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91.
Karim Boulabiar Gerard Buskes Melvin Henriksen 《Journal of Mathematical Analysis and Applications》2003,280(2):334-349
In J. Math. Anal. Appl. 12 (1995) 258–265, Araujo et al. proved that for any linear biseparating map from C(X) onto C(Y), where X and Y are completely regular, there exist ω in C(Y) and an homeomorphism h from the realcompactification vX of X onto vY, such that The compact version of this result was proved before by Jarosz in Bull. Canad. Math. Soc. 33 (1990) 139–144. In Contemp. Math., Vol. 253, 2000, pp. 125–144, Henriksen and Smith asked to what extent the result above can be generalized to a larger class of algebras. In the present paper, we give an answer to that question as follows. Let A and B be uniformly closed Φ-algebras. We first prove that every order bounded linear biseparating map from A onto B is automatically a weighted isomorphism, that is, there exist ω in B and a lattice and algebra isomorphism ψ between A and B such that We then assume that every universally σ-complete projection band in A is essentially one-dimensional. Under this extra condition and according to a result from Mem. Amer. Math. Soc. 143 (2000) 679 by Abramovich and Kitover, any linear biseparating map from A onto B is automatically order bounded and, by the above, a weighted isomorphism. It turns out that, indeed, the latter result is a generalization of the aforementioned theorem by Araujo et al. since we also prove that every universally σ-complete projection band in the uniformly closed Φ-algebra C(X) is essentially one-dimensional. 相似文献
(a)=ωψ(a) for all aA.
92.
Rotationally resolved photoelectron angular distributions from vibrational autoionization of the NO 14s ( nu = 1, N = 20, N(+)(R) = 20) level are measured by photoelectron spectroscopy, and they are analyzed using a theoretical model based on first-order coupling between the Rydberg level and the ionization continuum. The analysis reveals that lambda-changing collisions and l-changing collisions between the molecular-ion core and the outgoing electron are comparable in magnitude and account for 40% of the partial waves produced in the ionization continuum. 相似文献
93.
94.
Parvin Zare Maria Mahrova Emilia Tojo Anja Stojanovic Wolfgang H. Binder 《Journal of polymer science. Part A, Polymer chemistry》2013,51(1):190-202
A facile synthetic route for the preparation of dicationic ethylene glycol based‐ionic liquids (ILs) via the azide/alkyne “click” reaction is presented. The copper(I) catalyzed, microwave‐assisted azide/alkyne “click” reaction between diazido‐ethylene glycols and the corresponding alkyne containing IL‐head group enables a simple preparation of different sets of poly(ethylene glycol)‐based ILs. Beside tetra‐ and hexa(ethylene glycol)‐based ILs, also oligomeric (Mn = 400 g/mol) and polymeric ILs (Mn up to 1550 g/mol) could be prepared in good yield and with full conversion of the ionic head group. The prepared ILs were extensively characterized via NMR spectroscopy and ESI‐time‐of‐flight (TOF) mass spectroscopy, revealing the formation of multiply charged ions in the negative mode. Thermal stability proved to be exceptionally high (up to 300 °C) together with low glass‐transition temperatures. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
95.
This study is directed towards investigating the role of the surface treatment of clay particles on the rheological and thermomechanical
behaviour of clay-epoxy blends. Nanocomposites were prepared by mixing small amounts (5–10 mass %) of commercial organoclays
or raw clays with an epoxy system commonly used in civil engineering. Rheological characterisations in the liquid state revealed
a pronounced thixotropic character of the organoclay-based systems, which all exhibited a shear-thinning behaviour above a
critical stress threshold (yield stress), depending on both the intensity of interfacial interactions and the degree of filler
dispersion. On the other hand, systems based on raw clay particles behaved like Newtonian fluids, in the same way as the unreinforced
polymer matrix. Complementary dynamic mechanical analyses (DMA) performed on the cured cross-linked nanocomposites also showed
significant changes in the viscoelastic behaviour of the epoxy matrix due to the introduction of organoclays, whereas only
minor variations were observed following the introduction of raw fillers. These results were consistent with nanoscale morphological
characterisations performed by conventional X-ray diffraction (XRD) on the various hybrid systems. In this context, rheology
and DMA appear as attractive alternative methods for assessing the filler dispersion at a macroscopic (and possibly more relevant)
scale. This research is of practical interest for civil engineers, since clay reinforced-epoxies could in the future be used
as coating materials with enhanced barrier performances, in order to protect infrastructures against environmental ageing
or corrosion. 相似文献
96.
97.
98.
<正>The first three-component and regioselective synthesis of pyridazinones and phthalazinones from arenes,anhydrides and ArNHNH_2 in the presence of efficient recyclable heterogeneous catalyst,montmorillonite-KSF,in high yield and short reaction time is reported. 相似文献
99.
100.
We determine the behavior of track etch rate VT along the tracks in CR-39 detectors exposed to fission fragments from ^252Cf source. CR-39 detectors are etched at 70℃ in different concentrations of Na2COa-mixed 6M NaOH solutions for different etching time intervals of 5-10min starting from 15 min up to 210min. Two values of track etch rate are determined along the fission fragment trajectories. The variation in VT is correlated with the energy loss rate of the fission fragment in the detector material. 相似文献