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121.
Some simple boundary value problems are studied, for a new class of elastic materials, wherein deformations are expressed as non-linear functions of the stresses. Problems involving ‘homogeneous’ stress distributions and one-dimensional stress distributions are considered. For such problems, deformations are calculated corresponding to the assumed stress distributions. In some of the situations, it is found that non-unique solutions are possible. Interestingly, non-monotonic response of the deformation is possible corresponding to monotonic increase in loading. For a subclass of models, the strain-stress relationship leads to a pronounced strain-gradient concentration domain in the body in that the strains increase tremendously with the stress for small range of the stress (or put differently, the gradient of the strain with respect to the stress is very large in a narrow domain), and they remain practically constant as the stress increases further. Most importantly, we find that for a large subclass of the models considered, the strain remains bounded as the stresses become arbitrarily large, an impossibility in the case of the classical linearized elastic model. This last result has relevance to important problems in which singularities in stresses develop, such as fracture mechanics and other problems involving the application of concentrated loads. 相似文献
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Phenothiazinophanes, a novel class of phenothiazine based stilbenophanes are synthesized and characterized. All the phenothiazinophanes exhibited excellent photoluminescence properties. The cyclic voltammetry studies of the phenothiazinophanes demonstrated multiple absorption peaks due to the formation of radical cations (polarons) and dications (bipolarons). 相似文献
126.
Aluminum phthalocyanine (AlPc) in the presence of Ph3PO acts as a highly effective catalyst for cyanosilylation of various aldehydes to the corresponding cyanohydrin trimethylsilyl ethers. The reaction proceeds smoothly with 5 mol% catalyst loading at room temperature, giving up to 96% yield. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
127.
P. H. Veena Subhash Abel K. Rajagopal V. K. Pravin 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2006,57(3):447-463
This paper deals with the study of heat transfer characteristics in the laminar boundary layer flow of a visco-elastic fluid
over a linearly stretching continuous surface with variable wall temperature subjected to suction or blowing. The study considers
the effects of frictional heating (viscous dissipation) and internal heat generation or absorption. An analysis has been carried
out for two different cases of heating processes namely: (i) Prescribed surface temperature (PST) and (ii) Prescribed wall
heat flux (PHF) to get the effect of visco-elastic parameter for various situations. Further increase of visco-elastic parameter
is to decrease the skin friction on the sheet. The solutions for the temperature and the heat transfer characteristics are
obtained in terms of Kummers function.
Received: June 16, 2004; revised: February 8, 2005 相似文献
128.
A thermodynamic framework for a mixture of two liquids 总被引:1,自引:0,他引:1
In this study, we extend a thermodynamic framework that has been used with some success for describing the response of a variety of single constituent continua. Using the thermodynamic framework, we obtain a model for the mixture of two compressible fluids that has a much simpler structure than the model obtained earlier within the context of mixture theory. We also investigate the response of a mixture of two fluids that is constrained to have a constant volume, using the same thermodynamic framework. 相似文献
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Oxovanadium(IV)‐Salen Ion Catalyzed H2O2 Oxidation of Tertiary Amines to N‐Oxides– Critical Role of Acetate Ion as External Axial Ligand 下载免费PDF全文
Alagarsamy Mathavan Arumugam Ramdass Mohanraj Ramachandran Seenivasan Rajagopal 《国际化学动力学杂志》2015,47(5):315-326
The oxovanadium(IV)‐salen ion catalyzed H2O2 oxidation of N,N‐dimethylaniline forms N‐oxide as the product of the reaction. The reaction follows Michaelis–Menten kinetics and the rate of the reaction is accelerated by electron donating groups present in the substrate as well as in the salen ligand. This peculiar substituent effect is accounted for in terms of rate determining bond formation between peroxo bond of the oxidant and the N‐atom of the substrate in the transition state. Trichloroacetic acid (TCA) shifts the λmax value of the oxidant to the red region and catalyzes reaction enormously. The cleavage of N? O bond by vanadium complex leads to moderate yield of the product. But the percentage yield of the product becomes excellent in the presence of TCA. 相似文献