971 resultados para p-Groups
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A conjugated poly(p-CN-phenylenevinylene) (PCNPV) containing both electron-donating triphenylamine units and electron-withdrawing cyano groups was prepared via Knoevenagel condensation in a good yield. Gel permeation chromatography suggested that the soluble polymer had a very high weight-average molecular weight of 309,000. A bright and saturated red emission was observed under UV excitation in solution and film. Cyclic voltammetry showed that the polymer presented quasi-reversible oxidation with a relatively low potential because of the triphenylamine unit. A single-layer indium tin oxide/PCNPV/Mg-Ag device emitted a bright red light (633 nm).
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Sulfonated poly(p-phenylene)s (SPPs) containing sulfonic acid groups in their side chains had been directly synthesized by Ni(0) catalytic coupling of sodium 3-(2,5-dichlorobenzoyl)benzenesulfonate and 2,5-dichlorobenzophenone. The synthesized copolymers possessed high molecular weights revealed by their high viscosity, and the formation of tough and flexible membranes by casting from DMAc solution. The copolymers exhibited excellent oxidative stability and mechanical properties due to their fully aromatic structure extending through the backbone and pendent groups. Transmission electron microscopic (TEM) analysis revealed that these side-chain type SPP membranes have a microphase-separated structure composed of hydrophilic side-chain domains and hydrophobic polyphenylene main chain domains. The proton conductivities of copolymer membranes increased with the increase of IEC and temperature, reaching values above 3.4 x 10(-1) S/cm at 120 degrees C, which are almost 2-3 times higher than that of Nafion 117 at the same measurement conditions. Consequently, these materials proved to be promising as proton exchange membranes.
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We initiate the study of sets of p-multiplicity in locally compact groups and their operator versions. We show that a closed subset E of a second countable locally compact group G is a set of p-multiplicity if and only if E∗={(s,t):ts−1∈E} is a set of operator p-multiplicity. We exhibit examples of sets of p-multiplicity, establish preservation properties for unions and direct products, and prove a p-version of the Stone–von Neumann Theorem.
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In this paper, we study the Reidemeister spectrum for metabelian groups of the form Q(n) x Z and Z[1/p](n) x Z. Particular attention is given to the R(infinity)-property of a subfamily of these groups.
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Let G = Z/a x(mu) (Z/b x TL(2)(F(p))) and X(n) be an n-dimensional CW-complex with the homotopy type of the n-sphere. We determine the automorphism group Aut(G) and then compute the number of distinct homotopy types of spherical space forms with respect to free and cellular G-actions on all CW-complexes X(2dn - 1), where 2d is a period of G. Next, the group E(X(2dn - 1)/alpha) of homotopy self-equivalences of spherical space forms X(2dn - 1)/alpha, associated with such G-actions alpha on X(2dn - 1) are studied. Similar results for the rest of finite periodic groups have been obtained recently and they are described in the introduction. (C) 2009 Elsevier B.V. All rights reserved.
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Cellulose chemically modified with p-aminobenzoic groups, abbreviated as Cel-PAB, was used for preconcentration of copper, iron, nickel, and zinc from ethanol fuel, normally used in Brazil as engine fuel. The surface characteristics and the surface area of the cellulose were obtained before and after chemical modification using FT-IR, elemental analysis, and surface area analysis (B.E.T.). The retention and recovery of the analyte elements were studied by applying batch and column techniques.
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A new procedure was developed for the in situ characterization of the lability of metal species in aquatic systems by using a system equipped with a diffusion membrane and cellulose organomodified with p-aminobenzoic acid groups (DM-Cell-PAB). To this end, the DM-Cell-PAB system was prepared by adding cellulose organomodified with p-aminobenzoic acid groups (Cell-PAB) to pre-purified cellulose bags. After the DM-Cell-PAB system was sealed, it was examined in the laboratory to evaluate the influence of complexation time, mass of exchanger, pH, metal ions (Cu, Cd, Fe, Mn, and Ni), and concentration of organic matter on the relative lability of metal species. It was found that the pH and kinetics strongly influence the process of metal complexation by the DM-Cell-PAB system. At all pH levels, Cd, Mn, and Ni showed lower complexation with Cell-PAB resin than Cu and Fe metals. Note that relative lability of metals complexed to aquatic humic substances (AHS) in the presence of Cell-PAB resin showed the following order: Cu congruent to Fe >> Ni > Mn=Cd. The results presented here also indicate that increasing the AHS concentration decreases the lability of metal species by shifting the equilibrium to AHS-metal complexes. Our results indicate that the system under study offers an interesting alternative that can be applied to in situ experiments for differentiation of labile and inert metal species in aquatic systems.
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We studied the occurrence of O-type P elements in at least one species of each subgroup of the saltans group, in order to better understand the phylogenetic relationships among the elements within the saltans group and with those of species belonging to the willistoni group. We found that the O-type subfamily has a patchy distribution within the saltans group (it does not occur in D. neocordata and D. emarginata), low sequence divergence among species of the saltans group as well as in relation to species of the willistoni group, a lower rate of synonymous substitution for coding sequences compared to Adh, and phylogenetic incongruities. These findings suggest that the evolutionary history of the O-type subfamily within the saltans and willistoni groups follows the same model proposed for the canonical subfamily of P elements, i.e., events of horizontal transfer between species of the saltans and willistoni groups.
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We show that if p is a selective ultrafilter, then for each cardinal alpha <= omega(1), there exists a topological group G such that G(beta) is almost p-compact (in particular, countably compact), for beta < alpha, but G(alpha) is not countably compact. If in addition, we assume Martin's Axiom, then the result above holds for every alpha < c. (C) 2012 Elsevier By. All rights reserved.
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"Experimental Movie Project" (1945-46):; 1. "Below the Surface", Drehbuch des Testfilms, a) als Typoskript vervielfältigt, 46 Blatt, b) als Typoskript vervielfältigt, 26 Blatt, c) als Typoskript vervielfältigt, 26 Blatt, d) als Typoskript vervielfältigt, 26 Blatt "Experimental Movie Project" (1945-46): Memoranden zum Test; 2. 'Notes' 25.4.1946, Typoskript, 1 Blatt; 3. "Memorandum on Experimental Movie Project", 19.4.1946. Typoskript, 3 Blatt; 4. "Memorandum re: 'Below the Surface" (Juli 1945). Typoskript, 2 Blatt; 5. Dore Schary und Allen Rivkin: 'Memorandum, Subject: New Suggested Treatment for 'Below the Surface'", 13.7.1945. Typoskript, 2 Blatt; 6. Hans Richter: "Report about the film script 'Below the surface'", 7. u. 8.7.1945, a) Typoskript, 1 Blatt, b) Typoskript, 1 Blatt; 7. Hans Richter: Bestätigung der Vereinbarung mit dem American Jewish Committee, 3.7.1945. Typoskript, 1 Blatt; 8. "Notes and Suggestions re Experimental Motion Picture", Juni 1945. Typoskript, 2 Blatt; 9. Siegfried Kracauer; "Suggestions for the Dialogue" (4.4.1945). Typoskript, 3 Blatt; 10. "Motion Picture", März 1945. Typoskript, 5 Blatt; 11. "Project on a Test film", a) Typoskript, 4 Blatt, b) Typoskript, 5 Blatt; 12. "Memorandum re: 'Below the Surface'", a) Typoskript, 3 Blatt, b) Typoskript mit eigenhändigen Korrekturen von Theodor W. Adorno, 3 Blatt; "Experimental Movie Project" (1945-46): Korrespondenz zum Test-Film-Projekt:; 13. Friedrich Pollock: 1 Brief an Max Horkheimer, Santa Monica, California, 12.10.1945; 14. Theodor W. Adorno: 2 Briefe an Max Horkheimer, Los Angeles und Santa Monica, California, 1945; 15. Joseph M. Proskauer: 1 Brief von Max Horkheimer, o.O., 29.6.1945, 1 Brief mit Unterschrift an Max Horkheimer, o.O., o.D., 3 Blatt; 16. Alexander Hackenschmied, 1 Brief mit Unterschrift an Max Horkheimer, New York, 19.6.1945, 1 Blatt; 17. Gilbert Gabriel: 1 Brief von John Slawson, o.O., 22.3.1945, 2 Blatt; "The Police and Minority Groups" (1946):; 1. "The Police and Minority Groups". Typoskript, 2 Blatt; 2. Robert W. Kenny: "Police and Minority Groups - an Experiment". Als Typoskript vervielfältigt, 17 Blatt; 3. Davis McEntire, Robert B. Powers: "Police Training Bulletin. A Guide to Race Relations for Police Officers", State of California, 1946, 38 Seiten; Max Horkheimer: "Memorandum on a Study of Race Hatred in Post-War Germany" (1946):; 1. Memorandum, a) Typoskript, 8 Blatt, b) Typoskript mit eigenhändigen und handschriftlichen Korrekturen, 6 Blatt, c) Typoskript, 5 Blatt, d) Teilstück, Typoskript mit eigenhändigen Korrekturen, 1 Blatt e) Typoskript mit eigenhändigen Korrekturen, 5 Blatt, f) Teilstück, Typoskript mit handschriftlichen Korrekturen, 2 Blatt, g) Typoskript mit eigenhändigen Korrekturen, 7 Blatt, h) Teilstück, Typoskript mit eigenhändigen Korrekturen und Ergänzungen, 1 Blatt, i) Typoskript, 2 Blatt; 2. Theodor W. Adorno: "Ad Memorandum Neumann", Manuskript, 3 Blatt;
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Thesis (Ph.D.)--University of Washington, 2016-06
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Peer reviewed