中国水系的盒维数及其关系   总被引：15，自引：2，他引：13       下载免费PDF全文

朱晓华  蔡运龙 《水科学进展》2003,14(6):731-735

应用分形理论,系统地探讨了整个中国水系及其各组成流域水系的分形结构特征。通过研究,得出主要结论如下:(1)整个中国水系及其各组成流域水系的分形结构特征是客观存在的;(2)应用网格法系统地计算出了中国各流域水系的盒维数值:整个中国水系的盒维数值为1.4189,中国外流区水系的盒维数值为1.4305;(3)中国平原地区水系的盒维数值一般较大;(4)整个中国水系盒维数值与组成它的各个层次流域水系的盒维数值的平均值并不相等,一般而言,不同层次流域水系盒维数值的平均值小于整个水系盒维数值。  相似文献   

中国大陆山系、断层系与水系的空间维数及其关系   总被引：2，自引：0，他引：2  

朱晓华  蔡运龙  王建 《山地学报》2003,21(3):311-317

根据分形理论,应用网格法系统地探讨了中国大陆山系、断层系与水系的空间分形结构,并计算出中国大陆以及三大自然区山系、断层系与水系的空间维数,在此基础上还探讨了山系、断层系与水系空间维数在三大自然区的变化情况。得出的基本结论为：(1)中国大陆山系、断层系与水系的空间分形结构是客观存在的;(2)中国大陆山系的空间维数值为1．1513,中国大陆断层系的空间维数值为1．2507,中国大陆水系的空间维数值为1．4169;(3)在三大自然区中,山系、断层系空间维数值均以青藏高原区相对为最大,而以西北干旱区相对为最小,山系与断层系空间维数值的变化在空间上有着一致的对应关系,山系空间维数值较大,则断层系空间维数值亦较大,而水系空间维数值的大小依次为东部季风区水系、青藏高原区水系与西北干旱区水系;(4)中国大陆山系、断层系空间维数响应的关系为DF＝0．6884DM 0．4446(式中：DM为山系的空间维数,DF为断层系的空间维数)。该式不仅为山系、断层系关系的定量化研究提供了全新的手段,而且还为山系、断层系内在密切关系的证实提供了全新的分形理论的证据;(5)整个中国大陆山系、断层系与水系的空间维数值并不等于三大自然区相应要素空间级数值的简单加和平均值;(6)进行山系等地貌现象的分形研究,应遵循相同的分维计算方法,否则将失去进行分维数横纵向比较的意义。  相似文献   

Effects of process parameters on the comminution capability of high pressure water jet mill     

Longlian Cui  Liqian AnWeili Gong 《International Journal of Mineral Processing》2006

To improve comminution efficiency, the effects of several process parameters on the comminution capability of high pressure water jet mill were investigated. Fractal dimension of particle size distribution, as an index of water jet mill comminution capability, was used for describing the fineness of the comminution product. Nine process parameters including the pump pressure, the mixing tube length and diameter, the coal particle mass flow rate, the diameter of feed material particle, the standoff distance, loading times, hardness of the target and the impact angle were investigated individually. The results obtained from this study provide deeper insight into the high pressure water jet comminution technology and a basis for process parameters optimization. We also show that the fractal dimension of particle size distribution can be used to monitor the comminution capability and estimate the degree of particle comminution.  相似文献   

Cumulative Benioff strain-release, modified Omori's law and transient behaviour of rocks   总被引：1，自引：1，他引：1  

Yusuke Kawada  Hiroyuki Nagahama 《Tectonophysics》2006,424(3-4):157

Irreversible thermodynamic theories with internal state variables can be used to derive a general constitutive law for both transient and steady-state behaviours of rocks. This constitutive law can represent the concepts of damage and damage evolution in either the fibre-bundle model or continuum damage mechanics. We have previously proposed an empirically based constitutive law for both the transient and steady-state behaviours of rocks ultimately derived from laboratory experimental data. We show here that this law is concordant with the general constitutive law derived from irreversible thermodynamic theories, and that the relaxation modulus has a temporal power–law that depends on a structural fractal property of rocks. Our constitutive law predicts forms for the cumulative Benioff strain-release for precursory seismic activations and the modified Omori's laws of aftershocks, both aspects of the temporal fractal properties of seismicity. These seismic properties can also be derived by the fibre-bundle model or continuum damage mechanics. Our model suggests that these time-scale invariant processes of seismicity may be regulated by the fractal structures of crustal rocks.  相似文献   

分形在下庄铀矿田中的应用     

李社  管太阳  潘家永  曹双林 《铀矿地质》2006,22(5):305-310

本文运用分形理论对下庄地区铀矿床(矿点)的空间分布进行了研究。结果表明,铀矿床(矿点)的空间分布具有统计自相似性的分形特征,分数维可以用来定量描述铀矿床(矿点)的分布规律;应用盒计维数的统计方法计算了铀矿床(矿点)空间分布的分数维D值,并对西、中、东成矿活动区的分数维D值进行了比较,探讨了分数维D值的地质意义。实际资料计算结果显示网格数与标度之间具很好的相关性,其相关系数均达0.98以上。  相似文献   

新构造分异的地学信息分析——以山东半岛北部为例     

杜国云  王庆  孙祝友 《大地构造与成矿学》2006,30(1):114-119

水系图像空间特征与几何空间特征是新构造运动地表综合信息的反映,也是区域新构造差异的两种新的分析手段。新构造运动差异分析表明,山东半岛新构造运动受控于西侧的郯(城)-庐(江)大断裂,次级的NE-NNE向断裂则控制了整个半岛地区的E-W向差异运动。以NE向青(岛)-牟(平)断裂束为界,分为东、西两个新构造活动亚区。西部相对东部在新构造时期抬升,相对抬升幅度达30m以上。  相似文献   

能源生产的分形研究——以新疆为例   总被引：1，自引：1，他引：1  

李玉琳  高志刚  锁冠侠 《干旱区地理》2006,29(5):748-753

根据能源生产的实际领域年产量观测值带有一定的延续性而非随机性的特点,利用分形理论的基本原理,将不确定的非线性系统数量化,构造新疆能源生产领域时间序列,通过计算能源生产的分形结构特征和分维值,在无规则中找到秩序。并分析其代表的实际意义,以便更好地为能源生产方面的决策提供依据。  相似文献   

杉木种子涩籽的空间特征分析   总被引：1，自引：1，他引：1  

吴承祯  洪伟  林思祖 《山地学报》2006,24(1):117-122

杉木为我国南方山地主要造林树种,其分布范围广,造林种子需求量大,而涩籽是造成其种子发芽率低的重要原因之一。杉木不同分布区,山地环境条件差异较大,杉木种子涩籽的空间差异也较大。采用空间自相关、空间关联和分形理论等方法对福建省杉木种子涩籽的空间特征进行了分析,结果表明杉木种子涩籽空间异质性较大,其自相关系数和半方差函数变化与空间尺度密切相关;地理位置是影响杉木种子涩籽的重要因素之一,在杉木种子园的建立及种子调拨过程中应考虑杉木种子涩籽空间特征。  相似文献   

Nonlinear analysis of rainfall dynamics in California's Sacramento Valley   总被引：1，自引：0，他引：1  

Bellie Sivakumar  Wesley W. Wallender  William R. Horwath  Jeffrey P. Mitchell  Samuel E. Prentice  Brian A. Joyce 《水文研究》2006,20(8):1723-1736

This study investigates the dynamic nature of rainfall observed at the Sustainable Agriculture Farming Systems (SAFS) site in California's Sacramento Valley, which was established to study the benefits of winter cover cropping in Mediterranean irrigated‐arid systems. Rainfall data of four different temporal scales (i.e. daily, weekly, biweekly, and monthly) are analysed to determine the dynamic nature of precipitation in time. In an arid climate with seasonal precipitation this has large implications for land and water management, both in the short term and in the long term. A nonlinear dynamic technique (correlation dimension method) that uses the phase‐space reconstruction and dimension concepts is employed. Bearing in mind the possible effects of the presence of zeros (i.e. no rain) on the outcomes of this analysis, an attempt is also made to compare the dynamic nature of all‐year rainfall and winter rainfall. Analysis of 15 years of data suggests that rainfall dynamics at this site are dominated by a large number of variables, regardless of the scales and seasons studied. The dimension results also suggest that: (1) rainfall dynamics at coarser resolutions are more irregular than that at finer resolutions; (2) winter rainfall has a higher variability than all‐year rainfall. These results are indeed useful to gain information about the complexity of the rainfall process at this site with respect to (temporal) scales and seasons and, hence, the appropriate model (high‐dimensional) type. However, in view of the potential effects of certain rainfall data characteristics (e.g. zeros, measurement errors, scale effects) on the correlation dimension analysis, the discussion also emphasizes the need for further verification, and possibly confirmation, of these results. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

高密度电阻率法成像   总被引：4，自引：1，他引：4  

罗延钟  万乐 《CT理论与应用研究》2006,15(1):61-65

介绍在地质大学电法科研组“高密度电阻率法正、反演软件”的基础上,研制高密度电阻率法2.5维电阻率成像系统;讨论不平地形条件下高密度电阻率法2.5维电阻率成像的算法和软件,可用于九种常用电极装置观测结果的电阻率成像。对理论和实测数据的成像结果表明,该成像系统程序运行稳定,成像效果很好。  相似文献