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1
Content available A novel method to extract vanadium from vanadium-bearing steel slag using sodium carbonate solution
Gao M., Xue X., Li L., Yang H., Bai R., Wang H.
Physicochemical Problems of Mineral Processing
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2018
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Vol. 54, iss. 3
911--921
EN
A new method using sodium carbonate solution to treat a vanadium-bearing steel slag is proposed. The effects of the particle size, solid-to-liquid ratio, initial concentration of sodium carbonate solution, leaching temperature and stirring speed on the leaching rate of vanadium were investigated. The leaching kinetics of vanadium from the vanadium-bearing steel slag was studied, which indicated that the leaching rate was controlled by the step of diffusion through the solid layer around the unreacted core. The apparent activation energy for the process was 13.75 kJ/mol. By using this process, vanadium could be extracted effectively with the leaching rate of more than 80%.
2
Content available Smart services for enhancing personal competence in Industrie 4.0 digital factory
Sun J., Gao M., Wang Q., Jiang M., Zhang X., Schmitt R.
LogForum
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2018
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Vol. 14, no. 1
51--57
EN
Background: Adaptive digitalization and networking of machines, working parts, employees and other entities on the plant floor are core of realizing industry 4.0, so that information and instruction will be available everywhere and all the time in the production process. Thus, smart devices, especially smart wearables, will play a very important role to help workers being integrated in the in the future manufacturing environment, as information need to be transferred faster and with the right level of detailing with respect to the individual need of workers, factory managers etc. Methods: The implementation of an indoor localization system using Bluetooth beacons in the shop floor as part of an enterprise IoT platform was introduced. This sensor network is aimed to implement tracing and tracking of workers and working parts in the future smart factory, as well as the to the networking of the smart wearables with existing manufacturing machines. The investigated problem was the inaccuracy and the instability of the sensor signals by such Bluetooth sensor networks. To solve the problem, various algorithms were investigated. Results and conclusions: The possible solution of given problem was solved by finding an algorithm improving the communication between devices. Together with the location information from Beacon network and orientation information from the compass sensor, it is able to determine the machine in the near, which the employee with the Smart Glasses is currently pointing to.
PL
Wstęp: Zastosowanie sieciowych rozwiązań dla urządzeń i ich części, jak również jako wspomożenie dla pracowników na poziomie hali produkcyjnej jest podstawowym elementem wdrożenia Industry 4.0., dzięki czemu w każdym momencie i w każdym miejsce zapewnia się dostępność do potrzebnej informacji. W związku z tym, urządzenia mobilne typu smart będą odgrywały ważną rolę w integrowaniu pracowników w środowisko produkcyjne w przyszłości, informacja będzie mogła być przekazywana szybciej i z większą szczegółowością w odniesieniu do poszczególnych pracowników czy kadry zarządzającej. Metody: Zastosowanie wewnętrznej lokalizacji przy użyciu Bluetooth beaconów na poziomie hali produkcyjnej jako fragmentu zakładowej platformy Internetu rzeczy zostało wdrożone. Sieć sensorów ma na celu śledzenie pracowników oraz urządzeń w przyszłościowym zakładzie produkcyjnym, jak również ma być połączeniem z istniejącym parkiem urządzeń produkcyjnych. Badany problem polegał na nietrafności i niestabilności sygnałów sensorów używanych w tej sieci. W celu rozwiązania problemu poddano analizie różne algorytmy możliwych rozwiązań. Wyniki i wnioski: Znaleziono możliwe rozwiązanie analizowanego problem poprzez określenie odpowiedniego algorytmu poprawiającego komunikację pomiędzy urządzeniami. W połączeniu z lokalizacją informacji przy zastosowania sieci beaconów oraz zorientowaniu informacji pochodzących z sensorów, można było zlokalizować urządzenie znajdujące się w pobliżu danego pracownika przy użyciu okularów Smart Glasses.
3
Content available Effect of WO3 on the morphology and photodegradation of dimethyl phthalate of TiO2 nanotube array photoelectrode
Xin Y., Wang G., Liu Y., Zang Z., Gao M.
Environment Protection Engineering
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2018
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Vol. 44, nr 3
129--139
EN
WO3 modified TiO2 nanotube array (WO3/TNAs) photoelectrodes were fabricated via electrochemical deposition on TNAs/Ti photoelectrodes. The morphology and structure of WO3/TNAs photoelectrodes were investigated by scanning electron microscopy (SEM) and X-ray diffractometer (XRD). The effects of deposition potential, deposition duration, NaWO4 concentration, and calcination temperature on the morphology and the photocatalytic activity were investigated. The results showed that suitable amounts of WO3 promoted the photocatalytic activity of TNAs photoelectrodes for the degradation of dimethyl phthalate (DMP). The optimal conditions for the fabrication of WO3/TNAs photoelectrodes were as follows: deposition voltage 3.0 V, 10 min deposition duration, 0.01 mol/dm3 Na2WO4 concentration, 1.5 cm electrode gap, and 550 °C annealing temperature. The degradation rate of DMP reached 77% after 60 min of illumination by WO3/TNAs photoelectrode. Additionally, WO3/TNA photoelectrodes possessed superb stability for maintaining a high DMP degradation efficiency at more than 75% after 10 times of successive use with 60 min irradiation for each cycle. The enhancement of photocatalytic performance by the efficient combination of WO3 with TNAs would provide a theoretical basis for the practical application of WO3/TNA photoelectrodes in water treatment.
4
Content available remote Simulation of the Microtremor H/V Spectrum Based on the Theory of Surface Wave Propagation in a Layered Half-space
Zhang Z., Chen X., Gao M., Li Z., Li Q.
Acta Geophysica
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2018
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Vol. 66, no. 2
121--130
EN
Subsurface velocity structures must be estimated to predict longperiod ground motions and seismic hazards. Subsurface velocity structures can be constructed via an inversion of the horizontal-to-vertical (H/V) spectral ratio of microtremor (MHV) curves; thus, a method of simulating the MHV curves is key. In this study, we use the H/V spectral ratio of the surface wave (SHV) based on the surface wave propagation theory in a layered half-space to simulate the MHV curves at sites A and B of the Yuxi basin. Then, we attempt to analyze the features of the SHV curves. We find the H/V ratio of the microtremor loading source to be independent of the peak frequency of the SHV curve, but it has some relation to the amplitude of the SHV curve. Moreover, to reduce the error in subsurface velocity structures obtained by the MHV curves, we suggest that the SHV curves at near-peak frequencies should not be considered in the inversion, because the amplitude deviation is higher at the peak frequency of the MHV curve. In addition, the best frequency ranges for the inversion of the microtremor H/V spectrum are between the peak and trough frequencies of the microtremor H/V spectrum.
5
Content available remote Sensitivity analysis study of the source parameter uncertainty factors for predicting near-field strong ground motion
Li Z., Gao M., Jiang H., Chen X., Li T., Zhao X.
Acta Geophysica
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2018
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Vol. 66, no. 4
523--540
EN
Uncertainty factors have substantial influences on the numerical simulations of earthquakes. However, most simulation methods are deterministic and do not sufficiently consider those uncertainty factors. A good approach for predicting future destructive earthquakes that is also applied to probabilistic hazard analysis is studying those uncertainty factors, which is very significant for improving the reliability and accuracy of ground-motion predictions. In this paper, we investigated several uncertainty factors, namely the initial rupture point, stress drop, and number of sub-faults, all of which display substantial influences on ground-motion predictions, via sensitivity analysis. The associated uncertainties are derived by considering the uncertainties in the parameter values, as those uncertainties are associated with the ground motion itself. A sensitivity analysis confirms which uncertainty factors have large influences on ground motion predictions, based upon which we can allocate appropriate weights to those uncertainty factors during the prediction process. We employ the empirical Green function method as a numerical simulation tool. The effectiveness of this method has been previously validated, especially in areas with sufficient earthquake record data such as Japan, Southwest China, and Taiwan, China. Accordingly, we analyse the sensitivities of the uncertainty factors during a prediction of strong ground motion using the empirical Green function method. We consequently draw the following conclusions. (1) The stress drop has the largest influence on ground-motion predictions. The discrepancy between the maximum and minimum PGA among three different stations is very large. In addition, the PGV and PGD also change drastically. The Arias intensity increases exponentially with an increase in the stress drop ratio of two earthquakes. (2) The number of sub-faults also has a large influence on various ground-motion parameters but a small influence on the Fourier spectrum and response spectrum. (3) The initial rupture point largely influences the PGA and Arias intensity. We will accordingly pay additional attention to these uncertainty factors when we conduct ground-motion predictions in the future.
6
Content available Correction of sample-time error for time-interleaved sampling system using cubic spline interpolation
Qin G., Liu G., Gao M., Fu X., Xu P.
Metrology and Measurement Systems
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2014
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Vol. 21, nr 3
485--496
EN
Sample-time errors can greatly degrade the dynamic range of a time-interleaved sampling system. In this paper, a novel correction technique employing a cubic spline interpolation is proposed for inter-channel sample-time error compensation. The cubic spline interpolation compensation filter is developed in the form of a finite-impulse response (FIR) filter structure. The correction method of the interpolation compensation filter coefficients is deduced. A 4GS/s two-channel, time-interleaved ADC prototype system has been implemented to evaluate the performance of the technique. The experimental results showed that the correction technique is effective to attenuate the spurious spurs and improve the dynamic performance of the system.
7
Content available remote Stumpage Forestry Data Mining based on 3D Laser Point Cloud
Yun T., Xu H., Gao M., Tang C.
Przegląd Elektrotechniczny
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2013
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R. 89, nr 1b
155--158
EN
Terrestrial laser scanner (TLS) was used to obtain stumpage point cloud data. Firstly, we used the ball neighbourhood combining with a uniform grid method to represent the spatial topology construction of the point cloud, thereby reduced the amount of calculation. Secondly, we used Hough transform to calculate timber volume and abandoned branches and leaves interference according to different depth circular centers continuity. Thirdly through calculating the point cloud features, such as normal vector, curvature, bending, etc, then automatically located the secondary branches position; Finally, comparing with the really measurement trees parameters; the effectiveness of our proposed method is proved.
PL
W artykule przedstawiono wyniki prac dotyczących wykorzystania laserowego skanera przestrzeni (ang. Terrestrial Laser Scanner – TLS) do uzyskania danych dotyczących ilości drewna na danym terenie, w celu ustalenia opłaty wycinkowej. W tworzeniu struktury przestrzennej chmury danych, wykorzystano metodę siatki jednolitej w połączeniu z kulistą formą otoczenia, co dało ograniczenie liczby obliczeń. W drugim etapie zastosowano transformację Hougha, do obliczenia ilości drewna, wolnych gałęzi i zakłóceń wywołanych liśćmi, a na koniec wyznaczono parametry chmury danych, jak wektor normalny, krzywizna, zagięcia itp. Porównanie z danymi rzeczywistymi potwierdza skuteczność metody.
8
Content available remote A Iow complexity frequency domain pilot time domain doubly-average channel estimation for LOFDM systems
Gao M., Shen Y., Xu K
Przegląd Elektrotechniczny
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2011
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R. 87, nr 4
270-274
EN
In this work, a Iow complexity time domain channel estimation algorithm for LOFDM (Lattice Orthogonal Frequency Division Multiplexing) systems is proposed through doubly-average based on the equivalent time-frequency subspace projection and traditional frequency domain pilot time domain average (FPTA) algorithm with special pilot design. Furthermore, the interference problem is analyzed and the Cramer-Rao bound (CRB) of the time domain channel estimation for LOFDM systems is also deduced. Our theoretic analyses are confirmed by numerical results.
PL
Zaproponowano algorytm określania w dziedzinie czasu kanałów dla systemu LOFDM bazujący na projekcji czasowo-częstotliwościowej podprzestrzeni oraz systemu pilota FPTA. Przeanalizowano problem zakłóceń. Analizę teoretyczną potwierdziły rezultaty numeryczne.
9
Content available remote High focusing of radially polarized Bessel-modulated Gaussian beam
Gao X., Gao M., Hu S., Guo H., Wang J., Zhuang S.
Optica Applicata
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2010
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Vol. 40, nr 4
965--974
EN
The focusing properties of radially polarized Bessel-modulated Gaussian (QBG) beam are theoretically investigated in detail by vector diffraction theory. The QBG beam contains an optical vortex. Calculation results show that the intensity distribution in focal region of radially polarized QBG beam can be altered considerably by changing beam parameter and the topological charge of the optical vortex. Beam parameter can induce remarkable focus evolution in axial direction. While topological charge adjusts intensity distribution more significantly in transverse direction, for instance, one focal spot changes into one ring pattern. And some novel focal patterns may occur, including two-peak focus, one ring focus, two-ring focus, three-ring focus, and even dark hollow focus, which is very important in optical tweezers technique.
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