Advanced Materials Research Vols. 383-390

Abstract: The purpose of this paper is to find the pollution diffusion regularity near sewage outlet area of Yuncheng reach of the Fen River. A 2-D water hydrodynamic and quality model was used to simulate flow field, the water quality and contamination dispersion. The parameters of the model were calibrated with measured data of the water depth, flow and water quality in Yuncheng reach of the Fen River. According to the simulated result, the total area of pollution belt with 19 sewage outlets is 8.89km2 in normal year. And 3.89% of the reach has a worse water quality than V class in standard. The percentage of V and Ⅳ Class of water is 69.17% and 26.94%.In dry year, the total area of pollution belt with 19 sewage outlets is 8.89km2.The percentage of inferior V, V and Ⅳ Class of water is 27.80%, 69.46% and 2.74%. It was shown by the simulated results that the concentration gradient decreases with increasing distance to the outlets and the dilution and dispersion of pollutants was enhanced by a greater river flow.

Abstract: Numerical aperture NA and partial coherence sigma optimization in optical lithography is investigated for 100 nm dense lines under annular illumination and quadrupole illumination. Depth of focus (DOF) is calculated at different NA and sigma settings using PROLITH software. Based on the calculations of DOF, the NA and sigma settings are optimized by finding the values to maximize the DOF. At the optimum NA and sigma settings for 100 nm dense lines, the imaging performance is analyzed for semi-dense and isolated lines.

Abstract: The function of components and the theory of oil-paper capacitive bushing are introduced by analyzing its contracture, and the electric properties of insulation materials are instructed. The reasons and damages of lack of oil are proper illustrated, and the judging methods are offered. The distinguishing process of lack oil of bushing is illustrated by examples, and the accuracy and rationality of lack of oil finding by capacitive volume, dielectric loss angle, oil chromatogram analyzing and infrared ray test are demonstrated.

Abstract: A novel excitation system based on full controlled devices rectifier is proposed in this article, and the excitation system can provide double kinds of damping for power system by controlling the excitation voltage of DC side and exchanging reactive with generator. Through the Mat lab / Simu link simulation platform, a circuit model is established. This paper presents a current feed forward decoupling control method and the active and reactive current can be controlled independently by the method. The simulation results of two-area including four generators system shows the system damping ratio is improved significantly, and has better dynamic performance than conventional excitation system .

Abstract: The difficulty of anti-lock braking system based on slip ratio lies in acquiring the optimal slip ratio of various pavements. In this paper, a method based on slip ratio change direction and adhesion coefficient change direction and variable quantity, is proposed to identify optimal slip ratio. The fuzzy controller was designed and the computer simulation was fulfilled for single pavement and variable pavement. The results show that this method has better accuracy, calculation amount small and in real-time.

Abstract: Based on the dynamic mathematical model of induction motor, the mutual model reference adaptive system method (MRAS) for rotor speed identification is proposed to implement a speed sensorless direct torque control of induction motor. The model reference adaptive theory is flexibly used in the rotor speed and the stator resistance online identification. The reference model and adjustable model used in the mutual MRAS scheme are interchangeable. Therefore, The induction motor speed sensorless direct torque control system can obtain high-precision speed identification. Computer simulations and experimental results show that the method can solve the problems of speed control accuracy and system stability under the influence of motor parameter variation. The low speed performance of DTC is also improved.

Abstract: The Baixiangshan iron mine is a large scale underground mine under construction, and will be put into production in 2011. As hydro-geological conditions of the mine are extremely complicated, ground water inrush happened twice during excavation of the ventilation shaft in 2006 and 2009 respectively. The purpose of this paper is to control the ground water inrush and guide the safety production of the mine. Hence, the ground water state was firstly analyzed through the data of borehole and hydrologic geology. After that, hydro-geological models of the ground water system were built up. According to the hydro-geological models, mathematical models of the ground water were established. With the help of the software of Processing Modflow for Windows (PMWIN), the numerical model of the ground water was set up. Then, by using the SOR (Successive Over-Relaxation) iterative method, the numerical equations were solved. Finally, the district ground water inflow rate on the main mining levels and the dangerous districts of the ground water inrush was figured out. The results of the numerical solution are significant to the control of ground water inrush in the Baixiangshan iron mine.

Abstract: In order to understand the impact of reservoirs to water resource value more scientifically and rationally, and based on expatiating the study of water resource value theory, this paper reveals the mechanism of regulating reservoir changing water resource value, by some physical theory such as momentum and kinetic energy theory, as well as resource scarcity theory. It is that the reservoirs transfer the relative control pivot’s labor value to the flowing water resources, and change the scarcity value of regulating water resources, by dam working on regulating water resources. The paper provides a scientific basis for regulating reservoir obtaining compensation benefits.

Abstract: The 10kV distribution networks have complicated geographical environment and the lines with many branches, as well as high grounding resistance at fault point, thus result the difficult of locating fault. Traveling wave fault-location methods locate fault by the time of traveling wave from fault point to receiver or wave subtraction from fault point to two sides receivers, and the advantages of the methods are fast and have high precision. This paper introduced A, B, C, E four types traveling wave fault-location methods and their characteristics. Many simulations are taken for single-phase earth fault in a 10kV power distribution line with branches. By comparing the waves reflected from normal line and the fault one, the fault distance is determined by the first distortion point. As a result, the simulations indicate that the fault-location precision meet the actual requirement, Type C traveling wave fault-location method is feasible for the fault location in distribution networks.

Abstract: In the long evolution of the earth formation often form a complex geological structure, modeling for these complex geological entities (such as thinning-out, bifurcation, reverse, etc.) still require in-depth 3D modeling study. Because of discontinuity, complexity and uncertainty of distribution of 3D geo-objects, some models only are suitable for regular, continuous and relatively simple spatial objects, and some are suitable for discontinue, complex and uncertain geo-objects, but some improvements on these models, such as, updating of model, maintenance of topological and seamless integration between models, are still to be made. OO-Solid model, put forward by writer in 2002, is an object- oriented topological model based on sections. The OO-Solid Model is an object-oriented 3D topologic data model based on component for geology modeling with fully considering the topological relations between geological objects and its geometric primitives, Comparatively, it accords with the actual requirements of three-dimensional geological modeling . The key issue of 3D geology modeling is the 3D data model. Some data models are suitable for discontinue, complex and uncertain geo-objects, but the OO-Solid model is an object-oriented 3D topologic data model based on component for geology modeling with fully considering the topological relations between geological objects and its geometric primitives. OO-Solid model and data structure are designed. At last, 3D complex geological entities modeling based on OO-Solid are studied in this paper. These study is important and one of the core techniques for the 3DGM.