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15 November 2011, Volume 32 Issue 11 Previous Issue    Next Issue
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Observer design for Lipschitz nonlinear systems with time-delay Zhang, Yue (1); Yang, Hong-Jin (2); Zhao, He-Ping (2); Liu, Rui (2) 2011, 32 (11):  1521-1524.  DOI: - Abstract ( 309 )   HTML   PDF (1046KB) ( 691 )   To the problem of state observer design which is considered for a class of Lipschitz nonlinear systems with time-delay, new type full-order and reduced-order observers were given. Sufficient conditions for observers were presented by line matrix inequality (LMI) and proven through constructing Lyapunov function. The results indicated that the gain matrixes of full-order and reduced-order observers can be obtained easily by soluting line matrix inequality, so the solving process of the gain matrixes is simplified and the approach avoids the blindness of selecting the gain matrix. The simulation results for the model showed that the two kinds of state estimate errors converge to zero quickly, which indicates that the approach is effective. References | Related Articles | Metrics

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Adaptive control of coating weight for continuous hot-dip galvanizing Zhang, Yan (1); Shao, Fu-Qun (1); Wang, Jun-Sheng (2); Liu, Bao-Quan (2) 2011, 32 (11):  1525-1528+1533.  DOI: - Abstract ( 409 )   HTML   PDF (1485KB) ( 876 )   Due to the exsistence of large variable-time delays, nonlinearities and multivariable disturbances in the hot galvanizing coating thickness control processes, seriously coating weight error and nonuniform coating may usually happen. Based on the relative analysis of coating weight with air knives pressures, distances between air knives and strip speed, the model of adaptive feed-forward control and model-free adaptive feedback control were presented to control automatically air-knives pressure and position. An accurate and uniform zinc coating weight control is proposed and implemented. Simulation result showed that the precise and intelligent control schemes resolve effectively the above difficulties contrasting to PID control. The adaptive control model used in product application not only satisfy high quality control requirement but also change from manual adjustment to the automation control on coating weight. References | Related Articles | Metrics

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A vein recognition algorithm based on establishing HMM adaptively through using GA Xue, Ding-Yu (1); Jia, Xu (1); Cui, Jian-Jiang (1); Liu, Jing (1) 2011, 32 (11):  1529-1533.  DOI: - Abstract ( 376 )   HTML   PDF (872KB) ( 576 )   In order to recognize one's identity accurately, through using the extension direction of vein and location relations among contexts, hidden Markov model (HMM) was applied in vein recognition system and a vein recognition algorithm based on establishing HMM adaptively through using GA (genetic algorithm) was proposed. The skeleton information of vein is acquired after image pretreatment, and the thinned vein image was processed by Radon transformation, then each vein object can be expressed as an HMM; for identified train sample library, the parameters of the HMM were adjusted through using GA such that the observation probability values of all the tested images provided by true matching models are much larger than those provided by false models, thus the degree of the differentiation among vein objects was significantly increased. Experiments showed that the proposed algorithm has higher correct recognition rate and better real-time performances. References | Related Articles | Metrics

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Moving object detection and tracking using level set Xu, Yang (1); Wu, Cheng-Dong (1); Chen, Dong-Yue (1); Zhao, Ji (2) 2011, 32 (11):  1534-1537.  DOI: - Abstract ( 381 )   HTML   PDF (1289KB) ( 871 )   According to the disadvantages of the moving detection methods which were used commouly, the moving object detection method of combination of geodesics active contour model and background subtraction based on the principle of level set proposed. The level set function is used in the improved method without re-initialization, the number of iteration in the curve evolution and the execution time are significantly reduced, the exact moving object contour is obtained. Through comparison with the particle filtering and mean shift tracking methods, finally the highest efficiency and optimal Kalman filtering was used to predict the moving trajectory of objects. Experimental results showed that the method has better detection and tracking effect on the two kinds of rigid and non-rigid objects. References | Related Articles | Metrics

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A global particle swarm optimization algorithm Gao, Li-Qun (1); Li, Ruo-Ping (1); Zou, De-Xuan (1) 2011, 32 (11):  1538-1541.  DOI: - Abstract ( 693 )   HTML   PDF (360KB) ( 944 )   Particle swarm optimization (PSO) algorithm shows good performance on solving small-scale unconstrained optimization problem, however, it has poor convergence and stability on solving large-scale ones. In order to improve the performance of the PSO algorithms, a global particle swarm optimization (GPSO) algorithm was proposed. The GPSO introduces a new inertia weight, and it is defined as the product of an exponential type function and a random number, which is beneficial to keeping the global and local searching capabilities of the proposed algorithm. On the other hand, the GPSO adds small disturbance to the global optimal solution, which can effectively avoiding the premature problems in the convergence of the GPSO algorithm. Three particle swarm optimization algorithms were used to solve six unconstrained optimization problems. Simulation results demonstrated that the GPSO has faster convergence rate and stronger capability of escaping from the local optimum when compared with the other two existing particle swarm optimization algorithms. References | Related Articles | Metrics

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Robust H∞ control of closed-loop supply chain dynamic model with two-channel Zhang, Xue-Feng (1); Liu, Xiu-Ying (1); Liu, Hai-Xia (2) 2011, 32 (11):  1542-1545.  DOI: - Abstract ( 277 )   HTML   PDF (1172KB) ( 689 )   With the uncertainty of production delay, electronic distribution delay, external demand and collector recovery, according to production inventory, distribution inventory, customer virtual inventory, and third-party recycling inventory, the closed-loop supply chain dynamic model with two-channel, which combining with the actual operation situation about production, remanufacture, distribution, e-market, inventory and recovery, was established. The robustness operation of closed-loop supply chain was analyzed. A linear matrix inequality algorithm was giving to solve the robust control H∞ strategy of the closed-loop supply chain dynamic model with two-channel. The analyzed results showed that the impact of uncertainty on the operation of the closed-loop supply chain is restrained by the robust H∞ control strategy, and the operational cost of the closed-loop supply chain can be optimal. Finally, a simulation of appliance business verified the effectiveness of the method. References | Related Articles | Metrics

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Resource allocation model to achieve optimize profit in virtual data center Wang, Cong (1); Wang, Cui-Rong (1); Yuan, Ying (1) 2011, 32 (11):  1546-1549.  DOI: - Abstract ( 311 )   HTML   PDF (1128KB) ( 775 )   To solve the problem of the competition for physical bandwidth between virtual networks in virtual data center, a resource allocation model was proposed based on the game theory. Firstly, an overall profit optimization objective for bandwidth allocation of virtual networks was brought forward, and then the optimization problem was split into distributed game model, which can be implemented on the switches in the network. Under the given pricing mechanism, virtual networks run a non-cooperative game which achieves optimal bandwidth allocation at Nash equilibrium point. The proof and solution of the game model were also presented. Experimental results showed that the proposed model can achieve fair and rational bandwidth resource allocation among virtual networks. References | Related Articles | Metrics

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Location algorithm of RGB iris image based on integro-differential operators Zhang, Xiang-De (1); Dong, Xiao-Peng (1); Wang, Qi (1); Sun, Yan-Rui (1) 2011, 32 (11):  1550-1553.  DOI: - Abstract ( 370 )   HTML   PDF (1637KB) ( 1121 )   A location algorithm based on integro-differential operators was presented for solving the difficulty of precise segmentation in NICE:II. The R layer of RGB iris image is chosen first, and the Gabor filter and gradient information are used to detect the reflection area. Moreover, Adaboost algorithm is used to detect iris area in the whole image, then the upper and lower eyelids are detected. A center template based on integro-differential operators was adopted to search the outer boundary of iris through iteration step by step, and cluster analysis was used to remove the noise on iris boundaries. Because the inner boundary of iris is weak, the homomorphic filtering is adopted to enhance the iris area, then the inner boundary is located. The proposed algorithm was tested under NICE:II, and the accuracy of the new method is 98.22%. References | Related Articles | Metrics

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Speech denoising method based on the EEMD and ICA approaches Li, Jing-Jiao (1); An, Dong (1); Wang, Jiao (1) 2011, 32 (11):  1554-1557.  DOI: - Abstract ( 381 )   HTML   PDF (992KB) ( 1250 )   Speech denoising technology is one of the key problems in the practical application of speech recognition systems. Since speech signals are nonstationary, speech signal contained chirp was decomposed into several intrinsic mode functions (IMF) with the method of ensemble empirical mode decomposition (EEMD). At the same time, it eliminated the model mix superposition phenomenon which usually came out in processing speech signal with the algorithm of empirical mode decomposition (EMD). After that, several effective speech signal components were separated from intrinsic mode function through the algorithm of improved independent component analysis (ICA). Finally, reconstructed them in the purpose of noise elimination. The result showed that the new speech denoising method proposed above improves SNR up to 2.7412 dB in the condition that -10 dB SNR vehicle interior noise. References | Related Articles | Metrics

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Implementation of moving object extraction in video Yan, Ai-Yun (1); Li, Hai-Peng (1); Li, Jing-Jiao (1); Wang, Jiao (1) 2011, 32 (11):  1558-1561.  DOI: - Abstract ( 472 )   HTML   PDF (1215KB) ( 730 )   There are many shadows in moving target detection area which obtained by background subtraction based on Gaussian mixture model. Criterion of detecting shadow and judgment of Phong illumination model was improved, and a video moving object detection algorithm was presented. Combining the background subtraction and symmetry subtraction on Gaussian mixture model to get moving object, and using improved algorithm to remove shadow. The results showed that the improved standards reduce the average deal time by 18% to 30% and still obtain better results of removal shadow, and finally gain the precise motion target. References | Related Articles | Metrics

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Study on static recrystallization model of bridge weathering steel Wu, Hong-Yan (1); Du, Lin-Xiu (1); Liu, Xiang-Hua (1) 2011, 32 (11):  1562-1565.  DOI: - Abstract ( 295 )   HTML   PDF (1476KB) ( 575 )   The static soften behavior of a bridge weathering steel within the interval of passes was investigated with double-pass compression method using MMS-300 thermal-mechanical simulator. The influence of temperature and interval time was analyzed and the softening percentage of static recrystallization under different conditions was defined by the 0.2% stress offset method. The results showed that the static recrystallization occurs after the first pass compression deformation of 5~10 seconds, deformation temperature and interval time have a significant effect on the static recrystallization behavior, and the higher the deformation temperature is, the faster static recrystallization proceeds. The static recrystallization activation energy of weathering steel is about 190.57 kJ/mol and the static recrystallization dynamics model is described. References | Related Articles | Metrics

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Prediction of property distribution on the cross section of hot rolled DP steels Cai, Xiao-Hui (1); Liu, Xu-Hui (1); Liu, Zhen-Yu (1); Liu, Xue-Kai (1) 2011, 32 (11):  1566-1569.  DOI: - Abstract ( 279 )   HTML   PDF (1410KB) ( 607 )   The finite differential method was applied to calculating the temperature field and temperature curve of the cooling process of strip. Based on the experimental TTT curve, the CCT curve was deduced from Scheil's rule and Avrami equation. Then the temperature field and the phase transformation process were coupled to predict the ferrite grain distribution on the cross section of the strip. With the microstructure-property models the mechanical property distribution on the cross section, e.g. yield/tension strength, was calculated. The UFC (ultra fast cooling) technology and stepped cooling mode were applied to producing DP (dual phase) steels with low cost and good quality on site. The produced DP steels showed the low yield ratio, the tensile strength of 700 MPa and the ferrite grain size of 5~6 μm. This design process, adapting the cooling route based on the simulation results of the microstructure distribution, can decrease the production cost and increase the production efficiency. References | Related Articles | Metrics

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Analysis of plastic collapse load of defect-free pipe elbow with GM criterion Zhang, Shun-Hu (1); Zhao, De-Wen (1); Gao, Cai-Ru (1) 2011, 32 (11):  1570-1573.  DOI: - Abstract ( 355 )   HTML   PDF (1687KB) ( 655 )   With GM (geometrical midline) yield criterion, the plastic collapse load of defect-free pipe elbow under inner pressure was analyzed and an analytical solution was obtained. The solution showed that the collapse load is a function of wall thickness t, average radius r, yield strength as well as curvature radius R0. The collapse load increases with the increase of the curvature radius R0 and is the same as the burst pressure of straight pipe if R0&rarr∞ is assumed. The plastic collapse load calculated by the solution was compared with those based on Tresca, Mises, as well as TSS yield criteria. Tresca criterion predicts the lower bound of the collapse load, while TSS criterion predicts the upper bound. However, the collapse load on the GM criterion lies just between the TSS and Tresca solutions-most notably, the GM criterion almost has the same precision with the Mises solution. References | Related Articles | Metrics

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Effects of Sc and Zr on microstructure and mechanical properties of Al-Zn-Mg-Cu aluminum alloy Zhao, Zhi-Hao (1); Wang, Gao-Song (1); Zhang, Yi-Hang (1); Cui, Jian-Zhong (1) 2011, 32 (11):  1574-1577.  DOI: - Abstract ( 295 )   HTML   PDF (1579KB) ( 718 )   A series of Al-9.0Zn-2.8Mg-2.5Cu alloys with different additions of Sc, Zr and Sc+Zr were prepared by ingot-metallurgy processing. The metallurgical structure and mechanical properties were investigated by optical microscope, universal testing machine and other equipment. The results indicated that when Sc and Zr are added respectively, the tensile strength of alloy increases gradually and the elongation decreases with the increase of addition; the tensile strength and the elongation are 775 MPa and 785 MPa, 9.95% and 7.1%, respectively. When the addition increases from 0.15% to 0.25%. When Sc and Zr are added compositely, if the content of Sr is less than Zr, the tensile strength increases and then declines with the increase of additions, and the elongation gradually decreases. When the addition is up to 0.04%Sc and 0.12%Zr, the tensile strength reaches the maximum value of 775 MPa and the elongation declines to 9.85%. References | Related Articles | Metrics

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In-situ synthesized TiB2 toughened SiC microstructures and fracture toughness Wang, Wei (1); Lian, Jing-Bao (1); Yue, Xin-Yan (1); Ru, Hong-Qiang (1) 2011, 32 (11):  1578-1582.  DOI: - Abstract ( 272 )   HTML   PDF (2014KB) ( 636 )   Based on the previous work dealing with the process conditions of in-situ synthesized TiB2 particles reinforced SiC by pressureless sintering method, the microstructures and the mechanical properties of obtained TiB2/SiC ceramic composites were studied. It was found that the TiB2 particles distribute homogeneously in the SiC matrix with φ(TiB2) ranged from 5% to 20%. The equivalent-area circle diameters of TiB2 particles in ceramic composites with φ(TiB2) of 5% and 20% are 2.6 μm and 3.9 μm, respectively. Moreover, the introduction of TiB2 phases can suppress the growth of the SiC grains during the sintering. The relative density, Vicker's hardness and fracture toughness of obtained TiB2/SiC increase with the increase of the φ(TiB2). For TiB2/SiC composite with φ(TiB2) of 20%, the relative density, Vicker's hardness and fracture toughness are 94.8%, 29.1 GPa, 5.9 MPa·m1/2, respectively. Under optimized process conditions, the fracture toughness of TiB2/SiC ceramic composite reaches up to 6.3 MPa·m1/2. References | Related Articles | Metrics

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The abrasive wear properties of aluminum alloy 6061 reinforced with nano-SiC particles Li, Xiao-Dan (1); Zhai, Yu-Chun (1); Ma, Jun-Ping (1) 2011, 32 (11):  1583-1586.  DOI: - Abstract ( 217 )   HTML   PDF (1708KB) ( 738 )   Aluminium alloy 6061(AA6061) matrix composites reinforced with nano-SiC particles were produced. The microstructure, Vickers microhardness and characteristic wear properties of the composites were investigated. The results showed that the wear rate and the friction coefficient values of the composites are lower than the matrix alloy at 20 N load, the wear rate of 0.6%SiC/AA6061 decreases 50% than the matrix. This is attributed to the strong bonding between the matrix and the particles in the composites. So the presence of SiC particles in the composites improves the wear resistance because these particles remain intact and retain their load-bearing capacity, they promote the formation of iron-rich transfer layer. The dominant wear mechanisms are found to be abrasion for the AA6061 alloy and its composites at 20 N load. References | Related Articles | Metrics

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Non-templated preparation of 3D-interconnected macroporous hydroxyapatite Ru, Hong-Qiang (1); Chu, Bao-Shuai (1); Lin, Chun-Qing (1); Chen, Si (1) 2011, 32 (11):  1587-1590.  DOI: - Abstract ( 256 )   HTML   PDF (1850KB) ( 615 )   A novel synthesis method, called poly(vinyl alcohol) assisted foaming method (PAF method) for the preparation of porous hydroxyapatite (HA) scaffolds with 3D-interconnected macropores without using any templates or porogens or complicated chemical process was reported. XRD analyses revealed that the sintered macroporous HA is pure in compositions. SEM and CLSM results showed that the macroporous structures and pore sizes can be facilely tuned by adjusting the mass ratios of PVA to HA. The mass ratios PVA to HA of 4.4 and 4.9 produce macroporous HAs with uniformly distributed macropores with sizes ranging from 90 to 200 μm in sizes, which are similar to those of human bone in terms of macropore size and interconnectivity. It is therefore believed that such kind of 3D interconnected macroporous HA scaffolds have great potential for application in the area of bone tissue engineering. References | Related Articles | Metrics

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Mathematical model of burden distribution law for COREX shaft Li, Qiang (1); Zhang, Yu-Dong (1); Zhang, Li-Juan (1); Zou, Zong-Shu (1) 2011, 32 (11):  1591-1594.  DOI: - Abstract ( 290 )   HTML   PDF (1122KB) ( 614 )   An extended mathematical model of the material flow trajectory in free-space was developed to investigate the burden distribution process of COREX shaft. The influence of burden layer distribution of depth and width on the chute and the elaborating charging profile by multiple-linearization were considered in the model. The results showed that the flow trajectory of particles in free-space is determined mainly by the burden layer depth and particle size at the bottom of the chute. The terminal velocity of leaving chute is proportional to the rotation velocity and inverse dependence on the angle of the chute. The distance from the landing position of burden particle to the shaft centre at near throat increases with the increasing of the angle and rotation velocity of the chute. The packing process and charging profile under the different conditions of charging pattern and burden materials can be simulated by the model. References | Related Articles | Metrics

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Preparation of high titanium ferroalloy with low oxygen through vacuum reduction refining Dou, Zhi-He (1); Zhang, Ting-An (1); Yao, Jian-Ming (1); He, Ji-Cheng (1) 2011, 32 (11):  1595-1598+1614.  DOI: - Abstract ( 248 )   HTML   PDF (1664KB) ( 1087 )   To reduce oxygen content and inclusions in the high titanium ferroalloy prepared by the aluminum thermal reduction, the vacuum reduction refining method was used to prepare the low oxygen high titanium ferroalloy in which the high titanium ferroalloy prepared by aluminum thermal method was used as raw materials. Effects of the refining temperature and refining slags were studied. The high titanium ferroalloy was characterized by XRD, SEM and chemical elemental analysis. The results showed that the microstructure of the reduction refining alloy is uniform and compact, the inclusions in the alloy are effectively removed and the oxygen content decreases dramatically. The mass percent composition of Ti, Fe, Al, Si, O in the refined alloy prepared with CaO-Al2O3 as vefining slag at 2000°C is 74.5%, 18.2%, 2.17%, 0.81%, 3.20%, respectively, which is fully consistent with the technical indicators of the high quality high titanium ferroalloy. References | Related Articles | Metrics

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E-pH diagram of pretreatment of leaching for refractory gold ore Kim, Chang-Sok (1); Zhang, Ting-An (1); Mu, Wang-Zhong (1); Zeng, Yong (1) 2011, 32 (11):  1599-1602.  DOI: - Abstract ( 348 )   HTML   PDF (1157KB) ( 1360 )   E-pH diagrams of FeS2-H2O system and FeAsS-H2O system at 298.15 K were drawn to provide the thermodynamic basis for the pretreatment of pyrite and arsenopyrite before leaching. According to E-pH diagram of FeS2-H2O system, pyrite can be decomposed by O2 and other oxidants. The stable region of sulfur element is small and sulfur exists as HSO4- and SO42- basically in the stable region of water. According to E-pH diagram of FeAsS-H2O system, the decomposition of arsenopyrite is easier than pyrite. Oxidation potential was improved to oxidize sulfur and arsenic to be removed and avoid the formation of arsenite and sulfur elements during the pretreatment process. Verification of pressure oxidation was carried out with refractory gold ore. When the temperature, concentrate particle size, oxygen partial pressure, initial acid concentration, liquid-solid mass ratio, reaction time and stirring speed are 180°C, -0.075~+0.061 mm, 0.8 MPa, 60 g/L, 4:1, 120 min and 600 r/min respectively, average desulfurization rate is 93.85% and average arsenic removal rate is 95.91%. The experiment results are in good agreement with the calculation results of E-pH diagram. References | Related Articles | Metrics

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Research on fluctuation state of liquid aluminum in 300 kA and 400 kA aluminum reduction cell Li, Jian-Hong (1); Tu, Gan-Feng (1); Qi, Xi-Quan (2); Mao, Ji-Hong (2) 2011, 32 (11):  1603-1606.  DOI: - Abstract ( 231 )   HTML   PDF (2026KB) ( 561 )   Iron rod method was adopted for industrial metal flow measurement of six aluminum reduction cells. 300 kA and 400 kA cells with same and different height of cathode blocks, end cell and middle cells were analyzed. The characteristics of whole horizontal flow and regional vertical flow in liquid aluminum were investigated by analyzing the phenomenon of different measured iron rods, which show normal erosion, thick-thin-thick character, turned eroded surface, numerous eroded holes. The flow velocity of the cells with different cathode structures was compared. In the direction of cell length, there are four eddies with big-small-small-big state in same height of cathode blocks 400 kA cell and two homogeneous eddies in different height of cathode blocks 400 kA cell, while there are five homogeneous eddies in same height of cathode blocks 300 kA cell. References | Related Articles | Metrics

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Preparation of SrTiO3 thin films on Si(100) substrates with V-grooves Wang, Qi (1); Yu, Xiao-Ming (1); Qi, Yang (1) 2011, 32 (11):  1607-1610.  DOI: - Abstract ( 271 )   HTML   PDF (1466KB) ( 710 )   SrTiO3 (STO) thin films were grown on Si(100) substrates and Si(110) substrates with V-grooves by liquid phase deposition (LPD) and RF magnetron sputtering, respectively. In order to obtain high quality STO films by LPD, the influences of sedimentary solution temperature, substrate surface treatment methods, substrate placement and heat treatment process were investigated. In order to obtain high quality STO films with certain orientation at low substrate temperature by RF magnetron sputtering, the specific parameters, including sputtering power, sputtering pressure, annealing temperature and substrate temperature, were studied. The results showed that the crystalline state, texture, and surface morphology of STO films prepared by RF magnetron sputtering are better than those by LPD. References | Related Articles | Metrics

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Study on biomimetic hydroxyapatite coating on surface of AZ31 alloy Zhang, Ya-Jing (1); Zhang, Dan (1); Xi, Xiao-Hui (1); Jia, Hai-Long (1) 2011, 32 (11):  1611-1614.  DOI: - Abstract ( 326 )   HTML   PDF (1645KB) ( 731 )   A well-grown once and twice hydroxyapatite coatings on the surface of AZ31 magnesium alloy were produced in 24 and 48 h using a biomimetic technique. The coatings formed on the magnesium alloy were characterized by XRD, and the morphology of sample surfaces was observed by SEM. The samples were subsequently immersed in the simulated body fluid (SBF) for the degradation test. The results indicated that the degradation rate of the two-layer coating samples is slower than the single coating samples, the twice coatings are better than once coating, and it confirms the feasibility to control degradation rate of magnesium alloy by changing the morphology and thickness of coatings. References | Related Articles | Metrics

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Study on adsorption of trace Cu(II) on TiO2 nano-film Li, Hai-Jun (1); Zhang, Xia (1); Sun, Hai-Tian (2) 2011, 32 (11):  1615-1618.  DOI: - Abstract ( 288 )   HTML   PDF (1593KB) ( 535 )   TiO2 nano-film with homogeneous surface was prepared on the glass substrate by the sol-gel method. The film was characterized by SEM and XRD. The adsorption of trace Cu(II) was carried out taking TiO2 nano-film as an adsorbent. The effects of pH values, adsorption time, initial concentrations of Cu(II) and coexistent ions on the adsorption rates were studied systematically. The results showed that the film is composed of anatase TiO2 nanoparticles with the grain diameter about 50 nm. The adsorption isotherm of Cu(II) on TiO2 nano-film shows "L" type, which is explained by the monolayer adsorption. The Cu(II) adsorbed on TiO2 nano-film is eluted by 1.0 mol/L nitric acid efficiently. The optimum adsorption conditions are determined. References | Related Articles | Metrics

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Analysis the component of drug packaging combining with infrared image system and thermal analysis Zhang, Na (1); Qiao, Hui (1); Sun, Hui-Min (2); Zhang, Bao-Yan (1) 2011, 32 (11):  1619-1622.  DOI: - Abstract ( 287 )   HTML   PDF (1066KB) ( 863 )   Fourier transform attenuated total reflection infrared spectroscopy (FTIR-ATR) combined with thermal analysis were applied to the component analysis of four different types of plastic bottles, and the distribution of the component was studied by the infrared image system. The results showed that the main components of the bottles are polyethylene (HDPE) and a certain amount of polypropylene (PP). The results of the infrared image system are consistent with the experiment data of FTIR-ATR and thermal analysis. Infrared image system can detect trace impurities in a complex mixture, and provides a new powerful technique for the inspection of drug packaging. References | Related Articles | Metrics

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Influence of double axial cracks' angle on stress intensity factors of crack tip He, Xue-Hong (1); Qin, Xiao-Feng (1); Xie, Li-Yang (1); Qian, Wen-Xue (1) 2011, 32 (11):  1623-1626.  DOI: - Abstract ( 267 )   HTML   PDF (1182KB) ( 700 )   Stress intensity factor analysis of pipe cracks is the key to determine whether there exists crack propagation and to calculate the pipe fatigue fracture. The stress intensity factors at the double axial cracks' tip of pipes with different size, crack length and angles between cracks were calculated by universal finite element software ANSYS. The calculation results indicated that the stress intensity factor increases with increasing the angle between double axial-through cracks when the pipe size and crack dimensions are determined. The influence of angle between cracks on stress intensity factor is enhanced with increased ratio between crack length and pipe thickness at defined pipe size. The analysis may provide certain reference information for reasonable determination of the crack propagation and accurate calculation of the pipes' fatigue fracture. References | Related Articles | Metrics

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Inherent characteristics of the cylindrical panel blade Li, Hong-Ying (1); Xie, Li-Yang (1); Guo, Xing-Hui (2) 2011, 32 (11):  1627-1630.  DOI: - Abstract ( 262 )   HTML   PDF (1463KB) ( 570 )   An analytical method for calculating the inherent characteristic of cylindrical panel blade was proposed. The blade was simplified as a cantilevered open cylindrical shell mounted on a disc. By making mode shapes function of cantilevered girder in the longitudinal direction substitute for variational equations so as to simplify it into a constant differential equation in the other direction, the natural frequencies and the mode shapes were thus achieved by solving the equation. The results were also compared with that of the FEM. It showed that the analytical method provides high calculation precision. The as-obtained natural frequencies and the mode shape function can be further used to study the nonlinear characteristics and fatigue life of single blade or multi-blades. References | Related Articles | Metrics

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Simulation of handling impact load of bulk material by DEM method Song, Wei-Gang (1); Chen, Hong-Liang (2); Li, Qin-Liang (1); Yang, Yan-He (1) 2011, 32 (11):  1631-1634.  DOI: - Abstract ( 317 )   HTML   PDF (1201KB) ( 953 )   Based on discrete element method (DEM), the DEM software was used to simulate the bulk material handling process. Considering the current DEM method cannot be applied to calculating the motion of tiny particles, the particles were comparatively simulated with sizes of 75, 100 and 150 mm and it was found that the results were close to the actual operating conditions for particles with sizes of 50~300 mm. The impact coefficient was proposed to characterize the impact influence, which can be used to compare the impact effect in different cases of blanking height and particle size. The maximum impact force and coefficient of single particle and particle flow can be obtained by computer simulation, which reflect the impact effect of particle flow very well. The fact that the normal force of particles acting on the conveyor belt approximates to the gravity of bulk material confirms the accuracy of the calculation results. References | Related Articles | Metrics

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Numerical simulation for temperature field of workpiece affected by wear of micro-milling cutter Zhang, Jin-Feng (1); Gong, Ya-Dong (1); Liu, Yue-Ming (1); Cheng, Jun (1) 2011, 32 (11):  1635-1638.  DOI: - Abstract ( 261 )   HTML   PDF (1363KB) ( 590 )   Temperature can not be accurately measured and precisely controlled in micro-milling process. To this problem, from the point of the temperature, a finite element analysis model was built using the technology of arbitrary Lagrangian Eulerian adaptive grid and the method of thermo-mechanical coupling. According to actual micro-milling situation, the required parameters were reasonably set. It was combined with the important conditions that the cutting edge radius would become larger with the wear of micro cutter. Finally, the effect of temperature changes on the workpiece was numerically analyzed. The simulation results showed that the temperature changing trend of the workpiece in each thermal zone meets the actual temperature of the micro milling process. The results may have certain significance in practical micro-milling process. References | Related Articles | Metrics

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Study on structure parameters of the rubber seal ring of diaphragm chamber Ling, Xue-Qin (1); Liu, Jie (1); Zhang, Wei (2); Gong, Yun-Peng (1) 2011, 32 (11):  1639-1642.  DOI: - Abstract ( 286 )   HTML   PDF (1482KB) ( 825 )   The seal ring structure was reformed to improve the sealing performance and the experiment about the rubber properties were carried out in the US AXEL laboratory. The rubber seal ring model was built and analyzed by ANSYS, and the strain and stress under working state were calculated with the maximum contact stress as working ability criteria. The effect of structure parameters on sealing performance was then analyzed and the geometry dimensions were optimized. It was shown that the suitable width of sealing surface is 1.5 mm and the compressing distance is 3 mm, which can prevent the problems of tightness and early failure of the diaphragm chamber. This work may offer some useful information for the design of seal ring. References | Related Articles | Metrics

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The formation mechanism of the redox environment in the rich iron deposits of Gongchangling Xia, Jian-Ming (1); Wang, En-De (1); Zhao, Chun-Fu (1); Men, Ye-Kai (1) 2011, 32 (11):  1643-1646.  DOI: - Abstract ( 242 )   HTML   PDF (873KB) ( 767 )   The environment of mineral preservation was indificated by the mineral component of the metamorphic. The graphite came from muddy sediments which formed by metamorphism according to the mineral assembled, especially the graphite, cordierite and garnet in the second iron ore of Gongchangling. By the calculation of physical chemistry, the iron oxide can form hematite under the conditions of pure water while it can form magnetite under the conditions of graphite. The activity of the O2 which comes from H2O is very low by the relation of hematite and magnetite. The results can be used to explain the appearance of "two sides are large, the intergrade is small" and the appearance of the martite which is undergroud 500 m. References | Related Articles | Metrics

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Detection and disposal of the complex goaf in Longqiao iron mine Li, Hai-Zhou (1); Yang, Tian-Hong (1); Zhang, Hong-Hai (2); Ding, Ming (3) 2011, 32 (11):  1647-1650.  DOI: - Abstract ( 251 )   HTML   PDF (1618KB) ( 586 )   Local goaf collapse at -320 m level in Longqiao Iron Mine has caused the unknown goaf shape. Under the condition of unpermitted surface subsidence, in order to ensure the deep ore bodies safety, the interval layer should be remained. Based on the drilling detection, the goaf shape was definitely known, and then the FLAC3D was applied to analyzing the influence of stress distribution in the whole goaf under the conditions of different interval layer thickness. The results showed that the 25 m interval layer remained in next level can effectively alleviate stress distribution. It can also ensure the mining safety at the next level. References | Related Articles | Metrics

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Numerical modeling and experimental study on large-angle hinged skew slab bridge Zhang, Wen-Xian (1); Jin, Shu-Yang (2); Han, Zhi-Hui (3); Tong, Pei-Zhou (1) 2011, 32 (11):  1651-1654.  DOI: - Abstract ( 256 )   HTML   PDF (941KB) ( 537 )   Transverse load distribution of large-angle hinged skew slab bridge was studied, and the method to calculate the influence line of transverse load distribution with an empirical formula was put forward. In order to establish a reliable numerical model, shear-flexible grillage method was adopted, then organic glass model was made to verify the reasonableness of the numerical model. Numerical models of hinged skew slab bridges with different slabs, different skew angles were established to get the empirical formulas of the influence line of transverse load distribution. Finally, the reliability of the empirical formulas was validated by theoretical calculation. References | Related Articles | Metrics

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Study of reinforced concrete t beams strengthened with near surface mounted FRP under repeated overloading Zhu, Fu-Sheng (1); Xu, Ming-Lei (1); Sheng, Guo-Hua (1); Tian, Xing (1) 2011, 32 (11):  1655-1658.  DOI: - Abstract ( 315 )   HTML   PDF (958KB) ( 576 )   In order to recognize the effects of cracked degree and the strengthening parameters on the performance of reinforced concrete beams, 6 T-section pre-cracked reinforced concrete beams strengthened with near surface mounted CFRP sheets were tested. The failure modes, the bending moments and deflections of the strengthened concrete beams were discussed. The results showed that the reinforcements by using the near surface mounted CFRP sheets have an obvious impact on the flexural ultimate bearing capacities. The pre-cracked degree has a few influences on the ultimate bearing capacities and the failure modes of the strengthened concrete beams, but splits in the beams developed by pre-cracked process can produce more deflection of the pre-cracked beams. The more fissures are induced, the larger deflection is. The failure modes of all the beams strengthened with CFRP sheets are the debonding of CFRP sheets from the adhesive layer of epoxy. The bending performance of the strengthened beams can be in a good state if reliable shear strengthening can be assured. References | Related Articles | Metrics

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Natural benchmark selection method and application based on goal programming Guan, Zhi-Min (1); Dong, En-Fu (1); Zhang, Li-Li (2) 2011, 32 (11):  1659-1662+1667.  DOI: - Abstract ( 310 )   HTML   PDF (929KB) ( 531 )   To make benchmark management encourage behavior subjects to continuously explore the development regularity of things and show the good behaviors, a benchmark selection method based on the thought of Conforming to Natural Rule was proposed. This method adopts the way of combining behavior subjects' personalized options with group objective recommendation, and puts individual agent evaluation and democratic agent evaluation together to the process of benchmark selection. It takes into account the mass basis and scientificalness, and satisfies the logic of psychological science and management science. It also has theoretical value. Finally, the application of electric power company shows the effectiveness and feasibility of the proposed method. References | Related Articles | Metrics

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Complex network characteristics studies on volatility and liquidity of stock market in China Liu, Zhe (1); Zhuang, Xin-Tian (1); Fu, Jia (1) 2011, 32 (11):  1663-1667.  DOI: - Abstract ( 256 )   HTML   PDF (1361KB) ( 694 )   Based on the relevances of stock price volatility and liquidity, a threshold method to build a stock correlation network of Shanghai and Shenzhen stock market, and a study on the topological characteristics of this network were conducted. Empirical study showed that the prices volatility and liquidity among stocks mostly have the same change trend; in a certain range of threshold values, the stock correlation network has the characteristics of small world, namely, the change of a single stock's price volatility or liquidity can infect other stocks through the network, and this infection occurs more esasily within the intra-group; in a given range of threshold value, the distribution of stock correlation network is scale-free. In other words, there exist stocks with a few large market impacts in China. They play an important role in the overall price volatility (mobility) correlation of network. The results of empirical study is significant to guide the equity portfolio risk management. References | Related Articles | Metrics

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Construction of evaluation system for Chinese corporate social responsibility - Taking the listed companies of Shanghai and Shenzhen stock markets as an example Hong, Xu (1); Yang, Xi-Huai (1) 2011, 32 (11):  1668-1672.  DOI: - Abstract ( 370 )   HTML   PDF (696KB) ( 821 )   On the basis of stakeholder theory and existing studies, an evaluation index system of corporate social responsibility (CSR) was constructed via interviews and questionnaires, which includes 7 indexes and 27 sub-indexes. Then, an evaluation model of CSR was developed based on empirical study of 1265 listed companies of Shanghai and Shenzhen stock markets from 2005 to 2009. Using the model, the CSR performances of listed companies in recent five years were evaluated. The comprehensive evaluation results showed that the CSR levels of these companies are neither high nor balanced. The state-owned enterprises and large-scale enterprises undertake more CSR. Enterprises in the regions with rapid economic development and in high profitable industries make significant contributions to the social responsibility, while the CSR of newly established enterprises are more stronger. References | Related Articles | Metrics