Spin-Level Inversion and Spin-Temperature Mixing in Ruby

1959 ◽  
Vol 3 (4) ◽  
pp. 174-175 ◽  
Author(s):  
R. H. Hoskins
Keyword(s):  
Spin Temperature ◽  
Spin Level ◽  
Level Inversion

The Spin Temperature and 21 cm Brightness of the Intergalactic Medium in the Pre-Reionization era

2006 ◽  
Vol 637 (1) ◽  
pp. L1-L4 ◽  
Author(s):  
Michael Kuhlen ◽  
Piero Madau ◽  
Ryan Montgomery
Keyword(s):  
Intergalactic Medium ◽  
Spin Temperature

Radical Cation and Neutral Radical of Aza-thia[7]helicene with SOMO–HOMO Energy Level Inversion

2016 ◽  
Vol 138 (23) ◽  
pp. 7298-7304 ◽  
Author(s):  
Ying Wang ◽  
Hui Zhang ◽  
Maren Pink ◽  
Arnon Olankitwanit ◽  
Suchada Rajca ◽  
...  
Keyword(s):  
Energy Level ◽  
Radical Cation ◽  
Homo Energy ◽  
Neutral Radical ◽  
Level Inversion ◽  
Homo Energy Level

The Breakdown of a Low-level Inversion Studied by Means of Detailed Soundings with a Modified Radiosonde

1952 ◽  
Vol 33 (9) ◽  
pp. 373-379 ◽  
Author(s):  
Frank Gifford
Keyword(s):  
Minimum Temperature ◽  
Low Level ◽  
Short Series ◽  
Pilot Balloon ◽  
Level Inversion

A short series of unusually detailed temperature, humidity, and wind soundings to a height of about 750 mb., made at Silver Hill, Md. on the night of October 30th and 31st, 1950, and consisting of eight flights of specially modified radiosondes and 26 double-theodolite pilot balloon runs, is presented. The nocturnal breakdown of the ground inversion with steep wind gradients, a phenomenon first remarked by Durst in 1933, is here observed apparently to be associated with the sudden lowering of an upper (turbulence or subsidence) inversion. Alternative explanations for this are advanced, and implications for minimum temperature and stratus forecasting noted. The accuracy of the observations is discussed.

Proton Spin Lattice Relaxation in the Dimethylammonium Group

1993 ◽  
Vol 48 (5-6) ◽  
pp. 713-719
Author(s):  
K. Venu ◽  
V. S. S. Sastry
Keyword(s):  
Experimental Data ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Proton Spin ◽  
Spin Lattice Relaxation ◽  
Methyl Groups ◽  
Dipolar Interactions ◽  
Spin Temperature ◽  
Spin Lattice ◽  
Molecular Group

Abstract A model for the spin lattice relaxation time of the protons of dimethylammonium in the Redfield limit and common spin temperature approximation is developed. The three fold reorientations of the methyl groups, the rotation of the whole molecular group around its two fold symmetric axis and possible correlations among these motions are considered. The effect of these processes on the dipolar interactions among the protons within the same molecular group is taken into account. The resulting relaxation rate is powder averaged and used to explain the experimental data in literature on [NH2(CH3)2]3Sb2Br9 . The analysis shows that dynamically inequivalent groups exist in this compound and that the effect of proposed correlation among the different motions on the final results is negligible.

High-spin level structure of the semi-magic nucleusNb91

2014 ◽  
Vol 89 (3) ◽  
Author(s):  
P. W. Luo ◽  
X. G. Wu ◽  
H. B. Sun ◽  
G. S. Li ◽  
C. Y. He ◽  
...  
Keyword(s):  
High Spin ◽  
Level Structure ◽  
Spin Level

High spin level structure of 63 143 Eu80

1992 ◽  
Vol 343 (3) ◽  
pp. 367-368 ◽  
Author(s):  
M. Piiparinen ◽  
A. Ataç ◽  
G. de Angelis ◽  
S. Forbes ◽  
N. Gjørup ◽  
...  
Keyword(s):  
High Spin ◽  
Level Structure ◽  
Spin Level

Systematische Untersuchungen der dynamischen Protonenpolarisation in organischen Kristallen mit eingebauten Radikalzentren

1969 ◽  
Vol 24 (10) ◽  
pp. 1532-1541
Author(s):  
K. Grude ◽  
W. Müller-Warmuth
Keyword(s):  
Magnetic Field ◽  
Enhancement Factor ◽  
Electronic Transitions ◽  
Dynamic Polarization ◽  
Spin Temperature ◽  
Field Range ◽  
Stable Free Radical ◽  
Organic Systems ◽  
High Proton ◽  
Paramagnetic Centres

Abstract In order to produce high proton polarizations, several organic hydrocarbons have been doped with stable free radical molecules. Through the "solid state effect" a part of the electronic polarization in a magnetic field has been transferred to the protons of these materials. For this purpose, the "forbidden electronic transitions" of the combined electron-proton system have been saturated at about 37 GHz. The enhancement factor of the dynamic proton polarization was measured by pulsed NMR at 56 MHz. In phenanthrene with about 4 w.% bis-diphenylen-phenylallyl (BPA) a maximum polarization of 10.5% has been obtained at 1.5 °K and 13 200 gauss. This value may be increased by extending the temperature and magnetic field range. Systematic investigations in numerous organic systems have been carried out and have particularly yielded data on the frequency dependence and on the saturation behaviour of the enhancement curves. - Spin temperature theories of dynamic polarization have been considered to explain the results and to find possibilities for improving the polarization. In particular, the exchange interaction of the radicals and the distinction between relaxing and polarizing paramagnetic centres had to be taken into account.

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