Study of T2 relaxation for l-doublet transitions of OCS

1984 ◽  
Vol 62 (12) ◽  
pp. 1280-1285 ◽  
Author(s):  
S. C. Mehrotra ◽  
H. Mäder
Keyword(s):  
Quantum Number ◽  
Line Width ◽  
Pressure Dependence ◽  
Vibrational State ◽  
Rotational Quantum Number ◽  
Relaxation Times ◽  
T2 Relaxation ◽  
Excited Vibrational State ◽  
Transverse Relaxation ◽  
Rotational States

The pressure dependence of transverse relaxation times T2 has been measured for l-doublet transitions of OCS in the excited vibrational state (01 10) in rotational states with 29 ≤ J ≤ 42 by using the transient emission technique. The line width parameter decreases with an increase of rotational quantum number J from 6.54(12) MHz/Torr at J = 29 to 5.53(6) MHz/Torr at J = 42. The result has been compared with the results obtained from the modified Murphy–Boggs theory.

A Contribution to the Investigation of T2-Relaxation: Rotational Transitions of OCS and SO2

1984 ◽  
Vol 39 (7) ◽  
pp. 633-636 ◽  
Author(s):  
S. C. Mehrotra ◽  
G. Bestmann ◽  
H. Dreizler ◽  
H. Mäder
Keyword(s):  
Fourier Transform ◽  
Quantum Number ◽  
Pressure Dependence ◽  
Ground State ◽  
Vibrational State ◽  
Room Temperature ◽  
Rotational Quantum Number ◽  
Lower State ◽  
T2 Relaxation ◽  
Microwave Spectrometer

With use of a Fourier transform microwave spectrometer in the range of 4 GHz to 18 GHz, the pressure dependence of collisional coherence dephasing times T2 at room temperature has been determined for (a) the transition J = 0 → J =1 of OCS, 18OCS, and OC34S, (b) nine transitions of SO2 in ground state having 13 ≦ J ≦ 59, and (c) eight transitions of SO2 having 12 ≦ 7 ≦ 55 in the first excited bending vibrational state, where J is the rotational quantum number of the lower state.

scholarly journals J-Dependence of T2-Parameters for Rotational Transitions of SO2 and CH3OH in K-Band

1985 ◽  
Vol 40 (7) ◽  
pp. 683-685 ◽  
Author(s):  
S. C. Mehrotra ◽  
H. Dreizler ◽  
H. Mäder
Keyword(s):  
Fourier Transform ◽  
Quantum Number ◽  
Ground State ◽  
Significant Variation ◽  
Vibrational State ◽  
Rotational Quantum Number ◽  
Fourier Transform Spectrometer ◽  
Ground Vibrational State ◽  
Rotational Transitions ◽  
Upper Level

With the help of a microwave Fourier transform spectrometer in the range from 18 GHz to 26 GHz, the coefficients ß for the linear pressure depedence of collisional dephasing rates 1/T2 have been determined by the transient emission technique for fourteen pure rotational transitions of SO2 with 5 ≦ J' ≦ 66 in the ground vibrational state, twelve transitions with 8 ≦ J' ≦ 62 in the first excited bending vibrational state, and twelve transitions of methanol with 2 ≦ J' ≦ 11, where J' is the rotational quantum number of the upper level of a transition. The T2-parameter ß for the transition J(K-, K+) - 49(4, 46 ) - 48(5, 43) of SO2 in the ground state shows an anomalous behaviour, whereas the values for all other transitions show a J-dependence in accordance with previous results. No significant variation of T2-parameters with J has been found for the rotational transitions of CH3OH.

Modified Dunham potential for rovibrational diatomic systems

1995 ◽  
Vol 73 (1-2) ◽  
pp. 59-62 ◽  
Author(s):  
Marcin Molski ◽  
Jerzy Konarski
Keyword(s):  
Angular Momentum ◽  
Quantum Number ◽  
Standard Method ◽  
Diatomic Molecules ◽  
Rotational Quantum Number ◽  
Electronic States ◽  
Rotational States ◽  
Diatomic Systems ◽  
Rovibrational States ◽  
Rotational Angular Momentum

A modified Dunham potential with parameters depending on the rotational quantum number is employed to describe the rovibrational states of diatomic molecules. This approach, applied to H81Br, 115InD, 7LiH, and 40Ar2, gives satisfactory reproduction of the observed transitions using fewer Dunham parameters than in the standard method. The results obtained indicate the possibility of introducing the local internal potentials, which, in contradiction to the global ones usually used, depend on the rotational states of a rotating–vibrating molecule. Such a J dependence may be a result of rovibronic interactions, in particular, Coriolis-type nonadiabatic interactions coupling other electronic states through the rotational angular momentum.

Proton magnetic relaxation of water sorbed by methaemoglobin crystals

1973 ◽  
Vol 331 (1587) ◽  
pp. 457-468 ◽  
Keyword(s):  
Relaxation Rate ◽  
Relaxation Times ◽  
Transverse Relaxation Rate ◽  
Ferric Ions ◽  
Transverse Relaxation ◽  
Water Binding ◽  
Adsorption Sites ◽  
Protein Molecules ◽  
Proton Magnetic Relaxation ◽  
Limiting Value

P. m. r. relaxation times ( T 1 and T 2 ) have been measured as a function of regain and temperature for water sorbed by lyophilized methaemoglobin. The purpose of the work was to gain information regarding the nature and extent of water binding by the protein molecules. The T 1 results are interpreted in terms of an exchange between the sixth ligand position of the Fe (III) and other adsorption sites on the protein. At high temperatures the relaxation rate at a given regain reaches a limiting value which allows the fraction of ferric ions hydrated to be calculated. Above 16% regain all the Fe (III) is hydrated. At 21 and 35% regains a maximum appears in the relaxation rate at about -46 °C indicating a contribution from a more mobile phase which produces a T 1 minimum at that temperature. The T 2 data are consistent with a model in which the main contribution to the transverse relaxation rate comes from a tightly bound fraction of the water with ω 0 Ƭ c ≫1. The temperature dependence of T 2 exhibits three different regions: ( a ) a low temperature region where lg T 2 ∝ T -1 ; ( b ) an intermediate region with a steeper increase of T 2 with temperature; and ( c ) a high temperature where T 2 levels off.

Quantification of T1, T2 relaxation times from Magnetic Resonance Fingerprinting radially undersampled data using analytical transformations

2021 ◽  
Vol 80 ◽  
pp. 81-89
Author(s):  
Nikolaos Dikaios ◽  
Nicholas E. Protonotarios ◽  
Athanasios S. Fokas ◽  
George A. Kastis
Keyword(s):  
Magnetic Resonance ◽  
Relaxation Times ◽  
T2 Relaxation ◽  
Undersampled Data

Determining the effect of water temperature on the T1 and T2 relaxation times of the lung tissue at 9.4 T MRI: A drowning mouse model

2021 ◽  
pp. 101836
Author(s):  
Kodama Saki ◽  
Hata Junichi ◽  
Kanawaku Yoshimasa ◽  
Nakagawa Hiroshi ◽  
Oshiro Hinako ◽  
...  
Keyword(s):  
Mouse Model ◽  
Water Temperature ◽  
Lung Tissue ◽  
Relaxation Times ◽  
T2 Relaxation ◽  
Effect Of Water ◽  
T1 And T2

A quasi-classical trajectory study of the reagent initial rotation quantum state effect on the reaction He + T2+ → HeT+ + T using an improved ab initio potential energy surface

2012 ◽  
Vol 90 (2) ◽  
pp. 230-236 ◽  
Author(s):  
Ningjiu Zhao ◽  
Yufang Liu
Keyword(s):  
Angular Momentum ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Quantum Number ◽  
Relative Velocity ◽  
Energy Surface ◽  
Rotational Quantum Number ◽  
Chem Phys ◽  
Classical Trajectory ◽  
Positive Direction

In this work, we employed the quasi-classical trajectory (QCT) method to study the vector correlations and the influence of the reagent initial rotational quantum number j for the reaction He + T2+ (v = 0, j = 0–3) → HeT+ + T on a new potential energy surface (PES). The PES was improved by Aquilanti co-workers (Chem. Phys. Lett. 2009. 469: 26–30). The polarization-dependent differential cross sections (PDDCSs) and the distributions of P(θr), P([Formula: see text]r), and P(θr, [Formula: see text]r) are presented in this work. The plots of the PDDCSs provide us with abundant information about the distribution of the product angular momentum polarization. The P(θr) is used to describe the correlation between k (the relative velocity of the reagent) and j′ (the product rotational angular momentum). The distribution of dihedral angle P([Formula: see text]r) shows the k–k′–j′ (k′ refers to the relative velocity of the product) correlation. The PDDCS calculations illustrate that the product of this reaction is mainly backward scatter and it has the strongest polarization in the backward and sideways scattering directions. At the same time, the results of the P([Formula: see text]r) demonstrate that the product HeT+ tends to be oriented along the positive direction of the y axis and it tends to rotate right-handedly in planes parallel to the scattering plane. Moreover, the distribution of the P(θr) manifests that the product angular momentum is aligned along different directions relative to k. The direction of the product alignment may be perpendicular, opposite, or parallel to k. Moreover, our calculations are independent of the initial rotational quantum number.

Sign in / Sign up

Export Citation Format

Share Document