Infra-Red Spectrum of the Night Sky

Herman, R.; Herman, L. C.; Gauzit, J.

doi:10.1038/156114b0

Cited by 6 publications

(6 citation statements)

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“…In this way the effect of grain spoiling the resolution of the spectral lines was intentionally reduced, and many more bands are visible on careful inspection of the enlargement. In this spectrum the (1,0) and (2,1) bands were particularly intense, even more intense than the usually dominant (12, 7) and (11,7) bands. The preferential population of t>'=6 is particularly apparent, however.…”

Section: Of Active Nitrogen 85mentioning

confidence: 71%

“…The Av = 3 progression shows an abrupt decrease in intensity at z/=6 and then again at v'= 11. The Av=4 progression begins with (6, 2) and then gets much stronger at (11,7) and (12,8). A total of 31 bands of the N2 first positive system are observed.…”

Section: Of Active Nitrogen 85mentioning

confidence: 96%

“…When this radiation was first discovered [10][11][12][13] it was interpreted as the (0, 0) band of the N2 first positive system, assuming the above reaction scheme. The altitude of emission of the airglow was, at that time, very uncertain.…”

Section: Active Nitrogen and The Airglowmentioning

confidence: 99%

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The Infrared Spectrum of Active Nitrogen

Branscomb

1951

Phys. Rev.

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The equations can be simplified by the introduction of two new parameters:.6 A = f dxp{x)e-™<-xa \ 0=0(6, a)- J aIn terms of these, Eqs. (28) and (29) become R (b) = Ma)e ie + L(a)Ae ie , Mb) = L(a)e-ie +R(a)A*e-i°. (30) (31) (32)B is the phase shift per cell given by the ordinary WBK method. | A | 2 is the probability that the particle changes its direction of motion in going through one cell.Floquet's theorem tell us that the solutions to the wave equation for a periodic potential can always be written in the form u(x) exp[ijuof], where u(x) has the periodicity of the lattice and M is either purely real or purely imaginary. It is real for the energy levels corresponding to allowed levels, and imaginary for the stop bands between them. Equations (31) and (32) represent a linear transformation whose characteristic values are X=exp[±i/ix]. The secular equation obtained from Eqs. (31) and (32) isThe roots of this equation areWhenever the quantity in parentheses is negative, the equation has two imaginary roots, complex conjugates of each other. In this case \=cos0±i(sin 2 0-|,4| 2 )*which to first order in |i| satisfies |X| = 1. Whenever the quantity in parentheses is negative, we will be in an allowed energy range. As the energy is varied, for a given potential, sin0 will repeatedly go through zero. When sin0 comes close enough to zero, the term in parentheses in Eq. (34) becomes positive and both roots will be real. The roots, when real, will have their extreme values (i.e., farthest removed from unity) when sin0=O. For that value of energy, we have |x| = i±U|~*fc»-to first order in | .4 |. The zone boundaries occur when the quantity in parentheses is negative, we will be in an sin0=±|.4|. The fact that we have taken into account only the first-order correction makes our solution an approximate one, which is valid only if the coefficient | A j is small compared with unity. The method is therefore valid only when the region between bands is narrow. This condition is not as restrictive as the one applicable to the usual perturbation theory approach.It is possible that | A \ can be zero. In this case a particle can travel through the lattice without being reflected. The reflections caused by different parts of the cell must cancel in such a case. If | A | vanishes at an energy for which sin0=O, the spacing between adjacent bands vanishes and they touch each other.The author wishes to thank Professors Furry and Brillouin for helpful discussions, and the Atomic Energy Commission for a Predoctoral Fellowship.Thirty-one bands, including the (0, 0) band at 10,440A, of the N2 first positive system have been photographed in the Lewis-Rayleigh afterglow of active nitrogen. There is no indication that the v-0 level of the B 3 U state is preferentially populated as required by the "resonance" theory of atomic re-association using D(Ni) = 7.383 volts. The analogy between the Lewis-Rayleigh glow and the spectrum of the airglow is discussed briefly.

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Section: Of Active Nitrogen 85mentioning

confidence: 71%

Section: Of Active Nitrogen 85mentioning

confidence: 96%

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The Infrared Spectrum of Active Nitrogen

Branscomb

1951

Phys. Rev.

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“…Vooral mensen die zich aan de onderkant van de samenleving bevonden, waren bereid om grote risico's te lopen om met smokkel het hoofd boven water te houden. 62 De organisaties Winterhulp en Entr'Aide des Travailleuses lenigden de ergste nood. De Entr'aide voorzag in soep-en melkbede-lingen.…”

Section: Oorlog!unclassified

“…De armen uit de wijk konden bovendien op consultatie komen bij de medische dienst. 63 Vanaf 1943 hielden ze ook een bibliotheek open. Daarnaast bezocht de Entr'Aide politieke gevangenen en zocht de organisatie actief naar families die Joden onderdak wilden bieden.…”

Section: Oorlog!unclassified