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991.
992.
A first-principles analysis reveals that the catalytic efficiency of nitroxyl radicals in alkane oxidations is not simply correlated with their reactivity toward the substrate. 相似文献
993.
We present a space and time allocation problem that arises in assembly halls producing large building blocks (namely, a shipyard
which assembles prefabricated keel elements). The building blocks are very large, and, once a block is placed in the hall,
it cannot be moved until all assembly operations on this block are complete. Each block must be processed during a predetermined
time window. The objective is to maximize the number of building blocks produced in the hall. 相似文献
994.
In this paper, we show that the strict mononicity of the eigen-values of an uniformly elliptic operator of second order is equivalent to a unique continuation property. 相似文献
995.
The paper examines the inventory routing problem from the perspective of the present value of the cash flow associated with the distribution of a commodity such as propane. We analyze this problem for both deterministic and stochastic customer demands and validate our results on data from a real life distribution operation of propane. The analysis based on the present value of the cash flow indicates that optimization of propane deliveries based on efficiency/cost criteria alone will generate inferior solutions and it would be more advantageous for the company to set deliveries for a large percentage of the customers based on the present value of cash flow. In addition, in the case of stochastic demands, deliveries based on the cash flow consideration will tend to reduce the number of stockouts (i.e. improve both profit and service). 相似文献
996.
997.
Fogli Fabrizio Greco Nicola Bassi Paolo Bellanca Gaetano Aschieri Pierre Baldi Pascal 《Optical and Quantum Electronics》2001,33(4-5):485-498
A theoretical approach based on Bloch theorem and spatial harmonics has been used to investigate the propagation characteristics in planar periodic segmented waveguides. This analytical method allows to evaluate the field distribution, the effective index and the propagation losses of these structures, taking into account both the propagating and the counterpropagating field components, thus evidencing all the phenomena which can take place in: Bragg reflections, leaky waves, etc. Results for TE fields are presented and compared with those obtained using a paraxial 2D FD-BPM method and a Padé based one, showing that no more than (1, 1) order approximants are needed to provide good estimates of the device characteristics. 相似文献
998.
A route to 1-formyl-2-hydroxy-9-methylanthracene and 1-formy 1-2-hydroxy-9,10-dimethylanthracene is desribed. These two aldehydes were further converted into mono- or dimethylanthra[2,1-b]furans, besides the corresponding acids and esters, by condensation with ethyl bromoacetate. The related mono- or dimethyl-2-nitroanthra[2,1-b]furans were also prepared by reaction between the above aldehydes and bromonitromethane, followaed by heating in toluene in the presence of p-toluene-sulfonic acid. 相似文献
999.
1000.