Advanced Materials Research Vols. 476-478

Abstract: In this paper, a stable lattice Boltzmann model (LBM) based on non-ideal gases is presented for simulation of incompressible two-phase flows with large density ratio. To reduce the parasitic currents across the interface and correspondingly increase the numerical stability, the stress and potential forms of the surface tension force is employed. The applications to a stationary bubble and capillary-gravity wave with density ratio 1000 are given to verify this model. The numerical solutions is agree well with analytic solutions of the Laplace's law and capillary-gravity wave.

Abstract: A letters recognition method based on a small area of the feature matching is proposed, in which the unqualified letter in the string were recognized based on its geometric feature. In this method, firstly confirm label’s position by the extracted straight line characters. Then, rotate and zoom image according to the prior knowledge of label. Acquire the position of the string on the label and cut them out. And then single letters are segmented out using the projection method in the area of the string. Finally, compare geometrical characteristics of the extracted letters with its template to recognize and eliminate unqualified labels. The matching process proceeded only in the small region with letters and there is no need to search the irrelevant information. For this algorithm, so much time has been saved compared with traditional letter recognition method and projection method which is used for single character segmentation is very quick also. Theory analysis and experiment showed that the method can segment unqualified characters robustly and quickly.

Abstract: In this study, we reported the fabrication and characterization of a nano hetero junction (NHJ) structure which is synthesized by a 2-step hydrothermal growth (HTG) method. The zinc oxide (ZnO) nano rods (NRs) were grown by the 2-step HTG onto p-type nickel oxide (p-NiO) film e-beam deposited glass substrate to form n-ZnO-NRs/p-NiO NHJs. The electrical properties of the n-ZnO-NRs/p-NiO NHJs show a rectifying behavior of a p-n junction. The optoelectronic properties of the n-ZnO-NRs/ p-NiO NHJs under UV light (366 nm) light with good sensitivity were presented.

Abstract: This study makes a review of learning theories, methods, technologies and applications about robot soccer player’s behavior how to implement complex tasks. And pointed out that the limitations of its existence, as well as learning strategies of robot soccer. As a test bed of multi-agent system research of robot soccer system, many researchers conducted a study on the technology from different sides, and have achieved some success. The study indicated that researches currently on robot soccer system includes soccer robot architecture, collaboration, under the dynamic environment of a robot, sensor data fusion, complex reasoning and action learning in task, opponent modeling, and more.

Abstract: Thrust characteristics of permanent magnet linear synchronous motor (PMLSM) are analyzed. It shows that frequency spectrums of thrust ripple, which are mainly caused by end-effect, are quite similar for linear motors with different pole/slot combinations. To apply magnet skew technology, a method using piecewise magnet for skewing factor computation is introduced. According to this piecewise method, a policy for analyzing 3D skew effect model using 2D FEM algorithm is investigated. The application on a 14-pole/12-slot PMLSM validated the algorithm.

Abstract: In order to improve formability of Titanium alloy, the three-roll mill is used instead of two-roll during continuous rolling titanium alloy rod. Considering that the filling coefficient of titanium alloy rod is different from that of ordinary steels, a new pass design method has been illustrated in this paper. Based on the orthogonal experiment and finite element method, the spread formulae for round rod and triangle rod have been developed, and the program composition of pass for rolling TC4 rod has also been is used in experiment. The results showed that the proposed method is reasonable and could produce the qualified products.

Abstract: Combining with the outstanding performance of Ti (C, N), such as wear-resistant, withstand high temperature and alkali erosion, Ti-bearing blast furnace slag was modified, and Al-N-based materials were prepared in this paper. Based on the thermodynamic analysis, reasonable formula program was designed by the phase diagram, and then through high-temperature orthogonal experiments, a reasonable process condition was determined. The experimental results showed that the twice firing at the temperature of 1500°C was propitious to carbonitriding reaction. SiO2 was participated in carbonitriding reaction as reactant, which was conducive to the formation of Ti≡N bond. Eventually Al-N based materials that meet the design requirements were obtained.

Abstract: The B4C/BN nanocomposites were fabricated by hot-pressing process in this research. The B4C/BN nanocomposite powders were fabricated by chemical reaction and heat treatment process. The B4C/BN nanocomposites sintered bulks were fabricated by hot-pressing process at 1850oC for 1h under the pressure of 30MPa. In this research, the phase composition, microstructure, mechanical property and machinability of the B4C/BN nanocomposites fabricated by hot-pressing process were investigated. The XRD patterns results showed that there existed the B4C phase and h-BN phase in hot-pressed B4C/BN composites. The microstructure of the B4C/BN nanocomposites was investigated by SEM and TEM. The SEM micrographs showed that the B4C/BN nanocomposites bulks exhibited the homogenous and compact microstructure, and the h-BN particles were homogenously distributed in the B4C matrix. The TEM micrographs showed that there existed the weak interface between the B4C matrix grains and h-BN particles, as well as the microcracks within the laminate structured h-BN particles. The mechanical property of the B4C/BN nanocomposites decreased gradually with the increase of h-BN content. The B4C/BN nanocomposites exhibited the high mechanical property. The machinability of B4C/BN nanocomposites increased gradually with the increase of h-BN content, the drilling rates of the B4C/BN nanocomposites increased gradually with the increase of h-BN content.

Abstract: Reactive interface combination agent (RIC) was synthesized by using reaction mixture technique starting from polypropylene（PP）, ethylene-propylene or butadiene-styrene elastomer, epoxy compound and monomer-assisted in the presence of a free radical initiator. The chemical structure of the RICs and the effects of change in the ratio of raw material during its preparation on constitute and structure was investigated using fractional extraction and infrared spectroscopy. The prepared RICs consisted of unreacted PP and/or elastomers, homo-and/or copolymerization of monomer, and graft copolymer of PP and elastomers, and crosslinked copolymer of PP and/or elastomers in conjunction with polymer bridge chains derived from monomer.

Abstract: A pure spinel-type phase was attained by solid state reactions at room temperature, with no intermediate compounds. Its formation and the structural evolutions have been characterized by thermogravimetry-differential scanning calorimetry (TG/DSC) tests, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Related electrical analyses were also performed. The results showed that the powders and ceramics prepared by the solid state reactions at room temperature exhibit a good electrical property because of narrow grain size distribution, controlled morphology, and high purity. Most importantly, this new approach greatly simplifies the preparation processes.