Strength and dilatancy behaviors of deep sands in Shanghai with a focus on grain size and shape effect

With rapid development of infrastructures like tunnels and open excavations in Shanghai, investigations on deeper soils have become critically important. Most of the existing laboratory works were focused on the clayey strata up to Layer 6 in Shanghai, i.e. at depth of up to 40 m. In this paper, Layers 7, 9, and 11, which were mostly formed of sandy soils at depth of up to 150 m, were experimentally investigated with respect to physico-mechanical behaviors. The stress–strain behaviors were analyzed by the consolidated drained/undrained (CD/CU) triaxial tests under monotonic loading. One-dimensional (1D) oedometer tests were performed to investigate the consolidation properties of the sandy soils. Specimens were prepared at three different relative densities for each layer. Also, the micro-images and particle size analyzers were used to analyze the shape and size of the sand grains. The influences of grain size, density, and angularity on the stress–strain behaviors and compressibility were also studied. Compared to the other layers, Layer 11 had the smallest mean grain size (D₅₀), highest compressibility, and lowest shear strength. In contrast, Layer 9 had the largest mean grain size, lowest compressibility, and highest shear strength. Layer 7 was of intermediate mean grain size, exhibiting more compressibility and less shear strength than that of Layer 9. Also, the critical state parameters and maximum dilatancy rate of different layers were discussed.     

“人工智能+”背景下的数据安全与隐私保护探析

随着大数据和云计算的技术的深入应用，人工智能时代的机器学习和深度学习更需要日益增长的数据，因此数据安全与隐私保护变得更加迫切。本文介绍人工智能的定义以及特征，探究数据安全和隐私保护现状，分析数据安全和隐私保护面临的诸多问题，并提出在人工智能时代对数据安全和隐私保护的措施。     

土壤中石油污染物的脱附过程

文章中主要采用有机溶剂萃取法（OSE）对高浓度石油污染土壤进行修复，经过精馏操作，有效回收原油，建立脱附等温曲线，研究了石油污染物在土壤-有机溶剂两相间的迁移规律。     

Behaviour of Surface Defects in Wire Rod Rolling

Defects are often present in rolled products, such as wire rod. The market demand for wire rod without any defects has increased. In the final wire rod products, defects originating from steel making, casting, pre‐rolling of billets and during wire rod rolling can appear. In this work, artificial V‐shaped longitudinal surface cracks have been analysed experimentally and by means of FEM. The results indicate that the experiments and FEM calculations show the same tendency except in two cases, where instability due to fairly “round” false round bars disturbed the experiment. FE studies in combination with practical experiments are necessary in order to understand the behaviour of the material flows in the groove and to explain whether the crack will open up as a V‐shape or if it will be closed as an I‐shape.     

离心泵并联运行工况点的数值求解

建立了求解多台不同型号离心泵并联运行工况点的数学模型,给出了用数值计算中的“二分法”求解该模型的方法,并附有用Exce l计算的实例。     

双河油田注入水适应性及注水井酸化解堵研究

考察了双河油田双河联、江河联注入水堵塞地层的因素;膨胀性黏土，悬浮固体颗粒。细菌及悬浮污油。含膨胀性黏土的双河南、双河北及不含膨胀性黏土的双江岩心粉，在注入水中相对于地层水中的体积膨胀度分别为14．5％、11．1％及0．02％；注入100PV不含悬浮颗粒的等体积比地层水、注入水混合水使双河、双江岩心渗透率分别下降7％和4％、9％和7％。注入水中悬浮颗粒引起岩心渗透率下降，粒径越大、颗粒浓度越大、注入量越大，则渗透率越低。在粒径2．1μm或颗粒浓度3mg／L前后下降幅度变化较大。注入水中硫酸盐还原菌引起岩心渗透率下降，含菌量越大则渗透率开始下降时的注水量越小，注入含菌50个／L的水100PV使岩心渗透率下降7％。岩心对注水合油量敏感，注入含油量20mg／L的水50PV使岩心渗透率下降20％。在岩心注水实验中渗透率下降最严重的是双河南岩心，其次是双河北岩心．江河岩心较轻，注入精细过滤水的双河北岩心渗透率下降大大减少．说明悬浮固体是造成注水堵塞的主要因素。为了解除双河油田注水井的堵塞，研制了含黏土稳定剂、缓蚀剂、铁离子稳定剂、互溶剂的土酸液，与南阳油田使用的低伤害酸液一起，用于1口注水井的解堵，效果良好。图7表4参5。     

高温高盐高含水油藏提高水驱采收率配套技术

针对江汉油区高温高盐高含水油藏的储层条件,应用国内外油藏精细描述、油藏工程最新理论与技术,提出了高含水油田合理钻加密井、完善注采井网、水平井挖潜、不稳定注水及高温高盐油藏采油工艺配套技术措施,形成了一套适应高温高盐高含水油藏提高水驱采收率的配套技术。