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991.
考虑实际决策环境的不确定性和复杂性,提出一种具有多目标、多指标、多局势的灰靶决策模型.首先,将各局势在相应目标下的各指标集结为目标综合效果评价值,从而简化复杂的多层决策问题;然后,集成各局势到正负靶心的空间投影距离,提出一种新的综合靶心距,并以综合靶心距最小化准则为目标函数构建非线性优化模型来求解最优的目标权重;最后,以某种产品的零部件绿色供应商的选择为例,验证了基于正负靶心的多目标灰靶决策模型的有效性和实用性. 相似文献
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Recent numerical methods for calculating the flow of fluids of the integral type have been extended to the case of swirling flows in geometries of revolution. Such flows are important in rheometry, as it was suggested in early experimental results by Savins and Metzner [1]. After having developed the necessary background for the numerical calculation, we apply the method to the flow in disk-and-plate and cone-and-plate rheogoniometers. 相似文献
996.
Dr. Gunther Kolb Dipl.‐Ing. Hans‐Joachim Kost Prof. Dr. Volker Hessel Prof. Dr. Volker Hessel 《化学,工程师,技术》2011,83(4):465-478
In this contribution it is reported about the realization of efficient micro rectification equipment (MRA), which can be operated intermittently or continuously and be used both for analytical as well as for preparative separations of mixtures of liquid substances. Different binary systems were separated. A theoretical separation stage number of 12 was obtained together with a height equivalent to one theoretical plate of 1.08 cm. Compared to the state of microtechnology this can be regarded as an excellent progress. 相似文献
997.
本文提出了一种可在8位单片机上实现的非特定人汉语数码识别算法。该算法基于最大后验概率分类原理,利用二次多项式估计后验概率分布。其优点是识别算法的简单,不涉及动态规划过程。 相似文献
998.
The feasibility of a proposed system that combines a magnesium oxide/water chemical heat pump and a diesel engine as a cogeneration system is discussed based on experimental results. The combined system is intended to utilize the waste heat discharge from the engine by means of the chemical heat pump and to level the heat supply load of the engine, allowing enhanced energy utilization. The thermal performance of the chemical heat pump in the cogeneration system is estimated based on the results of a packed‐bed experiment. The estimation indicates that by storing the waste heat from the engine during low demand periods, the cogeneration system can produce more than several times the standard thermal output of the diesel engine during peak demand periods. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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Characterization of the granular packing and percolation threshold of reactive powder concrete 总被引:4,自引:0,他引:4
Olivier Bonneau Christian Vernet Micheline Moranville Pierre-Claude Aïtcin 《Cement and Concrete Research》2000,30(12):1861-1867
Reactive powder concrete (RPC) is a new cement-based material developed through microstructural engineering. RPC is composed of very fine powders: sand, crushed quartz and silica fume, all with particle sizes comprised between 300 and 0.02 μm, and a low water content, W/C<0.20. A very dense matrix is achieved by optimizing the granular packing of these powders. This compactness confers to RPC ultrahigh strength and durability.where Av depends on the nature and the dosage of the different mineral and organic components, and Bv is an invariant related to the granular packing. From 19 different RPC compositions, an average value of 12.1 with a standard deviation of 1.7 were found for Bv. The capillary porosity percolation threshold was also deduced from this relationship. It has been found that when the degree of hydration is equal to 26%, the capillary pore space is discontinuous. This last result is in agreement with the prediction of the NIST microstructural model by Bentz and Garboczi [D., Bentz, E. Garboczi, Percolation of phases in a three-dimensional cement paste microstructural model, Cem Concr Res 21 (2) (1991) 325–344]. A continuous determination of the degree of hydration based on electrical conductivity is proposed. 相似文献
The hydration kinetic of the cementitious matrix using electrical conductivity and isothermal calorimetry is presented. A linear relationship between the logarithm of conductivity ln(σ) and the degree of hydration , has been found:
ln(σ)=Av−Bv