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81.
Kaniuth [3] has given necessary and sufficient conditions for the regular representation of a discrete group to be type I or type II. We give a non-measure-theoretic proof of his results, plus additional information on the structure of the W∗ algebra generated by the regular representation. 相似文献
82.
83.
Lizarraga L Andrade EM Florit MI Molina FV 《The journal of physical chemistry. B》2005,109(40):18815-18821
The quasi-equilibrium electrochemomechanical behavior of relatively thick polyaniline films in sulfuric acid is investigated through experimental measurements and theoretical modeling. The leucoemeraldine (LE)-emeraldine (EM) conversion, or redox switching, is studied. The dependence of film volume and electrochemical charge is determined as a function of applied potential. It is observed that the film volume follows the charge, showing an expansion during the second half of the LE-EM oxidation. The model postulates the existence of a stable intermediate, protoemeraldine (PE), with a formal potential distribution for the PE-EM reaction. The volume change is modeled statistically considering contributions from mixing, polymer deformation, and electrostatic charge. The model shows very good agreement with the experiments, indicating that, in the conditions studied, the deformation contribution dominates the volume changes as a result of the conformational modifications undergone by the polymer in the PE-EM oxidation. 相似文献
84.
Caterina?Minelli Isabelle?Geissbuehler Rolf?Eckert Horst?Vogel Harry?Heinzelmann Martha?LileyEmail author 《Colloid and polymer science》2004,282(11):1274-1278
We present an extremely versatile method for the lateral organization of nano-scale objects (NOs) based on the phenomenon of polymer demixing. NOs are suspended in a solution of two immiscible polymers, which is used to form a thin polymer film by spin coating. During spin coating the two polymers separate to give a microphase structure, whose length scale depends on the experimental conditions. The NOs spontaneously partition into one or other of the polymer phases resulting in their lateral organization. In this work, the organization of CdSe nanoparticles and fluorescent organic dyes was studied by fluorescence microscopy. The NOs were organized in the polymer film in stochastic patterns or in ordered designs on substrates pre-patterned by soft-lithography techniques. Single-particle measurements, using confocal microscopy, showed that at low concentrations there was little aggregation of the particles. 相似文献
85.
Ponce AM Blanco SE Molina AS García-Domenech R Gálvez J 《Journal of chemical information and computer sciences》2000,40(4):1039-1045
A study was performed on xanthine-oxidase inhibition by 22 flavonoids, including flavones, flavonols, flavanones, and chalcones, using UV spectroscopy for experimental data and molecular topology to establish the structure-activity relationship (SAR) model. The flavonoids were classified into four groups according to their activity on xanthine-oxidase (inactive, low, significant, or high), and linear discriminant analysis was used to classify each compound within a group. The results led to a very good model, which was able to classify correctly as xanthine oxidase inhibitors, along with a test set of molecules including a variety of different compounds such as allopurinol, caffeic acid, esculetin, and alloxantin. 相似文献
86.
Xianqiao Liu Michael D. Kaminski Judy S. Riffle Haitao Chen Michael Torno Martha R. Finck LaToyia Taylor Axel J. Rosengart 《Journal of magnetism and magnetic materials》2007
This paper describes a single emulsion-solvent evaporation protocol to prepare PEGylated biodegradable/biocompatible magnetic carriers by utilizing hydrophobic magnetite and a mixture of poly(D,L lactide-co-glycolide) (PLGA) and poly(lactic acid-block-polyethylene glycol) (PLA-PEG) (26:1 by mass) polymers. We characterized the magnetic microspheres in terms of morphology, composite microstructure, size and size distribution, and magnetic properties. Results show that the preparation produces magnetic microspheres with a good spherical morphology, small size (mean diameter of 1.2–1.5 μm) by means of large size distributions, and magnetizations up to 20–30 emu/g of microspheres. 相似文献
87.
Bin Liu Rupa S. ShettyKristofer K. Moffett Martha J. Kelly 《Tetrahedron letters》2011,52(14):1680-1684
An efficient synthesis of 1,3,5-trisubstituted benzenes via a sequential Pd-mediated carbon-sulfur, carbon-nitrogen, and carbon-carbon bond formation reactions is reported. Selective amidation and sulfonamidation reactions are accomplished via Pd-catalyzed reactions between aryl chlorides and an acetamide or a methanesulfonamide. 相似文献
88.
V. D. Bondar’ S. P. Molina V. V. Sadovskii 《Journal of Applied Mechanics and Technical Physics》1999,40(5):979-988
We propose mathematical models for a knitted fabric in tension that can be used to calculate the strain of the cloth thread
from the properties of the cloth and the loads applied to the cloth. Under simplifying assumptions, the problem is reduced
to consideration of an elementary cell of the cloth that contains a thread loop. The loop is first modeled by a thread oval
with point forces and then by a plate with a hole under distributed loads. In strength analysis, this allows one to use methods
of elasticity theory. A number of hypotheses are used to establish the relation between the stress state of the thread oval
and the corresponding state of the plate, which makes it possible to model the mechanical behavior of a thread in the material
in a variety of forms. The theoretical relationships obtained are compared to the experimental data available in the literature.
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 40, No. 5, pp. 227–238, September–October, 1999. 相似文献
89.
M. Siles Molina 《Journal of Algebra》2008,319(12):5265-5278
Leavitt path algebras are shown to be algebras of right quotients of their corresponding path algebras. Using this fact we obtain maximal algebras of right quotients from those (Leavitt) path algebras whose associated graph satisfies that every vertex connects to a line point (equivalently, the Leavitt path algebra has essential socle). We also introduce and characterize the algebraic counterpart of Toeplitz algebras. 相似文献
90.