density wave

density wave

[′den·səd·ē ‚wāv]
(physics)
A sound wave or other type of material wave which causes the density of the matter through which it passes to alternately rise above and drop below its mean value.
References in periodicals archive ?
However, theory also allows the possibility that these electron pairs crystallize into a "pair density wave" (PDW) state where the density of pairs modulates periodically in space.
The density wave phenomena delays this feedback and, at some frequency, the delay is equivalent to a 180[degrees] phase lag; so at this frequency the pressure drop feedback is positive and if the gain is large enough, the channel flow becomes unstable and oscillates at that frequency highly concentrated around 0.5 Hz, where the associated resonance frequency is related with the fluid transit time along the heated channel, which could differ from 2 seconds, i.e., approximately 1 Hz.
The observed ordering of the magnetic moments was explained in terms of the spin density wave (SDW).
In order to solve this problem, scientists invoke what's known as the (https://www.youtube.com/watch?v=_GNPvYdvZAQ) density wave theory , in which the movement of the spiral arms is seen as different from the movement of actual matter (stars, gas, dust and planets) in them.
It could be an immense density wave moving through the galaxy.
Using ultrafast spectroscopy, Mahmood and co-authors of a 2013 Nature Materials paper were able to show that for extremely short periods of time " up to about 2 picoseconds " electrons clustered in a density wave that could be measured by its amplitude and phase.
1) where coil sides that belong to distinct phases are placed in the same slot and determine an important improvement both of the shape of the air-gap flux density wave and the induced voltages.
There are new chapters on topics such as Dirac electrons, super symmetry, charge density wave states in higher Landau levels, and unconventional QH effects in graphene.
When millions of ring particles in the same region become perturbed in this way, they generate a spiral density wave that propagates away from the disturbance.
Acoustic Density Wave impedance (X [10.sup.3] velocity (X [10.sup.5] Material kg/[m.sup.3]) (m/s) kg/([m.sup.2] * s)) Polymer melt 1.33 (a) 1000 (b) 13.30 Solid material 1.40 (e) 1400 (c) 33.53 PEEK delay line 1.30 (e) 2214.36 (b) 28.79 Steel 4340 (d) 7.80 5850 456.3 (a) Measured from capillary rheometer at 150[degrees]C.
The superconducting transition is sharp with an onset [T.sub.c] = 42 K, the highest of any 2-1-4 system, while long range spin density wave magnetic order of the Cu moments is also observed in this material.
This work now centres on analyzing the microscopic changes taking place within a superconductor when it hits that key temperature where mobile electrons organize into a wave-like periodic structure called a charge density wave.

Full browser ?