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71.
A Keggin-type heteropolyanion compound (HPO) was doped within the montmorillonite (MMT) structure by impregnation method. The synthesized catalyst was characterized by FT-IR, XRD, UV–vis, CV, SEM and elemental analysis. Based on chemical adsorption between HPO, and hydroxyl surface groups, HPOs nanoparticles were successfully located on the MMT. Moreover, the obtained nanocomposite was found as an efficient catalyst for oxidation of hydrocarbons under reflux and ultrasonic irradiation conditions.  相似文献   
72.
In this work, a penalization method is discussed in the context of vortex methods for incompressible flows around complex geometries. In particular, we illustrate the method in two cases: the flow around a rotating blade for Reynolds numbers 1000 and 10,000 and the flow past a semi‐circular body consisting of a porous layer surrounding a rigid body at Reynolds numbers 550 and 3000. In the latter example, the results are interpreted in terms of control strategy. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
73.
A new, facile, efficient, “green” and chemoselective procedure for the synthesis of indole derivatives has been developed with pulverization‐activation method catalyzed by Bi(NO3)3·5H2O (PAMC‐ Bi(NO3)3·5H2O) through grinding of indoles with aldehydes or Michael acceptors in the presence of catalytic amounts of Bi(NO3)3·5H2O under solvent‐free conditions.  相似文献   
74.

Abstract  

A new and practical promoter system for one-pot, efficient, chemoselective synthesis of 4-arylidene-2-phenyl-5(4H)-oxazolones using [(C14H24N4)2W10O32]-[bmim]NO3 under solvent-free conditions is described. The present work opens up a new and ecofriendly synthetic route to Erlenmeyer–Pl?chl adducts from primary benzyl alcohols in a one-pot operation.  相似文献   
75.
The airline industry is under intense competition to simultaneously increase efficiency and satisfaction for passengers and profitability and internal system benefit for itself. The boarding process is one way to achieve these objectives as it tends itself to adaptive changes. In order to increase the flying time of a plane, commercial airlines try to minimize the boarding time, which is one of the most lengthy parts of a plane’s turn time. To reduce boarding time, it is thus necessary to minimize the number of interferences between passengers by controlling the order in which they get onto the plane through a boarding policy. Here, we determine the passenger boarding problem and examine the different kinds of passenger boarding strategies and boarding interferences in a single aisle aircraft. We offer a new integer linear programming approach to reduce the passenger boarding time. A genetic algorithm is used to solve this problem. Numerical results show effectiveness of the proposed algorithm.  相似文献   
76.
Thiocyanation of various aromatic and heteroaromatic compounds has been achieved in the presence of ammonium thiocyanate (NH(4)SCN) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in methanol solution under ultrasound irradiation. An ultrasonic probe of 24 kHz frequency has been used for this study. Whereas the use of ultrasound increases the rate of reactions compared with reactions at reflux conditions, the electron-donor ability of aromatic nucleus enhances also the rate of reaction.  相似文献   
77.
In this paper we study the behavior of computable series of computable partial functions with varying domains (but each domain containing all computable points), and prove that the sum of the series exists and is computable exactly on the intersection of the domains when a certain computable Cauchyness criterion is met. In our point‐free approach, we name points via nested sequences of basic open sets, and thus our functions from a topological space into the reals are generated by functions from basic open sets to basic open sets. The construction of a function that produces the sum of a series requires working with an infinite array of pairs of basic open sets, and reconciling the varying domains. We introduce a general technique for using such an array to produce a set function that generates a well‐defined point function and apply the technique to a series to establish our main result. Finally, we use the main finding to construct a computable, and thus continuous, function whose domain is of Lebesgue measure zero and which is nonextendible to a continuous function whose domain properly includes the original domain. (We had established existence of such functions with domains of measure less than ε for any , in an earlier paper.)  相似文献   
78.
An expeditious, straightforward and efficient synthesis of diversely naphtho[1,2-e][1,3]oxazines via one-pot condensation reaction of ??- naphthol, 3-amino-5-methylisoxazole and arylaldehydes catalyzed by bismuth(III) trifluoromethanesulfonate is described. The reaction preferentially afforded 1,3-trans oxazines.  相似文献   
79.
Montmorillonite K-10 and KSF were found to be highly efficient, environmentally friendly and recyclable heterogeneous catalysts for the selective synthesis of a variety of 2-aryl-5,6-dihydro-4H-1,3-oxazines from arylnitriles and 3-amino-1-propanol under ultrasound irradiation. This new methodology provides excellent yields in short reaction times (10–25 min). The reaction work-up is very simple and the catalysts can be easily separated from the reaction mixture and reused several times in subsequent reactions. This catalytic system also exhibits excellent chemoselectivity in the synthesis of mono-oxazines from dinitriles.  相似文献   
80.
This paper reports an experimental work on the convective heat transfer of ferrofluid flowing through a heated copper tube in the laminar regime in the presence of magnetic field. Significant enhancement on the heat transfer of ferrofluid by applying various orders of magnetic field is observed in this experiment. Also in this experiment, the effect of magnetic nanoparticles concentrations and magnet position have been investigated. The main reason for the enhancement of heat transfer coefficient could be caused due to remarkable changes in thermophysical properties of ferrofluid under the influence of applied magnetic field.  相似文献   
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