Results 141 to 150 of about 223,941 (197)
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A NEMO potential that includes the dipole–quadrupole and quadrupole–quadrupole polarizability
Journal of Computational Chemistry, 2010AbstractTo increase the accuracy of molecular force fields a systematical and balanced improvement of the various terms included is needed. In this work, we have followed this strategy to improve the quality of the NEMO potential for the formaldehyde dimer by introducing local quadrupole moments and higher‐order polarizabilities.
Asbjørn, Holt +3 more
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Potential of Nuclear Quadrupole Resonance in Pharmaceutical Analysis
Analytical Chemistry, 2005Nuclear quadrupole resonance is a radio frequency (rf) spectroscopic technique, closely related to NMR, which can be used to detect signals from solids containing nuclei with spin quantum number >1/2. It is nondestructive, highly specific and noninvasive, requires no static magnetic field, and as such is currently used in the detection of explosives ...
Balchin, E +6 more
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Dipole-Quadrupole Interaction in Spherical Nuclei and Berry Potentials
Physical Review Letters, 1988We show that SO(3) gauge potentials arise in the Born-Oppenheimer description of the interaction between the dipole and quadrupole vibrations in even-even spherical nuclei and derive the effective Hamiltonian for the quadrupole motion.
, LeTourneux, , Vinet
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Collective potentials and dipole and quadrupole giant resonances
Nuclear Physics A, 1978Abstract The dynamic collective model is extended into the energy region immediately above the giant dipole resonances, i.e. into an energy region between 20 and 28 MeV. The total Hamiltonian is constructed and the dynamical problem is solved by diagonalizing the Hamiltonian in the basis of a five-dimensional harmonic oscillator.
Rolf Sedlmayr +2 more
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Potential distribution and focal properties of electrostatic quadrupole lenses
Journal of Physics E: Scientific Instruments, 1978The potential distribution of a quadrupole lens with circular electrodes is calculated by successive over-relaxation techniques involving the numerical solution of Laplace's equation in three dimensions. The results show that the modified bell-shaped model (parameters: 2z0=l-1.1a; b=1.44a) is a very close approximation to the potential function for the
S Okayama, H Kawakatsu
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Nonlocal potentials and the quadrupole moment of the deuteron
Journal of Physics G: Nuclear Physics, 1976It is demonstrated that for nonlocal potentials the quadrupole moment of the deuteron is not determined by the parameters which describe the scattering in the 3S1-3D1 state.
M W Kermode, J R Mines, M M Mustafa
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Quadrupole Oscillator Strengths of Helium Interacting with Debye Potentials
Few-Body Systems, 2012The influence of Debye potentials on the quadrupole oscillator strengths of helium atom is investigated using highly correlated wave functions within a framework of a variational method. The quadrupole oscillator strengths for the 1,3S–1,3D, 1,3P–1,3P and 1,3D–1,3D transitions of He for various screening parameters are reported for the first time in ...
Pinghui Jiang, Sabyasachi Kar
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Electrostatic quadrupole lens simulation in potential array relaxation programs
Rapid Communications in Mass Spectrometry, 1989Abstract Lens and ion trajectory simulation programs, such as the popular program SIMION, which employ potential array relaxation methods, are very useful in designing and modifying ion lens systems. Unfortunately, these programs cannot simulate lenses of certain geometries such as quadrupoles. Several approaches for portraying static
Palitha Jayaweera +2 more
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Time-orbiting-potential quadrupole magnetic trap for cold atoms
Physical Review A, 1998An analytical theory of the time-orbiting-potential quadrupole magnetic trap for cold atoms is developed. It is shown that the rotating magnetic field used to create the time-averaged harmonic potential is responsible for the formation of quasienergy states of an atom in the trap.
Vladimir G. Minogin +2 more
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Quadrupoles in potential flow: two model problems
Journal of Fluid Mechanics, 1982The Ffowcs Williams-Hawkings formulation of the sources of the acoustic analogy is examined by reference to two compressible inviscid flows whose density and velocity fields are known exactly. The purpose of this exercise is to generate some feel for the importance of the various source terms in determining the sound of moving surfaces with shocks, and
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