atomic number 20


  • WordNet 3.6
    • n atomic number 20 a white metallic element that burns with a brilliant light; the fifth most abundant element in the earth's crust; an important component of most plants and animals
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In science:

These are: a) A one amu (atomic mass unit) mass separation for light nuclei over a broad momentum range extending from about 1 GeV/c per nucleon, up to around 13 GeV/c per nucleon at best, for mass numbers A≈20.
Experimental study of a proximity focusing Cherenkov counter prototype for the AMS experiment
Because of the small numbers of Ca atoms in mainstream grains, however, individual grain ratios were uncertain by at least 20%.
Are Ti44-Producing Supernovae Exceptional?
The semiclassical theory of laser describes the regime where, due to a large number of photons in the laser cavity, one may treat the electrical field classically, but the two level atoms are treated quantum mechanically [20, 9].
Fluctuations relations for semiclassical single-mode laser
Results and Discussion. In following 16 illustrations (Tables) are given the results of calculations of atom number within amino acid side chains; the calculations, related to the amino acid system built either from only 16 noncontact or from all 20 AAs (16 non-contact plus 4 contact AAs).
Genetic Code as a Harmonic System: two Supplements
We could better understand the sizes of the condensates we produce (recall how in section 5.4 the 20% error on χm translates into nearly a factor of two uncertainty in the number of condensate atoms lost during the lifetime of the condensate).
Bose-Einstein Condensation of Atomic Hydrogen
Here, Nat ≈ 20 is the effective number of C atoms in the local region, ν0 = 10 ps−1 is the vibrational frequency, used also in Ep , and E ∗ ± (i) are activation barriers of the i + 1-th and i − 1-th defects for structures with i defects.
Nanoscale Processing by Adaptive Laser Pulses
From the large number of atoms in a macromolecule the use of the computational approach is restricted by the fragments of DNA helix not longer than 20 base pairs [27,28].
Modeling DNA Conformational Transformations on the Mesoscopic Scales
These parameters can then be used in the calculation of nuclear properties up to atomic numbers A ∼ 20 − 30.
Nuclei from QCD : Strategy, Challenges and Status
Nan -Nan ) with even number of atoms n ranging from 2 to 20.
Time-dependent density functional theory calculation of van der Waals coefficient of sodium clusters
For this atom, the RECPs were generated by other groups [6,7] where the same number of electrons (20) was explicitly included into calculations as in the case of the GRECP .
All-electron Dirac-Coulomb and RECP calculations of excitation energies for mercury atom with combined CI/MBPT2 method