Applied Mechanics and Materials Vols. 130-134

Abstract: The calculation method of contact force in contact-zone between adjacent layer wires has been analyzed. The principal radii of curvatures of wires were taken into consideration while obtaining the analytical expressions for contact stesses and sizes of contact surface. Meanwhile, a formular for shear stress of arbitrary point in half-space under contact-zone was derived on basis of the Boussinesq problem and it was simplified by using Gaussian quadrature. According to the results, the stress distribution could be unsderstood more thoroughly and the results is of great importance for studying looseness, fatigue and fretting wear of multilayered strands.

Abstract: A time-discontinuous Galerkin (TDG) finite element method for analyzing the dynamic response of cantilever beam subjected to moving force or moving mass is presented. The cantilever beam is discretized in space by finite element method, and the time-varying dynamic equations are derived. The TDG finite element method by which both the displacements and velocities are approximated as piecewise linear functions in time domain and discontinuous at the discrete time levels is adopted to solve the differential equations. This method inherits third order accuracy and the unconditionally stable behavior, moreover, it is endowed with large stability limits and controllable numerical dissipation. The numerical solutions are accord with analytic ones, which validates the feasibility and superiority of this method for solving the dynamic response of cantilever beam under moving force or moving mass.

Abstract: Carbon emission permit trading is widely considered an effective means to achieve optimal distribution of regional environment. The initial allocation of carbon emissions is the bases of the successful implementation of industry carbon trading. Developing low carbon economy and achieving the state’s energy saving targets are effective ways to the adjustment of economic structure, the improvement of energy efficiency and the development of new industries. The initial allocation of carbon emissions trading has a significant impact on the carbon emissions trading policy. The paper provides a theoretical basis for the choice of the allocation methods of carbon emission permit trading through the research on the fairness of carbon emission trading.

Abstract: In this paper, we presented two types of ferrite&si double layer substrate microstrip lines structures and derived waveguide admittance through coordinate rotation and Fourier transformation of Maxwell equations, then we analyzed its characteristics. We performed dispersion characteristic calculations on microstrip lines, discussed influence of various parameters of microstrip lines on dispersion characteristics and compared their characteristics, then we discovered parameters influence on one specific type of structure dispersion is minimum, especially on technique dimension of dielectric. It can make applications for IC fabrication.

Abstract: Electrochemical etching is an appropriate method for fabricating micro electrodes. We present a simple, fast, and cost-effective process for producing submicron electrode using multi-step electrochemical etching. In the study, we describe the single-step and multi-step electrochemical etching processes, respectively. In the single-step process, with machining time increasing, the intersection between micro electrode and electrolyte level will corrode off first, which could terminate the etching process. So, on the basis of the single-step process, we experimentally discussed the multi-step electrochemical etching process for the submicron electrode fabrication. Finally, the submicron electrodes were used in the electrochemical micromachining.

Abstract: The in-suit Dy-doped titanium dioxide nanotubes arrays were prepared by anodic oxidation method using Dy (NO₃)₃·6H₂O and pure Ti sheet. The sample was characterized by SEM, XRD and XPS for its size and structure. The photocatalytic properties of nanotubes arrays were researched by using methyl orange as target degradation under the visible light. The results showed that the catalytic activity of Dy-doped titanium dioxide nanotubes arrays was 72% under visible light. The catalyst has hight stability and potential industrial applications.

Abstract: F-doped TiO2 by hydrothermal synthesis method is prepared in this paper. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), infra-red (FT-IR) and diffuse reflectance spectroscopy (UV-vis). The photocatalytic performances of the samples were estimated by degrading Rhodamine B. which indicates that the reaction of photocatalytic degradation of Rhodamine B follows the zero order kinetic law. The photocatalytic performances are increased by F-doped. And F optimum doping dosage is 2.0%. After calcination at 500°C, the photocatalytic performance of the sample has not been obvious improved.

Abstract: The experiments focused on thin film buckling under impact load had been completed. The axial impact experiments were done to different films on the PMMA substrate with the drop hammer device, the buckling images of the film surface were recorded after impact, and the problem of stress release was studied. It was found that buckle’s initiation and propagation were influenced by the materials of thin films and the impact times, and meanwhile buckle’s local distribution phenomenon was also found.

Abstract: The composite nanofibers of Aluminum nanoparticles (AlNPs) and carboxymethyl cellulose nitrate (CMCN) have been successfully fabricated by electro-spinning, the fibers combined good mechanical properties of the fibers and high burning rates of AlNPs have valuable applications in the propellant. TEM images showed that AlNPs distributed evenly into the composite nanofibers. The morphology and diameters of AlNPs/CMCN nanofibers were strongly influenced by the solution concentrations and electrostatic field strength. By optimizing the solution concentrations and electro-static field strength, the smooth AlNPs/CMCN nanofibers were prepared.

Abstract: A flask solvothermal method was firstly utilized to facile synthesize greigite Fe₃S₄ micro-crystals (MCs). By using iron nitrate, element sulfur as raw materials as well as oleylamine as the solvent, high yield of Fe₃S₄ MCs with hexahedron microstructure was obtained. In addition, it was found that it was easily to achieve transformation between Fe₃S₄ and Fe₇S₈ through changing reaction temperatures and iron-sulfur ratios. The several different morphologies of Fe₃S₄ MCs were obtained by using other sulfur sources. The synthetic approach demonstrated here could be of great potential for the controlled synthesis of other metal chalcogenides.