Advanced Materials Research Vols. 457-458

Abstract: Al and Sb codoped ZnO thin films were prepared through a sol-gel spin coating method on glass substrates and annealed in different atmospheres. The XRD results show that the films have hexagonal wurtzite ZnO structure and SEM results reveal that the films annealed in hydrogen consist of hexagonal nanorods with diameters of 84 nm and lengths of 422 nm, however the films annealed in other atmospheres without nanorods. The photoluminescence (PL) spectrum shows that the emission peaks of the films are mostly at 390 and 460 nm, and the film annealed in hydrogen has the strongest intensity of peak at 390 nm and the film annealed in air has the strongest intensity of peak at 460 nm. The electrical properties show that the films annealed in hydrogen have a lowest resistivity of 1.02×10-3 Ω•cm.

Abstract: In this paper, a kind of giant magnetostrictive material (GMM) model based on hysteretic nonlinear theory was developed. Van de Pol nonlinear difference item was introduced to interpret the hysteresis phenomenon of the strain-magnetic field intensity (MFI) curve of GMM. The coupling relationship between MFI and frequency was obtained in partial least-square regression method to describe the driftage phenomenon of the strain-MFI curves of GMM in different frequencies. Based on above, the final relationship among strain, MFI and frequency was set up. The result of significance test shows that the effects of all of the items in the final model are remarkable, and that of forecast test shows that the model can describe the characteristics of GMA in different frequencies well. The new GMM model broadens the region of controlling frequency, and is easy to be analyzed in theory, which is helpful to vibration control.

Abstract: The paper discusses the strategies of green building materials, the personal safety problems and ecological materials, the appropriate and reliable technology, effective planning and design, interdisciplinary working and integrated collaboration in research on green building materials. In addition to these, the article studies the main categories of green building materials, including ecological safety materials, low-carbon materials, and recycled-content materials. This article also argues the strategy of earthquake resistant materials and structural strategy, the role of seismic designs in ecological safety strategies, reliable technology and conceptual design of earthquake engineering, etc.

Abstract: The transformation from part design model to manufacturing model is the key technology to realize the integration of CAD/CAPP/CAM, and the key factor is the transformation from design model to blank model .a method of generating casting model for cast then machined part is proposed. The methodology is composed of classifying the part surfaces according to manufacturing requirements, constructing a improved EAAG to recognize simple features, filtering the castable simple feature, enveloping the volumetric machining features containing nonnormal surfaces by means of constructing minimal enveloped auxiliary planes. An example is demonstrated to verify the validity and the effectiveness of the method.

Abstract: The optimization of spindle has important significance. The optimization method based on ANSYS is introduced and spindle mathematical mode of HTC3250µn NC machine tool is given. By scanning of design variables, the main optimized design variables are determined. The single objective and multi-objective optimizations are done. In the end, the main size comparison of spindle before and after optimization is given.

Abstract: The above knee (A/K) intelligent prosthesis controlled by magneto-rheological (MR) damper can compensate the basic movement function of amputees. This paper analyzed the existing torque devices of knee joint and introduced the configuration of A/K intelligent prosthesis controlled by MR damper. Dynamics model was given and virtual prototype was established. The control method based on computed torque was discussed and combined control simulation was done. The result indicates that A/K intelligent prosthesis controlled by MR damper can track human normal gait well.

Abstract: The semisolid slurry of A356 Al alloy was prepared by low superheat pouring and weak traveling-wave electromagnetic stirring (LSPWES), and then the slurry was further soaked for proper time and finally rheo-cast into a rheo-casting sample in this paper. The experimental results show that if the melt of A356 Al alloy is poured at 630-650°C and meanwhile stirred by weak electromagnetic field for a short time, the most primary α-Al grains solidified in the slurry are spherical and only a few are rosette-like. The shape of primary α-Al becomes more spheroidal and more homogeneous distribution in the microstructure by the process of the uniform temperature fields. The experimental results also show that the slurry temperature, injection pressure and speed have a great influence on filling ability. The higher the slurry temperature, injection pressure and speed, the higher the slurry filling ability, the more easily the die cavity is filled. With the given rheo-casting sample, if only the slurry temperature should be equal to or more than 585°C, or the injection pressure is equal to or more than 20 MPa, or the injection speed should be equal to or more than 0.24m/s, the rheo-casting sample die cavity can be filled completely. The microstructure of the castings indicates that the shape, size and numbers of the primary α-Al grains in different parts of the castings are highly consistent. After being held at 535 °C for 5 h and then aged at 160 °C for 16 h, the tensile strength, elongation rate and hardness of the rheo-casting samples with the above process are respectively 321.5 MPa, 8.03% and 105.9HB.

Abstract: In order to effectively correct the positioning error of Loran C to improve the positioning accuracy, it is necessary to study Loran C ground wave signal propagation delay variation with time, study the stability of propagation delay and timing characteristics. Take statistical analysis and pretreatment to Loran C ground wave signal propagation delay, test its stationarity, extraction its trend term, obtain stationary series, modeling to trend term and stationary series. The results show that Loran C ground wave signal propagation delay has good stability and repeatability, the time delay series can be fitted to combination model formed by G (2,1) cycle model and AR (p) from the regression model.

Abstract: IPv4 and IPv6 coexist in networks for a long time，however careful planning and choosing the right techniques actually make the transition to IPv6 smooth and easy. By introducing IPv4 and IPv6 communications solutions in this paper, we provide the particular deployment on IPv6 campus network, furthermore, we touch on the IPv6 network deployment plan. Researching the key technology of deployment and realizing IPv4 to IPv6 smooth transition.

Abstract: We have theoretically discussed the resonance modes in a two-dimensional photonic multiple quantum wells structure (QWs) consists of one photonic crystal with square lattice of parallel dielectric circular columns in air and some layers of columns are removed at constant intervals. The generation and frequency split of resonance modes are observed and explained with tight-binding approach. The effect of the interaction distance on the frequency split is also discussed.