Advanced Materials Research Vol. 499

Abstract: Closed extruding fine blanking parts is processed under strong hydrostatic pressure, material microstate and mechanical properties near the surface change greatly. In order to research the closed extruding fine blanking parts surface wear resistance, make a reciprocating friction test, and make wear resistance comparative analysis between closed extruding fine blanking parts and turning parts which has the same surface roughness. The results show that in the running wear stage and stable wear stage the wear resistance of closed extruding fine blanking parts is better than turning parts, closed extruding fine blanking process has greatly improved the surface wear resistance.

Abstract: The portal frame is one kind of the common structural styles in the light steel structure. And the portal frame is designed by tapered members, which can be suitable for the variety of the bending moment diagram. This paper introduces the new structure dividing the middle column into two parts on the top of the middle column and analysis the frame with SAP2000. The parameters are investigated such as the hinge joint and firm joint at the bottom of the column and also the parameter of the science of geometry, which influence the load-carrying behavior of the portal frame. The analysis gives that it’s avail for the frame if the angle of the dividing is thirty. Besides, some corresponding design proposal is obtained according to the analysis of the internal force.

Abstract: This paper shows enumerated electrical field is divided into primary field and secondary field according to two Maxwell circuitation equations combined with fact of induction resistivity log, and the primary field can be solved by analytic geometry method, the secondary field can be solved by finite difference Crisscross grid method. Finite difference Crisscross grid method is precise and advisable by means of comparing with analytic geometry method. Some formation factors such as relationship of log response and formation thickness, formation nonisotropy, formation penetration and measurement factors such as transmitter frequency, coil arrangement, coil span are simulated by finite difference Crisscross grid method.

Abstract: With the rapid development of the wind power, it is no longer an isolated power system and gradually incorporated in the local power grid. However, as the increasing proportion of the installed wind power capacity in the power grid, the affection of the wind turbine to the region power system is getting heavier, which inevitably bring some new problems to the power system. The low voltage ride through (LVRT) is the direct embodiment of the power quality. In this paper, we fist analyze the impact of the voltage drop on the double-fed wind turbine. Then, a LVRT control method is proposed based on hardware realization. The detailed explanation of the proposed control method is given at last.

Abstract: This formation of bromate during ozonation of polluted source water has long caused great concerns. This paper used KMnO₄ to control the bromate formation during water ozonation. KMnO₄ was added 10 min prior ozone to oxidize the organic pollutants. The initial Br- concentration was 1000 μg/L. The results showed that the bromate formation efficiency was low (<5%) during KMnO₄-ozone oxidation. Among KMnO₄ dose, ozone dose, and source water TOC, the single most important factor for bromate formation was the ozone dose. When the ozone dose was 3 mg/L or higher, the bromate concentration exceeded the national standard no matter what level of KMnO₄ was used. The organic pollution level had little influence on the bromate formation.

Abstract: In this paper, an effective and innovative thermal flow meter is presented. It is based on TDC-GP1 chip and the principle of time difference type ultrasonic flow measurement. Ultrasonic flow meter is applied widely and has some advantages such as non-contact, easily installed and maintained. But it is necessary to make the meter work more stable. The method of time difference can improve the stabilization and measured precision of the ultrasonic flow meter. TDC-GP1 is a chip which can transform time intervals into digital values with high precision. The design of the ultrasonic thermal flow meter is given details in the paper. Results of the experiments show that the innovative meter has low power consumption and high measured precision.

Abstract: Near-infrared (NIR) spectroscopy was successfully applied to chemical free and rapid determination of the organic matter in soil, and moving window partial least square (MWPLS) combining with Savitzky-Golay (SG) smoothing was used to the selection of NIR waveband. Thirty-five samples were randomly selected from all 97 collected soil samples as the validation set. The remaining 62 samples were divided into similar modeling calibration set (37 samples) and modeling prediction set (25 samples) based on partial least square cross-validation predictive bias (PLSPB). The selected waveband was 1896 nm to 2138 nm; the SG smoothing parameters and PLS factor OD, DP, NSP and F were 2, 6, 71 and 15, respectively; the modeling effect M-SEP and M-R_P were 0.219% and 0.944, respectively; the validating effect V-SEP and V-R_P were 0.243% and 0.878, respectively. The result provided a reliable NIR model and valuable references for designing specialized NIR instruments.

Abstract: In this work attapulgite and chitosan were employed to prepare composites as eco-friendly adsorbent. Study on the removal efficiency of the adsorbent for copper ions in aqueous solution was carried out. External factors such as the amount of attapulgite in the composites, temperature, initial concentration of copper ions, adsorption time and adsorbent dosage how to influence the removal efficiency of composites were investigated. The results showed that at room temperature, 0.37g adsorbent can reach maximum adsorption rate, which the mass ratio of attapulgite and chitosan is 1:1, the initial concentration of copper ions is 50mg / L and absorption time is 2h.

Abstract: When gantry-moving type numerical control machine works, support beams of the maglev system will exist outside disturbance, internal system parameter variations and unmodeled dynamics and so on, these factors will reduce system processing accuracy. We presented that suspension air-gap of beam suspension system was controlled by using the auto disturbance rejection control technology. The auto disturbances rejection controller can regard system model parameter variations and external disturbance influence of system as comprehensive disturbance, automatic on-line estimation and compensation. Meanwhile, for solving the traditional auto disturbances rejection controller’s problems which are much more parameters and complex parameters adjustment, the linear auto disturbances rejection controller was used. Under the precondition of ensuring control effect, parameters adjustment process of the auto disturbances rejection controller was greatly simplified. The simulation results show that beam magnetic suspension system using the linear auto disturbance rejection control scheme can achieve control requirements and achieve beams friction-free stable suspension.

Abstract: This paper concernes with the robust H_∞ control design problem for linear systems with actuator faults. A more practical model of actuator faults than outage is considered. An linear matrix inequality (LMI) approach of designing robust controller is presented for actuator faults. The resulting control systems are robust in that they provide guaranteed asymptotic stability and H_∞ performance when actuator faults occur and the performance in the normal case is optimized. A numerical example illustrates the effectiveness and the necessity of robust control.