关于我国海域无缝垂直基准构建方法的讨论

本文系统分析了海洋测绘垂直基准在海洋勘测、海洋开发海洋权益维护中的迫切性,提出我国海域无缝垂直基准构建的方法、实施的具体流程及需要解决的关键技术,目的是推动现代海洋测绘垂直基准框架体系的建设。     

白水煤矿煤矸石基本性能研究与分析

通过对白水煤矿煤矸石进行外观分类、化学组成、矿物成分分析和X衍射分析将其分为5种不同外型的煤矸石,其中,第Ⅲ类矸石属于高岭石质矸石黏土岩类矸石,其矿物相主要包括石英、高岭石、伊利石和少量的黄铁矿。实验研究不同类别矸石的粒径范围、陈化时间等对原材料塑性的影响表明:降低原料最大粒径,可以提高塑性,当粒径从-1.0 mm降低到-0.1 mm时,Ⅰ类矸石塑性指数IP提高了6.9;Ⅱ类矸石的IP提高了10.8;Ⅲ类矸石的IP提高了5.6;延长陈化时间,可以提高煤矸石的塑性,当陈化时间3 d时,陈化时间对塑性的贡献明显,当陈化时间4 d,陈化时间对塑性的贡献甚小。据此认为除第Ⅲ类煤矸石不适合制砖以外,其他矸石均可作为制备绿色墙体保温砌块的原材料,混合破碎至-0.5 mm,陈化3天,适合制备绿色墙体保温砌块的需要。     

鄂尔多斯盆地东部山西组山_2~3亚段砂岩判别图版、砂岩分布规律及成因探讨

勘探实践表明鄂尔多斯盆地东部山西组山32亚段含气性与岩性存在直接关系,石英砂岩储层往往是高产层。因此,寻找石英砂岩储层是该区勘探开发的重点。在岩心刻度测井的基础上,利用测井参数建立了3种类型砂岩的测井判别蛛网图版,并回归了石英相对百分含量与测井参数之间的关系式,利用此关系式对山32亚段砂岩类型进行识别,判识准确率达到80%。同时结合岩石薄片鉴定等资料,绘制了研究区砂岩类型平面分布图。单井结合平面图分析发现研究区存在3个环带状石英砂岩分布区域。从大地构造环境、物源、沉积环境等方面对该区山32亚段石英含量普遍较高和平面环带状分布原因进行了探讨,认为受海退影响的海岸线频繁变迁是形成石英砂岩分布的主要因素。     

Analytical and numerical analyses of the load‐bearing capacity of retaining walls laterally supported at both ends

This paper investigates the load‐bearing capacity of a perfectly smooth retaining wall laterally supported at both ends assuming that the wall fails by the development of three plastic hinges. The study considers the case of a cohesionless elastic–perfectly plastic backfill with a Mohr–Coulomb yield criterion and an associative flow rule in drained conditions. A kinematically admissible soil–structure failure mechanism is proposed and compared with the conventional solutions and with results from a numerical finite element modelling. The study shows that the proposed solution and the numerical solution are in good agreement. These solutions are found to be much more favourable for the wall than the conventional solutions. Copyright © 2010 John Wiley & Sons, Ltd.     

利用探空资料作3T测风图

介绍了3T测风图的原理和3T测风图软件的研制方法。系统采用面向对象编程技术，选用Visual Basic60作为开发语言，实现了3T测风图的任意时段，任意站点的查阅。     

Deterministic ground motion simulations with shallow crust nonlinearity at Garner Valley in Southern California

We present deterministic ground motion simulations that account for the cyclic multiaxial response of sediments in the shallow crust. We use the Garner Valley in Southern California as a test case. The multiaxial constitutive model is based on the bounding surface plasticity theory in terms of total stress and is implemented in a high‐performance computing finite‐element parallel code. A major advantage of this model is the small number of free parameters that need to be calibrated given a shear modulus reduction curve and the ultimate soil strength. This, in turn, makes the model suitable for regional‐scale simulations, where geotechnical data in the shallow crust are scarce. In this paper, we first describe a series of numerical experiments designed to verify the model implementation. This is followed by a series of idealized large‐scale simulations in a 35 26 4.5 km domain that encompasses the Garner Valley downhole array site, which is an instrumented and well‐characterized site in Southern California. Material properties were extracted from the Southern California Earthquake Center Community velocity model, CVM‐S4.26, considering its optional geotechnical layer, while the modulus reduction curves and soil strength were selected empirically to constrain the nonlinear soil model parameters. Our nonlinear simulations suggest that peak ground displacements within the valley increase relative to the linear case, while peak ground accelerations can increase or decrease, depending on the frequency content of the excitation. The comparisons of our simulations against hybrid three‐dimensional–one‐dimensional site response analyses suggest the inadequacy of the latter to capture the complexity of fully three‐dimensional simulations.     

Monitoring coastal evolution and associated littoral hazards of French Guiana shoreline with radar images

This paper aims at illustrating different case examples of monitoring active coastal evolutions using remote sensing synthetic aperture radar images (ERS 1–2 and Envisat) in humid tropical areas. Effectively, the radar satellite images may be acquired under most climate conditions, especially in cloudy tropical areas. As case examples, we studied herein French Guiana shoreline and its fast evolution under the combined influences of sea currents, sediments and swells. We focused on two aspects of French Guiana littoral evolution: (1) sedimentation and erosion processes linked to mud banks displacements around Kourou City, and (2) around Iracoubo village. Lastly, we compared this short-term sedimentation balance with long-term data showing the discrepancies of short- and long-term littoral evolutions on whole French Guiana. To conclude, this work demonstrates the importance of SAR imagery to provide high-quality and high-frequency update geographic information for coastal management and littoral hazards especially in such tropical humid and cloudy areas. To cite this article: H. Trebossen et al., C. R. Geoscience 337 (2005).     

Homogenization estimates for texture evolution in halite

In this work, the recently developed “second-order” self-consistent method [Liu, Y., Ponte Castañeda, P., 2004a. Second-order estimates for the effective behavior and field fluctuations in viscoplastic polycrystals. J. Mech. Phys. Solids 52 467–495] is used to simulate texture evolution in halite polycrystals. This method makes use of a suitably optimized linear comparison polycrystal and has the distinguishing property of being exact to second order in the heterogeneity contrast. The second-order model takes into consideration the effects of hardening and of the evolution of both crystallographic and morphological texture to yield reliable predictions for the macroscopic behavior of the polycrystal. Comparisons of these predictions with full-field numerical simulations [Lebensohn, R.A., Dawson, P.R., Kern, H.M., Wenk, H.R., 2003. Heterogeneous deformation and texture development in halite polycrystals: comparison of different modeling approaches and experimental data. Tectonophysics 370 287–311], as well as with predictions resulting from the earlier “variational” and “tangent” self-consistent models, included here for comparison purposes, provide insight into how the underlying assumptions of the various models affect slip in the grains, and therefore the texture predictions in highly anisotropic and nonlinear polycrystalline materials. The “second-order” self-consistent method, while giving a softer stress-strain response than the corresponding full-field results, predicts a pattern of texture evolution that is not captured by the other homogenization models and that agrees reasonably well with the full-field predictions and with the experimental measures.     

二维地震勘探变观量板图及其应用

在以炸药为震源的二维地震勘探野外资料采集施工中,需要避开各种不能钻井放炮的障碍物,根据勘查区设计任务书的施工参数,可以画出变观量板图。变观量板图具有快速变观的作用,野外所遇到的不同距离的障碍物可以通过变观避开,给施工提供方便,变观量板图具有实际应用价值。     

磁法仪器与电法仪器观测地磁场水平强度（H）精度及一致性的对比分析

对多年的观测资料进行综合对比分析,分别得出了磁法仪器与电法仪器观测地磁场中度（Ｈ）各自的精度、稳定性及两者之间一致性等结果。这对各地磁台采取不同观测仪器以便寻求最佳观测的组合形式,为有关部门研制地磁数字化观测系统均提供了理想的参考依据。