混炼工艺对防老剂RD残余量及胶料性能的影响

研究混炼工艺对防老剂RD残余量及胶料性能的影响。结果表明：在高温处理过程中，防老剂RD发生分解反应，且随着热处理温度的升高，其质量损失增大；防老剂RD在高温（155 ℃）混炼阶段加入比在低温（110 ℃）混炼阶段加入质量损耗增大20%；与在高温混炼阶段加入相比，防老剂RD在低温混炼阶段加入，胶料在老化前的物理性能相当，但是在热老化后的物理性能、耐磨性能和抗切割性能等均得到改善。     

Room temperature multiferroic properties of Ni-doped Aurivillus phase Bi5Ti3FeO15

Single-phase Aurivillius Bi₅Ti₃Fe_0.5Ni_0.5O₁₅ (BTFN) ceramics were synthesized by the solid-state reaction method. The substitution of Ni for half Fe ions does not introduce magnetic impurity phase but increases magnetic moment more than two orders. The ferroelectric and magnetic Curie temperatures are determined to be 1100 K and 726 K. The room-temperature multiferroic behavior of the BTFN ceramics were demonstrated by the ferroelectric (2P_r=8.5 μC/cm², 2E_c=74 kV/cm) and ferromagnetic (2M_r=27.86 m emu/g, 2H_c=553 Oe) measurements. The ferromagnetism can be ascribed to the aggregation of magnetic ions at the inner octahedra by Ni doping and the spin canting of magnetic-ion-based sublattices via the Dzyaloshinskii-Moriya interaction. The present work suggests the possibility of doped Bi₅Ti₃FeO₁₅ as a potential room-temperature multiferroic.     

无醛型弹性白胶浆成膜剂的研制

为了开发一种高固含量、粘度适中、不含游离甲醛的聚丙烯酸酯乳液成膜剂,对原有配方进行了调整,且改变了工艺,分别考察了外观、离子性、固含量、粘度、pH、离心稳定性、抗拉强度等。结果表明:延长聚合反应时间,两次添加引发剂,可以提高固含量。同时配方中加入丙烯腈可增加胶膜的弹性。     

大吨位钢箱型吊车梁的制作技术

某动力公司出海口基地码头的一高4 000mm、宽1 700mm的钢箱型吊车梁,截面之大、重量之重在国内很罕见,其制作工艺较为复杂。介绍了该钢结构构件的制作工艺,通过设计使用专用拼装胎具和翻转胎具,将控制钢制箱型吊车梁的焊接变形来防止扭曲作为控制重点,进而解决了大吨位构件的施工翻转问题。     

纳米CaCO3填充改性PVC复合体系的性能研究

研究了2种纳米CaCO3填充PVC对复合材料力学性能的影响。结果表明,纳米CaCO3可以显著提高PVC的冲击强度,而对拉伸强度和断裂伸长率影响较小;适当的基体韧性有助于获得较高的冲击强度,当添加25份经8%钛酸酯偶联剂处理的纳米CaCO3时,所得复合材料的冲击强度是未添加纳米CaCO3样品的4.25倍;扫描电镜结果显示,纳米CaCO3在基体中分散性良好,呈韧性断裂形态。     

Ghrelin Attenuates Liver Fibrosis through Regulation of TGF-β1 Expression and Autophagy

Ghrelin is a stomach-derived growth hormone secretagogue that promotes various physiological effects, including energy metabolism and amelioration of inflammation. The purpose of this study was to investigate the protective mechanism of ghrelin against liver fibrosis. Liver fibrosis was induced in C57BL/6 mice by intraperitoneal injection of CCl₄ (2.0 mL/kg of 10% CCl₄ v/v solution in peanut oil) two times per week for eight weeks. Ghrelin (10 μg/kg) was intraperitoneally injected two times per week for eight weeks. A second murine liver fibrosis model was induced by bile duct ligation (BDL) and concurrent ghrelin administration for four weeks. Hematoxylin eosin (H&E), and Masson’s trichrome were used to detect pathological changes to liver tissue. Western blotting was used to detect protein levels of transforming growth factor (TGF)-β1, phosphorylated Smad3 (p-Smad3), I-collage, α-smooth muscle actin (α-SMA), matrix metalloproteinases (MMPs) 2, tissue inhibitor of matrix metalloproteinases (TIMPs) 1, phosphorylated NF-κB (p-NF-κB), and microtubule-associated protein light chain 3 (LC3). In addition, qRT-PCR was used to detect mRNA levels of TGF-β1, I-collage, α-SMA, MMP2, TIMP1 and LC3, while levels of TGF-β1, p-Smad3, I-collage, α-SMA, and LC3 were detected immunohistochemically. Levels of aspartate aminotransferase and alanine aminotransferase were significantly decreased by ghrelin treatment. Ghrelin administration also significantly reduced the extent of pathological changes in both murine liver fibrosis models. Expression levels of I-collage and α-SMA in both models were clearly reduced by ghrelin administration. Furthermore, ghrelin treatment decreased protein expression of TGF-β1 and p-Smad3. The protein levels of NF-κB and LC3 were increased in the CCl₄- and BDL-treatment groups but were significantly reduced following ghrelin treatment. In addition, ghrelin inhibited extracellular matrix formation by decreasing NF-κB expression and maintaining the balance between MMP2 and TIMP1. Our results demonstrated that ghrelin attenuates liver fibrosis via inhibition of the TGF-β1/Smad3 and NF-κB signaling pathways, as well as autophagy suppression.     

华北油田分层注水技术现状与展望

分层注水技术水平直接影响着注水开发油田的整体开发效果。针对华北油田分注技术状况,剖析了目前分注工艺技术存在主要问题;结合华北油田储层特点,优选出桥式偏心分注、桥式同心分注、免投捞测调一体化分注等3种分注工艺,引进了高效测调工艺,开展了系列分注配套工具研究。详细介绍了三类分注工艺的特点和在华北油田的应用情况,指出了分注技术的发展趋势。     

基于隧道断面相对变形率判定围岩稳定性的研究

目前常用的判定围岩稳定性手段主要是监测隧道特征点或测线位移,但这种监测方法评价围岩稳定性存在诸多弊端。为此,本文从应变能角度对隧道围岩系统势函数进行理论分析。首先推导了围岩4个分区的应力、应变及位移表达式,进而分析各个分区的应变能,据此建立了隧道围岩系统势函数,并根据软岩破坏时的全应力应变曲线特征,确立隧道围岩系统势函数尖点突变模型,提出了定量评价围岩稳定性的理论依据。利用数值模拟手段,分析了不同荷载释放系数下隧道围岩特征点或测线位移、隧道围岩系统势能、隧道断面相对变形率3类指标变化规律。根据尖点突变模型,利用3类指标对围岩稳定性做出定量评价,并对3类指标下围岩破坏时的荷载释放系数进行对比分析,探讨了利用断面面积相对变形率指标判定围岩稳定性的可靠性。