孤岛油田聚合物后续水驱井下注水工艺

针对聚合物后续水驱井下注水工艺存在层窜、吐聚、吐砂严重以及地层压力测试成功率较低、分层注水方案难以实施、大部分主力油层不吸水、作业频繁、后续水驱效果不理想等问题,设计了后续水驱配套工艺,制定了新的作业施工方案,优化了分层测调方法。该技术在孤岛油田B19断块、东区注水示范区进行了试验和推广应用。结果表明,地层压力场重新分布,改善了吸水剖面,地层平均吸水率为105．5％,测试平均成功率达到92．2％,有效防止了关井后地层返吐造成的出砂现象,提高注水层段的合格率,平均达到70．15％,防止了因停注或压降造成的吐聚现象。     

长春市粉煤灰蒸压加气混凝土围护结构传热系数现场检测分析

本文分析了传热系数现场检测方法的原理及适用条件,用热流计法检测粉煤灰蒸压加气混凝土围护结构的传热系数,并将实测数据与设计值、理论计算值进行了分析与研究．     

预应力锚索张拉应力损失的探讨和解决方法

目前在边坡加固工程的预应力锚索张拉过程中张拉应力损失是极其常见的问题,常导致张拉质量低下等严重的工程质量问题．结合一高边坡治理工地的抗滑桩锚索张拉实例,做两组平行试验,探讨锚索张拉过程的应力损失问题,发现对锚索进行预张拉能有效的减少张拉应力的损失,在工程实际允许的情况下,预张拉应力越大,张拉应力损失越小．并总结出一些合理的锚索施工方法,同样能减少张拉应力的损失．     

Peirce机织物几何结构模型的探讨

织物几何结构就是纱线在织物内部的屈曲状态,它影响织物的外观效应和物理机械性能,必须精确计算.在被普遍使用的Peirce机织物几何结构模型中,暗含如下假设:1织物中经纬纱屈曲波高无论怎样变化,其和均等于经纬纱理论直径之和乘以压扁系数;2同一浮长覆盖下的纱线中心在同一水平面上,屈曲波高仅与织物密度和织造缩率有关.从两个方面对此进行验证,一是以经典教材多块织物样品为例,用Peirce公式计算结果评估自身的精确性;二是用Nedgraphics纹织系统设计同一经纬密度的各种结构的机织物,在电子提花机上织造后利用Keyence 3D共聚焦显微镜对织物正反面进行非破坏性测量,得到不同浮长织物的屈曲波高并进行分析.结果表明,Peirce机织物的几何结构模型存在不足,需进一步改进.     

A modern and robust methodology for modeling anisotropic creep characteristics of Ni-based DS and SC superalloys

According to more recent work,the Wilshire equations have shown good prediction accuracy in a wide range of materials and stress-temperature conditions,particularly in extrapolation of short term results to long term predictions.In the current paper,this methodology was further developed for modeling anisotropic creep characteristics(i.e.minimum creep strain εmin ,stress rupture life tf and time to a specified strain tε)of four typical Ni-based directionally solidified(DS)and single crystal(SC)superalloys,where a simple orientation factor related to the ultimate tensile strength(UTS)was introduced.The application of these simplistic approaches showed that the anisotropic creep characteristics in a wide range of stress-temperature conditions can be accurately simulated.Meanwhile,during the application of the modified Wilshire equations,break points occurring at the specified stress levels agree well with the transition of creep deformation mechanisms occurring in different stress regions,which provides confidence for using this method.     

An experimental study of the incipient bed shear stress partition in mobile bed channels filled with emergent rigid vegetation

This paper investigates the bed shear stress based on the condition of the incipient motion of sediment in a uniform-flow flume covered with emergent rigid vegetation,which is represented by arrays of circular cylinders arranged in a regular pattern.A total of 148 tests are performed to observe the influence of the vegetation density,bed slope,flow depth and sediment size on the bed shear stress.The tests reveal that when the sediment is in incipient motion,the resistances acting on the flow passing the rigid vegetation contain the vegetation resistance and the bed shear stress.This shear stress could be divided into two parts:the grain shear stress and the shear stress caused by sand dunes,which are the deformed bedform with the sediment incipient motion.An empirical relationship between the shear stress of the sand dune and vegetation density,the Froude number,the apparent vegetation layer velocity is developed.     

Deformation effect of lateral roof roadway in close coal seams after repeated mining

This paper analyzed the deformation mechanism in lateral roof roadway of the Ding Wu-3 roadway which was disturbed by repeated mining of close coal seams Wu-8 and Wu-10 in Pingdingshan No. 1 Mine. To determine the strata disturbance scope, the strata displacement angle was used to calculate the protection pillar width. A numerical model was built considering the field geological conditions. In simulation, the mining stress borderline was defined as the contour where the induced stress is 1.5 times of the original stress. Simulation results show the mining stress borderline of the lateral roadway extended 91.7 m outward after repeated mining. Then the original stress increased, deforming the roadway of interest. This deformation agreed with the in situ observations. Moreover, the strata displacement angle changed due to repeated mining. Therefore, reselection of the displacement angle was required to design the protective pillar width. Since a constant strata displacement angle was used in traditional design, the proposed method was beneficial in field cases.     

路堤下盖板涵的竖向土压力分布

由于盖板在填土压力作用下发生挠曲变形,针对盖板涵对竖向土压力分布的影响,推导了盖板涵竖向土压力分布计算公式.假设盖板发生弹性挠曲变形,填土服从Winkler弹性地基条件,对盖板上修正的Marston填土涵洞竖向土压力分布进行了分析.结果表明,该修正公式考虑了盖板涵内外土柱差异沉降的应力集中效应,可计算由于盖板挠曲变形而引起的土压力重分布.通过对鹤大高速公路某盖板涵进行现场测试以及有限元数值模拟分析,结果显示盖板涵土压力的分布特点与本文理论分析相一致,且理论公式计算结果值与现场实测值吻合较好.     

激光熔覆Co基合金应力场的数值模拟

为了分析co基合金熔覆过程的应力场,建立了激光熔覆预置co基合金粉末过程的三维模型,考虑温度变化对热物理参数的影响以及表面对流换热和辐射散热等影响因素,使用SYSWELD软件分析了激光熔覆过程中的应力场,并进行了试验验证。结果表明：通过比较分析扫描速度为5mm／s的涂层获得良好的冶金结合;工件残余应力均为拉应力,且最大值出现在z向距表面约2mm处,最大变形量出现在工件的边缘位置;随扫描速度的增加,工件的残余应力和变形均明显减小,这说明在其它工艺参数一定的前提下,适当降低扫描速度,能有效减小熔覆层的应力集中,获得质量优异的涂层。模拟结果为激光熔覆过程的工业化提供了理论依据。     

炎症反应在NAFLD发病中的作用研究进展

非酒精性脂肪性肝病（NAFLD）是临床上最为常见的的肝病之一,炎症反应贯穿了NAFLD整个病变过程,其发病机制尚未完全阐明。目前认为胰岛素抵抗（IR）、氧化应激以及内质网应激（ERS）在NAFLD发病中起着重要作用。就炎症反应通过参与IR、氧化应激和ERS影响NAFLD进展作一综述。