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261.
S. H. Wu K. S. Lee J. Y. H. Fuh 《The International Journal of Advanced Manufacturing Technology》2002,19(11):821-829
This paper presents a semi-automated approach for designing the gating system of a die-casting die. This approach combines
the P-Q 2 technique and feature-based parametric design for achieving the automatic generation of the geometries for the gating
system. It also enables users to integrate their expertise in the design at an early stage. User-defined gating features are
pre-defined and stored in a gating library, and are then retrieved from the library and applied to the gating part with the
desired parameters and locations during the design process. Algorithms based on the P-Q 2 technique are proposed for calculating
the related parameters of the gating system. A prototype design has been developed using this approach, and the system is
able to shorten the time for constructing the 3D geometries of the gating elements such as the gate, runner, overflow, shot
sleeve, sprue, etc. 相似文献
262.
介绍近年来美国生物能源的开发进展情况及其先进的支撑系统,提出如何使我国氮肥工业在发展我国生物能源中起促进作用。 相似文献
263.
The authors propose a framework for using knowledge-based systems to integrate the heterogeneous multidatabases of computer integrated manufacturing (CIM). For each database, a corresponding knowledge-based system is designed for directing knowledge-processing of shared information. This one-to-one method reduces the complexity of the problem. Specifically, the structure, features, and knowledge representation for a knowledge-based system are presented. Then, a prototype of an interface between manufacturing planning and computer-aided design is described. Due to the potential for rapid changes in the manufacturing environment, the linkages among CIM databases are designed to be dynamic, flexible, and adaptive to a wide variety of situations 相似文献
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267.
Xinyu Zhu Wing-Kit Choi Shin-Tson Wu 《Electron Devices, IEEE Transactions on》2002,49(11):1863-1867
A simple method is demonstrated for measuring the cell gap of reflective twisted nematic (RTN) liquid crystal (LC) cells. This method utilizes a single laser beam and crossed polarizer configuration such that Fabry-Perot effect and surface reflection are eliminated. Experimental results agree well with theory. 相似文献
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The mode of fuel management of the HTR-10 was studied, including the simulation of the fuel shuffling process and the measurement of the burnup of a fuel element. The prior consideration was the design of the equilibrium state. Based on this the fuel loading of the initial core and the fuel shuffling mode from the initial core through the running-in phase into the equilibrium state were studied. The code system VSOP was used for the physical layout of the HTR-10 at the equilibrium state and in the running-in phase. For the equilibrium state, in order to lessen the difference between the peak and the average burnup, 5-fuel-passage-through-the-core was chosen for the fuel management. The average burnup of the spent fuel for the equilibrium core is 80 000 MWd t−1, and the peak value of it is less than 100 000 MWd t−1 when the burnup of the recycled fuel element is under 72 000 MWd t−1. The mixture of fuel element and graphite element was used for the initial core loading, the volume fractions of the fuel and the graphite elements were 0.57 and 0.43, respectively. During the running-in phase, the volume fraction of graphite will decrease with the fresh fuel elements being loaded from the top of the core and the graphite elements discharged from the bottom of the core. The fuel shuffling mode is similar to that of the equilibrium state. The burnup limit of recycled fuel element is also 72 000 MWd t−1 and the peak burnup is less than 100 000 MWd t−1. Finally the core will be full of fuel elements with a certain profile of burnup and reaches the equilibrium state. According to the characteristics of the pebble-bed high temperature gas-cooled reactor, a calibrating method of concentration of 137Cs was proposed for the measurement of fuel burnup. 相似文献