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We study the non-negative solutions of the boundary value problem ?Δu = λ [expαu(α + u)]; x ? Ω. u = 0; x ? ?Ω, where α > 0, λ ? 0, Ω ? Rn is bounded with smooth boundary ?Ω.This problem arises in the theory of combustion. We study the estimates on the supremum norm of the solutions and estimates on the critical values of λ.  相似文献   
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We consider the system
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We report a preparation of new 6‐substituted‐5,6‐dihydrobenzo[c]phenanthridines by the reaction of azoles with quaternary benzo[c]phenanthridine alkaloids sanguinarine and chelerythrine. The prepared compounds have been characterized by NMR spectroscopy, mass spectrometry, and single‐crystal X‐ray diffraction. Conformational behaviors of carbazole derivatives in solution have been investigated by low‐temperature NMR experiments. Barriers to rotation around newly formed C6–N bonds were determined to be 12–13 kcal/mol. Quantum chemical calculations have been used to reproduce the experimental observations. Large structural effects on several 1H NMR resonances were observed experimentally, analyzed by Density Functional Theory (DFT) calculations at B3LYP/6‐311+G(d,p)/PCM level, and interpreted by ring‐current effects of the benzo[c]phenanthridine and carbazole units. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
25.
This paper examines a stochastic non-sequential capacitated production-planning problem where the demand of each period is a continuous random variable. The stochastic non-sequential production-planning problem is examined with sequence-independent and then with sequence-dependent set-up costs, and the worst-case error determined when an approximate solution is obtained by solving the deterministic equivalent. We prove in general that the worst-case error is not dependent on the nature of the set-up cost, and identify a family of approximations for the stochastic non-sequential production-planning problem.  相似文献   
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Various 1,6-anhydro sugars are synthesized utilizing salient features of gold-catalyzed glycosidations. All the reactions occurred under mild conditions in the presence of 7 mol % of AuBr3 enabling easy synthesis of 1,6-anhydro sugars from corresponding 6-hydroxy propargyl/methyl monosaccharides, disaccharides, and trisaccharides in good yields.  相似文献   
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Russian Journal of Electrochemistry - A micro-bricks shaped tungsten oxide (WO3) was prepared by hydrothermal method. The prepared material was characterized by field emission scanning electron...  相似文献   
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2,3-Dihydro-1H-1,5-benzodiazepine derivatives are synthesized by the condensation of o-phenylenediamine and various ketones in the presence of catalytic amount of LaCl3 under solvent-free condition. Dedicated to Loknete Balasaheb Vikhe Patil on the occasion of his 75th birthday  相似文献   
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Hydroxy (tosyloxy) iodobenzene (HTIB), a hypervalent iodine reagent, has been extensively used for oxidative transformations. We have developed a one‐pot synthesis wherein aldoximes when reacted with alkynes in the presence of HTIB result in the direct formation of isoxazoles. This simple and straightforward reaction allows for ease of purification while leading to the formation of high purity 3,5‐disubstituted isoxazoles in moderate yields.  相似文献   
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