Diffusion characteristic of sulfate anion in surface region of cement mortar at early stage

The SO_4~(2-)concentration distributions in surface region of cement mortar immersed in sulfate solution at early stage were measured by layered sampling method combined with chemical analysis, and the diffusion coefficients of SO_4~(2-)anions in surface region of mortar into internal area were calculated by means of instantaneous plane diffusion theory. The experimental results showed that the SO_4~(2-)concentration gradually reduced when the diffusion depth increased in the surface region of mortar. Diffusion coefficient(D) was relevant with the concentration and kind of environmental sulfate solution, which reduced with immersion time at the beginning, and then rose slowly after a period of time. The calculation of initial diffusion coefficient(D_0) and starting time of deterioration(t_∞) caused by sulfate attack was further attempted based on the data of diffusion coefficient, and it was found that D_0 and t∞ were all relevant with concentrations of sulfate and different kind of sulfate as well.     

Solidification/Stabilization of Zinc-lead Tailings by Alkali Activated Slag Cement

An appropriate proportion of alkali activated slag cement, abbreviated as AASC later, was determined based on strength test of paste specimens. Results showed that AASC prepared from 14% low modulus water glass and blast furnace slag presented its compressive strength of hardened cement paste of 69.6, 84.0 and 91.8 MPa at 3, 7, and 28 d curing ages respectively. Flowability of the fresh tailings-cement pastes and the strength development of hardened tailings-cement paste were also tested both in the cases with addition of AASC and Portland cement. The fresh tailings-cement paste added with AASC presented much better flowability and the corresponding hardened paste presented higher compressive strength, especially the long term strength, than those added with Portland cement. Therefore, tailings paste added with AASC allowed lager solid content than that of Portland cement in order to keep the similar flowability. SEM observation on the microstructure of the hardened tailings-AASC mixture pastes showed obvious cementation effect. MIP measurements also showed that the total porosity of the hardened tailings-cement pastes decreased, and the portion of larger pore also decreased when the dosage of AASC increased. It is believed that AASC is more suitable to be used as a binder for the stabilization of zinc-lead tailings and for its backfilling operation than Portland cement.     

油田井站单井自动计量系统研究

数字化油田的基本问题之一是建立安全可靠规范的油田井站单井自动计量系统。文章给出了数字化油田的三个基本内涵,结合纯梁采油厂48号井站,设计了油田井站单井自动计量系统。针对井站各井流量范围大小差别很大的特点,开发了复合流量计量技术。按照对单井数据进行综合利用的要求,基于 OPC 协议和 Visual Baisc 语言,开发了单井数据库。该系统投运以来,运行状态良好,达到了设计要求。     

高效低碱液态水泥速凝剂的性能及促凝机理研究

介绍了以硫酸铝为主要成分的速凝剂,通过对其组分的种类、数量的添加和优化来缩短水泥凝结时间,改善强度性能的试验研究情况;阐述了该速凝剂的促凝机理。试验结果表明：该速凝剂掺量为4％时,可使得P·O42．5水泥初凝时间缩短至小于2min,终凝时间缩短至小于5min;1d抗压强度达到15．5MPa,是空白试样的136％,28d抗压强度保留率达到105％。水泥水化样品的扫描电镜观察（SEM）显示,该速凝剂是通过促进钙矾石的快速大量生成而达到速凝效果的。     

遥感信息元数据集成服务系统的研究与实现

在SOA框架下研究遥感信息资源元数据的集成涉及的关键技术。系统中数据源以服务的方式动态接入,并通过一个中间代理层对外提供统一的服务;系统将W eb服务技术与联邦模式技术进行有机地结合,实现了异构遥感元数据的集成,支撑遥感数据的跨域共享。试用结果表明,系统完全达到了设计目标,效果良好。     

基于生命周期的数控转塔冲床寿命分布模型及控制

提出建立基于生命周期的数控转塔冲床寿命分布模型,揭示包含早期故障期和偶然故障期的故障机理和规律.模型表明,采取可靠性增长技术措施后的数控转塔冲床故障间隔时间分布是形状参数接近于1的威布尔分布,故障率A(t)曲线残存少许的浴盆曲线的左侧面,削掉了故障率高的曲线段,说明早期故障大部分已经在主机厂消除,可靠性增长的技术措施已经收到明显效果.基于生命周期的寿命分布模型的建立,为科学评估数控转塔冲床的可靠性水平提供了理论依据.     

无碱液态水泥速凝剂的性能及其促凝机理

采用无机-有机复合的方法在试验室成功合成无碱液态速凝剂(简称NSA速凝剂),并系统地研究了该速凝剂的添加对水泥凝结时间及强度发展的影响。此外,文中还分析了NSA速凝剂对水泥的促凝机理。     

几种化学物质对粉煤灰水泥活性激发效果

借助于水泥砂浆试样的抗压强度跟踪测试,考察了几种无机化学物质对粉煤灰水泥的活性激发效果,同时借助于对水泥硬化体样品的XRD测试和SEM观察,深入通探讨了添加激发剂的粉煤灰水泥硬化体的水化产物和微观结构特征。试验结果表明:激发剂显著促进了粉煤灰水泥的活性激发,尤其是早期活性,水泥强度显著提高;XRD测试和SEM观察也表明,与空白样品相比,掺加激发剂的粉煤灰水泥硬化体明显表现出致密化的结构特征,粉煤灰颗粒表面趋向于粗糙化;Ca(OH)2衍射峰和石英衍射峰明显减弱,表明在激发剂作用下粉煤灰中的活性成分与水泥水化放出的Ca(OH)2之间化学反应得到了加剧。     

低水灰比条件下水泥砂浆的抗硫酸盐侵蚀性能

硫酸盐侵蚀是混凝土耐久性研究的重要组成部分,被认为是引起混凝土材料失效破坏的主要因素之一。研究了低水灰比条件下掺有超细矿渣粉的水泥砂浆在不同种类和浓度的硫酸盐溶液中浸泡后的力学性能变化,同时,对侵蚀试样的孔结构进行了分析。试验结果表明:与普通水灰比相比,低水灰比条件下水泥砂浆的抗硫酸盐侵蚀性能改善更加显著;超细矿渣粉的引入不仅可以增加水泥砂浆的强度,而且可以改善其抗硫酸盐侵蚀性能;同时,矿渣粉掺加改变了水泥硬化体的孔隙率,水泥硬化体趋于致密化。     

爆燃压裂油井产能计算模型与增产效果分析

为了进一步提高爆燃压裂工艺设计与效果预测水平及工程应用效果,基于爆燃压裂原理和油藏渗流理论,利用保角变换方法,建立了爆燃压裂油井产能计算模型(包括流体从油藏边界渗流到爆燃裂缝的渗流外阻模型,和流体在裂缝中渗流入井的渗流内阻模型)并编制了计算软件。以低渗油藏油井F31-10井为例,计算、分析了油藏参数和爆燃裂缝参数对爆燃压裂油井增产效果的影响规律。研究结果表明:爆燃裂缝长度、裂缝数量和爆燃裂缝导流能力对油井增产效果有影响,影响程度由大到小依次是爆燃裂缝长度、裂缝数量和爆燃裂缝导流能力;在爆燃裂缝长度和裂缝数量一定的条件下,存在一个最佳的爆燃裂缝导流能力;爆燃压裂后油井增产倍数为1.365~2.115,且增加爆燃裂缝长度和爆燃裂缝数量比增加爆燃裂缝无因次导流能力对增产更有利。