Characterizing the deformation behavior of Tertiary sandstones

Tertiary sandstones possess deformational behavior different from hard rocks, especially the relatively larger amount of volumetric dilation during shearing. Such excess dilation contributes to the increase of crown settlement during tunnel excavation and accounts for several cases of tunnel squeezing within Tertiary sandstones. Therefore, the deformation behavior of Tertiary sandstones sampled from more than 13 formations was studied. To distinguish the volumetric deformation induced by hydrostatic stress or by shear stress as well as to decompose the elastic and the plastic components of strains, special experimental techniques, including pure shear tests and cycles of loading–unloading were applied.The experimental results reveal that the deformation of Tertiary sandstone exhibits the following characteristics: (1) significant amount of shear dilation, especially elastic shear dilation; (2) non-linear elastic and plastic deformation; (3) plastic deformation occurs prior to the failure state. Furthermore, features of plastic deformation were inferred from experimental results and, as a result, the geometry of plastic potential surface and the hardening rule were accordingly determined. A constitutive model, involving nonlinear elastic/plastic deformation and volumetric deformation induced by shear stress, is proposed. This proposed model simulates the deformational behavior for the shear-dilation-typed rocks reasonably well. Furthermore, tests on the versatility of the proposed model, including varying hydrostatic stress and stress paths, indicate that the proposed model is capable of predicting deformational behavior for various conditions.     

下扬子北缘前陆盆地构造变形样式

下扬子北缘前陆盆地经历了印支、燕山、喜山等多期构造改造,构造环境经开裂扩张—碰撞拼合—拉伸断陷等多次转换,最终形成了上部拉伸、中部逆冲推覆、下部拆离滑脱的"三层楼阁"式分层构造变形组合的构造几何学模式.其构造变形主要受中三叠世扬子地块与华北地块的陆—陆碰撞造山作用控制,具有横向上强弱分带、垂向上形变分层的特征.可划分为伸展变形、冲断褶皱变形、拆离滑脱变形等3种构造变形样式.      

立足于实际的数字系统级诊断

本文主要提出了一个立足于当前实际的系统级诊断模型。在这模型下，系统级诊断变得很容易。模型基于下列假定：将系统划分成既具有自测试又具有测试其它单位能力的一种单位；其测试能力和测试结果用模糊数学来描述；自测试时在各种情况下均能给出正确的结果；测试其它单位时，除测试者本身具有严重故障外，也均能给出正确结果。     

复杂山区静校正方法研究及效果

对于山区地震勘探，开展静校正研究是资料处理的主要问题之一。静校正精度与剖面质量密切相关，准确的静校正取决于合理的方法和正确的应用。本文在分析了复杂山区特点以及静校正难点的基础上，指出要解决好山区静校正，仅限于普通的方法是远远不够的，必须从四个关键点人手，即风化层延迟时的求取、基准面的确定、校正速度的研究以及表层模型的建立等。本文对上述问题的研究做了介绍，展示了合成延迟时法十等效速度模型反演十变速浮动基准面（地震参考面）静校正等综合技术在太行山区（山西沁源、大寨）、伊J；1丘陵山区等复杂地表区应用的例子。显著的处理效果表明，严重的山区静校正问题得到了较好的解决，满足了地下构造的叠加成像，提高了勘探精度及其整体效果。     

A Study on the Model of Forecasting System about the Actual Telephone Occupation in the Lead Development

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声表面波可程序抽头延迟线研究

报道声表面波可程序抽头延迟线的研制情况。对该器件的总体结构，电路原理框图、声表面波可程序抽头延迟线结构作了一个扼要的概念。同时分别报道了我所研制的各类声表面波可程序抽头延迟线器件性能指标及相应的图片说明，最后对该器件仍存在的一些问题作了探讨。     

31位低频声表面波可程序匹配滤波器

报道了３１位声表面波可程序匹配滤波器的结构、设计和性能参数。声表面波可程序抽头延迟线是近年来快速发展的直扩技术广泛应用的一种器件。它的强大信号处理能力和极高的运算速度，使得直扩序列信号的快速同步及匹配滤波较传统的技术大为简化。文章报道的３１位声表面波低频可程序抽头延迟线是一种用于扩频抗干扰通信系统所用的关键信号处理器件。在研制过程中，采用的ＣＯＭＳ／ＳＯＳ等新技术以及分裂抽头等新设计，使器件的时钟速率和主旁瓣比关键技术指标获得了较大的提高，完全满足系统要求     

Nonlinear black-box modeling in system identification: a unified overview

A nonlinear black-box structure for a dynamical system is a model structure that is prepared to describe virtually any nonlinear dynamics. There has been considerable recent interest in this area, with structures based on neural networks, radial basis networks, wavelet networks and hinging hyperplanes, as well as wavelet-transform-based methods and models based on fuzzy sets and fuzzy rules. This paper describes all these approaches in a common framework, from a user's perspective. It focuses on what are the common features in the different approaches, the choices that have to be made and what considerations are relevant for a successful system-identification application of these techniques. It is pointed out that the nonlinear structures can be seen as a concatenation of a mapping form observed data to a regression vector and a nonlinear mapping from the regressor space to the output space. These mappings are discussed separately. The latter mapping is usually formed as a basis function expansion. The basis functions are typically formed from one simple scalar function, which is modified in terms of scale and location. The expansion from the scalar argument to the regressor space is achieved by a radial- or a ridge-type approach. Basic techniques for estimating the parameters in the structures are criterion minimization, as well as two-step procedures, where first the relevant basis functions are determined, using data, and then a linear least-squares step to determine the coordinates of the function approximation. A particular problem is to deal with the large number of potentially necessary parameters. This is handled by making the number of ‘used’ parameters considerably less than the number of ‘offered’ parameters, by regularization, shrinking, pruning or regressor selection.     

小角度控制网的平差方法探讨

本文从改变常规平差元素——角度的观点,阐述了小角度网的平差方法.     

Developing real-time knowledge-based systems with PERFECT

PERFECT (Programming EnviRonment For Expert systems Constrained in reasoning Time) is aimed at providing the necessary engineering support in real-time knowledge-based system development. PERFECT bridges the gap between the traditional analysis and design methodologies, and the implementation tools for these systems. It does so by providing the means to construct a knowledge model and to choose a suitable inference strategy. Subsequently the properties of the knowledge model and inference strategy may be analysed. For instance, it may be checked whether the knowledge model contains sufficient knowledge to diagnose a fault in an industrial process. Moreover, it may be checked whether the inference engine is able to provide an answer to a certain problem in time. If not, the analyser of PERFECT proposes an alternative structure of the knowledge model. When the constructed knowledge model and the chosen inference strategy show the required time efficiency, the compiler of PERFECT may translate them to an actual real-time knowledge based system in COGSYS. In addition, guidelines are provided with respect to the design of the human-machine interface. The resulting system is an instrument—a source of information that can be used by the human operator during problem-solving, rather than a prosthesis—a device that solves the entire problem by itself and presents the outcome to the human operator.