爆聚法合成抗高温抗盐水基降滤失剂及性能评价

为了克服水相聚合法产物含量低、烘干过程分子量易增大和高能耗等问题,通过爆聚法利用单体苯乙烯磺酸钠和2-丙烯酰胺-2-甲基丙磺酸分别与丙烯酰胺和二甲基二烯丙基氯化铵合成制备了抗高温抗盐降滤失剂WS-1和WS-2。借助红外光谱（FT-IR）和热重分析（TGA）,表征了降滤失剂的分子结构和热稳定性,并且进行了降滤失剂在高温高盐水基钻井液中的流变性和高温高压滤失性能的影响实验。结果表明,具有刚性苯乙烯磺酸钠分子链段的降滤失剂WS-2具有良好的高温稳定性,热分解温度为310℃,降滤失剂WS-2在220℃饱和盐水基钻井液中高温高压滤失量为7.6 mL;具有大分子支链2-丙烯酰胺-2-甲基丙磺酸链段的降滤失剂WS-1热分解温度为270℃,200℃饱和盐水基钻井液中高温高压滤失量为1.6 mL;利用爆聚法合成的降滤失剂WS-1和WS-2均具有良好的抗温抗盐性能。      

Domestic-scale combined heat-and-power system incorporating a heat pump: analysis of a prototype plant

This paper introduces an innovative domestic scale combined heat-and-power plant (CHP), incorporating a heat pump (HP) for single-dwelling applications. The incorporation of a heat pump enhances the flexibility of a domestic scale CHP plant to satisfy domestic energy demand economically. The development, testing and subsequent thermodynamic analysis of the prototype plant are presented. First law thermodynamic analysis of experimental results is compared to equivalent second law analysis. Analysis of experimental results practically demonstrates that heat-pump incorporation satisfies extremely low domestic electrical requirements economically, whilst delivering relatively high thermal output, without resorting to electricity export.     

海洋无隔水管修井的数字孪生框架与可视化交互

为保障海洋无隔水管修井作业安全,构建了修井数字孪生系统.设计了海洋修井数字孪生系统五维模型框架,包括修井系统物理实体、虚拟实体、虚实数据交互、人工智能数据分析、作业决策服务.通过SolidWorks构建三维模型,将其导入U nity 3D来建立场景,构建修井系统的虚拟实体,利用虚拟现实技术提升交互性;基于OPC UA协...     

A first-ply failure analysis of composite laminates

A finite-element computational procedure is developed for the first-ply failure analysis of laminated composite plates. The procedure is based on the first-order shear deformation theory and a tensor polynomial failure criterion that contains the maximum stress, maximum strain, the Hill, Tsai-Wu and Hoffman failure criteria as special cases. By specifying the desired criterion, a first-ply failure analysis of composite laminates subjected to in-plane and/or bending loads can be achieved. A number of problems are presented to evaluate these failure criteria when applied to laminates subjected to in-plane and or bending loads.     

姜黄素对过度训练所致大鼠心肌细胞凋亡的保护作用

目的:研究姜黄素缓解过度训练所致的氧化应激,抑制大鼠心肌细胞凋亡的保护作用。方法:60只7周龄SPF级雄性Wistar大鼠经适应性饲养及训练后随机分为对照组(C组,12只)、过度训练组(OM组,24只)、姜黄素+过度训练组(COM组,24只)。C组不进行任何训练,OM组、COM组大鼠进行8周递增负荷游泳训练。训练期间,COM组以200 mg/(kg·d)剂量姜黄素进行灌胃,灌胃体积5 mL/kg,其余两组灌胃等体积0.5%羧甲基纤维素纳。末次训练后24 h,光镜观察心肌组织病理学改变,检测血清睾酮(T)、皮质酮(Cor)、心肌肌钙蛋白I(cTnI)浓度,以及心肌组织凋亡水平和核因子E2相关因子2(Nrf2)、血红素加氧酶-1(HO-1)、B淋巴细胞瘤因子-2(Bcl-2)、Bcl-2相关X蛋白(Bax)表达,同时测定心肌组织总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)活性以及丙二醛(MDA)浓度。结果:8周递增负荷游泳训练后,光镜下C组大鼠心肌组织结构正常;OM组出现组织病理学改变;COM组较OM组明显减轻。与C组比较,OM组血清Cor、cTnI、心肌细胞凋亡水平和促凋亡蛋白Bax表达水平及心肌MDA浓度均升高(p<0.01),血清T水平、心肌T-AOC和SOD活性(p<0.01)、心肌HO-1及抗凋亡蛋白Bcl-2表达水平(p<0.05)降低;心肌Nrf2表达水平无显著变化(p>0.05)。与OM组比较,COM组血清Cor、心肌细胞凋亡水平、Bax表达水平(p<0.01)和血清cTnI水平、心肌MDA浓度(p<0.05)降低,血清T水平、心肌Nrf2和Bcl-2表达水平、心肌T-AOC和SOD活性(p<0.01)、心肌HO-1(p<0.05)升高。组间T/Cor比值变化趋势与T变化相一致,Bcl-2/Bax比值变化趋势与Bcl-2变化相一致。结论:姜黄素通过上调Nrf2、HO-1蛋白表达,有效缓解过度训练引发的氧化应激,从而增加Bcl-2表达,减少Bax表达,抑制大鼠心肌细胞凋亡,保护心脏组织结构和功能正常。     

鄂尔多斯盆地东缘康宁地区二叠系致密储层成岩作用与孔隙度演化

鄂尔多斯盆地东缘康宁地区具有广阔的天然气勘探前景,是我国致密气勘探开发的重点区域之一。为研究其储层成岩作用及致密化机理,开展了铸体薄片鉴定、扫描电镜分析、X射线衍射测试、粒度分析等研究,对二叠系致密储层的岩石成分、孔隙类型和成岩演化等进行了深入探讨。结果表明：①岩石类型以细-中粒长石岩屑砂岩和岩屑砂岩为主,石英体积分数平均49%,岩屑体积分数平均36%,长石体积分数平均15%;②储层物性以低孔-特低渗型为主,平均孔隙度为7%,平均渗透率为0.46 mD,为典型致密储层;孔径小,喉道细,分选差,以次生溶蚀孔隙为主;③二叠系砂岩经历了压实作用、胶结作用、溶蚀-交代作用,成岩阶段为中成岩A-B期。④压实作用是导致储层致密的主要因素,使得初始孔隙度减少了16.39%,碳酸盐胶结作用和黏土矿物的充填作用次之,使孔隙度减少了约12.30%,后期溶蚀作用使孔隙度增加了6.01%,这一结论与现今实测平均孔隙度平均值7.46%较为吻合。上述研究成果对研究区致密气藏勘探中寻找次生溶蚀"甜点"具有一定的参考价值。     

求解不可压层流的一种全隐数值格式

该文基于SMAC(simplified marker and cell)方法,发展了一种在任意曲线坐标系中求解不可压黏性层流的全隐数值格式。基本方程是以逆变速度为未知变量的动量方程和关于压力修正量的Poisson方程。所有方程离散在MAC交错网格系统中进行。根据构造的全隐数值格式自编程序对一可简化成二维层流的后台阶流场进行计算,通过与已有的实验结果和计算结果进行比较,确认目前的计算结果优于比较的计算结果,和实验结果也相当吻合。为进一步验证该数值格式的可靠性,扩展程序对三维后台阶层流进行计算,结果表明,三维计算结果比二维计算结果更加接近实验结果。     

Onset of slugging criterion based on characteristics and stability analyses of transient one-dimensional two-phase flow equations of two-fluid model

A two-step approach has been used to obtain a new criterion for the onset of slug formation: (1) In the first step, a more general expression than the existing models for the onset of slug flow criterion has been derived from the analysis of singular points and neutral stability conditions of the transient one-dimensional two-phase flow equations of two-fluid model. (2) In the second step, introducing simplifications and incorporating a parameter into the general expression obtained in the first step to satisfy a number of physical conditions a priori specified, a new simple criterion for the onset of slug flow has been derived. Comparisons of the present model with existing models and experimental data show that the present model agrees very closely with Taitel & Dukler's model and experimental data in horizontal pipes. In an inclined pipe (θ = 50°), however, the difference between the predictions of the present model and those of existing models is appreciably large and the present model gives the best agreement with Ohnuki et al.'s data.     

On the fundamentals of electrochemical corrosion of X65 steel in CO2-containing formation water in the presence of acetic acid in petroleum production

Electrochemical corrosion behavior of X65 steel in CO₂-containing oilfield formation water in the presence of acetic acid (HAc) was investigated by various electrochemical measurements and analyses as well as thermodynamic calculations of ionic concentrations, reaction rate constants and equilibrium electrode potentials. A conceptual model was developed to illustrate corrosion processes of steel in oilfield formation water system. The anodic reactions of the steel contain a direct dissolution of Fe, Fe → Fe²⁺ + 2e, and the formation of corrosion scale, FeCO₃, by Fe + → FeCO₃ + H⁺ + 2e. The cathodic processes contain the reduction of H⁺, , H₂O and HAc, where reduction of HAc has the least negative equilibrium potential and thus dominates the cathodic process. With addition of HAc in the solution, both cathodic and anodic reaction rates increase remarkably. It is attributed to the fact that HAc inhibits or degrades the formation of protective scales due to the decrease of solution pH. Upon electrode rotation, the measured impedance decreases with the increase in HAc concentration. The FeCO₃ scale will not form on electrode surface. When HAc concentration is less than 1000 ppm, the adsorbed intermediate product is not significant, resulting in generation of a low-frequency inductive loop in EIS plots. When HAc concentration is more than 3000 ppm, the adsorption of intermediate product is significant, generating overlapped capacitive semicircles in EIS measurements.