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41.
Reversible hydration of amorphous V2O5 has been performed in order to study the effect of water upon the properties of the oxide. A drastic change of the ESR spectrum is observed, which turns from anisotropic to isotropic upon hydration. This has been interpreted in terms of a brownian motion which, by analogy with the V2O5 gels, is supposed to be due to the fibrous texture of the amorphous oxide. 相似文献
42.
M Leroy 《Canadian Metallurgical Quarterly》1998,27(22):1121-1123
43.
This paper presents an efficient branch and bound algorithm and near optimal heuristic algorithms for solving the problem of withdrawing inventory and/or service facilities for a good or service whose overall demand is declining over time. In particular, this paper models the problem faced by a manager who must consider closing up to M initially open and operating support facilities as demand shifts and declines over a T period planning horizon. The criterion is minimization of total estimated discounted costs. The costs considered are the variable operating cost at each facility, the transportation costs between facilities and demand centers, and the costs to operate and close each facility. Computational results are presented for both the optimum finding and heuristic algorithms. 相似文献
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"A sentence-completion test designed to measure attitudes toward superiors and subordinates was administered to 312 Air Force cadets in advanced training. The test was scored with acceptable reliability, and showed a correlation of .32 with a direct attitude measure of the same dimension, and of .27 with an indirect measure based on an information test. Interpretation of these values is restricted due to a correlation of -.45 with a direct scale of alienation, and the absence of significant correlations with reputational criterion measures." (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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F Courjault-Gautier D Hoet D Leroy HJ Toutain 《Canadian Metallurgical Quarterly》1994,270(3):1097-1104
The potent anticancer drug cis-diamminedichloroplatinum (II) (CDDP) interferes early with electrolyte transport by the renal proximal tubule. To study the early effects of platinum coordination complexes on apical Na(+)-coupled transport systems, we examined the effect of increasing concentrations of CDDP, trans-diamminedichloroplatinum (II) (TDDP) and cis-diammine-1,1-cyclobutane-dicarboxylate platinum (II) (CBDCA) on Na(+)-coupled uptake of P(i), methyl-alpha-D-glucopyranoside (MGP) and L-alanine by rabbit proximal tubule cells in primary culture. At 17 microM CDDP and 540 microM CBDCA, 1) cell viability (lactate dehydrogenase release) and ATP content were unaffected, 2) Na(+)-K(+)-ATPase activity was reduced by 40%, 3) Na(+)-coupled uptake of MGP and P(i) was reduced, whereas 4) Na(+)-coupled uptake of alanine rose to twice the control value. Alterations of Na(+)-coupled uptake of P(i), MGP and alanine were due to changes in Km, with no significant change in Vmax. At 333 microM TDDP, Na(+)-dependent P(i) and MGP uptake decreased, whereas Na(+)-independent uptake increased markedly and was associated with a decline in cell viability and ATP content. We conclude that 1) the TDDP-induced decrease in Na+/P(i) and Na+/glucose cotransport was associated with reduced cell viability, 2) both CDDP and CBDCA had different effects on Na+/P(i), Na+/glucose and Na+/alanine cotransport, arguing against an alteration of the Na+ gradient due to reduced Na(+)-K(+)-ATPase activity and 3) CBDCA induced alterations of Na(+)-coupled uptake similar to those of CDDP at concentrations 20 to 30 times higher.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
49.
A radiometric system for medical applications, including a set of six probes, facilitates the positioning of the probes and improves the precision in their location. An example of an experiment and of signal processing is shown which improves the recognition of the thermal structure. 相似文献
50.
Leroy Chiao Frederick K. Zack Robert G. Rinker Jan Thullie 《Chemical Engineering Communications》1987,49(4):273-289
Square-wave concentration forcing experiments have been performed for the ammonia synthesis reaction in an isothermal, fixed-bed, plug-flow reactor at a temperature and pressure approaching industrial conditions (703 K, 4.14Mpa). Using the optimal steady-state (OSS) production rate as a base for comparison, we have found that cycling between pure reactants (N2, H2) results in decreased time-averaged production rates as predicted by Wilson and Rinker (1982), while mixture cycling under appropriate conditions results in modest (but not insignificant) improvements over the OSS rate. We also have observed that the catalyst activity changes significantly under a variety of dynamic operating conditions. 相似文献