As metal oxide semiconductor, tungsten oxide is studied and applied extensively because of its electrochromic property, gasochromic property, photochromic property, and gas sensing property. In this paper, the doped and undoped WO3were prepared by the precipitation method and the molten salt method. The crystals were characterized by FT-IR spectrometer and fluorescence spectrometer. The fluorescence spectra showed that the doping lanthanum and strontium can effectively improve the luminescence properties of the product. IR spectra indicated that the products contain WO3and H2O. The photocatalytical degradation of methyl orange under UV light irradiation using WO3was investigated, which shows that the iron-doping can effectively improve the WO3photocatalytic degradation activity.
With sulfur-contained oil tanks undergoing chemical corrosions, the corresponding products (i.e. rust, mainly comprising of Fe2O3, Fe3O4 and Fe (OH)3) would react with hydrogen sulfide, sulfur, mercaptan sulfur and other active sulfur contained in the oil to produce highly oxidizing iron sulfide, which is liable to cause fire and explosions upon exothermic reactions. In this paper, the corrosion induced by low-temperature wet H2S and natural oxidations of corresponding products within the sulfur-contained oil tanks are simulated. An analysis is also made on the temperature changing patterns during the sulfidation of Fe2O3, Fe3O4, Fe (OH) 3, and their mixtures as well as in the natural oxidation process of sulfide. Research results indicate that due to the strong oxidation tendency revealed by ferrous sulfide generated from reactions between Fe2O3, Fe3O4, Fe (OH) 3, and their mixtures with wet H2S under anaerobic conditions, it can react with oxygen in the natural air violently to release a lot of heat. The higher the content of Fe2O3 and Fe3O4, the greater the risk of spontaneous combustion would be. Moreover, the oxidation of iron sulfide undergoes three phases in natural environment, i.e. oxidation induction, oxidation incubation, and oxidation acceleration.
Describes briefly ultrasonic positioning system (UPS) and digital magnetic compass (DMC) heading measurement principle,analyzed the advantages and disadvantages of each option. To improve the accuracy of the heading measurement, As the theoretical basis of adaptive Kalman filter, designed a kind of ups and dmc integrated navigation system. Based on both real measurement data, made a simulation experiment and confirmed the feasibility of the navigation system.
The paper applies the commercial software ABAQUS to establish numerical models of an original single-storey building and a reinforced building, and conducts experimental test to verify correctness of the computation models. Damages and dynamic characteristics of two kinds of models under seismic effects are studied systematically.-direction acceleration amplitudes of the wall obviously exceeded those in direction. In the same horizontal direction, accelerations of the left wall obviously exceeded those of the right wall. Compared with the original model, the-direction acceleration amplitude is decreased by 15.4 %, and the-direction acceleration amplitude is decreased by 49 % in the left wall of the reinforced model. As for right wall of the reinforced model, the-direction acceleration amplitude is decreased by 30.4 %, and the-direction acceleration amplitude is decreased by 17.6 %. In the direction, the power amplification factors of the reinforced model were less than those of the original model, and the value was decreased by 30 % for the power amplification factors corresponding to 1.3 g. In the direction, the power amplification factors of the reinforce model were less than those of the original model under different seismic effects, wherein the value of the reinforced model was decreased by 33 % for the power amplification factors corresponding to 1.3 g compared with the original model. Under the seismic effect of 0.1 g, damages took place to four wall bodies of the model at earliest, but its value was small. With increased seismic input excitation, damage degree of the wall bodies was also gradually increased. Under the seismic effect of 0.8 g, damages to four wall bodies were serious. Under seismic effect of 1.3 g, damage values of 4 wall bodies reached the maximum value 0.99, and the single-storey building will fail. Damages values of four wall bodies of the original model were relatively concentrated; while damage values of four wall bodies of the reinforced model were disperse. Under each seismic effect, the overall damage value was smaller than that of the reinforced model. This result fully indicates that reinforcement can reduce damages of wall bodies and generate anti-seismic effects.
This paper designed a fpga-based ultrasonic flowmeter, and used verilog language design fpga control unit.The microcontroller was the core of the ultrasonic transceiver circuit. Peripheral circuit is designed to be simple and reliable, the fpga advantage in raising the maximum clock frequency, greatly improves the measurement accuracy of the design.
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