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1.
Formation of porous polymer morphology by microsyneresis during divinylbenzene polymerization 下载免费PDF全文
Libuše Hanková Ladislav Holub Karel Jeřábek 《Journal of Polymer Science.Polymer Physics》2015,53(11):774-781
This article describes the investigation of the importance of various reaction conditions on microsyneretic pore formation during polymerization of divinylbenzene (DVB) under so‐called “solvothermal” conditions. To induce microsyneretic pore formation, the most important parameter is an unusually high dilution of monomers with a “good” porogen solvating the polymer chains. High dilution and solvation of the growing poly(DVB) chains promote the prolongation of the polymer chains rather than their interconnection by crosslinking. Consequently, when the polymer gel density reaches the point where syneresis starts, the polymer network is geometrically too extensive to be broken up into precipitating entities and, instead, porogen droplets are formed within the continuous polymer gel. The pore geometry created by microsyneresis offers high surface area in wide mesopores and hence, high capacity for supporting functional groups or reactions with much better accessibility than narrow pores between polymer microspheres produced by macrosyneresis in conventional styrenic polymer supports. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 774–781 相似文献
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Ladislav Pesek Leszek A. Dobrzanski Pavol Zubko Jaroslaw Konieczny 《Journal of magnetism and magnetic materials》2006
The paper presents mechanical properties of two kinds of Co-based and one Fe-based metallic ribbons by the depth sensing indentation (DSI) technique. Investigations were carried out on two kinds ternary alloy Co77Si11,5B11,5 and Fe78Si13B9 and multicomponent Co68Fe4Mo1Si13,5B13,5, which are so-called “zero-magnetostriction” materials. Metallic ribbons were investigated in amorphous state and partially crystallized state after annealing in 400°C in argon atmosphere. Heating of ribbons obtained by melt spinning technique was performed to check its effect on changes of mechanical properties. 相似文献
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N. M. Agababyan I. V. Ajinenko Yu. A. Belokopytov K. S. Belous H. Boettcher F. Botterweck M. M. Chapkin P. V. Chliapnikov F. Crijns A. De Roeck E. A. De Wolf K. Dziunikowska A. M. F. Endler A. Eskreys Z. C. Garutchava P. van Hal T. Haupt A. I. Katargin W. Kittel S. S. Megrabyan F. Meijers A. B. Micha?owska V. I. Nikolaenko K. Olkiewicz V. M. Ronjin R. Rosmalen H. M. T. Saarikko L. Scholten E. K. Shabalina J. Stepaniak O. G. Tchikilev V. A. Uvarov F. Verbeure R. Wischnewski S. A. Zotkin Y. V. Yarba EHS-NA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1990,46(3):387-395
We report on a study of ρ0, ρ+, ω, \(\bar K^{*0} (892)\) andK *0 (892) inclusive production in π+ p interactions at 250 GeV/c, for ρ+, \(\bar K^{*0} (892)\) for the first time in a π+ p experiment. The data are compared withK + p data in the same experiment, with results of other experiments and with quark-parton models. Interesting differences are found between ρ+,0 and ω production. 相似文献
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Valence bond ground states in isotropic quantum antiferromagnets 总被引:5,自引:0,他引:5
Ian Affleck Tom Kennedy Elliott H. Lieb Hal Tasaki 《Communications in Mathematical Physics》1988,115(3):477-528
Haldane predicted that the isotropic quantum Heisenberg spin chain is in a massive phase if the spin is integral. The first rigorous example of an isotropic model in such a phase is presented. The Hamiltonian has an exactSO(3) symmetry and is translationally invariant, but we prove the model has a unique ground state, a gap in the spectrum of the Hamiltonian immediately above the ground state and exponential decay of the correlation functions in the ground state. Models in two and higher dimension which are expected to have the same properties are also presented. For these models we construct an exact ground state, and for some of them we prove that the two-point function decays exponentially in this ground state. In all these models exact ground states are constructed by using valence bonds.Supported in part by N.S.F. Grant PHY-80-19754. Fellow of the A.P. Sloan Foundation and the Canadian Institute for Advanced ResearchN.S.F. Post-doctoral FellowSupported in part by N.S.F. Grant PHY-85-15288-A01 相似文献
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M. Adamus N. M. Agababyan I. V. Ajinenko Yu. A. Belokopytov H. Bia?kowska H. B?ttcher P. V. Chliapnikov F. Crijns A. De Roeck E. A. De Wolf K. Dziunikowska A. M. F. Endler W. Friebel H. Graessler P. van Hal J. K. Karamyan D. Kisielewska W. Kittel A. I. Kurnosenko B. B. Levchenko F. Meijers M. Merk A. B. Micha?owska V. I. Nikolaenko L. C. S. Oliveira K. Olkiewicz V. M. Ronjin A. M. Rybin H. M. T. Saarikko Y. T. M. Saarikko W. Schmitz L. Scholten N. A. Sotnikova J. Stepaniak O. G. Tchikilev L. A. Tikhonova V. A. Uvarov F. Verbeure R. Wischnewski EHS/NA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1988,37(2):215-229
The charged particle multiplicity distribution has been studied for non-single-diffractive π+ p andpp collisions at \(\sqrt s = 22\) GeV, for full phase space as well as for intervals in rapidity, azimuthal angle and transverse momentum. In general, the multiplicity distribution is well described by a negative binomial. From comparison of the distribution for negative or positive particles to that of all charged particles, cascading is favoured as an interpretation over stimulated emission. Interesting consequences follow from a comparison of our results to those at collider energies and toe + e ? data at comparable energy. Furthermore, evidence is given that the multiplicity distribution is not exactly of negative binomial type in every (connected or disconnected) phase space region. 相似文献
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T. S. Baller G. N. A. van Veen H. A. M. van Hal 《Applied Physics A: Materials Science & Processing》1988,46(3):215-220
Thin layers YBa2Cu3O7–x. are deposited by a laser ablation technique using a pulsed excimer laser operating at 308 nm. The influence of the substrate material and the annealing procedure on the superconducting behaviour of the 123 film and the reactions between the film and the substrate are studied by resistance, X-ray patterns and TEM measurements. The best results are obtained for deposition on (100) SrTiO3 substrates. The resistance of the 1 m thick film shows a metallic behaviour, an onset in superconductivity at a temperature of 90 K, and has zero resistance at 86 K. The 123 material has a preferential oriented c-axis perpendicular to the surface plane. 相似文献
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V. V. Aivazyan I. V. Ajinenko Yu. A. Belokopytov P. C. Bosetti H. B?ttcher F. Botterweck P. V. Chliapnikov F. Crijns A. De Roeck E. A. De Wolf Th. Driever K. Dziunikowska A. Eskreys W. Friebel Z. C. Garutchava V. G. Gavrjusev H. Graessler P. van Hal T. Haupt W. Kittel S. S. Megrabyan F. Meijers A. B. Micha?owska V. I. Nikolaenko L. C. S. Oliveira K. Olkiewicz L. P. Petrovikh E. Riipinen V. M. Ronjin A. M. Rybin H. M. T. Saarikko W. Schmitz L. Scholten R. Schulte O. G. Tchikilev L. A. Tikhonova A. G. Tomaradze V. A. Uvarov F. Verbeure R. Wischnewski A. Wróblewski S. A. Zotkin NA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1989,42(4):533-542
Forward-backward multiplicity correlations in σ+,K + p andpp collisions at 250 GeV/c ( \(\sqrt s \) =22 GeV) are given for all charges and for the different charge combinations. The correlations are found to be caused predominantly by centrally produced particles. It is demonstrated that this result is an agreement with observations at the ISR and the CERNp \(\bar p\) -Collider. The results are compared to expectations from LUND, DPM and FRITIOF Monte Carlo models and a geometrical picture relating correlations in hadron-hadron collisions toe + e ? data in terms of impact parameters is tested. 相似文献
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