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排序方式: 共有9386条查询结果,搜索用时 15 毫秒
961.
适用性 使用丝网印刷的方法对晶圆表面施涂聚酰亚胺保护层相对于传统的旋转-蚀刻工艺技术具有效率和成本的优势.丝网印刷晶圆表面保护只需要两步工序(印刷和固化),而旋转-蚀刻工艺需要七步或更多的工序. 相似文献
962.
Ming Dong F. Frank Chen 《The International Journal of Advanced Manufacturing Technology》2005,27(3-4):397-406
This paper is geared toward developing an integrated modeling framework and simulation models for understanding decision-making
issues of the supply chain network configuration in an integrated environment.
To achieve this objective, first, this paper presents an integrated modeling framework for multistage supply chains, in which
the interdependencies between model components are captured. Second, the state and resource-based simulation concepts are
used to model the supply chain network configurations. The employment of state and resource-based simulation techniques facilitates
the implementation procedure, since they are strong in modeling dynamic supply chain networks with highly interdependent components
subject to activity start-up conditions. To investigate the impacts of component commonality on integrated supply chain network
performance effectively, a new analytical measure of component commonality that consists of a component-level commonality
index and a product-level commonality index is defined. The results of analysis-of-variance and Tukey’s tests reveal that
there is a significant difference in performance measures, such as delivery time and order fill rates, when comparing an integrated
supply chain with higher component commonality to an integrated supply chain with lower component commonality. 相似文献
963.
Prof. Dr. med. Dipl. Psych. Frank Erbguth 《Ethik in der Medizin》2006,18(2):182-185
Ohne Zusammenfassung 相似文献
964.
Precise determination of the dielectric constant of microelectronic packaging materials is critical for the performance optimization of high frequency devices. Accurate empirical data, however, is difficult to obtain and often not available for these complex composite materials. In order to provide a basis for predictive model verification, dielectric analysis of a series of model microelectronic packaging materials was conducted. Physical characteristics of the composite constituents, including the morphology of the dispersed phase as well as the dielectric constant of the dispersed and host phases, were used to define the indeterminate variables. The results of these analyses provide a systematic verification of a newly developed physical model for predicting the effective dielectric constant of complex composite systems. The model considers an interphase zone surrounding each dispersed particle having unique physical and electrical characteristics. A physical interpretation is presented to explain the indeterminate variables incorporated in this model. 相似文献
965.
966.
Chris K. J. Hulston Peter J. Redlich W. Roy Jackson Frank P. Larkins Marc Marshall 《Fuel》1995,74(12):1870-1874
Well-characterized coals of different H/C atomic ratio and rank were reacted at 365°C with CO, H2 and CO---H2 mixtures in water in the presence and absence of sodium aluminate. The optimum H2/CO ratio for conversion was found to vary with the type of coal. It was <1 : 1 for low-rank and subbituminous coals, whereas the conversion of bituminous coals either did not vary with H2/CO ratio or reached a maximum at a higher H2/CO ratio (2 : 1). Even for a bituminous coal there was no advantage in reducing the water/coal ratio below 2 : 1 in NaAlO2-catalysed reactions. The conversions increased with increasing H/C atomic ratio of the coal and decreasing rank, with or without NaAlO2. Asphaltene yields increased with increasing coal rank and increasing proportion of CO in the H2---CO reacting gases. The mechanistic implications of these results are briefly discussed. 相似文献
967.
Flexible manufacturing systems (FMS) have been developed with the hope that they would provide a means to tackle a threefold challenge — better quality, lower cost and shorter lead times — by integrating machine tools, robots, material handling and storage systems, and computers. Control of the integrated system presented a new set of problems as well as challenges, which have been receiving considerable attention from the academic community as well as from industrial system users. Intelligent control, which involves using computers to assist in decision making at various stages of the control process, has been advocated by many researchers as a possible avenue to reach a solution to these problems. This paper provides a review of the state of the art in intelligent control of FMS, in an attempt to supplement earlier general reviews via a more focused perspective. The principles of several techniques, namely simulation, knowledge based, example based, petri nets, and hybrid approaches are briefly introduced, and publications are reviewed, followed by discussions ontheir potential. Suggestions for further research and development are also enumerated. 相似文献
968.
Ronald L. Sass Jeffrey A. Andrews Aiju Ding Frank M. Fisher Jr. 《Nutrient Cycling in Agroecosystems》2002,64(1-2):3-7
Growing concern over anthropogenic global climate change has intensified the need to develop accurate budgets of atmospheric methane and other greenhouse gases. Globally, flooded rice cultivation represents a major source of atmospheric methane that is expected to grow with human population. However, current estimates of global methane flux from rice paddies vary by roughly 50%. Understanding the sources of this large variability is critical for developing management strategies for atmospheric methane. Using data collected each growing season from Texas, USA, rice paddies over a 9-year period we examined the spatial and temporal sources of methane flux variability. Using standard deviation of the mean methane flux as a measured of variability, we found that accounting for rice plant height and grain yield reduced spatial variability from 25.2 to 17.7% of the mean. Temporal variability over the entire 9-year data set was 49% of the mean, 71% of which was explained by variations in average rice plant height and total nitrogen fertilizer application. The magnitude of temporal and spatial variability suggests that reliance on single-field studies for determination of global methane budgets may be questionable. 相似文献
969.
970.
This article describes a neural network model of speech motor skill acquisition and speech production that explains a wide range of data on variability, motor equivalence, coarticulation, and rate effects. Model parameters are learned during a babbling phase. To explain how infants learn language-specific variability limits, speech sound targets take the form of convex regions, rather than points, in orosensory coordinates. Reducing target size for better accuracy during slower speech leads to differential effects for vowels and consonants, as seen in experiments previously used as evidence for separate control processes for the 2 sound types. Anticipatory coarticulation arises when targets are reduced in size on the basis of context; this generalizes the well-known look-ahead model of coarticulation. Computer simulations verify the model's properties. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献