Applied Mechanics and Materials Vols. 121-126

Abstract: Creep relaxation is an important form of system failure, how to understand and analyze the effect of creep relaxation, to solve system failures and improve economic efficiency are of great significance. The paper describe researches of creep relaxation , mathematical models and theories at home and abroad in detail, and introduce the finite element method applied in this field. By comparing with the mathematical models, finite element Methods with test results, improving current mathematical models and utilizing finite element method is an important trend.

Abstract: To figure out the elements distribution in the seams, laser welding was carried out on the Al plates which coating with Si powder and Cu powder respectively, then electronic probe was used to analyze the microstructure in the section of the seams. Results indicated that alloying elements distribution in the weld is heterogeneous under the metal liquid movement in welding pool and the elemental diffusion co-functioning. There are two high concentration regions on both sides of the weld centerline, the content at the center is low, slightly higher and more homogeneous at the bottom. The distribution of the alloy composition in the weld is related to the specific gravity of the alloying elements. Though the specific gravity of Si and aluminum matrix is similar, it can flow with the liquid metal in the pool, so the concentration changes of Si in the weld are larger. Elemental fluctuation keeps steady in the weld joint.

Abstract: This article aims at the accelerating characteristic of coal filling material. We scientifically made a series of proportion on composite-cementing material through uniform design with Portland cement, sulpho-aluminate cement and gypsums. After having testing the capability of this, we found that some certain composite-cementing material strength has been improved, both early and later strength. Furthermore, we also continually analyzed the hydration products and microstructure of composite-cementing material, then determined that early hydration products were mostly ettringites and later were C-S-H-centered and CH-centered gel.

Abstract: High content of paraffin for condensate gas reservoir in Dalaoba and the precipitation of paraffin seriously affect the production and safety to bring about greater economic loss, therefore, it is necessary to develop the study on the precipitation of paraffin,deposition mechanism, variation discipline of phase state, prediction technology as well as the discipline for precipitation of paraffin of shaft.The paper establish the predication method on phase state simulation for paraffin precipitation. In order to better realize the site application, the predicted drawing version on paraffin precipitation of shaft is established to better predict the paraffin precipitation of shaft so as to provide the scientific basis for design on paraffin elimination and prevention on site as well as the construction and reasonable mining of condensate gas reservoir.

Abstract: The paper sets up mechanical model according to the characteristics of paste filling stope and determines the basic model units which are overlying strata, filling body, support and floor. The paper also establishes the mechanical parameters for controlling movement and deformation of overlying strata and sets up the relationship of all mechanical parameters. Based on this, the paper studies the stress evolution law under the condition of different filling ratio and filling step distance with the method of numerical simulation.

Abstract: A rapid casting method for complex parts is presented. In this method, casting moulds with complex cavity are manufactured by self-created rapid prototyping approach which called Selected Laser Partitioning for Prototyping. After surface coating treatment for moulds, complex parts are obtained by centrifugal casting. As application cases, metal impeller was casted by this method. A self-developed five-axis coordinate measurement machine was used to process the surface measuring of impeller. The Dimension accuracy grade of impeller is CT-3 and the surface roughness is Ra 6.3µm through making comparisons directly between CAD model and point cloud data of impeller surface. The result shows that this rapid casting method which has the characters of simple technology and low production cost reaches the level of precision casting.

Abstract: On the basis of research on the steel enterprise information system in the current domestic small and medium-scale iron and discovery of the adequate for the existing system, a idea of the combination the real-time database technology with advanced management services is put forward. By SBO platform we construct the general production framework based real-time database and design its main functional modules; at the same time, we summarize the overview of the interface method with real-time database, finally we realize the program .The program helps raise the level of corporate information production and productivity, reduce production costs significantly and improve their market competitiveness.

Abstract: The transglutaminase was purified through alcohol precipitation, ammonium sulphate precipitation, ultrafiltration, gel layer chromatography, and the purified alkaline was demonstrated to be electrophoretic by SDS-PAGE. Using the activity of alkaline protease as indicators. the purification of transglutaminase was optimized.The results indicated that the enzyme activity of purified transglutaminase was 107.86 U•mg-1, final purification factor was 10.42, Activity recovery factor was 27.3%,The enzyme properties of transglutaminase were also studied, The optimal conditions of transglutaminase were as follows:pH6.0, 40°C.After incubation at 40°C for 2h,the residual activity of the enzyme was ablve 90%,and the enzyme was relatively stable at pH5~7.

Abstract: The width of band gap is calculated with lumped mass method in order to study the wave propagation of longitudinal and transverse elastic wave of one-dimensional phononic crystal. The starting and terminating frequency is analyzed by changing the filling rate, the density difference of two materials, cross-section height ratio, and the Young's modulus of the scatter.

Abstract: The TiO2 particles were synthesized in the solvothermal method, and they were characterized by the means of scanning electron microscopy (SEM), X-ray powder diffraction (XRD), thermogravimetric analysis and differential thermal analysis (TG-DTA) and the N2 adsorption–desorption measurement. The photocatalytic property of as-prepared TiO2 particles was evaluated by the degradation experiment of methyl orange aqueous solution. Results indicated that TiO2 nanoparticles were the combination of anatase-TiO2 and rutile-TiO2 crystals with integrated crystals form and high crystallinity, which may be helpful for stabilizing the anatase and improving the photocatalytic activity. The adsorption-desorption isotherms was the typical type IV isotherm with a clear H2-type hysteresis loops in the desorption branch. The results showed mesoporous TiO2 particles had the average pore diameter of 3.587 nm, the average specific surface areas of 270.342 m2/g, and the average pore volume of 0.259 cm3/g. Meantime, the as-prepared TiO2 particles had good thermal stability and high photocatalytic activity, when being irradiated for 120 min, the degradation rate of the methyl orange aqueous solution could be up to 98.27%.