扬子与华北太宙基底差异的 Sm-Nd 同位素和 REE 新证据

本文通过对扬子崆岭杂岩和华北太华群和阜平群新太古代和古元古代斜长角闪岩、TTG片麻岩 Sm-Nd同位素和REE对比研究，讨论了同时代岩石对地壳主体增生时代、地幔性质和演化规律的揭示，表明两克拉通属不同大陆岩石圈陆块。     

Study of the liquefaction resistance of a saturated sand reinforced with Geosynthetics

This article presents various tests using a cyclic triaxial instrument, on samples of saturated Hostun RF sand, reinforced with circular sheets of geosynthetic material. Tests performed with different types of geosynthetics of different compressibility, rigidity and roughness characteristics indicate a significant increase in liquefaction resistance for samples reinforced with compressible, non-woven geotextiles. The undrained behaviour of saturated Hostun RF sand reinforced with non-woven geotextiles is analysed on the basis of different test series. This analysis highlights the influence of reinforcement compressibility on interstitial pressure distribution in the sample, thus showing the role of this type of inclusion in the increase in liquefaction resistance.     

Seismic data compression based on integer wavelet transform

Introduction With the development of the seismological observation technique and deep-going of seismicdata application fields, especially the digitization of data in earthquake station networks, theimprovement of the precision, the data quantity increases as geometric order, which bringdifficulty to saving and transfering these data. To keep all information, seismic data, like medicalimages, should be compressed without error in many applications. In generally, traditionalcompression meth…     

基于小波变换的遥感影像压缩编码

基于小波变换的图像压缩方法能在高压缩比的前提下保持好的重建图像质量,它的多分辨率特性与人类视觉系统非常相近,小波变换的编码技术被广泛地应用于遥感影像的压缩中。介绍了小波理论的相关知识,着重对嵌入零树小波、等级树分割、小波数据的形态学表示算法等方法进行了详细的论述,并对图像编码技术的发展方向进行了展望。     

天津泰达地区粉土振动液化特性的研究

本文以动三轴试验和原位测试数据为基础，以天津地区砂性土为例，探讨砂性土振动液化机理及孔隙水压力变化规律，采用多种方法分析判别砂性土液化，为高烈度地区重要工程建筑抗震设计提供重要数据。     

土工带加筋碎石土本构关系的三轴试验研究

通过碎石土和加筋碎石土的大型三轴试验,分析了土工带加筋碎石土的变形特性和土工带加筋对碎石土应力-应变关系的影响,采用双曲线函数拟合加筋土体的应力-应变试验曲线,建立了土工带加筋碎石土的非线性模型以克服经典的刚塑体模型不能反映加筋土体在达到破坏荷载前的变形形态的缺点,提出了土工带加筋土体切线模量的计算公式,该模型能正确反映土工带加筋土体的变形特性,在岩土工程方面有一定的实际应用价值.     

Strain accumulation in sand due to cyclic loading: drained triaxial tests

Our aim is the prediction of the accumulation of strain and/or stress under cyclic loading with many (thousands to millions) cycles and relatively small amplitudes. A high-cycle constitutive model is used for this purpose. Its formulas are based on numerous cyclic tests. This paper describes drained tests with triaxial compression and uniaxial stress cycles. The influence of the strain amplitude, the average stress, the density, the cyclic preloading history and the grain size distribution on the direction and the intensity of strain accumulation is discussed.     

Lame surfaces as a generalisation of the triaxial ellipsoid

In modern geodesy the triaxial ellipsoid as a generalisation of the ellipsoid of revolution has a significant position in studying the figure of the Earth. Lame surfaces represent a generalisation of the triaxial ellipsoid. The following paragraphs are devoted to curvatures of the Lame surfaces.     

鄂 北 地 区 钻 头 优 选 探 讨

为适应鄂尔多斯塔巴庙区块勘探开发需要，利用区域测井资料进行钻头选型，并结合现场实践优化钻头类型和钻井参数，提高钻井效率。通过新型PDC钻头推广应用,单口井所需钻头数量减少3~4只，减少起下钻3回次以上，缩短钻井周期3~5天。