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81.
Patrizia Longobardi Mercede Maj Akbar Rhemtulla 《Proceedings of the American Mathematical Society》2000,128(3):637-641
If a group has an ascending series of subgroups such that for each ordinal , and has no non-abelian free subsemigroup, then is right orderable if and only if it is locally indicable. In particular if is a radical-by-periodic group, then it is right orderable if and only if it is locally indicable.
82.
Let be a vector lattice of real functions on a set with , and let be a linear positive functional on . Conditions are given which imply the representation , , for some bounded charge . As an application, for any bounded charge on a field , the dual of is shown to be isometrically isomorphic to a suitable space of bounded charges on . In addition, it is proved that, under one more assumption on , is the integral with respect to a -additive bounded charge.
83.
M.A. Schneider P. Wahl L. Vitali L. Diekhöner R. Vogelgesang K. Kern 《Applied Physics A: Materials Science & Processing》2007,88(3):443-447
We use scanning tunneling microscopy and spectroscopy to study the energy dependence of hot-electron scattering processes
on metal surfaces via the determination of the energy-dependent phase-coherence length. From this an electron lifetime can
be determined, which in the case of electrons in the surface state of Ag(111) and in the case of the n=1 image-potential state
on Cu(100) shows good agreement with theoretical modeling and other experimental data. The method is based on the quantitative
analysis of electron interference patterns. A theoretical analysis shows that the phase-coherence length can be determined
in confining nanostructures of a characteristic length scale smaller than the phase-coherence length.
PACS 73.20.At; 73.50.Gr; 72.10.Fk; 68.37.Ef 相似文献
84.
Sulphur-headgroup organic molecules have been chemisorbed on Cu(1 0 0) as self-assembled monolayers (SAMs) in highly-ordered two-fold symmetry structures, and the electronic states induced at the interface have been measured by photoemission: a close similarity of the main interface states for methane-thiolate and mercaptobenzoxazole on Cu(1 0 0) in the same p(2 × 2)-phase is observed. The bonding states for methane-thiolate/Cu(1 0 0) in the p(2 × 2) and c(2 × 2) structures have been compared to ab-initio calculation of the total density of states (DOS) for the S/Cu(1 0 0) system in the same phases. The major role of the S-Cu bonding to determine the density of state evolution at the interface is brought to light. The observed differences in the two phases depend mainly on the charge distribution associated to the different molecular packing, with a minor role of the radical group. 相似文献
85.
Paolo Matteini Giovanni Agati Patrizia Pinelli Andrea Goti 《Monatshefte für Chemie / Chemical Monthly》2011,45(2):885-893
Abstract
The interaction of the model flavonoid glycoside rutin with the flavonoid reagent diphenylborinic acid 2-aminoethyl ester (DPBA) was investigated using a combination of HPLC–DAD–ESI–MS analysis, UV–visible spectroscopy, and semiempirical calculations. Mass spectra and spectroscopic data made it possible to describe the complexation pathway as addition of diphenylboron groups to the two available 3′,4′-o-diphenolic and the 5-hydroxy-4-keto coordinating sites of rutin. Semiempirical calculations were carried out to obtain the conformation of the most stable DPBA/rutin adducts. The results showed that a number of complexation dynamics can occur as a function of the characteristics of the medium (type and pH of the solvent) and of the amount of DPBA. This work suggests the possibility of substantially improving existing procedures for recognition of flavonoid compounds by choice of suitable experimental conditions. 相似文献86.
Patrizia Trovalusci Danilo Capecchi Giuseppe Ruta 《Archive of Applied Mechanics (Ingenieur Archiv)》2009,79(11):981-997
This paper presents an overview of the origin of multiscale approaches in mechanics. While the pioneer molecular models of
linear elastic bodies by Navier, Cauchy and Poisson were contradicted by experiments, the phenomenological energetic approach
by Green still seems suitable for simple materials only. Voigt’s molecular model, here reinterpreted in the light of contemporary
mechanics, reconciled the two approaches providing a conceptual guideline for developing constitutive models based on a direct
link between continuum and discrete solid mechanics. Such a theoretical background proves to be especially suitable for new
complex materials. An example referred to masonry-like materials is given. 相似文献
87.
Crystallization and vapor condensation are considered as the processes of sequential penetration of single atoms/molecules into condensate. In the course of these transitions the transitive radiation must be generated, which would carry away the liberated latent heat by photons of characteristic frequencies. The transient radiation is examined by the general Ginzburg-Frank theory. The emission of defined frequencies determined by the values of liberated latent heat is confirmed by analyses of several experiments of authors and other researchers. 相似文献
88.
Annali di Matematica Pura ed Applicata (1923 -) - Si fa l'analisi delle proiettività nello spazio hilbertiano riducendole a soli tre tipi aventi espressione analitica molto semplice. 相似文献
89.
90.
D. Vitali 《Fresenius' Journal of Analytical Chemistry》1897,36(1):307-308
Ohne Zusammenfassung 相似文献