原状土和动荷载作用后的土样进行压汞测试,用分形理论对压汞测试数据进行分析,探讨孔隙分布特征,提出孔径划分的方法,给出了卓越频率与土体孔隙变化的规律。研究结果表明：在动荷载作用后,天津滨海新区典型软土的孔隙分布发生改变,可分为3种类型;利用Menger海绵模型研究交通荷载作用下结构性软土的孔隙分布特性是可行的;用孔隙分维数可实现对卓越频率的预测以及路基土体变形行为的机制分析。 相似文献
16.
The fractal dimension of pores in sedimentary rocks and its influence on permeability 总被引：2，自引：0，他引：2
E. M. Schlueter R. W. Zimmerman P. A. Witherspoon N. G. W. Cook 《Engineering Geology》1997,48(3-4):199-215
Perimeter-area power-law relationship of pores in five sedimentary rocks are estimated from scanning electron micrographs of thin sections. These relationships for the pores of four sandstones were found to lie between 1.43 and 1.49, while that of an Indiana limestone was found to be 1.67. We show how the perimeter-area power-law relationship of pores, along with a pore-size distribution, can be used to estimate the hydraulic permeability. A discussion is given of how the fractal dimension of the pore perimeter derived by Mandelbrot for islands whose boundaries are fractal: P = εDAD/2, where ε is some constant that depends on the length of the measuring grid size and D is the fractal dimension of the pore perimeter, influences permeability. 相似文献
17.
应用分形理论来研究石油地质现象，是近年来地质学研究中的新方法和新思路。本文扼要介绍了分形和分维的基本概念和最新进展；并以四川地区为例，通过对川东、川西南、川南、川西北以及川中等地２００个气藏的统计研究，结果表明气藏的体积分布很好地遵从幂律分布规律，一定区域内油气藏的体积分布是一种分形分布。本文对分形分布的意义进行了探讨，提出了初步预测油气藏数目及储量的方法。该项成果为油气藏的研究开拓了新的领域。 相似文献
18.
We have analyzed the spatial distribution of galaxies from the latest release of the Sloan Digital Sky Survey of galactic
redshifts (SDSS DR7), applying the complete correlation function (conditional density), two-point conditional density (cylinder),
and radial density methods. Our analysis demonstrates that the conditional density has a power-law form for scales lengths
0.5–30 Mpc/h, with the power-law corresponding to the fractal dimension D = 2.2 ± 0.2; for scale lengths in excess of 30 Mpc/h, it enters an essentially flat regime, as is expected for a uniform distribution of galaxies. However, in the analysis applying
the cylinder method, the power-law character with D = 2.0 ± 0.3 persists to scale lengths of 70 Mpc/h. The radial density method reveals inhomogeneities in the spatial distribution of galaxies on scales of 200 Mpc/h with a density contrast of two, confirming that translation invariance is violated in the distribution of galaxies to 300
Mpc/h, with the sampling depth of the SDSS galaxies being 600 Mpc/h. 相似文献
19.
扇形沉积体是我国内陆及近海中、新生代含油气盆地的重要油气聚集体, 如何定量地表征沉积体的分布状况及内部结构参数的空间变化规律, 对指导油气勘探具有重要意义.扇形沉积体的生长过程是一个复杂的非线性动力学过程, 通过对其生长的沉积动力学、混沌动力学和分形动力学机制的分析, 认识到扇形沉积体的生长具有分形特征, 决口过程是造成其外部形态复杂多变的重要原因; 分形几何学理论在沉积体定量建模和模拟方面具有较好的应用前景.采用分形-地质统计学相结合的方法, 对扇形沉积体的外部形态和内部结构特征实施了计算机模拟, 并对模拟结果进行了讨论. 相似文献