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101.
There are two popular approaches to specifying the semantics of process algebras: labelled transition semantics and reaction semantics. While the notion of free name is rather unproblematic for labelled transition semantics this is not so for reaction semantics in the presence of a structural congruence for unfolding recursive declarations.We show that the standard definition of free name is not preserved under the structural congruence. We then develop a fixed point approach to the set of free names and show that it is invariant under the structural congruence. 相似文献
102.
Polypyrrole (PPy) doped with dodecylsulfate (DS) and an organic dye (indigo carmine, IC) was electrochemically prepared and characterized by Raman spectroscopy and X-ray diffraction (XRD). The photoelectrochemical properties of PPy-DS and PPy-DS-IC in contact with an electrolytic solution containing a redox couple were studied using the theories for the semiconductor ∣ electrolyte interface. Results indicate that the system containing IC presents a higher photocurrent density under polychromatic illumination and faster response time when compared with PPy-DS. This fact was assigned to the formation of molecular-scale paths in PPy-DS-IC. The IC molecules lying perpendicularly between PPy chains, as confirmed by the X-ray analysis, could facilitate the mass transport at the interface and increase the ordering degree to provide better electronic charge transfer in the bulk. Although the photoelectrochemical devices presented here do not present all the properties of inorganic-based devices, we discuss some strategies to enhance the photoelectrochemical properties and response time of conducting polymers used in these type of systems. 相似文献
103.
104.
W. L. Pearn M. H. Shu B. M. Hsu 《The International Journal of Advanced Manufacturing Technology》2004,24(1-2):140-147
The multiprocess performance analysis chart (MPPAC) based on the process capability index
Cpm, called Cpm MPPAC, is developed for analysing the manufacturing quality of a group of processes in a multiple process environment. The Cpm MPPAC conveys critical information of multiple processes regarding the departure of the process and process variability from one single chart. Existing research works on MPPAC are restricted to obtaining quality information from one single sample of each process ignoring sampling errors. The information provided from existing MPPAC charts, therefore, is unreliable and misleading and results in incorrect decisions. In this paper, we consider the natural estimator of Cpm based on multiple samples. Based on the natural estimator of Cpm, we consider the sampling errors by providing an explicit formula with the Matlab program to obtain the estimation accuracy of the Cpm. We tabulate the sampling accuracy of Cpm for sample size determination so that the engineers/practitioners can use it for their in-plant applications. An example of multiple precision voltage reference (PVR) processes is presented to illustrate the applicability of
Cpm MPPAC for manufacturing quality control. 相似文献
105.
Gilbert Baumslag Benjamin Fine Xiaowei Xu 《Applicable Algebra in Engineering, Communication and Computing》2006,17(3-4):205-217
Several suggestions are presented for developing cryptosystems, both classical and public key, using a combination of combinatorial group theory and linear groups. In particular, the Reidemeister-Schreier rewriting process is used as a one way function. These suggestions raise further questions concerning both implementation and security that are being explored in the thesis of Xu [16]. 相似文献
106.
衡阳钢管厂Φ89mm半浮芯棒连轧管机组是一种新型机组,其选配的变形工艺路线能很好地适应生产小规格的热轧无缝钢管。本文论述了该机组的工艺及设备结构特点。 相似文献
107.
近终形薄带连铸工艺技术比较 总被引:1,自引:0,他引:1
近终形薄带连铸是钢铁工业简化工序,节能降耗,降低成本最具有竞争能力的一项重大新工艺技术,本文报导了世界各先进工业国近年来开展研究的最新成果,分析比较了诸多机型的优缺点,并提出了突破工艺技术的技术关键和建议。 相似文献
108.
109.
110.
Jean-Baptiste Lesourd 《Energy Economics》1985,7(3):138-144
It is shown that, when the mean productivity of some factors, such as energy or materials, is upperly bounded (a condition usually arising in energy production or in the process industries where energy takes part in physico-chemical processes), the production function may not be convex and, under some further conditions, is concave. Consequences of this model on the economics of energy savings are examined, and it is shown that energy savings may be considered at three levels: in the short run, by action on labour factors: in the medium run, by investment and action on labour factors; in the long run, by technological innovation, investment in new technologies and action on labour factors. Empirical findings along these lines are thus confirmed. 相似文献