Three dimensional shear wave velocity structure of crust and upper mantle in South China Sea and its adjacent regions by surface waveform inversion

IntroductionHistorically, surface waves provided much of our understanding of the lateral heterogeneity in the crust and the upper mantle, especially in oceans or desert areas. Traditional method utilizes the great circle theorem for surface waves. It assumed that surface wave propagates along the great circle connecting epicenter with station. Firstly, traditional surface wave analysis was carried out by using multi-frequency-filter dispersion analysis to acquire the group or phase velocity d…     

岩溶交代—充填型矿床铅锌品位分维及其地质意义

利用分形理论研究了江永岩溶交代－充填型矿床铅锌品位的分形结构特征，结果表明铅，锌品位分布具有自相似性，矿床成因类型与成矿构造类型分别是影响品位分维D值大小的主，次因素，分维D值在一定程度上为解决矿床地质问题提供了某些定量信息。     

Research on the multifractal characteristics of the temporal—spatial distribution of earthquakes over New Zealand area

Using the Hill estimator,general multifractal characteristics of events in the New Zealand area have been dis-cussed.Results show that the spatial distribution of shallow events has apparent clustering characteristics,inde-pendent of the threshold magnitude;but for deep events these characteristics are not clear.While the time interval distribution has obvious clustering characteristics both for deep and shallow events,although with a different scal-ing range,the Hill estimates tend to indicate that the time interval distribution has a unifractal rather than a multi-fractal nature.All above reveal that the seismicity nature for shallow and deepevents is apparently different.     

广义地震应变能释放的多重分形特征

利用基于小波变换的多重分形谱估计方法，研究了以中国东西部地区为代表的板内地震活动和以新西兰、日本为代表的板缘地震活动广义应变能释放的多重分形特征．结果表明，中国东、西部地震活动广义应变能释放的多重分形特征有明显差别，新西兰与日本的地震活动广义应变能释放的多重分形特征也有明显不同；地震活动的多重分形特征与构造的复杂程度有关．      

三维GIS场景绘制中的硬件加速

三维GIS的场景绘制涉及许多复杂对象且数据量巨大，给表达的真实性和实时性带来困难。基于NV扩展的OpenGL应用开发，可以充分利用图形加速卡的功能，有效地实现绘制性能的提高。该文阐释了加速原理和实现过程，并进行了实例研究和对比分析。     

江苏及邻区地震时序的多重分形特征及其预报意义

研究了江苏及邻区1970年以来5．5级以上地震的多重分形特征，着重用推广GP法研究了地震前后多重分形的广义维数谱Dq和奇异性谱f(a)。研究结果表明：所有震例的广义维数谱和奇异性谱均经历了远离地震时，异常出现时和异常消失时的三个特征变化阶段，异常出现的时间在震前半年至一年半内；多数震例异常在震前几个月内回返恢复，少数在震后数个月内恢复。上述结果说明利用地震时序的多重分形特征对于该地区半年至一年尺度的中强地震预报是有意义的。     

Interpretation of single-well tracer tests using fractional-flow dimensions. Part 2: A case study

Generalized equations using fractional-flow dimensions were derived to estimate the Darcy and groundwater-flow velocities obtained from the point-dilution and the single-well injection-withdrawal field tests. Flow velocities can only be estimated from single-well tests if the kinematic porosity or the hydraulic conductivity and hydraulic gradient are known a priori. A pumping test performed on the boreholes will yield an estimate of the fractional-flow dimension and the extent of the flow region by applying the generalized radial flow (GRF) model of Barker [Barker JA (1988) A generalized radial flow model for hydraulic tests in fractured rock. Water Resour Res 24(10):1796–1804]. These parameters are used in the generalised equations for the single-well tracer tests to estimate the flow-through area and, therewith, the Darcy or flow velocity. The generalized procedure, described in detail in Part 1 of this paper, is applied to two boreholes on the Campus Test Site located at the University of the Free State, Bloemfontein, South Africa, and it is shown that the two independent tests (i.e. the point-dilution and the single-well injection-withdrawal tests) yield similar estimates of the natural-seepage velocity in the aquifer. The estimated natural-flow velocity obtained by using fractional dimensions is about two times higher than the velocity estimated by using the standard method (i.e. flow dimension n=2, flow thickness equal to length of the sealed-off section of the borehole). Electronic Publication     

一种新的二维电阻率模拟方法

目前，对地下介质作电阻率成像需要将研究区域网格化。本文以格林函数为数学工具导出了网格化地电模型二维问题的边界积分方程，该方程适合于电阻率成像。用边界单元法求解该方程可以得出空间电位分布，从而进行视电阻率模拟。计算与实验结果的对比表明，这种方法是正确、可行的。     

Fractal analysis of the roughness and size distribution of granular materials

The roughness, i.e. general shape and surface irregularity, of particulate soil is an important characteristic that affects the mass behavior of the soil. Characterization of roughness has typically been limited to visual comparison of particles to standard charts, although other more quantitative methods such as Fourier analysis have also been used. Particle size distribution is another important mass-behavioral characteristic of granular soils, and similar to roughness, is defined within limited boundaries. Fractal geometry can be applied to irregular or fragmented patterns such as roughness and grain size distribution to provide quantifying and unique numerical values. This paper presents an evaluation of the applicability of fractal dimensioning techniques to the quantification of both physical particle roughness and grain size distribution of granular soil. The divider and the area-perimeter fractal dimensioning techniques are used to quantify roughness of planar profiles of individual sand grains. The characterization of the size distribution of granular material using fractal geometry is evaluated through Korcak's fragmentation theory. As shown herein, both the divider and the area-perimeter fractal dimensioning techniques are useful in characterizing soil particle roughness, and the results confirm the importance of differentiating between textural and structural aspects of roughness. Fractal geometry can also be used to quantify the size distribution of granular soils with relatively well-graded size distributions.     

新疆塔里木北部地区压,扭,张破裂面分维数D值测算

本文精测了新疆塔里木北部地区压、张、扭三类不同性质断层断面的起伏高度和长度,利用谢和平及Parisean(1994)的公式,测算了断面分维数D,又由D值测算了粗糙度JRC值,发现压、张、扭三类断层的D和JRC值有明显差别,所取得D值与美国的San Andrees断层的D值具有一定的相似性。