* An atomic object in parsing:

# An atomic parsing expression consists of:

An atomic parsing expression consisting of the empty string always trivially succeeds without consuming any input.

An atomic parsing expression consisting of a nonterminal A represents a recursive call to the nonterminal-function A.

" OQL is a functional ( expression-oriented ) language, in which each query is a typed expression ( type can be atomic object, collection object, or literal )".

According to this expression, an atomic system at absolute zero retains an energy of ½hν.

If S is a variable of this sort and t is a first-order term then the expression t ∈ S ( also written S ( t ) or St ) is an atomic formula.

If R is such a k-ary relation variable and t < sub > 1 </ sub >,..., t < sub > k </ sub > are first-order terms then the expression R ( t < sub > 1 </ sub >,..., t < sub > k </ sub >) is an atomic formula.

The phosphoprotein P is a cofactor for L. The atomic structure is now available for two of them, N and M. The genome is transcribed sequentially from NS1 to L with reduction in expression levels along its length

; atom: given an expression returns True if its value is atomic ; False if not.

From Fleming's stunned expression, it is clear Graham reports their unexpected odyssey, its three crew fatalities, their discovery on Mars of a once advanced human civilization destroyed long ago by atomic war, and its descendants reverted to barbarism.

From this point atomic units can be used to simplify the expression into

That my silence and gravity, as you write in the letter, could be taken as an expression of shock at your reports that it was possible to make an atomic bomb is a quite peculiar misunderstanding, which must be due to the great tension in your own mind.

In atomic physics, it is a multiplicative term appearing in the expression for the energy levels of an atom in a weak magnetic field.

Hence it is the atomic number alone that determines the chemical properties of an element ; and it is for this reason that an element can be defined as consisting of any mixture of atoms with a given atomic number.

However, physicists distinguish between atomic physics — which deals with the atom as a system consisting of a nucleus and electrons — and nuclear physics, which considers atomic nuclei alone.

A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus.

The law of definite proportions contributed to, and was placed on a firm theoretical basis by, the atomic theory that John Dalton promoted beginning in 1803, which explained matter as consisting of discrete atoms, that there was one type of atom for each element, and that the compounds were made of combinations of different types of atoms in fixed proportions.

When investigating the stability of crystal oscillators and atomic clocks it was found that they did not have a phase noise consisting only of white noise, but also of white frequency noise and flicker frequency noise.

However, physicists distinguish between atomic physics — which deals with the atom as a system consisting of a nucleus and electrons — and nuclear physics, which considers atomic nuclei alone.

He developed a method using a rapid laser technique ( consisting of ultrashort laser flashes ), which allows the description of reactions at the atomic level.

The atomic structure of carbon fiber is similar to that of graphite, consisting of sheets of carbon atoms ( graphene sheets ) arranged in a regular hexagonal pattern.

In organic chemistry, aromatic compounds contain atomic rings, such as benzene rings ( the Kekulé structure ) consisting of five or six, usually carbon, atoms.

In August, 1947, the Denver Post ran a copyrighted story that claimed the military was building a secret base consisting of huge caverns for atomic weapons defense purposes.

An atomic formula is an wff consisting of either a sentential letter or an n-place predicate letter followed by n terms.

Dreyfus doesn't deny that we can choose to see human ( or any ) activity as being ' law governed ', in the same way that we can choose to see reality as consisting of indivisible atomic facts ... if we wish.

Io has an extremely thin atmosphere consisting mainly of sulfur dioxide (), with minor constituents including sulfur monoxide (), sodium chloride (), and atomic sulfur and oxygen.

The term can also refer to the organization of protons and neutrons within an atomic nucleus, e. g. the Alpha particle ( a. k. a. as " α-cluster "), consisting of two protons and two neutrons ( as in a helium nucleus ).

Early atomic time scales consisted of quartz clocks with frequencies calibrated by a single atomic clock ; the atomic clocks were not operated continuously.

This central charge would thus be approximately half the atomic weight ( though it was almost 25 % off the figure for the atomic number in gold ( Z = 79, A = 197 ), the single element from which Rutherford made his guess ).

Over 99. 94 % of an atom's mass is concentrated in the nucleus ,< ref group = note > In the case of hydrogen-1, with a single electron and nucleon, the proton is, or 99. 95 % of the total atomic mass.

The simplest atomic orbitals are those that are calculated for systems with a single electron, such as the hydrogen atom.

Like single covalent bonds, double bonds can be described in terms of overlapping atomic orbitals, except that, unlike a single bond ( which consists of a single sigma bond ), a carbon-carbon double bond consists of one sigma bond and one pi bond.

Whereas the mass number simply counts the total number of neutrons and protons and is thus a natural ( or whole ) number, the atomic mass of a single isotope is a real number.

This molecular orbital theory represented a covalent bond as an orbital formed by combining the quantum mechanical Schrödinger atomic orbitals which had been hypothesized for electrons in single atoms.

In this case typically middleware for distribution is used which typically includes an atomic commit protocol ( ACP ), e. g., the two-phase commit protocol, to allow distributed ( global ) transactions ( vs. local transactions confined to a single DBMS ) across the participating databases.

* The atomic mass unit ( u ) is defined so that a single carbon-12 atom has a mass of 12 u ; 1 u is approximately .< ref group =" note "> Since the Avogadro constant N < sub > A </ sub > is defined as the number of atoms in 12 g of carbon-12, it follows that 1 u is exactly 1 /( 10 < sup > 3 </ sup > N < sub > A </ sub >) kg .</ ref > The atomic mass unit is convenient for expressing the masses of atoms and molecules.

Hydrogen, for example, with a single proton, has an atomic weight of 1. 007825 u.

The use of average atomic masses derived from the standard atomic weights found on a standard periodic table will result in an average molecular mass, whereas the use of isotopic masses will result in a molecular mass consistent with the strict interpretation of the definition, i. e. that of a single molecule.

Nuclear fusion is the process by which two or more atomic nuclei join together, or " fuse ", to form a single heavier nucleus.

In probability theory, an elementary event ( also called an atomic event or simple event ) is an event which contains only a single outcome in the sample space.

For example, a single electron in an unexcited atom is pictured classically as a particle moving in a circular trajectory around the atomic nucleus, whereas in quantum mechanics it is described by a static, spherically symmetric wavefunction surrounding the nucleus ( Fig.

The revised definition seems to imply that the ideal atomic clock contains a single caesium atom at rest emitting a single frequency.

Different elements have a different atomic mass, and as collections of single atoms, molecules have a definite molar mass, measured with the unit mole ( 6. 02 × 10 < sup > 23 </ sup > individual molecules, Avogadro's constant ).

An atomic mass unit is, for roughly 40 atoms per cubic meter .</ ref > However, even if every single atom and particle could be removed from a volume, it would still not be " empty " due to vacuum fluctuations, dark energy, and other phenomena in quantum physics.