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911.
D.A. van Beek K.L. Man M.A. Reniers J.E. Rooda R.R.H. Schiffelers 《The Journal of Logic and Algebraic Programming》2006,68(1-2):129
The hybrid χ (Chi) formalism integrates concepts from dynamics and control theory with concepts from computer science, in particular from process algebra and hybrid automata. It integrates ease of modeling with a straightforward, structured operational semantics. Its ‘consistent equation semantics’ enforces state changes to be consistent with delay predicates, that combine the invariant and flow clauses of hybrid automata. Ease of modeling is ensured by means of the following concepts: (1) different classes of variables: discrete and continuous, of subclass jumping or non-jumping, and algebraic; (2) strong time determinism of alternative composition in combination with delayable guards; (3) integration of urgent and non-urgent actions; (4) differential algebraic equations as a process term as in mathematics; (5) steady-state initialization; and 6) several user-friendly syntactic extensions. Furthermore, the χ formalism incorporates several concepts for complex system specification: (1) process terms for scoping that integrate abstraction, local variables, local channels and local recursion definitions; (2) process definition and instantiation that enable process re-use, encapsulation, hierarchical and/or modular composition of processes; and (3) different interaction mechanisms: handshake synchronization and synchronous communication that allow interaction between processes without sharing variables, and shared variables that enable modular composition of continuous-time or hybrid processes. The syntax and semantics are illustrated using several examples. 相似文献
912.
Customers are sensitive to the flavour of water. Customers evaluate drinking water based on their expectations, on experiences with their usual drinking water and on experiences with alternative waters. The Philadelphia Water Department provides one example of success in developing a better understanding of customer perceptions and attitudes about tap water taste and odour. Philadelphia found that customers do communicate in ways that water utilities can understand. Water utilities can enhance that communication and collect useful data. In addition, water utilities can characterise their tap water flavour, track it for changes and correlate changes to customer complaints. 相似文献
913.
V. N. Dermanskii N. V. Khmelevtsov R. V. Faizulina O. N. Moleva D. V. Sokhanchuk 《Metallurgist》2007,51(1-2):55-59
The temper-rolling mills in flat-rolled products shop No. 3 at the MMK has been equipped with the Vytyazhka automated system
to measure the elongation of strip (ASEMS) rolled on the mill. The elongation (relative elongation) of the strip is determined
through a frequency-based method of measuring the speed of the strip before and after reduction. The system transmits and
displays information on the temper-rolling of each coil. The information is shown as a diagram on the monitor of an industrial
computer. The reliability of the system allows it to be in continuous use. Introduction of the automated elongation measurement
system makes it possible to monitor the reductions being made during temperrolling, which in turn enables the shop to reduce
the number of products having properties that do not meet customers’ requirements.
__________
Translated from Metallurg, No. 1, pp. 62–63, January, 2007. 相似文献
914.
915.
916.
I. F. Kurunov V. N. Loginov S. S. Lyapin N. S. Polyakov V. N. Titov 《Metallurgist》2007,51(7-8):425-433
The use of schungite as a partial replacement for coke is practiced in Russia at a number of metallurgical plants, both in
the production of foundry iron (its primary use) and in making conversion pig iron. The largest amount of coke is replaced
when foundry iron is being made, the replacement coefficient in this case having a value within the range 0.8–1.3. Studies
that included continuous monitoring of the temperature of the carbon blocks in blast furnaces with volumes of 1719, 3200,
and 5580 m3 unambiguously demonstrate that the thickness of the slag crust in blast furnaces increases with the use of schungite. Protecting
the lining of the hearth through the use of schungite is also accompanied by a decrease in coke consumption.
__________
Translated from Metallurg, No. 8, pp. 53–57, August, 2007. 相似文献
917.
918.
N. E. Esipova E. V. Blinov T. G. Movchan I. O. Bannykh 《Russian Metallurgy (Metally)》2007,(2):148-152
The corrosion resistance of the convex and concave sides of bent plates from a high-nitrogen non-magnetic steel has been studied in aqueous solutions of sulfuric and hydrochloric acids. Weighing and hydrogen methods are used to control the corrosion rate of bent-sample sides and to find a number of effects that complement the picture of the stress corrosion of iron alloys and support the existence of the mechanochemical deformation sign effect. 相似文献
919.
E. A. Garber I. A. Kozhevnikova P. A. Tarasov A. A. Zavrazhnov A. I. Traino 《Russian Metallurgy (Metally)》2007,(2):112-119
A new procedure for the calculation of contact stresses and hot-rolling forces for wide strips 0.8–1.5 mm thick has been developed and tested. This procedure takes into account the presence of a stick zone in the deformation zone and stress distributions in both elastic and plastic regions in the deformation zone. The average error in the force calculation according to the new procedure is 5%, which is more than two times smaller than the calculation error of well-known force calculation procedures. The developed procedure is used to simulate the contact stresses in the deformation zones of working stands in a six-stand 1700 mill during rolling of strips thinner than 1.0 mm. A number of new relations for the state of stress in a strip have been revealed upon simulation. Some of these relations are as follows: in the last stands, the length of elastic regions accounts for 10–17% of the total deformation-zone length; the maximum normal contact stresses are 1300–1400 MPa, which corresponds to the stresses in the deformation zones of cold-rolling mills; the stick-zone length accounts for 85–99% of the deformation-zone length; and the contact stresses in the stick zone are virtually independent of the friction coefficient. The developed calculation procedure can be used to optimize the technological regimes of wide-strip mills. 相似文献
920.
Radioimmunoassay was employed to examine distribution of antigenic structures of bovine serum albumin (BSA), absorbed by the gastrointestinal tract, in the blood serum and organs of intact rats. It was shown that 3 h after administering 3H-BSA an appreciable amount of its antigenic structures could be identified in the blood serum, liver, spleen, and carcass of the animals. The total amount of antigenic determinants of BSA which got into the internal environment of the body from the intestine amounted to about 0.2% of the dose administered. The highest specific content of antigenic structures of BSA supplied via the intestinal barrier was detected in the spleen. 相似文献