Advanced Materials Research Vols. 457-458

Abstract: This paper focuses on the thermo-mechanical behaviors of a shape memory alloy (SMA) plate with a circular hole under biaxial uneven tension. The phase transformation behaviors of SMA under complex stress state are formulated based on the one-dimensional phase transformation model developed by Zhou and Yoon. The stress field equation of the SMA plate with a circular hole is derived according to linear elastic mechanics. The phase transformation behaviors near the region around the circular hole are numerically simulated under different conditions of applied stress.

Abstract: In this paper fuzzy logic control is introduced in auto adjust control system of air in bus. Fuzzy controller employs fuzzy control model of two inputs and one output. The paper also introduces the hardware framework, working principle and software of the system, analyzing merits of fuzzy logic technique, putting emphasis on the design of the fuzzy controller. In the controlling process, fuzzy controller samples temperature signal in bus and calculate deflection and deflection rate of temperature, looks up corresponding output in controlling table, and calculates its precision, then fuzzy controller gives related signal to motors and valve, acquiring satisfactory effect.

Abstract: A new algorithm for image zooming based on cartoon and texture decomposition is presented in this paper. The basic idea is to first decompose the image into cartoon and texture, and then zoom each part separately with different image zooming algorithms. Finally, the zoomed images will be synthesized into one image. The zoomed parts of the image are found by minimizing the different variational functional in the wavelet domain which use the Besov norm to measure the regularity of the parts. Unlike the traditional image zooming by interpolation, the variation model and image cartoon-texture decomposition is incorporated in the zooming algorithm. Experimental results have verified the validity of the new algorithm.

Abstract: The fatigue life study of the hatch corner plays very important roles in design of hatch corner. The target function is the gravity of the hatch corner, and the constraint function is fatigue accumulation damage in the present paper. The structure optimal design theory has been combined with the fatigue life assessment method, to assess a hatch corner fatigue life of a large bulk carrier, and to optimize the hatch corner based on meeting the fatigue life. The hatch corner has been optimized under meeting yield strength and buckling strength. The numerical results show that the optimum method is fit to optimize the hatch corner.

Abstract: Spatial multiplexing in the multi-user MIMO downlink allows each user in the system to receive multiple data subchannels simultaneously using the same time and spectral resources. In this paper, a successive iterative optimal algorithm based on signal-to-leakage-and-noise-ratio (SLNR) maximization algorithm is proposed, which make use of the unused subspace of some known users to improve the space gain of the other users and has no strict constraint on transmit and receive antennas numbers. According to the simulation results, the proposed algorithm outperforms the original SLNR algorithm, and has a considerable improvement in the system performance.

Abstract: The diffusion processes of lithium ions in La_2/3-xLi_3xTiO₃ (x=0.06, 0.11) compounds were investigated by dielectric relaxation method. Prominent relaxation dielectric loss peaks, peaks P1 and P2 in La_0.56Li_0.33TiO₃ and peaks P3 and P4 in La_0.61Li_0.18 TiO₃, were observed. From the shift of peak position with frequency, the activation energy of 0.36~0.42 eV and the pre-exponential factor of relaxation time in the order of 10^-14 ~ 10^-13 s were obtained if one assumes Debye relaxation processes. The activation energies of lithium ion diffusion in La_2/3-xLi_3xTiO₃ compounds and the characteristic vibration frequency for the ionic hopping motion are higher than those measured by ⁷Li nuclear magnetic resonance (NMR) spectroscopy and that of the typical phonon frequency (about 10¹³Hz). These values of relaxation parameters strongly suggest the existence of interaction between the relaxation species (here lithium ions or vacancies). Basing on the coupling model, the decoupled relaxation parameters of the dielectric relaxation peaks is: P₁ (0.14 eV, 2×10^-13 s), P₂ (0.25 eV, 1.8×10^-13 s), P₃ (0.17 eV, 4×10^-13 s) and P₄ (0.3 eV, 2.7×10^-13 s). These decoupled parameters are very close to the NMR measurement results and the reciprocal of the typical phonon frequency. Judging from the relaxation parameter of the peaks and combining with the crystallographic characterization, it is suggested that the P₁ (P₃) and P₂ (P₄) peaks are associated with the lithium ion diffusion in the ab planes and between the adjacent ab planes, respectively.

Abstract: Martensitic high carbon high strength SAE 52100 bearing steel is one of the main alloys used for rolling contact applications where high wear resistance are required. Due to its high fatigue strength, SAE 52100 is recently being used not only for the production of bearings but also shafts. Refining of prior austenite grain through repeated quenching is a procedure that can be used to enhance the material’s strength. In this work, the microstructure of repeatedly quenched SAE 52100 steel and its fatigue strength under rotating bending were investigated. It was found that repeated furnace heating and quenching effectively refined the martensitic structure and increased the retained austenite content. Repeated quenching was found to improve the fatigue strength of SAE 52100.

Abstract: In this present work, N-Ce co-doped TiO₂ nanopaticles were prepared via sol-gel process and characterized by TG - DTA and XRD. Their performance of photocatalytic degradation of methylene blue under visible light were investigated. N-Ce co-doped TiO₂ appeared to be somewhat more efficient than the starting TiO₂. The effects of catalyst compsition, catalyst amount, reaction temperature and solution pH on their photocatalytic activity towards methylene blue were studied and discussed. Experiment results depicted that activeness of catalyst N_0.4Ce_0.06/TiO₂ was highest. Using this catalyst, when the catalyst amount was 0.3 g/L，the reaction temperature was 40 °C and pH of the solution was 9.0 the degradation rate of mehylene blue in 4h could reach 94.00%.

Abstract: Independent task scheduling algorithms in distributed computing systems deal with three main conflicting factors including load balance, task execution time and scheduling cost. In this paper, the problem of scheduling tasks arriving at a low rate and with long execution time in heterogeneous computing systems is studied, and a new scheduling algorithm based on prediction is proposed. This algorithm evaluates the utility of task scheduling based on statistics and prediction to solve the influence of heterogeneous computing systems. The experimental results reveal that the proposed algorithm adequately balances the conflicting factors, and thus performs better than some classical algorithms such as MCT and MET when the parameters are well selected.

Abstract: The paper expounds the topology of TCR type SVC and proposes the controller’s implementation. Based on instantaneous reactive power theory, the paper ascertains the overall algorithm on SVC reactive power compensation. It can be refined to three steps: the extraction of active component and reactive component of fundamental, the modeling of compensation susceptances required and the four components of fundamental, and the establishing relationship of the fundamental equivalent susceptance of TCR and the triggering angle.The control performance of the algorithm is valued on accuracy and real-time.