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1.
F. Liu W. Wang W. Zheng Y. Wang 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,42(3):435-440
In this study, spatially resolved measurements of the
emission intensity of OH (A2Σ↦X2Π, 0-0) and the
vibrational temperature of N2 (C) have been performed during a positive
pulsed streamer discharge with a wire-plate electrode configuration at
atmospheric pressure. The effects of pulse peak voltage, pulse repetition
rate and the added O2 flow rate on the spatial distributions of the
emission intensity of OH (A2Σ↦X2Π, 0-0) and the
vibrational temperatures of N2 (C) perpendicular to the wire in the
direction towards the plate (in the radial direction) are investigated. It
has been found that the emission intensity of OH (A2Σ↦X2Π, 0-0) increases with increasing pulse peak voltage and pulse
repetition rate and decreases with increasing the distance from the wire
electrode. When the different oxygen flows are added in N2 and H2O
mixture gas, the emission intensity of OH (A2Σ↦X2Π, 0-0) decreases with increasing the flow rate of oxygen. The
vibrational temperature of N2 (C) is nearly independent of pulsed peak
voltage and pulsed repetition rate, but increases with increasing the added
O2 flow rate and keeps almost constant in the radial direction under
the present experimental conditions. This measurement plays a crucial role
in understanding the discharge characters of pulsed streamer discharge and
establishing the molecule reaction dynamics model of pulsed streamer
discharge. 相似文献
2.
We investigate the quasiparticle conformational defects (excitons, polarons and bioplarons) in the phenylene vinylene oligomers.
The conformations are determined by means of the minimization of the total Hartree-Fock energy calculated at 3–21G level.
The infrared vibrational transitions are calculated and the types of vibrations are assigned. The theoretical spectra are
in good agreement with the experimental vibrational spectrum of poly(p-phenylene vinylene).
Presented at the Czech-Israeli-German Symposium “Dynamical Processes in Condensed Molecular Systems”, Prague, Czech Republic,
26–30 May 1997.
The quantum mechanical calculations were performed on the following computers: Power Challenge XL at Prague Supercomputing
Centre, Charles University, IBM Power 2 at Supercomputing Centre of the Czech Technical University and Power Challenge XL
at Supercomputing Centre Brno.
The work is supported by Projects No. 202/94/0453 and 202/97/1016 of the Grant Agency of the Czech Republic and by Project
No. 155/96 of the Grant Agency of the Charles University. 相似文献
3.
V. I. Starikov 《Optics and Spectroscopy》2011,110(3):340-350
The coefficients γ of broadening by self-pressure, and pressure of nitrogen, oxygen, and air are calculated for absorption
lines of the rotational band and for the ν2 band of the ozone molecule for temperatures 296, 252, and 212 K. The calculations are performed by the semiclassical method
using rectilinear and exact trajectories for interacting molecules. It is shown that the experimental data obtained for the
two bands at T = 296 K can be reconstructed better using different isotropic intermolecular interaction potentials. The experimental and
calculated broadening coefficients of ozone absorption lines for the rotational band and for the ν2 and ν1 + ν3 vibrational bands were used to determine the parameters of an analytical model, which permits one to calculate γ in a wide
range of rotational quantum numbers, 0 ≤ J ≤ 45, 0 ≤ K
a
≤ 20, and temperatures of 200–296 K. 相似文献
4.
Rotational and vibrational temperatures of He, O2. and CO2have been examined in carbon and molybdenum cathodes as functions of pressure and discharge current. The rotational temperature is strongly dependent on the conditions. The rotational temperatures of CO+, N
2
+
, C2, CN, and OH are identical in simultaneous measurements. 相似文献
5.
T. Doerk J. Ehlbeck P. Jauernik J. Stańco J. Uhlenbusch T. Wottka 《Il Nuovo Cimento D》1992,14(10):1051-1063
Summary CARS (Coherent Anti-Stokes Raman Scattering) has developed into a powerful tool for studying molecular systems. One of its
possibilities is to derive vibrational and rotational temperatures as well as concentrations of molecules from measurements
of the energy level population differences. A very good spatial resolution of CARS technique is one of its important advantages.
This feature has been utilized for making spatially resolved measurements of the vibrational and rotational temperatures of
N2 in a d.c.-excited transverse-flow CO2 laser discharge. Apart from that also spectra of CO2, CO and O2 in the discharge have been taken, which allowed us to evaluate the spatial distributions of those components in the discharge.
Additionally first investigations of a microwave-excited CO2 laser module have been performed for comparison.
Paper presented at the ?XI European CARS Workshop?, Florence, Italy, 23–25 March, 1992. 相似文献
6.
From the independence of the contour of spectral density of the rotational (orientation) correlation function of a rigid molecular
top of arbitrary symmetry on temperature in the frequency scale based on the reduced time of rotational orientation relaxation
and from the near independence of the rotational contour of vibrational and vibronic absorption bands of dipole transitions
in the same coordinates in a model of “regular diffusion” of the transition oscillator with a classically rotating rigid molecular
top, it is suggested that it is possible to use the halfwidth of the contour for estimation of temperatures. Data are presented
on the halfwidth of 48 contours of bands of A, B, and C types at this frequency for 12 compounds for a temperature range of
from units to 500 degrees of absolute temperature measured experimentally and (for low temperatures) calculated by the quantum
theory.
Institute of Molecular and Atomic Physics, Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 3, pp. 312–317, May–June, 1997. 相似文献
7.
8.
To gain more information about the highly excited rotational states of the Δv = 1 sequence of OD vibration-rotation bands, the spectrum has been produced in an inductively coupled plasma discharge and
measured with a Fourier transform spectrometer between 1670 and 5768 cm−1. Along with the extension of 1–0 band, we have been successful in recording the 2–1 band for the first time. A nonlinear
least square fit of these bands yielded equilibrium molecular parameters forv = 0, 1 and 2 levels with a standard deviation of 0·0032 cm−1. The centrifugal distortion parameters show a systematic vibrational dependence. 相似文献
9.
Francesco Cramarossa Santolo de Benedictis Giovanni Ferraro 《Journal of Quantitative Spectroscopy & Radiative Transfer》1980,23(3):291-301
A local vibro-rotational analysis of the excited species, produced in a 35 MHz discharge reactor in flowing nitrogen, has been carried out by measuring radial and axial emission intensities of some vibrational sequences and selected rotational lines of the (0,2) band of the second positive system (SPS) of N2 (C3Πu - B3Πg), in the pressure range 5–35 torr.Radial from lateral band or line emission intensities have been obtained by applying Abel's inversion technique to derive the corresponding vibrational and rotational temperatures with the use of Boltzmann plots. General maps of emission intensities and of vibrational and rotational temperature distributions within the reactor have been drawn.It is shown that a decrease of a factor 103 in the emission intensities from the core to the periphery of the discharge corresponds to a variation in TV and TR of only a factor ?2. This result has been interpreted on the basis of the kinetic mechanisms for the excitation and deexcitation of chemical species under discharge conditions. The decrease of V and the increase of TR with increasing pressure are interpreted according to V-R (vibration-rotation) energy-transfer mechanisms. 相似文献
10.
The original experimental device for studying the radial dependences of emitted radiation, generated by the cylindrically
symmetric positive column of the DC glow discharge, is proposed. Principle of detection of the radial intensity profiles of
the spectral lines by means of the special scanner with two movable conic mirrors is described. The function of the scanner
was verified experimentally and by the method of raytracing. As an example, the radial profiles of lines emitted by the positive
column of the neon glow discharge are presented. No significant changes were found.
This work is a part of the research plan MSM 0021620834, that is financed by the Ministry of Education of the Czech Republic. 相似文献
11.
D. Messina 《Proceedings of the Combustion Institute》2007,31(1):825-832
Time-resolved CARS measurements of rotational and vibrational temperatures of nitrogen in nanosecond pulsed discharge at atmospheric pressure are reported. Experiment is first performed with a discharge in pure air where spatial and temporal evolution of temperature distribution is recorded by delaying the probe lasers relative to the discharge pulse in the range 10 ns to 1 ms. The experiments demonstrate that a strong vibrational non-equilibrium can be sustained in N2 at 1 bar. The effect of different colliding partners on the vibrational relaxation of N2 is studied for discharges in CH4/air mixtures with different equivalence ratio. The observed temperature distributions suggest that thermal equilibrium is not fully achieved in this mixture. Effect of the discharge on the ignition of a premixed CH4/air flame is also investigated for various equivalence ratio. 相似文献
12.
TheA
2
Π
ustate of O2
+ was earlier established as an inverted state contrary to previous assumptions. The rotational analysis of a few more bands
of theA-X system of O2
+ has now been completed. These studies show that the spin-orbit coupling constantA in theA
2
Π
ustate gradually varies with the vibrational quantum numberν and is found to be positive forν⩾6. It has also been observed that the spia-rotation interaction is not negligible in theA
2
Π
ustate. The spin splitting constantγ is reported for various vibrational levels of this electronic state. 相似文献
13.
G. Leyendecker J. Doppelbauer D. Bäuerle P. Geittner H. Lydtin 《Applied Physics A: Materials Science & Processing》1983,30(4):237-243
The suitability of local temperature measurements by cw Raman spectroscopy for the CH4/H2 CVD system has been established. The temperature profiles in a model reactor were derived from H2 pure rotational lines and from hot bands of thev
1 vibrational band of CH4. Experimental results are presented for substrate temperatures of 773 K and of 1473 K. High accuracy of measurement and excellent agreement with theoretical solutions for the temperature field within the reactor were found. 相似文献
14.
15.
The vibrational kinetics of CW CO2 lasers has been analyzed within the framework of a temperature model. The necessity of taking into account the coupling of the vibrational modes of the CO2 molecule in determining the occupation numbers and the store of vibrational energy in individual modes is shown. Expressions that connect vibrational temperatures with the rates of excitation and relaxation of the lower vibrational levels of modes have been obtained. The ratios between the vibrational temperatures on selective excitation of the 00° 1 level and on excitation of CO2 molecules in an electric discharge as well as the character of the dependences of vibrational temperatures on the pumping-energy value are discussed.__________Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 1, pp. 72–79, January–February, 2005. 相似文献
16.
17.
The rotational (TR) and vibrational (Tv) temperatures of N2 molecules were measured in a high‐pressure cylindrical dielectric barrier discharge (C‐DBD) source in Ne with trace amounts (0.02 %) of N2 and dry air excited by radio‐frequency (rf) power. Both TR and Tv of the N2 molecules in the C 3Πu state were determined from an emission spectroscopic analysis the 2nd positive system (C 3Πu → B3Πg). Gas temperatures were inferred from the measured rotational temperatures. As a function of pressure, the rotational temperature is essentially constant at about 360 K in the range from 200 Torr to 600 Torr (at 30W rf power) and increases slightly with increasing rf power at constant pressure. As one would expect, vibrational temperature measurements revealed significantly higher temperatures. The vibrational temperature decreases with pressure from 3030 K at 200 Torr to 2270 K at 600 Torr (at 30 W rf power). As a function of rf power, the vibrational temperature increases from 2520 K at 20 W to 2940 K at 60 W (at 400 Torr). Both TR and Tv also show a dependence on the excitation frequency at the two frequencies that we studied, 400 kHz and 13.56 MHz. Adding trace amounts of air instead of N2 to the Ne in the discharge resulted in higher TR and Tv values and in a different pressure dependence of the rotational and vibrational temperatures. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
18.
T. Shukurov 《Journal of Applied Spectroscopy》2007,74(1):23-30
The effect of high foreign-gas pressure (He, Ar, N2 up to 220 atm and CO2 up to 90 atm) on the contours of perpendicular and hybrid IR absorption bands for symmetric top molecules has been studied.
It has been established that over the entire studied pressure range, the shape of the contours of the perpendicular vibrational
bands ν4 and ν5 for chloroform, deuterochloroform, and bromoform is stable and changes relatively little as the pressure increases. The effect
of collisions on the band contours is estimated by comparing the contours for mixtures of compressed gases with the contours
calculated in the approximation of the J-and M-diffusion models. It has been shown that intramolecular perturbation of free
rotation by Coriolis forces is the determining factor in formation of the contours of the perpendicular bands, successfully
competing with the perturbing effect of the foreign gases, evidence for which comes from the insignificant changes in the
shape of the bands as the pressure of the foreign gases increases.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 1, pp. 25–30, January–February, 2007. 相似文献
19.
H. Martínez F. B. Yousif 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,46(3):493-498
This paper considers the electrical and optical characterization of glow
discharge pulsed plasma in N2/H2 gas mixtures at a pressures range
between 0.5 and 4.0 Torr and discharge current between 0.2 and 0.6 A.
Electron temperature and ion density measurements were performed employing a
double Langmuir probe. They were found to increase rapidly as the H2
percentage in the mixture was increased up to 20%. This increase slows
down as the H2 percentage in the gas mixture was increased above 20%
at the same pressure. Emission spectroscopy was employed to observe emission from the pulsed
plasma of a steady-state electric discharge. The discharge mainly emits
within the range 280–500 nm. The emission consists of N2 (C-X) 316, 336,
358 nm narrow peaks and a broad band with a maximum at λmax = 427 nm. Also lines of N2, N2
+ and NH excited states were
observed. All lines and bands have their maximum intensity at the discharge
current of 0.417 A. The intensities of the main bands and spectral lines are
determined as functions of the total pressure and discharge current.
Agreement with other theoretical and experimental groups was established. 相似文献