考虑介质变形和长期导流能力的裂缝性气藏压裂产能模拟研究

在气藏开采过程中，由于孔隙压力的不断降低，使得介质变形而导致渗透率的变化，进而影响井的产量。针对这一问题，提出了各种流体与固体耦合的数值模拟模型。然而，对于裂缝性储层和多相渗流问题，流固耦合模型中许多参数不易获取，且求解难度很大，使得耦合模型存在一定的应用局限性。很少有文献在气井产能模拟时将介质变形和就地的长期导流能力加以综合考虑。文章考虑介质变形引起的天然裂缝渗透率的变化和裂缝导流能力随时间递减的影响，建立了裂缝性气藏压裂后气水两相渗流数学模型，推导出了数值计算模型；本模型易于编程求解，对于研究裂缝性气藏的渗流特征，特别是进行单井压后产能预测具有一定的实用意义。计算表明：不考虑介质变形和导流能力递减所预测的气产量偏高；目前普遍使用的气藏数值模拟软件中，假定渗透率、裂缝导流能力为常数，以致模拟计算结果比实际偏高。     

空调器用风冷冷凝器换热能力实验研究

实验测定了几种不同铜管、肋片组合的冷凝器在不同的风量和风机转速下的换热量，发现采用内螺纹铜管和迎风侧平片、背风侧冲缝片的冷凝器具有最优的换热性能。分析了多流路冷凝器中不同流路之间的制冷剂分配不均匀性和再热现象。     

稀土元素的分离技术

对目前稀土元素分离过程中几种常用的分离技术进行了综述，使用得较多的仍然是溶剂萃取法和离子交换法，而且新方法也在不断地出现。     

Kinetics of Zn and Pb evaporation from liquid iron

The evaporation kinetics of Zn and Pb from liquid iron at 1600°C were studied under argon pressure 0.1 to 50 bar in an induction furnace. It was found that the limiting step of evaporation under p_Ar < 1 bar is diffusion in the melt. Diffusion in the gas phase becomes rate-determining with increasing argon pressure. The phase boundary reaction has no effect on the evaporation of Zn and Pb. The evaporation of Zn can evidently be reduced by increasing argon pressure above 1 bar, while the evaporation of Pb is not significantly effected by changes of argon pressure.     

SiCp/2024复合材料的氢脆敏感性研究

在浸泡、阴极极化、阴极极化同时迭加拉伸变形、添加As₂O₃毒化剂等常见致氢条件下,通过慢应变速率拉伸试验研究了SiC_p/2024复合材料的力学性能,考察了断口形貌.测定了该材料在按几种常用充氢条件充氢后的氢含量.发现虽然强烈阴极极化使材料力学性能下降,但其原因在于阴极极化引起的碱性腐蚀,与氢脆无关.获得了不同于前人研究的新结论:在本文试验条件下SiC_p/2024材料不发生氢脆,也不发生不可逆氢损伤,其原因与该材料难以充入氢有关.     

循环流液相等电聚焦方法及应用研究

利用循环流液相等电聚焦技术，对Ｈｂ、Ｃｙｔ．Ｃ和ＢＳＡ混合物进行分离，对ＲＮａｓｅＡ粗制品进行精制。该方法上样量大，活性回收好。对聚焦过程中扩散、对流和电渗的影响进行了讨论。     

High density lipoprotein conversion mediated by human plasma phospholipid transfer protein

Phospholipid transfer protein (PLTP) was purified from lipoprotein-free human plasma, obtained upon treatment of plasma with dextran sulfate and Ca2+, by employing a series of column chromatography. Upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the purified PLTP showed a single main band, corresponding to the molecular mass of 78 kDa. However, isoelectric focusing of the purified preparation gave multiple bands with pI ranging from 4.3 to 5.1, indicative of microheterogeneity. Purified PLTP was shown to possess not only phospholipid transfer activity, but also high density lipoprotein (HDL) conversion activity (Tu, A.-Y., Nishida, H. I., and Nishida, T. (1990), FASEB J. 4, A2148; Jauhiainen, M., Metso, J., Pahlman, R., Blomqvist, S., van Tol, A., and Ehnholm, C. (1993) J. Biol. Chem. 268, 4032-4036). Isolated HDL3 was enlarged to the size of HDL2b upon incubation with purified PLTP for 6 h at 37 degrees C at the PLTP/HDL3 molar ratio of approximately 1:45. Both the HDL conversion and the phosphatidylcholine transfer activities of purified PLTP were effectively inhibited by rabbit anti-PLTP immunoglobulin G. The primary importance of PLTP in the HDL enlargement that occurs in human plasma upon incubation at 37 degrees C was shown by the strong inhibitory effect of the anti-PLTP immunoglobulin G. The process of PLTP-mediated HDL enlargement was accompanied by the release of apoproteins, primarily apoA-I. HDL3 enlargement mediated by PLTP was effectively inhibited by the addition of free fatty acids.     

Effect of stress triaxiality levels in crack tip regions on the characteristics of void growth and fracture criteria

The behaviour of void growth in the crack tip regions of four specimen geometries with different stress triaxiality levels have been investigated by the FEM method and experimental observations in plane strain and plane stress cases respectively. It was found that the shape change of growing voids, the configurations of a blunting crack tip and the sizes of decreasing ligament between the void and the crack tip are strongly dependent upon the stress triaxiality levels. Under the condition of plane stress, the stress triaxiality on the ligaments of cracks are nearly the same for different specimen geometries, also the void growth, crack tip blunting asnd decreasing of ligament size are identical for various specimens with increasing load levels, which lead to the conclusion that the J_i-value is independent of specimen geometries. However, in the plain strain case, different void growth, crack tip blunting and decreasing in ligament size for various stress triaxiality levels directly caused the J_i-value to be dependent on the specimen geometries. It was found that when the void is linked to the blunting crack tip by the extrapolation to the zero ligament from FEM calculations, the J_i values, measured experimentally, are underestimated slightly.     

Highly active lanthanum doped nickel anode for solid oxide fuel cells directly fuelled with methane

Lanthanum doped nickel and YSZ composite anode (LaNi–YSZ) exhibited a greatly reduced polarization resistance and high performance for electrochemical oxidation of hydrogen and methane, which resulted from a fine anode structure with a high dispersion of nickel catalyst and a high catalytic activity towards methane.