Advanced Materials Research Vol. 787

Abstract: By analyzing the process of Agent Federation-Based rapid design for electric motor in depth, Petri Net is introduced to model and analyze the task conflict, design conflict, resource conflict and cost conflict at each stage of rapid design. Analyzing the model of coordination conflict, and we can make reasoning through the Fuzzy Petri Net in the process of coordination. The model adequately describes the dynamic behavior of multiple factors such as task allocation, design coupled and resource coordination, a task allocation framework designed to generate drawings for the rapid design of Agent Federation, providing a design framework which is from task allocation to generate drawings for Agent Federation-based rapid design.

Abstract: A finite element model with functionally graded materials is established. Furthermore, the distributions of the maximum contact stresses on monolithic substrates under Hertz contact conditions have been analyzed. The effect of the coating thickness is obtained by single-layer coating systems. With increasing the coating thickness, the distribution of maximum radial stress is moved from the coating surface to coating/substrate interface. Meanwhile, the depth of maximum shear stress is moved away from the interface. The location of the maximum shear stress within the multilayer coating systems is not changed. The deformation of the model is more serious with the increase of the applied load.The results can provide some insights regarding the design of the graded coatings in the engineering application.

Abstract: To resolve such problems as higher electrode wear and low machining efficiency of micro-EDM, a new piezoelectric self-adaptive micro electrical discharge machining system (PSMEDM), based on inverse piezoelectric effect, was developed in this paper. In this new system, a piezoelectric actuator with high frequency response was applied as the micro feeding system to regulate the discharge gap. The machining mechanism and machining process were elaborated. The paper focus on the planning of PSMEDM process and the electrode wear problem. Special attention is paid on the influence of machining parameters such as open voltage, capacitance, resistance, spindle rotational speed and initial feed speed on machining efficiency by using signal to noise analysis method based on orthogonal experiment.

Abstract: CAE technology is the most common method to study properties of impeller in a centrifugal compressor. The fluid field was numerically simulated by CFX program to obtain the distribution rules of pressure, turbulence intensity and erosion wear. Based on fluid-solid interaction, stress and deformation were analyzed by Ansys program. According to the simulation results, the maximum deformation and equivalent stress of the impeller are all located on the junction between the blade trailing edge and the shroud. The most serious damaged part by erosion wear in impeller is on the pressure surface of long blade. The erosion wear area on blade pressure surface caused by particles impact primarily locates on blade trailing edge root and middle part. In the flow field, the turbulent intensity on suction surface is greater than that on pressure surface in the corresponding position and the greatest turbulent intensity is located on the leading edge of suction surface. There is backflow phenomenon around the suction surface of long blade and the short blade has significant effect to reduce backflow. The results of numerical simulation explain some actual impeller failure cases and can be applied to anti-wear impeller design and repair.

Abstract: The carrier-diffusion wave and thermal wave during photothermal process were studied in a three-dimensional semiconducting microcantilever. The green function method was used to obtain the theoretical expressions for carrier density and temperature during optical excitation. The space distribution for carrier density and temperature were given graphically for different heat sources.

Abstract: Eleven instrumentations professional was integrated to measuring & control technology and instrumentation specialties in 1998, and its professional connotation is widely. During the elite education transformation to mass education, how to change education idea and cultivating talents are the most important. Discipline superiority had been fully utilized to outstanding "pipeline inner detection technology "and "visual inspection technology" characteristic and the detection technology was used as the core features. A series of reforms has been processing from course system refined to the specialty profession construction and students' practical ability training in order to form the professional characteristics.

Abstract: The dispatching center of power-grid companies is also the data center of the power grid where gathers great amount of operating information. The valuable information contained in these data means a lot for power grid operating management, but at present there is no special method for the management of operating data resource. This paper introduces the operating analysis and data mining system for power grid dispatching. The technique of data warehousing online analytical processing has been used to manage and analysis the great capacity of data. This analysis system is based on the real-time data of the power grid, to dig out the potential rule of the power grid operating. This system also provides a research platform for the dispatchers, help to improve the JIT (Just in Time) management of power system.

Abstract: The oil and gas reserves of Gu83 block in Gulong oilfield is very abundant, but the development is very difficult because the sand bodies are thin, scattered and lack of horizontal continuity. Guided by the theory of sequence stratigraphy and reservoir sedimentology, using drilling core, logging and seismic data, the researcher found that the interest area belongs to delta front subfacies deposition, which can be mainly classified by four miscrofacies types including underwater distributary channel, mouth, sheet sand and bay between distributary. The plane distribution of sedimentary microfacies are mainly controlled by the west and north provenance, the two source collected in the middle east of the work area.

Abstract: Based on the actual conditions of the project and related experience, the seepage model of diversion tunnel and its surrounding rock mass was built to analyze its seepage stability. The seepage field was calculated by using finite element method (FEM) and cut-off negative pressure method. Two typical cross-sections and working conditions were chosen to evaluate the seepage stability of the surrounding rock mass. According to the results, the seepage gradient is larger when one tunnel is filled with water while the other is empty. The maximum seepage gradient is less than the allowable seepage gradient, so the surrounding rock mass of the diversion tunnel can meet the demand of seepage stability.

Abstract: Efficiency is becoming increasingly important in grid connected photovoltaic inverter design. Transformer in grid connected inverter system is removed to improve the efficiency of system. Traditional Power loss calculation methods often neglected ripple current effects. However, Photovoltaic inverters seldom operate at the maximum rated power due to variation of irradiation. Therefore, the ripple current effects on component power loss on the light load condition should not be neglected. The paper analyzes the work principle of a transformerless grid connected inverter in detail, and establishes a mathematical model of component power loss which includes ripple current effects. An experimental prototype is made and experiment results verify the correctness of the 2éQ: theoretical analysis"theoretical analysis.