Time filter

Source Type

Nie P.,Shenyang Aerospace University | Dong H.,Shenyang Aerospace University | Li Z.-Q.,Shenyang Aerospace University | Gao H.,Shenyang Aerospace University | Li B.,Bluestar Beijing Chemical Machinery Co.
Beijing Gongye Daxue Xuebao/Journal of Beijing University of Technology

End effect, stop standard and artificial components of empirical mode decomposition (EMD) are improved in this paper, and the contrast test of simulation signal verifies the feasibility of the improved method. Acoustic emission signals were collected in the cutting process and the improved empirical mode decomposition method was used to decompose them into a series of intrinsic mode function components. Artificial components that were produced in the decomposition were then removed according to correlation coefficients of the IMF components and original signal, and normalized energy of the IMF components was extracted as characteristic vector. The characteristic vector was divided into two groups: one group was used to train the least squares support vector machine and the other was used to identify the tool wear state. The experiment result shows that it can effectively characterize tool wear states. Source

Liang H.,University of Science and Technology Beijing | Tong C.-N.,University of Science and Technology Beijing | Wang H.,Bluestar Beijing Chemical Machinery Co.
Beijing Gongye Daxue Xuebao/Journal of Beijing University of Technology

The thickness of the rolling mill mechanism model does not gradually satisfy the current control accuracy requirements, therefore, a modeling and control method based on the data driven of strip thickness is presented. In this method, the subtractive clustering is adopted to divide the input space into several clusters. Least square support vector machine (LS-SVM) is utilized to estimate the model of the nonlinear system and forecast the output value in each cluster subset. The linear predictive control algorithm is used to implement the predictive control. The global control values are obtained by weighted strategy of the controllers. Numerical simulations show the effectiveness of the proposed method. Source

Yue W.,Shenyang University of Chemical Technology | Zhang L.,Shenyang University of Chemical Technology | Liu X.,Bluestar Beijing Chemical Machinery Co. | Liu G.,Bluestar Shenyang Research Institute of Light Industry Machinery | Liu Y.,Shenyang University of Chemical Technology
Huagong Xuebao/CIESC Journal

To investigate the influence of current density on transfer characteristics in the electrolysis cell of chlor-alkali industry, the fluid flow, heat and mass transfer of anode chamber at different current densities were simulated numerically using computational fluid dynamics software. The distributions of velocity, temperature and concentration in a grille of the anode chamber were obtained. Taking liquid circulation rate, maximum velocity near the membrane, temperature and concentration at the membrane surface as indices, the performance of the electrolysis cell at different current densities was evaluated. Liquid circulation rate and temperature of membrane surface increased and concentration of brine decreased with increasing current density. Under typical working conditions for current density of 4.5 kA·m-2, average temperature of the electrolysis cell and of the membrane surface were 86.39℃ and 87.40℃, respectively. Average temperatures of the electrolysis cell and the membrane surface could be maintained at the values of the typical working conditions by lowering inlet temperature of brine when current density increased. ©, 2015, Chemical Industry Press. All right reserved. Source

Huang Y.,China Institute of Metrology | Gao Y.,China Institute of Metrology | Zhang H.,China Institute of Metrology | Li B.,Bluestar Beijing Chemical Machinery Co.
Beijing Gongye Daxue Xuebao/Journal of Beijing University of Technology

Global positioning system (GPS) common/all-view method is currently international hot technology for long-distance time and frequency transfer, and it is also one of the main tools. Its core is the GPS time transfer receiver and post-processing algorithms. The high real-time multi-channel GPS time transfer receiver based on EURO-160 GPS board and the real-time data processing algorithms are introduced in this paper. To verify the accuracy, the experiments of common clock and non-common clock on zero-based line with the foreign commercial GPS P3 code receivers are carried out. Results show that the high real-time GPS receiver and the foreign commercial GPS P3 code receiver have the same technology level. Source

Cao Y.-L.,Beijing University of Chemical Technology | Li Z.-L.,Beijing University of Chemical Technology | Wang F.,Beijing University of Chemical Technology | Liu J.-J.,Beijing University of Chemical Technology | And 4 more authors.
Wuli Huaxue Xuebao/ Acta Physico - Chimica Sinica

A simple galvanostatic electrodeposition method was used to synthesize an active Ni-Sn electrode on a Cu foil substrate. Characterization by high-resolution transmission electron microscopy (HRTEM), energy-dispersive spectroscopy (EDS), and X-ray diffraction (XRD) revealed that the crystal structures of the deposited films transformed from amorphous structures composed of Ni crystal embryos and amorphous Ni-Sn to Ni3Sn4/Ni3Sn2 mixed crystals with increasing Sn content. Scanning electron microscope (SEM) images indicated that the amorphous Ni-Sn electrode possessed a smooth surface with uniform distribution of small particles, whereas the Ni3Sn4/Ni3Sn2 mixed crystalline electrode exhibited a rough surface composed of lamellar structures. The polarization curves measured in 1 mol· L 1 NaOH solution at 25 ° C indicated that the amorphous Ni-Sn electrode showed a smaller overpotential (85 mV) and better electrocatalytic performance for hydrogen evolution than the mixed crystalline electrode. Electrochemical impedance spectroscopy (EIS) results showed that the hydrogen evolution reaction occurs on the Ni-Sn alloy electrode under a mixture of Volmer and Heyrovsky control. The higher activity of the amorphous Ni-Sn electrode was attributed to the faster charge transfer and electrochemical adsorption and desorption rates of hydrogen atoms compared with those on the mixed crystalline electrode. © Editorial office of Acta Physico-Chimica Sinica. Source

Discover hidden collaborations