Advanced Materials Research Vol. 773

Abstract: In this paper, in order to enhance the equivalent shear strength of the corrugated ribbon sandwich structures, one new optimal design concept is brought forward to design the corrugated ribbon sandwich structures subjected to biaxial shear loads. Based on the performance harmony concept, the equivalent shear properties have been investigated and given. Analytical results show that the equivalent shear properties of the corrugated ribbon sandwich structure depend on not only the lattice truss cores, but also the facesheets, the interface and the shear loads imposed on the facesheets.

Abstract: The deformation mechanism of unit cell wall is investigated by use of FEM, and the numerical simulation results show that the predominant deformations consist of shear deformation and compressive deformation. One new model based the shear deformation and the compressive deformation is put forward to investigate the longitudinal shear modulus of honeycomb cores. Owing to taking skin effect into consideration in our model, it is found that the equivalent shear modulus depends on not only the material properties and configuration parameters of cores, but also the material properties and configuration parameters of facesheets.

Abstract: According to field synergy principle, analyzes the relationship of the effect for heat transfer with mass transfer in porous media. Using the divergence equation, express the degree of gas phase velocity vector and temperature gradient velocity in the process of heat and mass transfer, and the field synergy angle θ play an important role in heat and mass transfer either global or partial. In the result, the heat and mass transfer would be constrained by each other while πθ>π/2, and be promoted whileπ/2>θ0, and be independency while θ=π/2. The divergence equation of field synergy principle present the method of strengthen the heat and mass transfer in porous media.

Abstract: The adsorption equilibria of pure linear alkanes, involving n-pentane, n-hexane, and n-heptane in pillared layered materials are simulated using configurational-bias Monte Carlo (CBMC) techniques in grand canonical ensemble. In the CBMC simulation, pillared layered pores are modelled by a uniform distribution of pillars between two solid layered walls with a given size of interlayer gallery. And a grid model is employed here to calculate the interaction between fluid molecules and two layered boards. Our simulation results are in a good agreement with the reported experimental data on the adsorption of nitrogen at 77 K, indicating that the grid model used in this work is effective. Then, a series of CBMC simulations of the adsorption isotherms of pure n-pentane, n-hexane, and n-heptane in pillared layered pores with three different porosities ψ = 0.98, 0.94 and 0.87, and three pore widths H = 1.02, 1.70 and 2.38 nm at temperature T = 300 K has been carried out.

Abstract: The spherical precursors - [Ni_1/3Co_1/3Mn_1/3]Ox and Li [Ni_1/3Co_1/3Mn_1/3]O₂ were synthesized by an ultrasonic atomization method via two routes. The [Ni_1/3Co_1/3Mn_1/3]Ox and Li [Ni_1/3Co_1/3Mn_1/3]O₂ powders were characterized by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The experimental results show that the initial concentration of the raw solution would affect the size of precursor [Ni_1/3Co_1/3Mn_1/3]Ox particles. The Li [Ni1/3Co_1/3Mn_1/3]O₂ particles which were prepared from the mixture of LiNO₃ and [Ni_1/3Co_1/3Mn_1/3]Ox were much larger than the precursor particles and those prepared from the LiNO₃-[Ni_1/3Co_1/3Mn_1/3]Ox may maintain the size of the precursor particles.

Abstract: Hollow (Ni_0.8Co_0.1Mn_0.1)O_y spheres were fabricated with ultrasonic spray pyrolysis method. Particle morphology of (Ni_0.8Co_0.1Mn_0.1)O_y was carefully controlled by regulating the concentration of the solution containing mixed sulfates and reaction temperature. Lower solution concentration contributes to cracked hollow structure and higher temperature leads to lager particle size. Crystal phase of precursors was characterized by XRD. Morphology and microstructures of (Ni_0.8Co_0.1Mn_0.1)O_y were observed by SEM and TEM. The results of ultrasonic atomization process show promise properties requirement for commercial applications.

Abstract: Molecular dynamics simulations of water-based nanolubrication in Couette flow are carried out. The water molecules are simulated by the TIP3P model. Three different shear rates are 20 m/s and 40 m/s and 60 m/s, and the vertical pressure acted on the metal wall are 10GPa, 20 GPa, 30 GPa and 40 GPa respectively. The simulated results show that the greater pressure, the smaller the stable value of friction spacing, while the reduction rate of the stable value becomes small. Meanwhile, as pressure increases, the stabilization time is longer. However, under the same pressure, shear rate of influence on the friction spacing is not obvious. The friction spacing increases with the number of particles, showing that the presence of nanoparticles can enhance the bearing capacity.

Abstract: The irregular physical and chemical properties can induce by the synergy effects of alloy elements in bimetallic clusters. Research on the influence of alloys concentration on the frozen structure of bimetallic cluster plays a key role in exploring new structural materials. In this paper, the influence of the Cu concentration on the frozen structures of the (CoCu)₃₀₉ clusters was investigated by using molecular dynamics simulation based on an embedded atom method. The (CoCu)₃₀₉ clusters with different Cu concentration were frozen from 2000 K to 200 K. It was found that the Co₃₀₉ cluster was formed by the Co bulk-like hcp structures and the Cu₃₀₉ cluster was constructed by the form with a 5-fold symmetry axe. The icosahedron structural transformation is strongly related to doping Cu atoms. Furthermore, two methods of icosahedrons structural transformation were found during the freezing processes of the Co-Cu clusters with different Cu concentration. The irregular phenomenon of the structure transformation induced with the 30% and 40% Cu concentration. The synergy effects of the Co-Cu on the surface are the key reason for the irregular icosahedrons.

Abstract: Material modification of TiO₂ photo-catalyst (NMTi) by doping urea and cobalt via sol-gel method was used to achieve high efficiency degradation of rhodamine B (RhB) under visible light (Vis). Although good removal (up to 42% of TOC removed) of RhB by Degussa P25 under ultra violet irradiation, P25 did not effectively degrade RhB (up to 14% TOC removed) under Vis. In the batch photo-catalytic experiment with Vis irradiation, the removal efficiencies of absorbance and TOC by NMTi were 28 and 30%. We used terephthalic acid as fluorescence probe to catch hydroxyl radical (OH) and calculated their quantum yields. The OH yields of NMTi with Vis irradiating was 8.91×10^-6 while P25 of 2.65×10^-6 (P25 of 1.44×10^-5 and NMTi of 1.00×10^-5 under UV). The OH yields of NMTi were higher than that of P25 under Vis, but otherwise under UV irradiation. Therefore, our new composited NMTi was more effective than P25 under Vis for both absorbance and TOC removal of RhB. It seemed possessed the application potential under Vis irradiation.

Abstract: The CuO/CeO₂ and CuO/PrO₂-CeO₂ catalysts were prepared by the hydrothermal method, and characterized via XRD, SEM and N₂ adsorption-desorption techniques. The study shows that the BET surface area and pore volume of the CuO/PrO₂-CeO₂ catalysts increase with the increase of praseodymium content. The CuO/CeO₂ catalyst presents higher catalytic activity in compare with the CuO/PrO₂-CeO₂ catalysts although the addition of praseodymium promotes textural properties of the CuO/CeO₂ catalysts, and it proves that the interaction of CuO and CeO₂ has a crucial role in CO-PROX.