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121.
Eric Howard 《Contemporary Physics》2019,60(4):328-329
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Prof. Dr. Mateo Alajarin Dr. Raul‐Angel Orenes Prof. Dr. Judith A. K. Howard Dr. Elinor C. Spencer Prof. Dr. Jonathan W. Steed Dr. Aurelia Pastor 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(8):2389-2397
Tris(2‐ and 3‐ureidobenzyl)amines with Cs symmetry self‐assemble in solution forming mixtures of regioisomeric capsular aggregates, one of which is chiral and the other centrosymmetric. Under certain conditions, a predominance of the centrosymmetric regioisomer is found before equilibrium, that is, a mixture close to the statistical ratio of the two species is reached. In the solid state, there is a preference for the centrosymmetric capsules. Molecular models of both regioisomeric aggregates have been built and analyzed for comparison. Guests inside capsules formed by self‐assembly of desymmetrized tris(3‐ureidobenzyl)amines feel different magnetic environments, depending on whether they are inside a chiral or an achiral regioisomeric container. Of special significance are the experiments with a more flexible triurea endowed with an ureidopropylic arm, which self‐assembles with the same efficiency as the more rigid tris(ureidobenzyl)amines. 相似文献
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This work is concerned with the design of a leading edge for a flat-plate model used to study laminar and transitional boundary layers. For this study, the flow over the complete boundary-layer model, including leading edge, flat section, and trailing-edge flap, is modeled. The effect of important geometrical features of the leading edge on the resulting pressure distribution, starting from the well-known symmetric modified super ellipse, is investigated. A minimal pressure gradient on the measurement side of the plate is achieved using an asymmetrical configuration of modified super ellipses, with a thickness ratio of 7/24. An aerodynamic shape optimization is performed to obtain a novel leading edge shape that greatly reduces the length of the non-zero pressure gradient region and the adverse pressure gradient region compared to geometries defined by ellipses. Wind tunnel testing is used to validate the numerical solutions. 相似文献
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Howard C. Johnson 《International Journal of Mathematical Education in Science & Technology》2013,44(5):741-743
The purpose of this article is to delineate procedures for viewing education software intended for use in a mathematics classroom. These procedures are applicable at all levels. 相似文献
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A series of predominately hydroxyl-ended polyesters were made from tridecanedioic acid derived from crambe oil. Comparison materials with sebacic and adipic acids were also prepared. Suitable polyesters were converted into polyurethane elastomers by chain extension and cross-linking with a diisocyanate and further diol. Polyesters based on ethandiol were unsuitable for the production of flexible urethanes as a slow crystallization occurred on standing; this did not happen when mixed ethane- and propan-diols were employed in polyesterification. Polyurethanes based on diphenylmethane diisocyanate are stronger than those made with the mixed isomers of toluene diisocyanate. Polyurethane networks based on brassylic acid have a lower 相似文献
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Victor Z. Sun Uh‐Joo Choe April R. Rodriguez Howard Dai Timothy J. Deming Daniel T. Kamei 《Macromolecular bioscience》2013,13(5):539-550
An arginine‐leucine block copolypeptide (R60L20) is synthesized, which is capable of forming vesicles with controllable sizes, able to transport hydrophilic cargo across the cell membrane, and exhibit relatively low cytotoxicity. The R60L20 vesicles also possess the ability to deliver DNA into mammalian cells for transfection. Although the transfection efficiency is lower than that of the commercially available transfection agent Lipofectamine 2000, the R60L20 vesicles are able to achieve transfection with significantly lower cytotoxicity and immunogenicity. This behavior is potentially due to its stronger interaction with DNA which subsequently provides better protection against anionic heparin.