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1.
磨粒的分形多为无规分形,其分形维数计算比有规分形维数复杂得多, 利用计算机来完成分形维数计算是一种有效方法.作者阐述了分形维数的定义和磨粒分形维数计算方法、无标度区间的计算原理,基于真彩色图像处理原理,设计了磨粒分形维数计算的硬件系统;在软件设计中,引入了无标度区间的计算,克服了原有磨粒分维计算方法的不足,利用Visual C++完成了基于Windows平台的磨粒分形维数计算程序的设计,为运用铁谱技术研究磨粒的复杂特征提供了计算工具.  相似文献   

2.
基于GIS的河网分形研究   总被引:2,自引:0,他引:2  
目的探讨在GIS支持下河网分维数的计算方法以及不同分维的意义。方法应用数字高程模型,在GIS支持下提取陕北黄土高原韭园沟流域的河网,利用空间分析方法、分形理论以及统计学知识进行计算、模拟。结果基于霍顿水系定律得到韭园沟流域河网分维数是1.662,基于分形基本定义得出的是1.589。结论①利用GIS计算河网分维数与传统方法相比,具有高效、简捷、检验性好的优点;②对同一河网,使用不同方法得到的分维数不同,表明河网分形性质丰富多彩;③分形维数对比时一般应满足计算方法一致,且在同一个无标度域内。  相似文献   

3.
提出以河床表面分形维数从整体上量化河床形态,并依据表面积—尺度法原理,在对现有面分维计算方法的表面积估算、边界处理及无标度区判断等方面进行改进的基础上,给出了适用于具有不规则边界的表面分形维数计算方法,该方法对河床表面分维计算具有较好的适用性.将典型河段的年内冲淤变化、局部河势、河型与河床表面分形维数变化结合起来,说明了河床表面形态具有一定的分形特征,河床表面分形维数可随着河床的冲淤变化而改变,河床形态冲淤起伏愈剧烈,则河床表面分形维数愈大,其能定量反映河床形态的复杂程度,可用于河势量化分析、河型判别以及河道形态阻力计算等相关问题研究.  相似文献   

4.
豫北地区城镇体系空间结构的多分形研究   总被引:7,自引:0,他引:7  
以河南省北部为研究区,对城镇体系空间结构的多分形性质进行了实证研究,证明城镇体系是地球表面分形支体上发育的多标度分形系统.计算结果表明,豫北地区城镇体系的多分维Dq和奇异谱f(a)在参数q≈-1处发生了标度间断 ,多分形测度只在q∈[0,+∞)范围内发育,当q≤1时,标度紊乱,f(a)函数和Dq谱均不收敛,从而证明:多分形是由单分形演化而来,城镇体系的多分形结构是由测度集中区向测度疏散区不断发展、逐渐形成的.另外,从人地关系、系统演化以及测算方法等角度对有关问题进行了初步探讨.  相似文献   

5.
豫北地区城镇体系空间结构的多分形研究   总被引:15,自引:2,他引:13  
以河南省北部为研究区,对城镇体系空间结构的多分形性质进行了实证研究,证明城镇体系是地球表面分形支体上发育的多标度分形系统。计算结果表明,豫北地区城镇体系的多分维Dq和奇异谱f(a)在参数q≈-1处发生了标度间断,多分形测度只在q∈[0, +∞)范围内发育,当q≤1时,标度紊乱,f(a)函数和Dq谱均不收敛,从而证明:多分形是由单分形演化而来,城镇体系的多分形结构是由测度集中区向测度疏散区不断发展、逐渐形成的。另外,从人地关系、系统演化以及测算方法等角度对有关问题进行了初步探讨。  相似文献   

6.
土石混合体粒度分形特性及其与含石量和强度的关系   总被引:3,自引:0,他引:3  
利用分形理论论证土石混合体的层次性,建立土石混合体的二维分形结构模型,提出粗、细料无标度区间粒度分维值的概念;通过100组筛分析实验分析土石混合体的粒度分形特征并分析其与含石量的关系;通过大型三轴试验分析土石混合体的粒度分维值与抗剪强度的关系。研究结果表明:土石混合体具有统计意义上的自相似性,一般存在2个粒度无标度区间,具有2个粒度分维值,但对于最优级配土石混合体是一维分形;土石混合体粒度分维值与含石量及强度之间均呈抛物线性关系,对于只具一维分形的土石混合体具有最大的密实度和抗剪强度。  相似文献   

7.
振动波形的分形判别及特征提取   总被引:34,自引:0,他引:34  
首先给出了寻找振动波形的无标度区的方法,波形在无标度区内可视为无规分形,利用文中的公式可以求得波形的盒维数。振动式的验表明,波形确实存在在无标度区;盒维数为波形的一个重要特征,可以用于对振动状态的分类识别;与频域模在数识别的方法相比较,盒维数方法更简单易行。  相似文献   

8.
作者根据许多地质体在很宽的标度范围内普遍具有的标度不变性和自性,尝试将分形理论应用于石油地球物理勘探中。还运用重建相空间法对实际的地震资料进行了处理,计算出关联维娄对关联维数与钻井结果的关系进行了解释。  相似文献   

9.
通过实地观测获取南京市路域植被情况数据,对草类、灌木类、乔木类3种不同植被类型图斑形状指数标度-频度关系、自相似分形特征及决定系数进行网格法分析。在此基础上,通过变异矩阵分析、分维计算等方式,对满足分形特征的不同道路和坡向的路域植被进行植被配置合理性、空间异质性和生态稳定性的对比分析和量化考察。应用空间异质性理论与分形理论,将网格法与变异函数法结合,依次分析标度-频度关系、分形特征、空间异质性,准确计算出路域植被的分维指标数据。结果表明:连续的道路路域各植被类型存在标度-频度关系和自相似分形特征,分维指标可以准确定量地评价路域生态系统的空间异质性与生态稳定性。  相似文献   

10.
基于lnC(r)~lnr关系曲线最小曲率值的无标度区的识别   总被引:1,自引:0,他引:1  
为计算关联维数D2,应确定G.P算法过程中的无标度区.从ln C(r)~ln r关系曲线的几何特征出发,分析关系曲线最小曲率的分形意义,结果表明:以最小曲率点作为计算无标度区的基点,以曲线上两点间夹角的大小作为线性相关性的判断依据,能够准确判断关联维数计算时的无标度区上下限.编制Matlab计算程序,对Lorenz混沌系统进行计算,表明该方法的适用性.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

19.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

20.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

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