37 research outputs found
On well-posedness, stability, and bifurcation for the axisymmetric surface diffusion flow
In this article, we study the axisymmetric surface diffusion flow (ASD), a
fourth-order geometric evolution law. In particular, we prove that ASD
generates a real analytic semiflow in the space of (2 + \alpha)-little-H\"older
regular surfaces of revolution embedded in R^3 and satisfying periodic boundary
conditions. We also give conditions for global existence of solutions and prove
that solutions are real analytic in time and space. Further, we investigate the
geometric properties of solutions to ASD. Utilizing a connection to
axisymmetric surfaces with constant mean curvature, we characterize the
equilibria of ASD. Then, focusing on the family of cylinders, we establish
results regarding stability, instability and bifurcation behavior, with the
radius acting as a bifurcation parameter for the problem.Comment: 37 pages, 6 figures, To Appear in SIAM J. Math. Ana
THE ELECTRONIC SPECTRUM OF TANTALUM METHYLIDYNE, TaCH
Present address: School of Chemistry, University of Sydney, Building P11, Sydney, N. S. W. 2006. Australia.Author Institution: Department of Chemistry, University of British ColumbiaTantalum methylidyne, TaCH, has been produced in a supersonic free jet expansion in helium by the reaction between laser ablated tantalum and methan e. TaCD has been made similarly using . Pulsed dye laser excitation spectra from the ) state of TaCH have been assigned to two electronic transitions whose upper states have which proably is , and . The (0,0) bands of these states lie at 15638.6 cm and 16398.3 cm , respectively. Wavelength resolved fluorescence emission from the excited state has revealed a low lying electronic state above the ground state; this appears to be a state. Two of the state vibrational fundamentals have been determined for TaCH(TaCD): cm and cm . The values determined for the state were cm and cm . High resolution spectra are being recorded for selected bands; these will allow the molecular structure and the spectroscopic parameters to be detedmined accurately. The magnetic and quadrupolar hyperfine structure of Ta is fully resolved in the high resolution study
A variational problem for constant mean curvature surfaces with free boundary
SIGLETIB: RN 4020 (768) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman
Focus on London
Includes bibliographical referencesAvailable from British Library Document Supply Centre- DSC:3964. 2177(2003) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo