Advanced Materials Research Vol. 978

Abstract: Conventional and nanosturctured Al₂O₃–13 wt% TiO₂ ceramic coatings were deposited by plasma spraying on TiAl alloy surface. Laser remelting experiment on as-sprayed coatings was carried out and the influences of laser remelting on microstructure and thermal barrier effect of the coating were researched. The results show that the as-sprayed conventional coating has a typical plasma-sprayed lamellar-like structure, while the nanostructured coating consisted of both fully melted regions and partially melted regions. The laser-remelted conventional coating exhibits column-like crystals which grew along the direction of the heat current, while the nanostructured coating composed of fine equiaxed grains with some remained nanoparticles. The nanostructured ceramic coating has higher thermal barrier effect than the conventional ceramic coating does. The thermal barrier effect of the as-sprayed coatings decreases after laser remelting.

Abstract: Research on beneficiation of iron from iron-polymetallic was conducted according to the properties of the ore. The separation results show that magnetic separation is the best way to concentrate the iron mineral. The results show that iron concentrate assaying 60.15% Fe can be obtained with the recovery of 76.48%.

Abstract: To select a suitable decolorizing resin for Limonium bicolor Kunze (Bge.). polysaccharides (LBPs), the decolorization effect of crude LBPs by five resins are studied. And the adsorption equilibrium of LBPs pigment on the selected resin was investigated.The results show that the decolorization ratios of LX-46 is higher than those of other resins. Under optimized dynamicad sorption conditions (flow rate of 1.5BV/h, 2BV of 6mg/ml LBPS solution in 298K), the decoloration, deproteinization and polysaccharide recovery ratios of LX-46 resin were 92.08%, 92.79% and 86.53%, respectively. The above results show that macroporous anion exchange resins are suitable for the decolorization of crude LBPs.

Abstract: Complex surfaces can be manufactured by using ultra-precision diamond turning processing technology, whereas the surface roughness of the workpiece is influenced by many factors, the relationships among these factors are very complex, and little research reports are found. In this paper, influences of the turning parameters on surface roughness are investigated and analyzed under different related parameters such as spindle speed, feed rate and depth of cut. The result shows that the slotted tool could obtain better surface roughness than the non-slotted tool under the same conditions. Through changing the magnetic field intensity, finishing gap, rotational speed of tool and finishing time, an orthogonal experiment is conducted to obtain the optimal finishing process parameters.

Abstract: To further analyze the deformation and stress of inclined double-roller enveloping hourglass worm gearing, based on the research of geometric characteristic analysis of non-parallel double-roller enveloping hourglass worm gearing and solid modeling of non-parallel double-roller enveloping hourglass worm, helical-line of tooth-surface are obtained using software MATLAB, 3-D model of the worm gearing are established using Pro/E. Finally, finite element analysis based on Workbench are carried out in three different meshing positions of worm gearing. The research methods used in this paper has something referential value for the study of the same type of worm gearing.

Abstract: According to the requirements of the aircraft power supply equipment, the high voltage DC-DC power converter module is developed. In this paper, the HVDC (High Voltage DC-DC Converter) topology is studied. The starting circuit is designed based on the control chip TL3844. The components parameters are calculated. An overvoltage protection circuit and a current limiting protection circuit are designed to improve the stability of the system. At the same time voltage compensation circuit is designed to compensate the voltage.

Abstract: With the popularization and application of electric vehicles, charging and discharging load will bring new challenges to safe and stable operation of the power grids. Charging and discharging control is becoming an important power system operation strategy as well as generation dispatch. A volume of research has been devoted to charging control (including vehicle-to-grid, so-called V2G) which can not only alleviate the adverse effects of charging load but also support the grid operation such as leveling the load and promoting the integration of renewable generation. This paper analyzes the impact of electric vehicles charging and discharging on the power system.

Abstract: An overvoltage online monitoring and data analysis device based on optical fiber voltage sensor is designed. The device adopts BGO crystal as sensing head, optical fiber as transmission medium. Four A/D converters with sampling rate of 20 MHz are equipped in Data acquisition unit to achieve four-channel concurrent high-speed data acquisition. Virtual instrument LabVIEW is used to complete data analysis and processing. Compared with other voltage monitoring device, it has good anti-interference performance and fast transient response. Physical simulation experiments prove that the system can meet the requirements of overvoltage monitoring. Its application provides accurate data for power system fault analysis and insulation coordination design.

Abstract: The gearbox is an important module of wind turbine. In order to diagnosis the fault of wind turbine gearbox, a method based on the improved neural network is proposed. According to the characteristics of the wind turbine gearbox, several vibration sensors are set in the gearbox, so as to acquire the feature vector of gearbox. After training, the improved neural network is verified with some test samples. The result proved that the method is suitable for fault diagnosis in gearbox of wind turbine.. Keywords: wind turbine gearbox, fault diagnosis, particle swam, neural network.

Abstract: ] In interpreting courses,it is necessary to use some mechanical euipments and electronic resources for improving interpreting abilities. Some researchers call them as external causes for being sucessful interpreters. Some researchers think that they are regarded as indispensable factors for being sucessful. The authors have researched them with investigation and data processing. From the investigation and data processing,the author has concluded her conclusions from scientific study and detail analysis. The author hopes that her study will be helpful for interpreting reform and researchers for her field. However, with the limitation of research condition, there is still some disadvantages to be overcome for future research, and the author will have to improve them and advance them in her later research. [key words] mechanical euipments; electronic resources; electronic resource system; electronic materials; information technology