scholarly journals Excitation Spectrum of I2 Induced by Laser Radiation Near the Dissociation Limit of the B–State

1983 ◽  
Vol 1 (2) ◽  
pp. 83-112 ◽  
Author(s):  
Simon Gerstenkorn ◽  
Paul Luc
Keyword(s):  
Laser Radiation ◽  
Excitation Spectrum ◽  
Dissociation Limit ◽  
Molecular Constants ◽  
Vibrational Levels ◽  
Theoretical Predictions ◽  
X State ◽  
Good Agreement

The study of the excitation spectrum of I2 induced by laser radiation near the dissociation limit of the B state enables us to determine the molecular constants of the vibrational levels v′ = 78, 79 and 80; the latest being situated only 1.6 cm−1 from the dissociation limit. The molecular constants are now in good agreement with theoretical predictions. Revised values of the dissociation limits of the B and X state are proposed: they are 20043.176 ± 0.016 and 12440.200 ± 0.020 cm−1 respectively. The excitation spectrum from 20022 to 20039.5 cm−1 is entirely reproduced, together with the assignments and the wavenumbers of all observed lines, principally for calibration purposes.

scholarly journals The Schumann-Runge O2 Emission, Following Visible Multiphoton Excitation of NO2

1983 ◽  
Vol 1 (2) ◽  
pp. 113-130 ◽  
Author(s):  
Y. Matsumi ◽  
Y. Murasawa ◽  
K. Obi ◽  
I. Tanaka
Keyword(s):  
Excited State ◽  
Excitation Spectrum ◽  
Wavelength Range ◽  
Vibrational Relaxation ◽  
Multiphoton Excitation ◽  
Vibrationally Excited ◽  
Multiphoton Process ◽  
Vibrational Levels ◽  
Visible Laser ◽  
X State

The Schumann-Runge emission (B3Σu− − X3Σg−) of oxygen was observed in the wavelength range of 220–300 nm, when NO2 was irradiated with a focused visible laser (470–580 nm). The excitation spectrum of the emission also showed the Schumann-Runge transition from highly excited vibrational levels (v″ = 22–26) of the X state to the v′ = 1–3 levels of the B state of oxygen. The highly vibrationally excited O2 (Evib ≃ 30000 cm−1) is once produced through a multiphoton process of NO2 and then absorbs one more photon. The resulting excited state of O2 emits fluorescence in the UV region. Even at 40 torr of NO2, no rotational-vibrational relaxation in the B state was observed. The mechanism of the multiphoton process is discussed.

Vibration-rotation bands of trideuteromethyl iodide

1965 ◽  
Vol 288 (1412) ◽  
pp. 39-49 ◽  
Keyword(s):  
Fine Structure ◽  
Coupling Constants ◽  
Coriolis Coupling ◽  
Molecular Constants ◽  
Rotational Constants ◽  
Vibrational Levels ◽  
Theoretical Predictions ◽  
Vibration Rotation ◽  
Combination Bands

The rotational fine structure of six parallel and nine perpendicular vibration bands of tri­deuteromethyl iodide has been analysed, and molecular constants have been derived. These include the band origins, the rotational constants in different vibrational levels, the α A i and α B i values, and the Coriolis coupling constants ς i for the fundamental degenerate vibrations. The ς values for overtone and combination bands have been compared with values calculated from the ς i values of the fundamentals, and agree closely with previous theoretical predictions.

Spectroscopy of the hydrogen molecular ion at its dissociation limit

1988 ◽  
Vol 324 (1578) ◽  
pp. 275-287 ◽  
Keyword(s):  
Ion Beam ◽  
Double Resonance ◽  
Spectroscopic Studies ◽  
Spin Rotation ◽  
Dissociation Limit ◽  
Hyperfine Constants ◽  
Vibrational Levels ◽  
Theoretical Predictions ◽  
Deuterium Isotopes ◽  
Vibration Rotation

Previous theoretical and experimental work on the ion and its deuterium isotopes HD+ and D£ is briefly reviewed. Spectroscopic studies of the vibration rotation levels are discussed, and recent work on the infrared photodissociation of the high-lying vibrational levels is described. Earlier work that made use of ion-beam techniques to study the vibration—rotation levels of HD+ is reviewed, and compared with the most recent theoretical predictions. The nuclear-hyperfine and spin—rotation structure of HD+ is described, and recent observations of the vibration-rotation satellite lines that will yield absolute values of the deuterium hyperfine constants are presented. We conclude by describing our attempts to observe radiofrequency—infrared double-resonance spectra.

An analysis of the ion-pair state of I2 by a sequential three-photon excitation

1993 ◽  
Vol 71 (10) ◽  
pp. 1734-1740
Author(s):  
Faten S.M. Abd El-Hameed
Keyword(s):  
Ion Pair ◽  
Photon Absorption ◽  
Dissociation Limit ◽  
Molecular Constants ◽  
Two Photon Absorption ◽  
Photon Excitation ◽  
Vibrational Levels ◽  
Color Spectrum ◽  
The One ◽  
Pair State

A three-photon absorption technique that utilizes a visible [Formula: see text] transition followed by two-photon absorption was applied to characterize the high-lying vibrational levels of the [Formula: see text] ion-pair state of I2, which correlates with I−(1S) + I+(1D) at the dissociation limit. The multiphoton spectrum was examined at high resolution using either a single tunable dye laser (3P1C), or two independently tunable pump and probe dye lasers (3P2C), operating in the blue–green region. The one-color spectrum excited by a single laser shows transitions that have not been assigned by previous workers; these rotational lines are interpreted as being due partly to 3P1C transitions to the [Formula: see text] ion-pair state, for which molecular constants are derived to be (for ν′ = 60–74, J′ = 3–100):[Formula: see text](all in cm−1 with one standard deviation in the last quoted digit in parentheses).

Spektroskopische Bestimmung der Dissoziationsenergie des C2-Moleküls aus den 3IIg -Termen

1967 ◽  
Vol 22 (11) ◽  
pp. 1744-1748 ◽  
Author(s):  
G. Messerle ◽  
L. Kkauss
Keyword(s):  
High Pressure ◽  
Dissociation Limit ◽  
Dissociation Energies ◽  
Vibrational Levels ◽  
Good Agreement

By means of a new vibration formula of BRODERSEN, taking account of observed vibrational perturbations, the dissociation limit of the 3IIg states of C2 has been determined. In order to do this, some further SWAN bands (A3IIg—X′3IIu) and five high pressure bands (v′=6) have been analyzed. The extrapolations of vibrational levels of the A3IIg and B3IIg states lead to dissociation energies D0 (C2) = 6,07 eV and 6,09 eV, respectively, in good agreement with values obtained by other methods.

scholarly journals A Generalized Approach for Evaluating the Mechanical Properties of Polymer Nanocomposites Reinforced with Spherical Fillers

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 830
Author(s):  
Julio Cesar Martinez-Garcia ◽  
Alexandre Serraïma-Ferrer ◽  
Aitor Lopeandía-Fernández ◽  
Marco Lattuada ◽  
Janak Sapkota ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polymeric Nanocomposites ◽  
Mechanical Reinforcement ◽  
Future Studies ◽  
Three Phase ◽  
Theoretical Predictions ◽  
Filler Network ◽  
New Research ◽  
Good Agreement ◽  
Research Avenue

In this work, the effective mechanical reinforcement of polymeric nanocomposites containing spherical particle fillers is predicted based on a generalized analytical three-phase-series-parallel model, considering the concepts of percolation and the interfacial glassy region. While the concept of percolation is solely taken as a contribution of the filler-network, we herein show that the glassy interphase between filler and matrix, which is often in the nanometers range, is also to be considered while interpreting enhanced mechanical properties of particulate filled polymeric nanocomposites. To demonstrate the relevance of the proposed generalized equation, we have fitted several experimental results which show a good agreement with theoretical predictions. Thus, the approach presented here can be valuable to elucidate new possible conceptual routes for the creation of new materials with fundamental technological applications and can open a new research avenue for future studies.

scholarly journals Bichromatic Photoassociation Spectroscopy for the Determination of Rotational Constants of Cs2 0 u + Long-Range State below the 6S1/2 + 6P1/2 Asymptote

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3963
Author(s):  
Jizhou Wu ◽  
Jie Ma ◽  
Yuqing Li ◽  
Wenliang Liu ◽  
Peng Li ◽  
...  
Keyword(s):  
Long Range ◽  
Spectroscopic Technique ◽  
Rigid Rotor ◽  
Simple Analysis ◽  
Rotational Constants ◽  
Vibrational Levels ◽  
Photoassociation Spectroscopy ◽  
Rotor Model ◽  
Good Agreement

This article demonstrates new observation of the high-resolution ro-vibrational bichromatic photoassociation spectra (BPAS) of Cs2 in the 0u+ long-range state below the asymptotes 6S1/2 + 6P1/2. By combining with a modulation spectroscopic technique, precise references of the frequency differences have been engineered through the BPAS, with which the rotational constants of low-lying vibrational levels of the Cs20u+ long-range state have been accurately determined by fitting the frequency differences to the non-rigid-rotor model. The rotational constants for the newly observed seven ro-vibrational levels are summarized and disagreement for the level ῦ = 498 is clarified. The rotational constants of different vibrational levels demonstrate strong perturbations of the related energy structures. A simple analysis is performed and shows good agreement with experimental results.

The Reduction of Bias Error in Transfer Function Estimates Using FFT-Based Analyzers

1984 ◽  
Vol 106 (1) ◽  
pp. 29-35 ◽  
Author(s):  
P. Cawley
Keyword(s):  
Transfer Function ◽  
Random Excitation ◽  
Analogue Computer ◽  
Bias Error ◽  
Testing Time ◽  
Theoretical Predictions ◽  
Set Up ◽  
Modal Mass ◽  
Time Required ◽  
Good Agreement

The susceptibility to bias error of two methods for computing transfer (frequency response) functions from spectra produced by FFT-based analyzers using random excitation has been investigated. Results from tests with an FFT analyzer on a single degree-of-freedom system set up on an analogue computer show good agreement with the theoretical predictions. It has been shown that, around resonance, the bias error in the transfer function estimate H2 (Syy/Sxy*) is considerably less than that in the more commonly used estimate, H1 (Sxy/Sxx). The record length, and hence the testing time, required for a given accuracy is reduced by over 50 percent if the H2 calculation procedure is used. The analysis has also shown that if shaker excitation is used on lightly damped structures with low modal mass, it is important to minimize the mass of the force gage and the moving element of the shaker.

Theoretical Prediction of Motions of High-Speed Planing Boats in Waves

1978 ◽  
Vol 22 (03) ◽  
pp. 140-169
Author(s):  
Milton Martin
Keyword(s):  
High Speed ◽  
Damping Ratio ◽  
Nonlinear Effects ◽  
Theoretical Method ◽  
Valuable Insight ◽  
Response Characteristics ◽  
Theoretical Predictions ◽  
Response Amplitude Operators ◽  
Phase Angles ◽  
Good Agreement

A theoretical method is derived for predicting the linearized response characteristics of constant deadrise high-speed planing boats in head and following waves. Comparisons of the theoretical predictions of the pitch and heave response amplitude operators and phase angles with existing experimental data show reasonably good agreement for a wide variety of conditions of interest. It appears that nonlinear effects are more severe at a speed to length ratio of 6 than of, say, 4 or less, principally because of the reduction of the damping ratio of the boat with increasing speed, and the consequent increase in motions in the vicinity of the resonant encounter frequency. However, it is concluded that the linear theory can provide a simple and fast means of determining the effect of various parameters such as trim angle, deadrise, loading, and speed on the damping, natural frequency, and linearized response in waves, and that this can furnish valuable insight into the actual boat dynamics, even though the accurate predictions of large motions and peak accelerations would require a nonlinear analysis.

On Wall Effects in Cavity Flows

1984 ◽  
Vol 28 (01) ◽  
pp. 70-75
Author(s):  
C. C. Hsu
Keyword(s):  
Numerical Results ◽  
Cavity Flows ◽  
Two Dimensional ◽  
Wall Effects ◽  
Free Jet ◽  
Theoretical Predictions ◽  
Experimental Findings ◽  
Good Agreement

Simple wall correction rules for two-dimensional and nearly two-dimensional cavity flows in closed or free jet water tunnels, based on existing linearized analyses, are made. Numerical results calculated from these expressions are compared with existing experimental findings. The present theoretical predictions are, in general, in good agreement with data.

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