Applied Mechanics and Materials Vols. 148-149

Abstract: The technology of applying aluminum-water reaction to underwater vehicle is analyzed combining with the energy identity of metal fuel and different aluminum powders. The present research situation and development foreground are studied.

Abstract: In this paper an electrochemical drilling method for machning micro holes using a flatted electrode instead of the traditional cylindrical electrode is presented. Both electrochemical drilling processes, in which the cylindrical electrode and the flatted electrode were used respectively, were introduced under same machining conditions. The taper of the micro holes between entrance and exit was reduced and machining speed was improved when the flatted electrode was used compare with cylindrical electrode. The flow field simulation was taken out to investigate the reasons for micro holes electrochemical drilling has advantage in taper reducing and machining speed increasing with flatted electrodes.

Abstract: The carbon-containing LiMnPO4 compounds were prepared by solid-state reaction with different carbon source: carbon black, citric acid, sucrose, or resorcinol formaldehyde resin. The structure, surface morphology and electrochemical performance of LiMnPO4 were characterized by X-ray diffractometry, scanning electron microscopy and electrochemical measurement respectively. The AC impedance and Cyclic Voltammetry was also discussed. The results showed that the electrochemical performance of LiMnPO4/C was affected by different carbon source. The particle size of LiMnPO4/C using resorcinol formaldehyde resin as carbon source was about 100~300 nm. The initial discharge capacity is 121.6mAh/g at 0.02C and an overall reversible capacity of 110mAh/g has been retained after 20 cycles. While at 0.1C, the discharge capacity was 110mAh/g; and more than 60mAh/g at 1C.

Abstract: GIS based labor and social security systems must be convenient and easy to use. The service and cloud computing oriented spatial architecture is a very promising architecture. This paper studied service and cloud computing based architecture for geographical information platform in labor and social security applications. The spatial cloud computing applies geographical information system has an important application prospect in labor and social security application.

Abstract: The solidification microstructure of Mg-6Zn-3Y alloy under super-high pressure was investigated by using X-ray diffraction (XRD) and scanning electron microscope (SEM). The results show that the dendritic structure of Mg-6Zn-3Y alloy under super-high pressure (GPa level) can be evidently refined with the increase of solidification pressure. When the pressure increases to 2 GPa, Y element can’t solubilize in matrix of a-Mg, the primary Y solid solution is distributed in the shape of polygon block in the matrix. When the pressure is up to 4 GPa, the primary Y solid solution appears as symmetrical petaline shape. So Y solid solution exhibits the different morphology with the change of the pressure

Abstract: In this paper, the pretreatment of concentrates by extrusion machine was present to improve the granulation of blends comprising some 30% iron ore concentrates and enhance the sintering performance. It is shown that by pretreatment of fine concentrates through extrusion machine, the content of +3mm fractions of granulation mixture and sinter mixture permeability are elevated by 10% and 35%, respectively. In the meantime, an increase in sinter productivity from 1.51 to 1.62t.m-2.h-1 is attainted in pot tests with similar sinter tumble index and at lower coke rate. The mechanism of the pretreatment of concentrates process to improve sintering performance of fine iron ore concentrates was demonstrated by mineralogy that better permeability help form more calcium ferrite and good microstructure of sinter, further proven by the better metallurgical performance of sinter.

Abstract: The profile error of a globoidal cam resulting from motion errors of two coordinated rotational axes of a machine tool in machining is studied. A novel method of solving profile error is presented. According to this method, the minimum distance from a point on the profile actually machined to the desired profile is referred to as the profile error. Then, the mathematic model of profile error resulting from the motion errors of the machine tool is built. After that, the type TC40 globoidal cam is employed as an example to analyze the machining error. The linear influence coefficients of the motion errors of the two coordinated rotational axes on the profile error are determined. The maximum value of the machining errors resulting from the motion errors of the two rotational axes of machine tool is yielded. A novel method of improving the velocity of solving the maximum value by using the linear influence coefficient is presented. At last, an isogram is introduced to analyze the influence of the motion errors of the two coordinated rotational axes of the machine tool on the globoidal cam profile error.

Abstract: A classification method for underwater echo is introduced, which based on fractal theory and learning vector quantization (LVQ) neural network. The fractal dimension was extracted from the underwater echo by continuous wavelet transform. Combining with accumulative energy as input of a LVQ neural network, neural network was used to classify four kinds of underwater echo. The experimental results showed this method is effective and reliable.

Abstract: One of the fundamental problems in scientific computing is to find solutions for linear equation systems. For finite element problem, Cholesky factorization is often used to solve symmetric positive definite matrices. In this paper, Cholesky factorization is massively parallelized and three different optimization methods - highly parallel factorization, tile strategy and memory scheduling are used to accelerate Cholesky factorization effectively. A novel algorithm using OpenCL is implemented. Testing on GPU shows that performance of the algorithm increases with the dimension of matrix, reaching 785.41GFlops, about 50x times speedup. Cholesky factorization is remarkably improved with OpenCL on GPU.

Abstract: The EFDC model is applied to predict the flow field of two typical circulating water body impacted by both pump driven current and wind-driven current. The result demonstrates that there exists strong effect between pump driven current and wind-driven current. The wind can effectively reduce the area of low velocity zone of pump drive current as well as the power consumption of pump. And the increased high velocity area could better inhibit the algae growth and thus prevents degradation of water quality.