Advanced Materials Research Vols. 443-444

Abstract: Magnetic bearing is a high-performance mechatronic bearing, which can suspend parts in space stably using magnetic force. Its characteristics such as high speed, high precision, and low power consumption and so on make it valuable to research and widely to apply in the future. The paper summarized the working principle of magnetic bearing and its characteristics, research and application status. Based on these, it introduced the new application such as used for vibration reduction, dynamic absorber and in mining electromechanical device in engineering field, so as to increase efficiency and save more energy.

Abstract: .As a new way of storing energy, magnetic suspension flywheel energy storage, has provided an effective way in solving present energy problems with the characteristics of large energy storage, high efficiency and fast charge-discharge speed and so on. The paper mainly elaborated the basic principle of magnetic suspension energy storage system, introduced the structural features of flywheel rotor, magnetic bearing, electric machine, electric power system and other auxiliary body. On this basis, it analyzed applications on electrical peak-modulating, Uninterruptible Power Supply, Hybrid Electric Vehicle, satellite attitude control and so on, on the purpose of the further development and promotion of this new technology.

Abstract: This paper is concerned with the enhancement of the Capacity Factor for wind turbines, especially offshore. In particular the work describes analysis of data on a wind turbine drive train to enhance the reliability of components, reduce maintenance time and provide early warning of failures from the understanding of mechanical dynamics.

Abstract: Skewed pole is a kind of effective structure which can weaken the cogging torque in surface mounted permanent magnet synchronous motor (PMSM), as well as reduce noise and vibration. In this paper, the most appropriate skewed pole angle was calculated and the influence of skewed pole on the machine performance, such as cogging torque, back EMF and harmonics were analyzed. The correction of the conclusion is verified by using Maxwell 3D FEA software.

Abstract: The ramp B of one overpass was designed as curved steel orthotropic box girder, whose deck was welded with open shaped bulb ribs in the range of driveways. Then, one detailed finite element model was built to simulate the structure. For the two arrangements of bulb towards and back to web in the cantilever, the tangential stresses of diaphragm cutout were compared under the action of vehicle load. In accordance with above research, it can be concluded that the stress will be more reasonable with the bulb back to web. After altering the transverse position of the vehicle load and calculating the tangential stress along the edge of diaphragm cutout, based on further analysis, it’s generally believed that the following two reasons made the arrangement of bulb back to web more appropriate at least. First of all, the diaphragm connected with the rib adjacent to the web could share part of vertical load. What's more, it could increase the distance from the edge of the cutout to the web center. What come next was to change the diaphragm cutout size, and that parameter optimization was carried out. The results show that a radius of 40-50mm is more applicable for the arc on the bottom of the diaphragm cutout.

Abstract: As the long transmission line, complex mechanism, poor performance of regulation and control and low sensitivity of mechanical let-off, so it can not meets the requirements of stable tension. Therefore, the let-off mechanical was improved. This paper takes let-off system of SAURER400 rapier loom as experimental subject, mathematical modeling to every parts of loom, and takes simulation and comparison. The simulation results show the improvement of mechanical can meet the basic requirements of weaving, and it indicates the works that done former are effective and correct.

Abstract: In order to study the catalytic activity in the preparation of fuel gases from catalytic pyrolysis of coal, the author selects Ni_xO_y/γ-Al₂O₃、Cr_xO_y/γ-Al₂O_3，Ag_xO_y/γ-Al₂O₃ and Co_xO_y/γ-Al₂O₃, respectively as the metal oxide supported catalysts from the previous experiment’s results. These catalysts have been added to Shenhua coal for a series of experiments. After these experiments, GC (gas chromatography) has been used for the analysis on the yield changes of CO and CH₄ which result from the experiments. The results show that all of these catalysts have a positive influence on the yield of CO and CH₄. As to the yield of CO, catalytic activity of Cr_xO_y/γ-Al₂O₃ represents the most prominent performance at medium temperature period and Co_xO_y/γ-Al₂O₃ represents the same performance at high temperature period, while Ni_xO_y/γ-Al₂O₃, in which a great number of aluminum acid nickel spinels are reduced into metallic Ni at high temperature period, which results in different catalytic activity center from raw metallic Ni reduced from NiO. Consequently, the former reduced Ni shows outstanding catalytic activity. As to the yield of CH₄, four catalysts mentioned above represent either the similar catalytic activity with CO or the individual characteristic —on one hand ,due to the strong adsorption of AgO and CrO₃, CH₄ gas is changed into H₂ via pyrolysis at medium temperature as the yield of CH₄ slumps ,on the other hand, due to an enormous amount of H₂ production ,there is a drastically chemical reaction between H₂ and these catalysts at high temperature, in which the yield of CH₄ upswings toward the maximum amount greatly at the same time. Therefore, Cr_xO_y/γ-Al₂O₃, Ag_xO_y/γ-Al₂O₃ and Co_xO_y/γ-Al₂O₃ are more efficient at medium temperature and high temperature respectively. However, Ni_xO_y/γ-Al₂O₃ demonstrates the positive influence only from 800°Con. All of these results depend on the essence of catalysts to some extent. The study would have some theoretical guidance about increasing the utilization of coal and about industrial application of fuel gases generated from catalytic pyrolysis of coal.

Abstract: . The southeast of Shanxi province was famous for Lu silk in Ming and Qing dynasties, which mainly includes Ze and Lu regions. This thesis discuses the existing spinning wheels and looms in this region, and try to explore the historical development of textile machinery from Song dynasty to 1980s.It will contribute to the research on development of wooden looms in ancient China.

Abstract: : The author has found the sucking process outflow phenomenon existing in piezoelectric pump during the outflow experiment. To explain the reason of outflow in sucking process, the fluid-structure interaction model of piezoelectric vibrator, fluid and check valve is founded. The simulation analysis turns out that the pump chamber pressure increases sharply in the later of sucking process because of the flow inertia, which is the root cause of sucking process outflow. The output flow should include two part, bulk flow and inertial flow, which will provide theoretical reference to piezoelectric pump outflow control.