长江日流量混沌变化特性研究——Ⅰ相空间嵌入滞时的确定   总被引：26，自引：3，他引：26       下载免费PDF全文

丁晶  王文圣  赵永龙 《水科学进展》2003,14(4):407-411

为了以新途径探索长江水量变化规律并在此基础上做出预测,全面而系统地研究了宜昌站日流量混沌变化特性并建立了新预测模型.重点论述相空间嵌入滞时的确定.分析了传统的自相关函数法和真实矢量场法确定嵌入滞时的优劣,并提出以广义相关函数合理确定嵌入滞时的方法.研究结果表明广义相关函数法是一个合理又可操作的途径.  相似文献   

新疆天山地区地貌分形与多重分形特征研究   总被引：1，自引：0，他引：1  

李锰  朱令人  龙海英 《内陆地震》2003,17(1):20-26

利用投影覆盖法和投影覆盖概率对新疆天山地区不同构造地貌类型进行了分形与多重分形特征的研究。结果表明：在所研究的标度范围内，不同地貌区均表现出明显的多度域分形，分维值总体上呈现出高山区＞中低山区＞盆地区特点，多重分形谱Dq的形态和值域范围也表现出不同特征。研究认为，地貌表面的分维值与地貌形成的内外力地质作用方式和强度密切相关，并提出5-6km的尺度可作为地貌学研究中宏观与微观作用的分界点。  相似文献   

自相似和自仿射分形裂纹力学     

A．Yavari S．Sarkani E．T．MoyerJr张乃铃  安镇文陈学忠 《世界地震译丛》2003,(3):63-80

研究了断裂面分形特征的力学特征，同时研究了自相似和自仿射分形裂纹尖端附近应力和应变的奇异性结构，讨论了二维和三维固体中分形裂纹的3种经典断裂型式和第四种断裂型式。发现分形断裂力学中有6种断裂型式。同时，结果表明J积分与路径有关。阐明了文献中提出修改的、且被证明与路径无关的，积分仅局部与路径无关，而且没有物理意义。可以推测，分形，积分应当是单位裂纹扩展分形测度的势能释放率。我们计算了某些应变硬化材料中分形裂纹应力知应变奇异性的幂。结果显示，分形裂纹尖端的应力和应变比光滑裂纹的应力和应变有较弱的奇异性。  相似文献   

三峡工程建立水库诱发地震监测预报系统     

董泰 《国际地震动态》2003,(1):41-41

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高浓度黏性泥石流堆积层理结构中筛积层和粗化层形成机理的研究   总被引：5，自引：0，他引：5  

王裕宜  詹钱登  韩文亮  邹仁元 《沉积学报》2003,21(2):205-210

根据高浓度黏性泥石流的观测资料,应用不同类型黏性泥石流的流变特性和流体结构的分类指标-流核比,对高浓度黏性泥石流堆积中的混杂层、筛积层和粗化层理结构进行了成因差异分析。侧重分析了砾石质点在高浓度黏性泥石流蠕动流场中作向上垂直运动的魏森伯效应,并在表面富集形成了筛积层的成因,及其它与粗化层结构的区别。  相似文献   

一种新的粒度指标:沉积物粒度分维值及其环境意义   总被引：28，自引：2，他引：28  

柏春广  王建 《沉积学报》2003,21(2):234-239

根据分形理论，对1000个不同类型沉积物样品的粒度分形结构及其分维值作了定量计算。结果表明：各类型沉积物都具有良好的统计自相似性，并且各自有着不同的分维值。粒度分维值的大小与分选好坏密切相关。没有经过外力搬运与分选的风化破碎物质(碎屑物)——断层泥、冻土的粒度分维值接近于碎形体的分维值2．60左右；经过外力搬运但分选作用较弱的冰碛物、水石流、泥石流堆积物的粒度分维值也接近2．60；而经过强烈外力分选作用的河床、湖泊沉积物、潮滩及海底沉积物的分维值明显偏小。鉴于此，本认为分维值可以作为沉积物类型判别的重要参数之一。  相似文献   

分形学:现代地图学的非线性数学分析方法   总被引：3，自引：0，他引：3  

龙毅  毋河海  陈仁喜  蔡金华 《测绘信息与工程》2003,28(2):1-3

分析了地图学的传统数学分析方法，讨论了对象复杂性与方法简单化的矛盾，阐述了分形几何学，为现代地图学研究的定量化、系统化提供了新的数学分析方法。  相似文献   

杭州湾地区浅层气分布及对工程特性的影响     

许章宏 《华东铀矿地质》2003,(2):50-55,49

本文以杭州湾大桥工程为重点试图对杭州湾地区浅层天然气在杭州湾地区的形成、分布特征作一概括，分析了浅层气喷发对土层及工程基础产生负摩阻力、沉降等危害，从浅层气的成因机制上找出工程施工中解决浅层天然气的对策(控制性释放)。  相似文献   

STRUCTURAL CHARACTERISTICS OF THE NIUSHOU MOUNTAIN AND ITS GEOLOGICAL SIGNIFICANCE IN CENTRAL NINGXIA     

ZHANGJin MAZongjin RENWenjun LEIYongliang 《大地构造与成矿学(英文版)》2003,27(1):165-178

There are many thrust-related structures occurring in the Paleozoic strata of the Niushou Mountain in the central part of Ningxia Hui Autonomous Region. The fault-related folds are the typical structures in this area. Based on the analysis about these structures and their relationships, the processes by which these structures of the Miboshan Formation were formed are reconstructed, and the strata underwent about three stages of deformation: (1) horizontal shortening, (2) folding, and (3) thrusting. And the fact that the Niushou Mountain is the leading edge of an old thrust sheet was proved, the Niushou Mountain, the Daluo Mountain and the Xiaoluo Mountain together constitute the front part of this old thrust zone, so the Niushou Mountain and the Ordovician strata in the central and southern parts of Ningxia now are likely allochthons. In the period from middle Ordovician to Devonian, the areas of the central and southern Ningxia belonged to the back-arc foreland basin of North Qilianshan orogen, which was adjacent to the continent in the north. In the later part of the early Paleozoic period, the Niushou Mountain was formed after the closure of the back-arc foreland basin.  相似文献   

POSITIVE INVERSION STRUCTURE OF THE CENTRAL STRUCTURE BELT IN TURPAN-HAMI BASIN   总被引：2，自引：0，他引：2  

ZHUWenbin MARuishi GUOLingzhi SUNYan XUMingjie HUDezhao 《大地构造与成矿学(英文版)》2003,27(1):179-190

The central structure belt in Turpan-Hami basin is composed of the Huoyanshan structure and Qiketai structure formed in late Triassic-early Jurassic, and is characterized by extensional tectonics. The thickness of strata in the hanging wall of the growth fault is obviously larger than that in the footwall, and a deposition center was evolved in the Taibei sag where the hanging wall of the fault is located. In late Jurassic the collision between Lhasa block and Eurasia continent resulted in the transformation of the Turpan-Hami basin from an extensional structure into a compressional structure, and consequently in the tectonic inversion of the central structure belt of the Turpan-Hami basin from the extensional normal fault in the earlier stage to the compressive thrust fault in the later stage. The Tertiary collision between the Indian plate and the Eurasian plate occurred around 55Ma, and this Himalayan orogenic event has played a profound role in shaping the Tianshan area, only the effect of the collision to this area was delayed since it culminated here approximately in late Oligocene-early Miocene. The central structure belt was strongly deformed and thrusted above the ground as a result of this tectonic event.  相似文献