Advanced Materials Research Vols. 602-604

Abstract: A series of Pt₁₀₀ and bimetallic PtNi catalysts were prepared on various supports namely amorphous silica (Degussa), crystalline silica (Chempure) and cerium oxide (CeO₂). The samples were prepared via precipitation method using NaBH₄ as a reducing agent. H₂-TPR analysis revealed that total reduction of the metal salts to metal particles occurred during this stage. All catalysts were tested for the hydrogenation of benzene to cyclohexane. It was found that the catalysts exhibited a decrease in the catalytic reactivity in the order of amorphous silica, crystalline silica and CeO₂. This is mainly due to the surface area and acidity of the support. Comparison of the PtNi catalysts with their respective monometallic catalyst showed that only the PtNi prepared on Chempure exhibited an enhanced reactivity. This is due to alloying of PtNi. For catalysts prepared on Degussa, the low H₂-chemisorption properties as well as lack in Pt peak shift in the XRD profiles leads to the believe that Ni and Pt may exist separately. H₂-TPD analysis supports these findings.

Abstract: Non-continuous nano-silver layer deposited on the PET filament by the use of vacuum sputtering technology and then become continuous with the help of newly electroless spray plating process.The functionality and durability of the Silver-coated PET filament was tested and analyzed. The results showed that it has good electrical conductivity. With the weight increasing goes up, the electrical conductivity increases obviously,then prone to slow increment .

Abstract: The Ni/Co/Fe plated fabric was obtained by electroless plating. The surface morphology, crystal structure, composition,surface resistance and microwave absorption performance of Ni/Co/Fe plated PET fabric were investigated. The results show that the composites possess effective microwave absorption. The characteristics of microwave absorption can be controlled by adjusting element ratios in composition. This kind of composite has great potential and investigation value in microwave absorbing fields.

Abstract: The problem of free surface deformation is involved in variable fields ranging from material processing to metallurgy. In order to investigate the transient evolution of fluid field and free surface deformation numerically, three numerical simulation methods are proposed among which one is based on level set method, the other two are based on moving mesh method. Afterwards, a benchmark problem of sessile droplet is chosen to test and verify each numerical method. A comparison of each numerical result and experimental result shows a good agreement between each other. Comparison and discussion of three numerical methods are made in the end.

Abstract: The complex surface is modeled by triangular surface, B-spline or non-uniform rational B-spline first and then the planing of the cutter is followed in reverse engineering. But this require CAD/CAM software and operator’s experiene. Because of this，the research on direct NC cutter generation from point cloud have become the focus of research in reverse engineering. The normal，curvature，surface vary et al parameters are calculated by principle component analysis method and so on, which define the local feature of the surface hidden in the point cloud. Then，based on local feature，point cloud is simplified. It is proved that two points with minimal orientation-distance on a pair of smooth surfaces are conjugate points. Thus the conjugate problem between the tool surface and the part surface is converted into optimization process of orientation-distance function. The cutter trace and the cutter interference are achieved by local and global optization of the orientation-distance function.

Abstract: Simulated the sintering process of the porous ITO gas-sensitive material with Materials Explorer 5.0. Observed the the process of neck formation and growth, grain growth and pore shrunk. Than, compared the result with experimentation. We found that the simulation results were similar to the microstructure photos. At the same time, we could observe the migration process of atoms in simulation results which we cannot observe in actual experiment. It proves that we get the theory basis of the experiment result estimate and proved the guiding effect of molecular dynamics simulation to the actual experiment.

Abstract: In this paper, according to the requirements of the topic, through the large market research and a series of calculation, I design the requirements of the grinding wheel frame and the spindle. In combination with relevant patent reform on the basis of grinding machine, The guide part of the drive system, micro feeding and automatic feeding mechanism is analyzed and design calculation, so that the machine can greatly reduce the labor intensity of workers and improve the processing accuracy. On this base of the design, I design and select the suitable rail to guarantee the processing precision and the wheel frame seat movement accuracy by using the calculated data and shape dimensions. At last, I design structural and shaping of the centerless cylindrical grinding machine.

Abstract: A Two-level method is proposed to solve the one-dimensional cutting-stock problem during the production process in this paper. First, nested layer cycle is designed to enumerate all the feasible cutting patterns, then a integer linear programming model is established with quantity demands as the constraint. The best cutting scheme is obtained finally according to the branch and bound method. The effectiveness of the proposed method is proved through a real world example, the calculations demonstrate that scheme obviously improves the utilization rate of stock

Abstract: The rotation accuracy of the machine spindle is an important accuracy index, and has numerous influence factors. According to the structure characteristic of the spindle system, an integrated model of the spindle rotation error is established in this paper. By this model, the impact law and cumulative effect of various error sources on spindle rotation accuracy can be analyzed. Taking the lathe spindles as an example, the modeling and analysis method for spindle error are introduced. Visualization of spindle center track is achieved by programming.

Abstract: According to the presence of the rounded protuberances or tubercles located on the leading edge, a similar leading edge of humpback whale pectoral fin with the “paraganglioma” has been made on the leading edge of NACA63-210 wing, an bionic NACA63-210 airfoil is designed with convex-concaved leading edges, and the 3-dimensional flows around the bionic wing are simulated for the drag reduction purpose.