Xi an Technological University
Xi an Technological University
Yang Z.,Xi an Technological University |
Tao D.,Xi an Technological University |
Guo Y.-C.,Xi an Technological University |
Yang T.,Xi an Technological University |
Li J.-P.,Xi an Technological University
Zhuzao/Foundry | Year: 2014
Microstructure and tensile properties of three kinds of compacted graphite cast irons, no-alloyed, Cu-Mo-Sn alloyed and Cu-Mo-Sn-Cr alloyed, were studied by using optical microscopy, scanning electron microscopy and mechanical properties testing in the paper. The effects of multi-component micro-alloying on vermicularizing, the ratio of yield strength and ultimate tensile strength (σ0.2/σb), retention rate of strength at elevated temperatures were analyzed. The results showed that the obvious effects of multi-component micro-alloying elements on vermicularizing was not observed, but the improving formation of pearlite and strengthening the microstructure of matrix took place when elements Cu, Mo, Sn and Cr were added. Meanwhile, the ratio of σ0.2/σb of Cu-Mo-Sn and Cu-Mo-Sn-Cr alloyed compacted graphite cast iron at room temperature was increased, and the elongation was decreased compared to the normal compacted graphite cast iron. The strength retention rate of three kinds of compacted graphite cast irons at 350°C kept almost the same lever, however, it was improved greatly, increased from 56% to over 71%, at 500°C compared to compacted graphite cast iron. Fracture analysis of test material showed that cleavage-dimples mixed fracture mechanism, but cleavage was the dominant fracture mechanism at room temperature. With addition of multi-alloying elements, the number of dimples and tear edges on fracture surface of compacted graphite cast iron reduced and toughness decreased.
Sun X.,Xi an Technological University |
Feng X.,Xi an Technological University
International Journal of Control and Automation | Year: 2014
Sliding mode controller (SMC) is a highly significant nonlinear controller under condition of certain and partly uncertain dynamic parameters of system. This paper focused on design and implementation of a sliding mode controller for STATCOM. Intend for its application to wind farm connection to the grid. The proposed inverse system sliding mode controller based on nonlinear feedback linearization technology for system decoupling, which enhance the transient stability of wind farms and stabilizes the grid voltage about the given operating point when the fault occurs closer to the wind farms. The simulation results have shown the improved performance of the proposed controller has better control effectiveness and efficiency compared with the conventional controller of inverse system, the proposed controller on wind power system and which assist in improving capability of the wind farms to ride through disturbances, dynamic power flow control of the transmission lines, enhancing power oscillation damping under a sudden fault. Moreover, the proposed control scheme is very simple and easy to implement. © 2014 SERSC.
Ma B.J.,Xi an Technological University |
Han B.,Xi an Technological University
Applied Mechanics and Materials | Year: 2014
The test-bench is used to simulate aircraft's posture in the air and it is for testing dynamic relief force when the fiber is paying off at high speed. In this paper, through analysis and contrast of the horizontal motion and the pitch motion, the scheme of movement is achieved. Based on the scheme of movement, the structural design and analysis on the stiffness and strength of key parts are done in the paper, the results shows that movement can be achieved. © (2014) Trans Tech Publicutions, Switzerland.
Du Y.,Xi An Technological University |
Liang H.,Xi An Technological University
Open Automation and Control Systems Journal | Year: 2015
The material loading operation plan by artificial preparation has been unable to meet the requirements of the timely delivery when the third party logistics enterprises are involved in vendor managed inventory strategy. According to the characteristics of the easily broken material the multi-objective optimization model was established. The objective functions of this model were the vehicle loading weight utilization rate and the volume utilization rate. The five constraints were introduced. The optimal solution of the model was obtained by genetic algorithm. The solving process was introduced including the pre processing coding, the individual coding, the fitness selection and the genetic operation. The genetic algorithm program was designed by using MATLAB genetic algorithm toolbox. The easily broken material boxes loading optimization of the VMI distribution center was as an example to verify the validity of the program. Thus a whole solution which contains the optimization model and the solution procedure was provided for the easily broken material loading. © Yanwei and Henggang; Licensee Bentham Open.
Yao X.,Xi An Technological University |
Tian W.,Xi An Technological University |
Wu L.,Xi An Technological University
Advanced Materials Research | Year: 2014
Electrochemical methods were employed to investigate galvanic corrosion behaviors of super13Cr and P110 couples in NaCl solution at different temperature. Corrosion morphologies and products of the couples were analyzed by SEM, EDS and XRD. The results showed that there were potential difference distinctly between super 13Cr and P110 steel in NaCl solution at different temperature, when its contacted, galvanic corrosion of super 13Cr-P110 steel couples will occurred. P110 was accelerated to corrode as anode and super 13Cr was protected as cathode in the coupling. Super 13Cr-P110 steel couples could not be used as P110 without any protection in NaCl solution at 20˚C to 80˚C. Corrosion current density and galvanic corrosion of super13Cr-P110 steel couples increased with increasing temperature in NaCl solution, of which corrosion products are Fe3O4. © (2014) Trans Tech Publications, Switzerland.
Jin X.,Xi an Technological University |
Li Y.,Xi an Technological University
2010 International Conference on Mechanic Automation and Control Engineering, MACE2010 | Year: 2010
Image processing technology is introduced into numerical control machining, by way of image preprocessing, feature extracting and discriminatory analyzing, the data of image boundary contour processing are obtained. The tool path for CNC machining is directly generated by the data. This method is able to meet the demand of complex image processing, and to provide a solution about CAD/CAM and numerical control machining in future machining technology. ©2010 IEEE.
Du Y.,Xi an Technological University
ICCMS 2010 - 2010 International Conference on Computer Modeling and Simulation | Year: 2010
The best purchases of raw materials of manufacturing enterprises can be determined by accurate requirement forecasting to decide order quantities. According to the characteristics of the boiler manufacturers, the weighted coefficients and initial values ware chose which have a direct impact on the forecasting results. The exponential smoothing model was applied to predict the requirement of raw materials.The mean square error was calculated. The prediction model was verified by example. The error between the forecasting results and the actual needs is smaller. The exponential smoothing model was proved to be effective for boiler manufacturers to forecast requirement of raw materials. © 2010 IEEE.
Gao M.,Xi An Technological University |
Wang Y.,Xi An Technological University
Proceedings - 2011 International Conference of Information Technology, Computer Engineering and Management Sciences, ICM 2011 | Year: 2011
An improved maximum between-cluster variance (Otsu) method based on iteration was proposed for the purpose of realizing target recognition and target tracking effectively. Improved Otsu method was used to segment image collected by CCD, so as to extract the target from image and finish the target localization. By calculating centroid of the target in a single frame and extracting feature point of outline constituted by centroids of the single-frame target within unit interval, a polygon can be formed, the gravity center of which was taken as the target position. Filter model was established of which the control input is nonzero based on Kalman filter Principle, which was combined with target position at this moment can be used to predict the gravity center of the target at the next moment. The experiment and simulation results indicated that improved Otsu method can solve the problem that target and background are segmented mistakenly when image thresholding. Kalman filtering was able to predict target trajectory effectively after target being recognized. The requirement of target tracking was satisfied and target tracking was realized through this improved Otsu target tracking algorithm based on iteration. © 2011 IEEE.
Wu Z.-C.,Xi an Technological University |
Zhang X.-L.,Xi an Technological University
Optik | Year: 2013
A dual-polarization electro-optical Q-switched Nd:YAG ceramic laser was studied. By selecting the appropriate size of calcite crystals, the dual-polarization Q-switched pulse was achieved by characteristics of calcite crystal. Experimental results show that compared with the traditional single-polarization electro-optical Q-switched laser, insertion loss is reduced, dynamic to static ratio is greatly improved, thermally induced birefringence of electro-optical Q-switched Nd:YAG ceramic laser is effective compensated. The output power of 19 W and the pulse width of 13 ns are obtained at the repetition rate of 1 kHz and pumped power of 144 W. The dynamic to static ratio is 71%. The results formed the basis for the further development of the high power and high efficiency ceramic red laser. © 2012 Elsevier GmbH.
Lu L.,Xi an Technological University |
Wang Q.,Xi an Technological University |
Zhang Y.,Xi an Technological University
Revista Tecnica de la Facultad de Ingenieria Universidad del Zulia | Year: 2016
With the development of current underwater detection technology, the error accuracy about underwater target location needs to be increased. Aim at the problem about location of underwater targets, location array model of cross array with five sensors is proposed, and the error about it is analyzed in this paper.Through the principle of location array structure of cross array with five sensors, the model of location system is established, the RBF function network is used to recognition and process to signal, and the location accuracy is analyzed by the target distance, time difference and ocean sound velocity, and the result of simulation is give in this paper. In the array structure of cross array with five sensors, difference position data is tested, the result of the experiment is accord with the theory analysis. Location array structure of cross array with five sensors is set up, and the location accuracy is analyzed by the target distance, time difference and ocean sound velocity. The experiment is shown that the location array model of cross array with five sensors is better than to locate the underwater target the location array model of cross array with four sensors.