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991.
Supply chain management has offered a way to improve the industrial environment becomes more competitive. While, the commonly seen methodologies may be effective in solving the production–distribution problem only from supplier- or customer-oriented consideration, those cannot present the interactive relationship between upstream and downstream enterprises. In the competitive semiconductor industry environment, considering the viewpoints of the supplier and consumer simultaneously is particularly required, because multiple manufacturing and demanding steps are performed at separate situations, concurrently. In this paper, we propose an interaction-oriented approach, which bases on the analytic hierarchy process (AHP) methodology and proportional rule, to solve the semiconductor distribution problem with multiple quantitative and qualitative criteria. The developed approach gives an expected satisfaction for the all participators of the whole chain while the cooperative information is shared perfectly and effectively. Analysis results demonstrate the proposed methodology is efficient and effective through a real world case study. 相似文献
992.
993.
I. Lum E. Biro Y. Zhou S. Fukumoto D. R. Boomer 《Metallurgical and Materials Transactions A》2004,35(1):217-226
Electrode pitting was investigated in resistance spot welding of 1.5-mm-thick sheet aluminum alloy 5182 using a medium-frequency
direct-current welder and electrodes with a tip face curvature radius of 50 mm and tip face diameter of 10 mm. Detailed investigation
of the metallurgical interactions between the copper electrode and aluminum alloy sheet was carried out using scanning electron
microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX) and X-ray diffraction (XRD). The results indicated that electrode
degradation, which eventually leads to weld failure, proceeded in four basic steps: aluminum pickup, electrode alloying with
aluminum, electrode tip face pitting, and cavitation. Since pitting and cavitation result from Al pickup and alloying, periodic
electrode cleaning could extend electrode tip life by limiting the buildup of Al on the tip face. This work is part of the
effort to improve electrode tip life in resistance spot welding of aluminum alloys for automotive applications. 相似文献
994.
In order to develop highly efficient upconversion (UC) material, Er3+-doped oxyfluoride glass ceramics containing BaYF5 nano-crystals were fabricated for the first time. The randomly distributed BaYF5 nano-particles with the size of nearly 25 nm precipitated from the glass matrix at about 700 °C, then tended to aggregate slightly with the increase of heating temperature, resulting in the enhancement of Er3+ UC emission in the wavelength ranging from 500 nm to 700 nm. The UC process was found very sensitive to Er3+ content: with the increase of Er3+ content from 0.5% to 1.0%, the UC intensity behaved with drastic exaltation; while further increasing Er3+ content to 2.0% resulted in a notable fluorescence quenching. Significantly, the UC efficiency of present glass ceramic preponderates notably over that of the previously reported glass ceramic containing LaF3, implying its superior UC potentiality. 相似文献
995.
利用流体力学理论 ,结合目前国内外最新的两相流理论和实验研究成果 ,在描述气液两相流水力计算、热力计算和流型判断的数学物理模型基础上 ,研制出适用于海洋、沙漠、丘陵地区原油与伴生气、凝析天然气与凝液输送工艺的一套新的计算模拟软件TFTCS。介绍TFTCS软件的结构、功能、适用范围。用该软件对锦州 2 0 - 2海底湿天然气管道进行模拟计算 ,并与管线生产数据进行对比 ,用国外同类软件PIPEPHASE进行验算。实例计算分析表明 ,该软件功能完善 ,操作方便 ,计算结果可靠 ,能满足油气混输管道的设计计算和生产管理的需要 相似文献
996.
997.
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999.
本文对混合工质R407C与R12的物理和热力性质进行了比较分析,并针对汽车空调制冷系统的特点,对两种工质在变工况下进行了制冷系统的理论循环分析,阐明了在汽车空调制冷系统中使用R407C的可行性。 相似文献
1000.
Nanostructure in an Al-Mg-Sc alloy processed by low-energy ball milling at cryogenic temperature 总被引:1,自引:0,他引:1
F. Zhou S. R. Nutt C. C. Bampton E. J. Lavernia 《Metallurgical and Materials Transactions A》2003,34(9):1985-1992
Spray-atomized Al-7.5Mg-0.3Sc (in wt pct) alloy powders were mechanically milled at a low-energy level and at cryogenic temperature
(cryomilling). The low-energy milling effectively generated a nanoscale microstructure of a supersaturated face-centered cubic
(fcc) solid solution with an average grain size of ∼26 nm. The nanoscale microstructure was fully characterized and the associated
formation mechanisms were investigated. Two distinct nanostructures were identified by transmission electron microscopy (TEM)
observations. Most frequently, the structure was comprised of randomly oriented equiaxed grains, typically 10 to 30 nm in
diameter. Occasionally, a lamellar structure was observed in which the lamellas were 100 to 200 nm in length and ∼24 nm wide.
The morphology of the mixed nanostructures in the cryomilled samples indicated that high-angle grain boundaries (HAGBs) formed
by a grain subdivision mechanism, a process similar to which occurs in heavily cold-rolled materials. The microstructural
evidence suggests that the subdivision mechanism observed here governs the development of fine-grain microstructures during
low-energy milling. 相似文献