川西地区微晶白云母的矿物学特征研究

川西地区微晶白云母是一种新型白云母资源,其主要化学成分S iO245.7%,A l2O330.51%,K2O 11.63%,H2O 4.53%,与白云母的化学成分理论值接近,主要杂质离子F e,M g等以类质同象置换八面体中的A l3+。呈微细薄板状结晶形态,粒径小于10μm,一般1μm~5μm,平均5.5μm,厚度平均0.8μm,径厚比值小,平均6.9。结晶程度高,水化程度低或几乎未水化,不含蒙脱石间层矿物。微晶白云母的晶胞参数a=0.520 01 nm,b=0.906 33 nm,c=2.003 96 nm,α=90.00,°=β95.79,°γ=90.00,°属2M1型白云母,在结构矿物学上显示出与水云母和绢云母具有一定的差异性。     

Conditional Simulation with Patterns

An entirely new approach to stochastic simulation is proposed through the direct simulation of patterns. Unlike pixel-based (single grid cells) or object-based stochastic simulation, pattern-based simulation simulates by pasting patterns directly onto the simulation grid. A pattern is a multi-pixel configuration identifying a meaningful entity (a puzzle piece) of the underlying spatial continuity. The methodology relies on the use of a training image from which the pattern set (database) is extracted. The use of training images is not new. The concept of a training image is extensively used in simulating Markov random fields or for sequentially simulating structures using multiple-point statistics. Both these approaches rely on extracting statistics from the training image, then reproducing these statistics in multiple stochastic realizations, at the same time conditioning to any available data. The proposed approach does not rely, explicitly, on either a statistical or probabilistic methodology. Instead, a sequential simulation method is proposed that borrows heavily from the pattern recognition literature and simulates by pasting at each visited location along a random path a pattern that is compatible with the available local data and any previously simulated patterns. This paper discusses the various implementation details to accomplish this idea. Several 2D illustrative as well as realistic and complex 3D examples are presented to showcase the versatility of the proposed algorithm.     

A new approach to the three-dimensional quantification of angularity using image analysis of the size and form of coarse aggregates

This paper describes a system for the acquisition and analysis of 3D data from the surfaces of coarse aggregate particles. The technique uses laser triangulation to acquire data from the upper hemispheres of particles passing along a conveyor belt. Methods of determining particle size and form in three dimensions are described and a new approach to the quantification of angularity is presented. The algorithm uses mathematical morphology to provide a geometrically meaningful interpretation of particle shape. The relative advantages of 2D and 3D analysis of aggregate particles are discussed, and results are presented which demonstrate the validity of this approach.     

Regional deterministic characterization of fracture networks and its application to GIS-based rock fall risk assessment

The study investigates the possibility to incorporate fracture intensity and block geometry as spatially continuous parameters in GIS-based systems. For this purpose, a deterministic method has been implemented to estimate block size (Bloc3D) and joint frequency (COLTOP). In addition to measuring the block size, the Bloc3D Method provides a 3D representation of the shape of individual blocks. These two methods were applied using field measurements (joint set orientation and spacing) performed over a large field area, in the Swiss Alps. This area is characterized by a complex geology, a number of different rock masses and varying degrees of metamorphism. The spatial variability of the parameters was evaluated with regard to lithology and major faults. A model incorporating these measurements and observations into a GIS system to assess the risk associated with rock falls is proposed. The analysis concludes with a discussion on the feasibility of such an application in regularly and irregularly jointed rock masses, with persistent and impersistent discontinuities.     

Wavelet transformation of mode shape difference function for structural damage location identification

In this paper, a new approach to structural damage detection is presented using mode shape difference between the reference and damage states. In order to capture and display the signal of damage, wavelet transformation is performed upon the mode shape difference function. Results show that this presentation of signal is effective for damage detection. Furthermore, practical aspects of damage identification are investigated, including understanding and using the frequency contents of the mode shape difference function, the mother wavelet function and the resulting wavelet coefficients due to the band‐limited filtering of wavelet transformation. This proposition is experimented. Results are assertive of the proposed concept. Copyright © 2007 John Wiley & Sons, Ltd.     

"震情三分律"和"对称填补"模式与当代数学理论的某些相似性

根据邢台直接前震N-t图(与M-t图完全一致)和5次MS≥6.0地震活动时序相关性,采用“震情三分律”方法可分别得到大震前82 d,59 d的短期预测和30 h的临震预测;与此同时,若条件许可再采用“对称填补”方法又可作出强震到来前的“活动范围”预测区。指出,此二者都与当代数学理论有某些相似的特性。     

Influence of surface heterogeneity on scalar dissimilarity in the roughness sublayer

While it is generally known that surface heterogeneity weakens the application of Monin–Obukhov similarity (MOS), few studies have investigated how seasonal changes in the degree of surface heterogeneity at a particular site may influence the validity of the similarity application. Exploiting seasonal changes in forest function associated with senescence, we conduct a unique evaluation of the effects of surface heterogeneity on the validity of similarity theory at two sites through time. Using high frequency (10 Hz) velocity and scalar time series collected within the roughness sublayer over mixed hardwood deciduous and coniferous forests during both periods of peak leaf area and senescence of deciduous foliage, we examined conformity with proposed universal flux-variance predictions and agreement amongst normalized standard deviations of different scalars (temperature, water vapour and carbon dioxide concentrations). Normalized scalar standard deviations were elevated above MOS flux-variance predictions, with more pronounced deviations observed during and following senescence, particularly in the case of CO₂. Power-law scaling of normalized standard deviations as a function of stability was upheld and robust to seasonal changes in surface heterogeneity. However, dissimilarity of normalized standard deviations for the scalars increased during senescence, as heterogeneity in the source/sink field increased. Scalewise decomposition of scalar time series using wavelet analysis indicated that correlations between scalars were conservative through much of the inertial cascade but decayed for eddies < 10 m. Senescence lowered correlations between scalars over a wide range of eddy sizes. These results demonstrate how seasonal changes in surface physiology can cause a temporal production of heterogeneity in the source/sink field, thus weakening similarity applications in the roughness sublayer.     

Estimates of parameters of grain-size distribution from weight frequencies

When grains of a sediment sample are separated by sieving into a number of size classes, the weight of the grains belonging to a particular size-class is called the weight frequency of that class. That the weight frequencies cannot be used as simple frequencies for the calculation of the mean and standard deviation of size of grains is well known. A method is developed in this paper for estimating these two as well as a third parameter, named shape parameter, by minimizing a quadratic form that arises naturally as an analogue of the ² statistic. Two fully worked out numerical examples, with simulated data, are presented to illustrate the method. A computer program in FORTRAN language is also appended. Comparative study shows that the quicker conventional method used by geologists may produce reasonably good estimates of standard deviation when the sample size is large, but the estimates of mean may show large deviations.