岩体三维节点偶对分析及其应用

本文讨论了节点偶对分析的三维扩展。节点偶对分析是针对摩擦滑动节理单元的约束边界进行的序列矢量判定。在三维节理单元的分析中,几何约束和相应的力学判据极为复杂,采用节点偶对等效结合力方法才能迎刃而解。文中对三维转向节理模型的分析得到合理的结果,它表明本文所提出的方法可成功地应用于节理岩体的有限元分析。     

兰州市地域结构分析

兰州市是西北干旱地区典型的河谷盆地型城市，通过分析了兰州市域地域结构的特征，模式以及市区的结节地域和均质地域，讨论城市地域结构形成与发展的影响因素，兰州市域地域结构呈现带状分散多中心组团结构形态，而且各功能区的均质度，紧凑度都比较低，城市结节地域结构虽然发生了不同程度的变形，但仍遵循六边性构造的理论模型。     

Assessment of reliability in water distribution networks using entropy based measures

Entropy based expressions for measurement of reliability and redundancy have recently been reported. These measures approach assessment of the reliability of the distribution network from the intrinsic redundancy of the network layout. The paper extends earlier work on entropy functions by including a more explicit statement of the alternate paths available in the network and by recognizing that under certain circumstances, e.g., failure of some part of the network work, an outflow link from a node under normal working condition may become an inflow link to the same node. The measures are assessed by comparison with parameters measuring Nodal Pair Reliability and percentage of flow supplied at adequate pressure for a range of networks and link failure conditions in this networks. The entropy measures are shown to reflect changes in the network reliability, as measured by these two comparative parameters, very well.     

Digital modeling studies for evaluation of hydrogeological characteristics in Shadnagar granite basin,Andhra Pradesh,India

The use of digital models has increased significantly in recent years with the accessibility of fast computing machines. A variable dimensioned digital model was constructed for the Shadnagar granite basin using SPECTRUM-7 micro computer to integrate various hydrogeological characteristics and for their quantitative evaluation. The basin has an areal extent of 437 sq km and is demarcated with clear water divides in all directions. Transmissivity, recharge and discharge at each cell of the basin area were estimated by trial and error simulation of the hydrogeological phenomenon under steady state condition. Dynamic simulation at representative nodes facilitated the estimation of storage coefficient. The capability of the constructed model was established by the conformance of the simulated hydrographs with the actual behaviour of the ground water system. The entire studies ammended the earlier arrived estimates of various input/output hydrogeological parameters and evolved a methodology for efficient processing of aquifer simulation data     

Nodes and Field of Tourist Origins to Ancient Village——A Case Study of Huangcheng Village in Shanxi Province of China

Based on Hagget's theory of spatial structure,researches on the nodes and field of tourist origins to Huang-cheng Village in Shanxi Province of China have been explored.Nodal hierarchy structure of tourist origins is analyzed with cluster analysis and the gravity model.And field of tourist origins is analyzed with attraction radius index(R)and geography concentration index(G).In the field analysis,R and G of Huangcheng Village are compared with Xidi Village that is a world heritage located in Huangshan City of Anhui Province in China.According to comparison of loca-tions of two areas,influential factors for field area of Huangcheng Village are identified.It is concluded that:1)cluster analysis and gravity model can be complementary methods to each other for nodal hierarchy structure analysis of tour-ist origins;and 2)as far as location is concerned,the weak intensity effect of tourism resources in the tourist region is a major cause for explaining why tourist origins to Huangcheng Village are mainly its neighboring areas.Moreover,it is suggested that the regional effect of tourist resources should be regarded as a component of destination attractiveness when applying gravity model.     

Remnants of the amalgamation of the east and west Cathaysia blocks revealed by a short-period dense nodal array

The Cathaysia block located at the southeast South China block (SCB) is considered formed by the amalgamation of the east and west Cathaysia blocks along the Gaoyao–Huilai and Zhenghe–Dapu deep faults (here referred as GHF and ZDF, respectively). Although the extension of the ZDF to the northeast, which represents the amalgamation of the two sub-blocks has been confirmed, the development of the GHF to the southwest remains to be verified. To better constrain the detailed deep structure beneath the southwest Cathaysia, which hold great significance for revealing the evolution of the SCB, a linear seismic array with 331 nodal geophones was deployed across the Sanshui basin (SSB). Combining with the regional 10 permanent stations (PA), we obtained two profiles with teleseismic P-wave receiver function stacking. The most obvious feature in our results is the ascending Moho towards the coastal area, which is consistent with the passive margin continental and extensional tectonic setting. The stacking profile from the dense nodal array (DNA) shows that the Moho is offset beneath the transition zone of the Nanling orogeny and SSB. We deduce that this offset may be casued by the deep extension of the GHF, which represents the remnants of the amalgamation of the Cathaysia block. From the other evidences, we infer that the widespread and early erupted felsic magmas in the SSB may have resulted from lithospheric materials that were squeezed out to the surface. The relative higher Bouguer gravity and heat flow support the consolidation of magmas and the residual warm state in the shallow crustal scale beneath the SSB. The sporadic basaltic magmas in the middle SSB may have a close relation to deep extension of the GHF, which serves as a channel for upwelling hot materials.     

结节区视角下江苏省区域空间结构演化研究——对区域共振轴结构模式的探讨

长时间序列的区域空间结构的演化规律, 一直是空间结构模式分析中的薄弱环节, 而历史过程的长时段分析, 有助于对区域空间结构现状研判和对未来优化提供科学支撑。本文从结节区的视角, 对江苏省域地区过去2800 年间发展轴线产生、发展、主导、跃迁的全过程进行系统解析。选取春秋、隋、元、今4 个时点作点-轴、双核型空间结构的横向比较, 认为存在4 个发展阶段:春秋至南北朝、隋至南宋、元至清、民国至今;其中, 元至清和民国至今阶段, 分别发现区域发展中存在双核共振轴、港城共振轴现象。共振轴结构模式指区域中心城市(或市区)轴与门户港城(或港口县域)轴及其交通链接所形成的一种空间结构现象, 存在于过渡型区域发展背景下的沿江与沿海区域。最后, 从城市职能的变迁、点-轴型发展轴的跃迁、现代交通线的布局、相邻区域(上海)4 方面对江苏省区域空间结构的演化机理进行分析。     

大地震的18.6年周期

将全球分为15个研究区,用1900~2009年M_W≥7.0地震目录,统计分析了各区大地震与月球交点运动周期的关系,得出15个研究区中有10个区,大地震存在统计意义上的18.6 a周期:活跃段为12.4 a,平静段为6.2 a;环太平洋地震带北、南、西、东4大区的大地震,不仅有这样的周期,而且其地震活跃段的时间存在一定规律.用第6个18.6 a(1991~2009年)期间的大地震,检验据前5个18.6 a(1900~1990年)地震目录所得18.6 a 周期的稳定性和实用性,发现有这种周期的地区多数的周期性是稳定的.大地震18.6 a周期的可能成因有: (1)18.6 a潮波通过调制日潮和半日潮调制大地震; (2)上地幔内流体的潮汐(地内潮)作用; (3)18.6 a潮波通过影响地球自转变化调制大地震.     

Using GIS for analysis of urban systems

It is recognized that the spatial organization of urban system can be abstracted as three main components: a set of points, which describes the structural characteristics such as social and economic properties of individual city; a set of lines, which indicates the patterns of interaction among the cities; a set of spheres, which indicates how and to which extent each city affects the area around it. Even if such substance of urban system coincides with the main purpose of GIS for spatial or geometric data types such as point, line and region, little attention has been given to this point. By an evidence analysis of China, the application of potential analytical capabilities of GIS for urban system is attempted in this study. We find GIS acts as an efficient tool not only for the spatial structure analysis of urban system, which including potential distribution of cities, extraction of principal linkages among cities, and delimitation of subsystems; but also for the verification of socio-economic attributes and dynamics of urban system. This revised version was published online in July 2006 with corrections to the Cover Date.     

Temporal and spacial analysis of regional composite nodal plane solutions for small earthquakes

A method is proposed in this paper for the analysis of temporal and spatial characteristics of composite nodal plane solutions for small earthquakes. With this method, the interested region is devided into small areas according to the geological features of the region. As an example, 107 composite nodal plane solutions are calculated for the adjoining region of Shaxi, Hebei and Neimenggu. The temporal and spatial characteristics of the variations of the solution parameters before and after the great Tangshan main earthquake in 1976 have been analysed and some interesting results are obtained. The Chinese version of this paper appeared in the Chinese edition ofActa Seismlogica Sinica,13, 9–20, 1991.