Results 191 to 200 of about 10,072,628 (333)

Ruled Surfaces as Pseudospherical Congruences

open access: yes, 2009
Two-dimensional ruled surfaces in the spaces of constant curvature Rⁿ, Sⁿ, Hn and in the Riemannian products Sⁿ x R¹, Hⁿ x R¹ are considered. A ruled surface is proved to represent a pseudospherical congruence if and only if it is either an intrinsically
Nevmerzhitska, O.M., Gorkavyy, V.O.
core  

Mixed‐Metal Promotion in a Manganese‐Molybdenum Oxynitride as Catalyst to Integrate C─C and C─N Coupling Reactions for the Direct Synthesis of Acetonitrile from Syngas and Ammonia

open access: yesAdvanced Materials, EarlyView.
Transition metal oxy/carbo‐nitrides show great promise as catalysts for sustainable processes. A Mn‐Mo mixed‐metal oxynitride attains remarkable performance for the direct synthesis of acetonitrile, an important commodity chemical, via sequential C─N and C─C coupling from syngas (C1) and ammonia (N1) feedstocks.
M. Elena Martínez‐Monje   +7 more
wiley   +1 more source

Counterintuitive Fluorescence Blue Shift in Symmetry Breaking Dicationic Bis(indolium) with Two‐Photon Absorption Properties for NIR Living Cell Imaging

open access: yesAdvanced Materials, EarlyView.
Highly water‐soluble dicationic bis(indolium) dyes have been prepared, showing excellent two‐photon absorption and light emission. Their fluorescence behavior discloses an unusual increasing blue shift with increasing solvent polarity, which, in parallel, is beneficial for enhanced detection in biological media.
Carlos Benitez‐Martin   +5 more
wiley   +1 more source

Microscopic Insights into Magnetic Warping and Time‐Reversal Symmetry Breaking in Topological Surface States of Rare‐Earth‐Doped Bi2Te3

open access: yesAdvanced Materials, EarlyView.
Magnetic doping of the topological insulator Bi2Te3 with erbium adatoms induces out‐of‐plane magnetism and breaks time‐reversal symmetry, opening a Dirac gap and driving a Fermi surface transition from hexagonal to star‐of‐David geometry. Microscopy, spectroscopy, and magnetic dichroism reveal atomically controlled magnetic interactions that tailor the
Beatriz Muñiz Cano   +18 more
wiley   +1 more source

Solvent‐Free Thermal Defect Engineering in Molecular Frameworks With Volatile Linkers

open access: yesAdvanced Materials, EarlyView.
Thermal removal of neutral volatile linkers enables precise and solvent‐free generation of metal vacancies in MOFs. This strategy affords redox‐stable, coordinatively unsaturated FeII sites with tunable spin, ligand coordination, and catalytic behavior. The approach offers a general route to design defect‐functional materials through local coordination
Sonia Martínez‐Giménez   +9 more
wiley   +1 more source

Peripheral longitudinal consolidations. [PDF]

open access: yesJ Bras Pneumol
Marchiori E, Hochhegger B, Zanetti G.
europepmc   +1 more source

Note on the structure of a ruled surface.

open access: yesJournal für die reine und angewandte Mathematik (Crelles Journal), 1969
Maruyama, M., Nagata, M.
openaire   +2 more sources

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