منابع مشابه
Sextic Double Solids
We study properties of double covers of P ramified along nodal sextic surfaces such as non-rationality, Q-factoriality, potential density, and elliptic fibration structures. We also consider some relevant problems over fields of positive characteristic. 2000 Mathematics Subject Classification. Primary 14E05, 14E08, 14G05, 14G15, 14J17, 14J45. All varieties are assumed to be projective, normal, ...
متن کاملDouble-quantum cross-polarization NMR in solids
Double-quantum NMR is a useful way to obtain spectra of quadrupolar nuclei ('D, "N, ...) in solids. This allows measurements of the chemical shifts for these nuclear spins. The theory of Hartmann-Hahn cross polarization between I = 1/2 and such S = 1 spins is discussed. Particular attention is drawn to the cross polarization of the double-quantum transition. The thermodynamics and the dynamics ...
متن کاملNMR double-quantum spin decoupling in solids
A. Pines, S. Vega, * and M. Mehring~ Department of Chemistry, University of California, Berkeley, California 94720' (Received 8 December 1977) The problem of spin-decoupling spin I = 1 nuclear with large quadrupolar splittings co& (e.g. deuterium) from dilute 5 spins via double-quantum transitions is dealt with. The normal two-spin-1/2 single-quantum decoupling problem (I = 1/2, S = 1/2) is fir...
متن کاملHeteronuclear double-quantum MAS NMR spectroscopy in dipolar solids.
A new pulse sequence for high-resolution solid-state heteronuclear double-quantum MAS NMR spectroscopy of dipolar-coupled spin-12 nuclei is introduced. It is based on the five-pulse sequence known from solution-state NMR, which is here applied synchronously to both spin species. The heteronuclear double-quantum (HeDQ) spinning-sideband patterns produced by this experiment are shown to be sensit...
متن کاملDrops on soft solids: free energy and double transition of contact angles
1Physics of Fluids Group, Faculty of Science and Technology, Mesa+ Institute, University of Twente, 7500 AE Enschede, The Netherlands 2School of Engineering and Materials Science, Queen Mary University of London, London E1 4NS, UK 3Department of Mechanical Engineering, University of Maryland, College Park, MD 20742, USA 4Physique et Mécanique des Milieux Hétérogènes, UMR 7636 ESPCI-CNRS, Univ. ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Advances in Mathematics
سال: 1983
ISSN: 0001-8708
DOI: 10.1016/0001-8708(83)90025-7