Results 341 to 350 of about 12,413,187 (395)

Double Aromaticity and Ring Currents in All‐Carbon Rings

Chemistry – A European Journal, 2009
AbstractDouble aromaticity of neutral, planar rings of carbon atoms is demonstrated through visualisation of the induced ring currents, mapped at the ipsocentric B3LYP/6‐31G(d)//B3LYP/6‐31G(d) level for species C6 to C30, with onset of delocalised current in the in‐plane π system at C10/C11.
Patrick W, Fowler, Noriyuki, Mizoguchi, David E, Bean, Remco W A, Havenith   +3 more
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Ring Current Dynamics

Space Science Reviews, 2006
This chapter reviews the current understanding of ring current dynamics. The terrestrial ring current is an electric current flowing toroidally around the Earth, centered at the equatorial plane and at altitudes of ∼10,000 to 60,000 km. Enhancements in this current are responsible for global decreases in the Earth’s surface magnetic field, which have ...
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“Ring currents” static hypersusceptibilities

International Journal of Quantum Chemistry, 1980
AbstractThe Hückel–London theory has been applied to the calculation of the “ring currents” octopole hypersusceptibilities of a series of conjugated compounds. Our calculations have been performed using fourth‐order Rayleigh–Schrödinger perturbation technique. This is believed to be the first calculation of this kind.
J. Gayoso, B. Maouche, O. Ouamerali, A. Baba‐Ahmed   +3 more
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Topological definition of ring currents

Physical Chemistry Chemical Physics, 2016
A definition of ring currents in a velocity vector field is proposed according to topological criteria: ring currents are axial vortices confined in, or rotating beyond, a separatrix, i.e., the boundary which marks the limits of the vortex.
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Current status of contraceptive vaginal rings

Contraception, 2013
Contraceptive vaginal rings (CVR) offer a new, effective contraceptive option, expanding the available choices of hormonal contraception. Various ring prototypes have been evaluated: progestin-only rings and combined progestin-estrogen rings, as well as different combination of progestins and estrogens.
Vivian, Brache, Luis José, Payán, Aníbal, Faundes   +2 more
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Current inducting techniques for superconducting rings

Journal of Superconductivity, 2005
A procedure has been developed to generate a persistent current in superconducting rings. The basis of the method is a magnetic circuit made of a permanent neodymium-iron-boron magnet and an iron core; the current induced in the superconductor comes only from the energy of the permanent magnet avoiding the power supply.
H. González-Jorge, E. Carballo, J. Peleteiro, G. Domarco   +3 more
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Mesoscopic persistent current in small rings

Physical Review B, 1993
Small normal-metal rings threaded by a constant magnetic flux have been shown to carry a mesoscopic persistent current at low temperatures. The current is a few-electron effect and its sign and amplitude depend on the microscopic configuration of disorder. Assuming a Gaussian current distribution, we characterize the effect by three quantities, the rms
, Riedel, , von Oppen F
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Photoinduced Charge Currents in Mesoscopic Rings

Physical Review Letters, 2005
The temporal and spatial controllability of charge distribution in submicron structures opens new avenues for potential applications and for the understanding of nonequilibrium processes. Here we suggest a novel way to trigger and control within picoseconds charge currents and magnetic moments in nanoscopic and mesoscopic ring structures by applying ...
A, Matos-Abiague, J, Berakdar
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Linearized ring current models for the retrieval of π ring current strength in monocycles

Chemical Physics Letters, 2013
Abstract Three different ring current models (RCMs) have been used to study the relationship between the π contribution to parallel NICS scans and the ring current strength for monocycles. The models have been linearized and they have been applied to retrieve the ab initio ring current strengths in a set of 28 organic and inorganic monocycles ...
MONACO, Guglielmo, ZANASI, Riccardo
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Ring Currents in Large [4n + 2]‐Annulenes

ChemInform, 2004
AbstractFor Abstract see ChemInform Abstract in Full Text.
Soncini A., Fowler P. W., Jenneskens L. W.   +2 more
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