Advanced Materials Research Vols. 160-162

Abstract: The effect of a high magnetic field (up to 12T) on the lamellar eutectic spacing changes was investigated in the diffusion liquid Al/solid Cu. It was found that the lamellar eutectic alloy is formed in the diffusion process and its spacing has the non-monotonic relationship with the magnetic field intensity. With the increase of magnetic field intensity, the lamellar eutectic spacing decreases rapidly. When the magnetic field intensity B exceeds 4T, the lamellar eutectic spacing begins to increase until 8T, and then, decrease again. This phenomenon could be attributed to the effects of high magnetic fields suppressing nature convection and inducing thermo-electromagnetic convection in the liquid Al.

Abstract: The finite element contrast model such as concrete filled steel tube support, U-steel support and hollow steel tube support were established with ANSYS software, combining with engineering practice and relative design scheme of concrete filled steel tube test, respectively analysis their influencing factors and mechanical properties such as support effect, bearing capacity and so on. The economic benefit of each support was been analysised by comprehensive comparison of the material using condition and mechanical performance. The results show that, comparing with traditional U-steel support, retractable concrete filled steel tube support is a new style support with high bearing capacity, a large variety of sizes, higher economic benefit, and hence fit to support the deep soft rock broken jointed rock mass.

Abstract: A large number of frames damaged due to the poor lateral stiffness in “5.12” earthquake. Additonal flange wall could effectively improve the lateral stiffness. This paper analyzed the behavior capability of special-shaped column of the practical engineering structures, meanwhile, obtained N-M curve, Mx-My curve and M-φ of biaxial eccentricity compression based on numerical integration method.The results show that,the failure mode of special section column after reinforcing and rectangular column under the biaxial eccentricity compression are conform,including fail in tension or compression and the limit failure. When the axial compression ratio is quite slightly,and section eccentric tension destruction, the thrust increases, the anti-bending ability increases.When section bearing destruction, along with axle strength enlargement, the anti-bending ability reduces.And the results reveal the axial compression ratio could influence the bearing capacity and ductility of frame’s column obviously.

Abstract: The design of steel column base plays a very important role in steel structure design. Through large-scale analysis software ANSYS, this paper analyzes the steel column base by finite element numerical simulation analysis,and discuss the fracture behavior of steel pipe column and fillet weld in different thickness, axial compression ratio and different sectional area. The results showed that, the section of most likely break focus on the ends and in the middle of the steel pipe column and fillet weld,and with the increase of thickness, cracking capability of the steel pipe column and fillet weld first increased and then decreased, and axial compression ratio of the specimen has little effect for cracking capability,and with the increase of sectional area, the less prone to fracture of the steel pipe column and fillet weld.

Abstract: A kind of new classical-quantum correspondence principle is proposed using the idea of closed-orbit theory. The quantum spectrum function is introduced by means of the eigenvalues and the eigenfunctions in the system of one-dimensional nano-microstructure. The Fourier transformation of the quantum spectrum function is found corresponding with the classical orbits in the system. These results give new evidence about the classical-quantum correspondence. All the methods and results can be used in a lot of other systems, including some two-dimensional and three-dimensional systems. The researches about these systems are very important in the field of applied science, for example, molecular reaction dynamics and quantum information.

Abstract: The ring-closing reaction of chloride polyether polyol was calculated by Gaussian03 software. The Density Function Theory (DFT) method were employed to study the geometry structures of chloride polyether polyol and the product was obtained on the base of B3LYP/6-31G+ model in this paper. The transitional states (Ts1, Ts2) during the ring-closing process were found by TS method and the energy changing of the system was proved by IRC calculation. Results showed that the ring-closing of chloride polyether polyol had two transition states: hydrogen transferring and the formation of new carbon-oxygen bond. The total energy of reactants was -1459.99627a.u and product is -1460.31170 a.u. The energy of the system was reduced by 175.47621kJ/mol. The ring-closing of chloride polyether polyol was exothermic and stable in thermodynamics.

Abstract: High-quality Gallium-doped zinc oxide (ZnO:Ga) films have been prepared on epi-GaN/sapphire (0001) substrates by the metalorganic chemical vapour deposition (MOCVD) method. The relative amount of gallium doping was varied from 0 to 8% (atomic ratio). The structural, electrical and optical properties of the ZnO:Ga films have been investigated in detail, as a function of Ga content. All the prepared samples have the wurtzite structure of pure ZnO with a strong (0002) preferred orientation. The microstructure for the surface of films was markedly influenced by the amount of Ga doping. The resistivity decreases continuously with adding Ga content and reaches to the value of 8.4×10-3 Ω•cm at 8%. The average transmittance for the deposited ZnO:Ga samples in the visible range was over 75%.

Abstract: A new composite, wood-polymer composite, was fabricated by formation of poly (methyl methacrylate) in wood cellular structure. Methyl methacrylate (MMA) monomer and a few of 2,2'- azobisisobutyronitrile (AIBN) as an initiator, as well as several drops of pyrimidine as catalyst were first impregnated into wood porous structure under a pressure condition, and then initiated for thermal polymerization through a catalyst-thermal treatment. The mechanical properties of the composite were tested, and the composite was also analyzed by SEM and DSC to further correlate its performance. The results indicated that the modulus of rupture, modulus of elasticity, compression strength and hardness of Wood-PMMA Composite were improved by 68.28%, 110.27%, 62.43%, 357% over those of Untreated Wood, respectively. The SEM observations showed that PMMA generated and filled up wood pores under the employed conditions, and thus reinforced the mechanical properties of wood. DSC analysis suggested that Wood-PMMA Composite was more thermal stability than Untreated Wood as the formation of PMMA within wood pores.

Abstract: Porous NiTi shape memory alloys were fabricated by thermal explosion method using different Ti and Ni powder as initial materials. The effect of process parameters including heating rate, and particle size of Ti on pore characteristic and phase composition was analyzed. Microstructure, phase composition, and mechanical properties were studied by SEM, XRD, and compression test, respectively. The mechanism of thermal explosion reaction was studied. The results show higher heating rate and smaller Ti particle size result in higher porosity and bigger pores. The thermal explosion reaction starts with the melting of a eutectic between β-Ti(Ni) and Ti2Ni and the main phases of as-reacted products are TiNi phase which are the desired phases. NiTi2 and TiNi3 phases are also present in small amounts. The content of TiNi phase increases with increasing heating rate or decreasing Ti particle size. The compressive strength and Young’s modulus of compacts decrease with the increase of the porosity.

Abstract: The insufficient filling and shrinkage are often produced in the process of injection molding. These defects cause the production efficiency to reduce and production cost to rise. In this paper, the forming process of Dn40-type control valve is analyzed to find the main reason for such forming defects by using CAE tools and comparing with the good forming process of a Dn50-type control valve. Results show that big difference between wall thicknesses and bad exhaust system in injection mold is the main reasons for insufficient filling. In the meantime, measures to prevent defects are investigated. Modifying the local structure of the injection mold is provided to avoid the defects. Using reasonable parameters in the injecting process and modified injection mold, the injection product have a smooth surface and good forming. The experiment verified the feasibility of the measure for prevention of defects.