Advanced Materials Research Vol. 908

Abstract: A new heteronuclear Ln-Co carbonyl cluster, Ce₄Yb₂(μ₃-L)₄(CF₃COO)₈(DMF)₆Co (L=(CO)₆Co₂CC(COO)₂^-), has been synthesized by reaction of (CO)₆Co₂CC(COOH)₂ with Ce (OOCCF₃)₃2H₂O and Yb (OOCCF₃)₃2H₂O. The cluster structure was characterized by single-crystal X-ray diffraction and IR. The crystal is monoclinic crystal system and C2/c space group. X-ray analysis revealed that the heterometallic cluster belonged to a rare class of Ln-Co carbonyl cluster bridged by carboxylate groups of carbonyl cluster ligands. The cluster was monometric unit and exhibited cage-like configuration.

Abstract: Organic phenolic gel is commonly used to be a deep profile control agent which applies to use in the high water cut oilfields where heterogeneity is severe, improve the contradiction of inter-reservoir layer and inner layer, expand water sweeping zone, and achieve the purpose of stable oil production and water control. Organic phenolic weak gel is mainly affected by the concentration of each component and reaction temperature. In this paper, formaldehyde was replaced by urotropin, which is not only delaying the gelation time, but also avoiding pollution. In addition, a water-soluble phenolic resin oligomer has been synthesized by the method of two-step alkali catalysis with appropriate mole ratio as an auxiliary crosslinking agent. Considering the concentration of each reactant as the factor, the orthogonal experiments have been designed to optimize the traditional organic HPAM-phenolic weak gel. We have found that the optimized weak gel has a better stability, longer gelation time, better salt resistance and environment friendly. It can better meet the needs of oilfield deep profile control.

Abstract: Find a good biological characteristic of repair material of bone tissue engineering has been a hot research in the Department of orthopedics. Although there are various kinds of bone repair materials and methods, but no one can perfectly replace the human bone. Especially in the sports competition fierce, sports injury is one of the most common damages. Repair the damage of the traditional method of bone often because of their poor biocompatibility, lack of materials, not with the individual growth and other problems. It greatly reduced the effects of restoration. And titanium mesh and bone graft has the advantages of simple operation, low rejection, shapeable, implantation can close bone combined with host bone formation, and have fixed a support function, bone defect repair and can obtain satisfactory.

Abstract: The characteristics of inequigranular sandstone reservoirs in S3 Formation in Lei 64 Area are strong heterogeneity, complex pore structures and shale-bearing, therefore accurate calculation of water saturation becomes focus and difficult in calculation of oil reserves of inequigranular sandstone reservoirs. Based on the pore geometric conduction theory and effective medium conduction theory, a conductivity model for inequigranular sandstone reservoirs is established in this paper. In this model, the pore geometric conduction theory is used to describe the influence of pore structures on sand conductivity, the effective medium conduction theory is used to describe the influence of shale on sand conductivity. The two kinds of theory are combined through conductivity of equivalent pore fluid. Then, the log data of Lei xxx are processed with the model, and the results are compared with well test results. The results show that the new model can be applied in saturation evaluation of inequigranular sandstone reservoirs in Lei 64.

Abstract: Joints are the weak parts in the concrete frame structures, which are easy to be damaged in earthquake and cause the entire collapse of the structure. FRP pasted on the surface to strengthen frame joints have a good effect in experiments, but the pasted FRP can not effectively constrain the core area of the joints and will increase the difficulty of construction when using in actual engineering. The paper studied the feasibility of Sprayed FRP used to reinforce concrete frame joints, the advantages and mechanism of Sprayed FRP were analyzed. The study may provide the basis for the popularization and application of this new technology in actual engineering.

Abstract: Polyimide (PI) was chosen as the matrix of the composite, barium titanate/polyimide (BT/PI) nanocomposite films were prepared by in situ polymerization. In order to improve the dispersion and the physical-chemical properties of BT surface, barium titanate was modified by Al₂O₃ coating and modified BT/PI nanocomposite films were prepared. The prepared modified BT was characterized by X-ray diffraction (XRD) analysis, and scanning electron microscopy (SEM), and the dielectric properties of the composites were characterized in detail. It was shown that surface modification with Al₂O₃ is the chemical process and there were new substances forming. When BT was modified by 10 wt% Al₂O₃, the dielectric constant of the composite film was 18.96 (10³ Hz), the loss tangent 0.005, breakdown strength 70 MV·m^-1, energy storage density 0.41 J·cm^-3. The dielectric constant of BT modified by Al₂O₃ is decreased while the dielectric strength of the modified BT/PI composite film is increased.

Abstract: By Scanning Electronic Microscope (SEM), X-ray diffraction analyzer (XRD) and Cross hatch scanning analysis method, the corrosion behaviors of the HR3C steel in high temperature steam and supercritical water was investigated. The results indicates that within the scope of these tests, the corrosion rate of HR3C steel increases with an increase in temperature, which negatively correlates with the pH value of working medium, while the pressure has fewer effects on it. For specimens with the exposure time of 100h under various corrosion conditions, the oxide films almost cant be detected on all specimen surfaces, indicating the high corrosion resistance of HR3C steel. After long time oxidation corrosion in high temperature or supercritical water, the common oxide film of HR3C steel is always composed of four layers, from the oxide layer to the steel matrix, which are Fe₃O₄, pyknotic Cr₂O₃, partial oxidation layer with rich Cr element, and (Fe, Cr) ₃O₄ spinel layer in turn.

Abstract: In this paper, by means of Scanning Electronic Microscope (SEM), X-ray diffraction analyzer (XRD) and Cross hatch scanning analysis, the Structure and mechanism of cracking and spalling for Super304H steel oxide films in high temperature steam were investigated. With the oxidation proceeding, the surface of Super304H steel specimens is covered by a large amount of tiny holes, which causes the occurrence of an outer oxide layer. The Super304H oxide film generally has a double-layer structure: the outer layer mainly for iron oxide Fe₃O₄, also being covered by a small amount of Fe₂O₃, and the inner layer with the FeCr₂O₄ spinel phase as primary component. Because of the inhomogeneity of oxide distribution, large amounts of smaller gaps appear in the Super304H steel oxide films. Due to the differences among the outer layer, the inner layer and steel matrix in thermal expansion coefficient, when the steam temperature around the specimen changes periodically, the stress variation arise in the Super304H steel and oxide films, which causes the cracking and spalling of oxide films.

Abstract: At present, the superheater and reheater pipes in supercritical and ultra-supercritical boilers have encountered with widespread problems of high temperature steam oxidation, seriously affecting the operation safety and economy of the power generation unit. After several tests and contrastive analysis on the main chemical composition and microstructure of specimens before and after shot peening treatment, this paper developed a set of detailed surface shot peening process with specific process parameters, and finds that for the Super304H oxide film, the relative content of Cr element increases by shot peening treatment, with the relative Cr content of the treated specimen being 2.65% higher than that of the untreated, displaying that the anti-oxidation properties of high chromium austenitic steels in high temperature steam is effectively increased.

Abstract: In this paper, for Super304H steel, the growth law of oxide films and the heat transfer characteristics between the pipe and the working fluid were investigated by using numerical software ANSYS, which simulated comprehensively the effects of pipe size, flow rates of steam, flue gas temperature, and steam temperature on the formation and thickness of the oxide film. A bigger pipe wall thickness, a smaller steam flow rate or a higher flue gas temperature will lead the faster growth of the oxide film thickness, the heat flux density through the wall being smaller and the wall temperature being higher. With increases in steam temperature and thickness of the oxide film, the heat flux through the wall decreases with a small amplitude, and the average temperature of tube walls increases slightly.