川西非常规气藏压裂改造工艺初探

新场地区须家河组五段地层为砂泥岩互层的非常规储层,储层厚度平均500 m左右,脆性矿物含量约60%且天然裂缝发育,通过体积压裂改造具备形成大型缝网的条件。针对该类储层的地质特征,在引进国外页岩气压裂工艺的基础上,研制形成的降阻水体系降阻率达到80%、探索形成的分层压裂工艺及体积压裂的规模、排量、停泵次数等施工参数,通过现场实施得到验证,压后平均产量为3.5×104m3/d,取得较好改造效果。     

Structural stability of chemically delithiated layered (1 − z)Li[Li1/3Mn2/3]O2–zLi[Mn0.5−yNi0.5−yCo2y]O2 solid solution cathodes

Lithium has been chemically extracted from the layered oxide solid solutions Li[Li_1/3Mn_2/3]O₂–(z)Li[Mn_0.5−yNi_0.5−yCo_2y]O₂ (0 ≤ y ≤ 1/2 and 0.25 ≤ z ≤ 0.75) and characterized by X-ray diffraction. The weak super lattice reflections that occur in the parent samples at around 2θ = 20–25° vanish on extracting a significant amount of lithium due to the removal of lithium from the transition metal layer and a consequent loss of the ordering between the Li⁺ and the transition metal ions. Additionally, the chemical delithiation process results in an incorporation of some protons from the chemical delithiation medium into the layered lattice, which has an influence on the structure of the delithiated samples. While the incorporation of a higher concentration (0.4 per formula unit) of protons results in the formation of O1 or P3 phases, delithiated samples with <0.2 protons maintain the initial O3 structure. However, the electrochemically charged samples maintain the initial O3 structure.     

可溶性大豆多糖在花生蛋白奶中的应用研究

花生蛋白奶制品风味独特,含有丰富的营养,但其产品稳定性差,常出现乳液分层,甚至沉淀,严重影响产品质量.本文通过离心沉淀率,乳化分层现象来研究可溶性大豆多糖等几种乳化稳定剂对花生蛋白奶(由m花生仁:V水=1 1:13制成)稳定性的影响,结果表明可溶性大豆多糖可作为营养强化剂和稳定剂加入到花生蛋白奶中,其合理添加量为0. 3%.     

基于分层图的动态RWA算法的仿真与实现

RWA问题是光网络中的一个核心问题。随着RWA优化算法求解方式的简化,算法的运算效率得到了提高,但却牺牲了解的优化性能。如何使优化效率和时间效率协调统一是当前光网络中RWA优化算法设计的难点。对光网络中动态RWA问题进行了阐述,对基于分层图的动态RWA算法进行了仿真与分析,仿真证明,该算法可以大幅降低网络的阻塞性能,且算法稳定性更好、资源利用率较高。     

Poly[(3‐hydroxybutyrate)‐co‐(3‐hydroxyvalerate)]/layered double hydroxide nanocomposites

BACKGROUND: The thermomechanical performance of poly[(3‐hydroxybutyrate)‐co‐(3‐hydroxyvalerate)] (PHBV) is associated with its crystallization. Enhanced nucleation using a stearate‐functionalized synthetic layered double hydroxide (LDH) presents a potential solution. RESULTS: PHBV crystallization varied with concentration of LDH. At lower LDH concentration, thermal history‐induced cold crystallization was present. The extent of this order–disorder transition decreased with increasing LDH concentration and was completely eliminated at 7 wt% LDH. PHBV did not have a melt recrystallization peak but the introduction of LDH resulted in an increasingly pronounced melt recrystallization with increasing LDH concentration. Polarized optical microscopy coupled with differential scanning calorimetry and wide angle X‐ray diffraction (WAXD) analysis indicated increased lamella thickness in the nanocomposites compared to pure PHBV. WAXD and transmission electron microscopy showed that the nanocomposites had an intercalated but aggregated dispersion. CONCLUSION: The concentration of nanofiller provides unique effects in PHBV. Mechanical performance was found to scale with composition as determined using dynamic mechanical analysis and tensile testing. Copyright © 2008 Society of Chemical Industry     

模拟填筑层数及水位对坝体变形及稳定性的影响

坝体的变形及稳定性计算分析中,合理地选择模拟填筑层数并考察水位对坝体变形及稳定性的影响是十分必要的。首先以变形和稳定性系数作为评价指标,利用强度折减法计算坝坡的稳定性系数,基于FLAC^3D建立坝体的分层填筑三维数值模型,对施工填筑期的数值模拟填筑层数的选取标准进行了研究。其次,在合理的模拟填筑层条件下,研究了不同蓄水位对坝体的变形和稳定性的影响。结果表明:坝体的变形以沉降为主,模拟计算的坝体沉降与填筑层数关系很大。相对坝体沉降来说,水平位移和稳定性系数对填筑层数的敏感性小,应以满足坝体沉降的精度标准选择模拟填筑层数,建议模拟填筑层数不少于10层,坝越高,选取的模拟填筑层数宜越多;坝体的水平位移对库水位位置较敏感,沉降和稳定性系数对库水位位置敏感性小。这些结果在坝体变形和稳定性研究中对确定合适的填筑层数和考虑库水位的影响具有指导意义。     

分层取水技术在KLSK水利枢纽建设中的应用

KLSK水库是一座不完全多年调节水库,向下游河道放水的任务主要由发电洞实现。为了保证自发电洞下泄水的水温与天然河道尽量一致,发电洞进水口布置采取了分层取水设计。目前,我国已建的高坝大库布置为分层取水的工程实例并不多。本文介绍KLSK水库发电洞分层进水口的布置设计,并借助一年的放水水温监测资料,分析分层取水效果,以供今后同类工程设计借鉴。     

层状边坡的地震动输入方法研究

层状边坡是自然界中最常见的边坡之一,研究其动力响应规律对边坡的稳定性评价具有重要意义。为真实模拟弹性波在层状地基中的传播过程,首先建立层状地基的黏弹性人工边界模型,然后根据波动力学理论推导了考虑介质交界面的一次反射的等效荷载计算公式,并通过两层地基算例验证该输入方法的精度;针对层状边坡,采用本文提出的地震动输入方法和一种传统的输入方法分别研究其动力响应规律。研究表明:在两层地基算例中,本文提出的地震动输入方法能较好满足工程抗震的精度要求;在边坡的动力分析中,与传统方法相比,采用本文方法的边坡塑性应变能累积效应更加明显,且动力安全系数相对较小。     

层状氢氧化镁铝对碘离子的吸附性能

研究了层状氢氧化镁铝对水溶液中碘离子的吸附性能,考察了吸附时间、吸附剂加入量、碘离子初始浓度及pH值对吸附性能的影响,发现当吸附时间为7h,吸附剂加量大于2.4g/L,pH值在6.0～9.0之间时,吸附效果最好.     

考虑禁锢空气影响的层状土壤Green-Ampt入渗模型及试验验证

为考虑土壤孔隙中禁锢空气对入渗水流的阻滞作用,引入饱和度系数Sa（Sa小于1）来量化湿润区的饱和程度,建立了改进的层状土壤Green-Ampt入渗模型（MGAM）,并提出了由土壤物理特性参数估算Sa的计算公式。为检验MGAM的适用性,分别在室内长土柱和田间进行层状土壤的积水入渗试验,并采用MGAM、传统的Green-A...