tetrad

Definitions

  • WordNet 3.6
    • n tetrad the cardinal number that is the sum of three and one
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Webster's Revised Unabridged Dictionary
    • Tetrad (Chem) A tetravalent or quadrivalent atom or radical; as, carbon is a tetrad .
    • Tetrad The number four; a collection of four things; a quaternion.
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Century Dictionary and Cyclopedia
    • n tetrad In cytology, a group of four chromosomes formed by the division of a single chromosome; a quadripartite chromosome.
    • n tetrad The number four; also, a collection of four things. Also quadrad.
    • n tetrad In chem., an atom the equivalence of which is four, or an element one atom of which is equivalent, in saturating power, to four atoms of hydrogen.
    • n tetrad In morphology, a quaternary unit of organization resulting from individuation or integration of an aggregate of triads. See triad, dyad.
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Chambers's Twentieth Century Dictionary
    • n Tetrad tet′rad a group of four:
    • n Tetrad tet′rad (chem.) an atom, radical, or element having a combining power of four
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Etymology

Webster's Revised Unabridged Dictionary
L. tetras, -adis, Gr. , : cf. F. tétrade,

Usage

In literature:

How we went down the tetradic steps, and of Panurge's fear.
"Gargantua and Pantagruel, Complete." by Francois Rabelais
How we went down the tetradic steps, and of Panurge's fear.
"Gargantua and Pantagruel, Book V." by Francois Rabelais
Four, or the tetrad, is the most perfect of numbers and the root of all things.
"Three Thousand Years of Mental Healing" by George Barton Cutten
The tetrad for the perfect figure, the cube, length, depth, and width.
"Notes and Queries, Number 77, April 19, 1851" by Various
In figure 130 one lagging chromosome shows the dyad nature of the products of the division of the tetrad.
"Studies in Spermatogenesis (Part 1 of 2)" by Nettie Maria Stevens
During the tetrad division in the basidium nuclear reduction occurs.
"Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 3" by Various
Such an axis of symmetry is known as a tetrad axis of symmetry.
"Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7" by Various
The widespread, if not universal, formation of tetrads, i.e.
"Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 8" by Various
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In science:

As a consequence, on curved space-time spinors can be described only with respect to some orthonormal tetrad field.
Quantum Theory within the Framework of General Relativity
The time-like element of the tetrad coincides with the unit tangent vector to the world line.
Quantum Theory within the Framework of General Relativity
The tetrad field along L is obtained by Fermi -Walker transport rather than parallel transport.
Quantum Theory within the Framework of General Relativity
Here we use the tetrad gauge7 that is algebraic and, at the same time, is formulated in an invariant way.
General exact solution of the Einstein-Dirac equations with the cosmological constant in homogeneous space
With the tetrad gauge being used here, all equations are formulated as the first-order equations only for two invariants of the spinor field and Ricci rotation coefficients of the proper bases defined by the spinor field.
General exact solution of the Einstein-Dirac equations with the cosmological constant in homogeneous space
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