Key Engineering Materials Vol. 522

Abstract: We investigate the solution of the Gnedenko system with multiple vacation of a repairman. By using-semigroup theory of linear operators, we prove well-posedness and the existence of the unique positive dynamic solution of the system.

Abstract: In our research, in accordance with the traditional sand therapy practice usually held in Turpan areas, we built an indoor sand therapy laboratory in Xinjiang University. After heating the sand with a heater for one week, we obtained similar temperature in every layer of the sand to that in the sand therapy. Male rabbits were treated with the sand therapy and medication and compared with normal control. The blood, joint fluid and mechanical properties of the bones were compared. The comparison of the mechanical properties of the bone, as well as our clinical experience with the sand therapy shows the effectiveness of such a treatment.

Abstract: In order to resolve the problem of difficult planning the layout in oil transportation network, a new planning method based on evolution is put forward out in the paper. Firstly, the economic effect in the growth process of oil transportation network is analyzed, then, the attachment formula comes with the growth of the network; based on it, the growth process of adding nodes and edges is discussed, and the clustering coefficient is arrived to balance the degree of the nodes. Case study shows that the evolution designing method is reasonable.

Abstract: Method for calculating assembly yield in two-dimension multi-station assembly processes is developed based on Number-Theoretical Net (NT-net). The discrepancy of NT-net is analyzed, and the principle of generating good lattice point (glp) based on NT-net method is introducted. Afterwards, taking fixture locating variations which are sampled using NT-net method for input vectors, the samples are substituted into state space model of dimension variation propagation in multi-station assembly processes to get output vectors. The statistics for qualified sample is accomplished, after comparing output vectors with the variations of measuring points on component. Assembly yield in two-dimension multi-station assembly processes is gained when qualified sample divided by total sample. Finally, a real case in automotive body floor assembly is given as an example to calculate the assembly yield in two-dimension three-station assembly processes. The result is validated by using Monte carlo simulation. It provides a new way to predict assembly yield in two-dimension multi-station assembly processes.

Abstract: Dielectric elastomer functional materials are new polymer with excellent performance, particularly suitable for power generation of low frequency and large deformation energy source. Based on the dielectric elastomer film material structure, the power generation principle of dielectric elastomer material was discussed, and the influence on the electrical conversion efficiency from elastomer material elongation and area was analyzed by the experiments. The results show that output charge voltage was directly proportional to the size and elongation of the material. This provides the basis for dielectric elastomer material application in the electricity generation.

Abstract: In the present research, a sizing agent containing benzotriazole UV absorber was used as coating to enhance the UV stability of PBO fibers. The sizing coating was characterized by XPS and SEM. The effect of UV absorber on UV stability of PBO fibers was studied by an accelerated photo-aging method. The experimental results show that UV stability of coated PBO fibers was obviously improved compare to uncoated PBO fibers. After 480 h of UV exposure, the tensile strength retention and intrinsic viscosity retention of coated PBO fibers was higher than that of original PBO fibers. SEM photograph shows that no significant change of surface morphologies, meanwhile some latitudinal crack appeared on the original PBO fiber surface.