http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Topological contact dynamics I: symplectization and applications of the energy-capacity inequality
Mü,ller, Stefan,Spaeth, Peter Walter de Gruyter GmbH 2015 Advances in geometry Vol.15 No.3
<B>Abstract</B><P>We introduce topological contact dynamics of a smooth manifold carrying a cooriented contact structure, generalizing previous work in the case of a symplectic structure [27] or a contact form [5]. A topological contact isotopy is not generated by a vector field; nevertheless, the group identities, the transformation law, and classical uniqueness results in the smooth case extend to topological contact isotopies and homeomorphisms, giving rise to an extension of smooth contact dynamics to topological dynamics. Our approach is via symplectization of a contact manifold, and our main tools are an energy-capacity inequality we prove for contact diffeomorphisms, combined with techniques from measure theory on oriented manifolds. We establish non-degeneracy of a Hofer-like bi-invariant pseudo-metric on the group of strictly contact diffeomorphisms constructed in [4]. The topological automorphism group of the contact structure exhibits rigidity properties analogous to those of symplectic diffeomorphisms, including C</P>
New materials for glass-ceramic X-ray storage phosphors
A. Edgar,M. Secu,S. Schweizer,J. -M. Spaeth,G. V. M. Williams,J. Hamlin 한국물리학회 2004 Current Applied Physics Vol.4 No.2-4
The development of transparent glass ceramics as X-ray storage phosphors and their advantages over their crystalline coun-terparts are briey reviewed. Measurements of conversion eciency, stimulation eciency, storage times, and optical transparencyare reported for the particular case of europium-doped uorobromozirconate glass, in which rubidium and lithium replace the usualsodium component fraction. Annealing at 280.C converts the as-prepared glass into a glassceramic which contains Rb2BaBr4 andRbBa2Br5 nano- and micro-crystallites. Only the RbBa2Br5 structure shows signicant photo-stimulated luminescence after X-irradiation, and the maximum storage phosphor eciency is 8% of that for the standard commercial storage phosphor BaFBr:Eu.
Spatial resolution of a glass-ceramic X-ray storage phosphor
A. Edgar,G.V.M. Williams,S. Schweizer,J.-M. Spaeth 한국물리학회 2006 Current Applied Physics Vol.6 No.3
The spatial resolution of a glass-ceramic X-ray storage phosphor imaging plate has been measured using a scanned and focussed laserbeam. The glass ceramic comprises orthorhombic phase barium chloride crystals containing europium ions embedded in a uorozirco-nate glass matrix. The modulation transfer function extends to signicantly higher frequencies than for a commercial imaging plate basedmercial plate. The modulation transfer function has a bimodal character which we ascribe to component responses from the focussedlaser beam volume and from the surrounding scattering halo. A limitation on performance of this particular glass ceramic is the occur-rence of bubbles and other defects which scatter the read-out light beam and reduce the uniformity of the response.