共查询到20条相似文献,搜索用时 31 毫秒
1.
O. ?palek J. Hruby M. ?ensky V. Jirásek J. Kodymová 《Applied physics. B, Lasers and optics》2010,100(4):793-802
A centrifugal spray generator of singlet oxygen, O2(1Δg), for driving a chemical oxygen-iodine laser was developed and its operation was experimentally studied. Modeling of the
liquid separation from the gas flow showed that the separator designed could remove droplets larger than 0.5 μm from gas,
which is very important for the laser operation. This result was confirmed by experiments. Experimental studies proved that
O2(1Δg) could be produced with a high efficiency (chlorine utilization 0.68–0.87 and O2(1Δg) yield 0.35–0.7) even at very high generator pressures (25–70 kPa), which cannot be attained by other O2(1Δg) generators. 相似文献
2.
Kinetic processes taking place in the atomic-molecular system O-O2-O3 in the middle atmosphere with the participation of oxygen molecules in the excited electronic states O2(a
1Δg) and O2(b
1Σ
g
+
) are analyzed in detail. The possibility of increased ozone production under the influence of solar radiation during the
laser excitation of O2 molecules in the a
1Δg state is demonstrated on the basis of numerical modeling. Upper and lower bounds are determined for the densities of O2(a
1Δg) molecules at which the ozone concentration increases in the irradiated zone.
Zh. Tekh. Fiz. 68, 15–23 (August 1998) 相似文献
3.
单重态氧发生器作为氧碘化学激光的核心部件,为化学激光器提供化学能。通过对工业喷射器及旋风分离器的研究,结合产生单重态氧的化学反应环境,进行了大量模拟及设计改进工作,研制了一种新型喷射型单重态氧发生器,并进行了相关实验研究。喷射型单重态氧发生器利用喷嘴能够产生比传统发生器类型更多的气液表面,获得足够的反应效率,可以大幅度降低发生器液体使用量,从而减小发生器辅助系统,提高体积效率。为满足O2(1)停留时间短及分离效率高的要求,利用气液两相喷射的高初速度以旋风分离器完成气液分离。新型发生器氯气利用率可达97%~99%,其O2(1)产率为40%~50%。 相似文献
4.
V. S. Pavlovich 《Journal of Applied Spectroscopy》2007,74(4):501-507
We used known experimental data to analyze the influence of intermolecular interactions on the position of the 0-0-band a1Δg → X3Σ
g
−
phosphorescence of molecular oxygen in solutions. A bathochromic (red) shift caused by dispersion interactions and fluctuations
of the internal electric field (induction effect) is analyzed employing new formulas obtained by us in the framework of the
Onsager model. The contributions from intermolecular repulsion and higher multipole interactions to the shift of the spectrum
are also discussed. It is found that the polarizability in the a1Δg state is higher than in the X3Σ
g
t-
state by 0.19 ± 0.03 Å3. Taking into account the induced nature of O2 phosphorescence in solutions, it is noted that the change of polarizability Δαeg = 0.19 Å3 should differ from the change of Δαeg inherent in free molecular oxygen.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 4, pp. 453–459, July–August, 2007. 相似文献
5.
Hollow cathode (HC) lasers usually operate in a single axial mode without any optical selection. This is attributed to the
large homogeneous linewidth of the gain curve due to the relatively high filling pressure of these lasers. Collisional and
Doppler broadening (ΔνC and ΔνD) of the Cd+ 636 nm and Cd+ 538 nm lines (laser transitions of the HeCd+ laser) excited in a HC discharge tube were determined using a Fabry–Perot interferometer technique. It was found that in
the pressure range 7–25 mbar ΔνD was nearly constant, while, as expected, ΔνC increased linearly with pressure. The broadening constants were α(636 nm)= (47±2) MHz/mbarand α(538 nm)=(11.8±0.5) MHz/mbar.
The first constant is large enough to explain single-mode operation of the red HeCd+ laser; but in the case of the green laser, the exact reason for the single-mode operation remained unclear.
Received: 23 November 2000 / Revised version: 30 March 2001 / Published online: 7 June 2001 相似文献
6.
M. V. Zagidullin N. A. Khvatov M. S. Malyshev 《Russian Journal of Physical Chemistry B, Focus on Physics》2011,5(6):969-973
The results of our experimental study of the kinetics of formation of O2(1Σ) molecules in energy-exchange reactions O2(1Δ) + I(5
p,2
P
1/2) and O2(a,1Δ) + O2(a,1Δ) are presented. The ratio of rate constants was obtained for these reactions (4800 ± 300). Setting the rate constant of
the deactivation of O2(1Σ) molecules on CO2 molecules at 4.1 · 10–13 cm3/s, we evaluated the rate constants for these reactions at a temperature of approximately 330 K: (1.7 ± 0.2) · 10−13 and (3.6 ± 0.5) · 10−17 cm3/s, respectively. 相似文献
7.
Absolute spectral luminosity from an O2–O2(a)-H2O gas flow formed by a chemical singlet oxygen generator was measured at 600–800 and 1230–1310 nm wavelengths. The results
were used to determine the rate constants for O2(a, 0) + O2(a, 0) → O2(X, 0) + O2(X, 0) + hν (λ = 634 nm) and O2(a, 0) + O2(a, 0) → O2(X, 1) + O2(X, 0) + hν (λ = 703 nm) collision-induced emission ((6.72 ± 0.8) × 10−23 and (7.17 ± 0.8) × 10−23 cm3/s, respectively). 相似文献
8.
In an effective-mass approximation it is shown that in a heavily doped slightly compensated crystal the narrowing of the band
ΔEg>0 on complete ionization of the impurity is equal to the sum of the exchange interaction ΔEg
(exc) of the majority charge carriers and of the energy of the correlation interaction ΔEg
(cor) of a nonequilibrium minority charge carrier with a screening cloud of majority ones. When the mean-square fluctuation of
the potential energy of an electron (hole) is much higher than the thermal energy, the approximation ΔEg/EB=1.3(NaB
3/v)0.58+2.7(NaB
3/v)0.23
is obtained, where v is the number of equivalent energy minima (valleys) at different values of the quasimomentum of the
majority charge carriers,
are the Bohr energy and radius; ε is the dielectric permittivity of the crystal lattice; m is the effective mass of the state
density in one valley; N is the concentration of the doping impurity. The values of ΔEg and of the high-energy edge of the interband radiating recombination calculated by the model suggested agree with the data
on low-temperature photoluminescence of n-Si, p-Si, p-GaAs, and p-GaSb for 3·10−3<NaB
3<2.
Belarusian State University, 4, F. Skorina Ave., Minsk, 220050, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 64, No. 3, pp. 367–373, May–June, 1997. 相似文献
9.
J. J. Camacho M. Santos L. Díaz L. J. Juan J. M. L. Poyato 《Applied Physics A: Materials Science & Processing》2010,99(1):159-175
A spectroscopic study of ambient air plasma, initially at room temperature and pressures ranging from 32 to 101 kPa, produced
by high-power transverse excitation atmospheric (TEA) CO2 laser (λ=9.621 and 10.591 μm; τ
FWHM≈64 ns; power densities ranging from 0.29 to 6.31 GW cm−2) has been carried out in an attempt to clarify the processes involved in laser-induced breakdown (LIB) air plasma. The strong
emission observed in the plasma region is mainly due to electronic relaxation of excited N, O and ionic fragments N+. The medium-weak emission is due to excited species O+, N2+, O2+, C, C+, C2+, H, Ar and molecular band systems of N
2+(_{2}^{+}(
B
2\varSigma u+^{2}\varSigma _{\mathrm{u}}^{+}
–X
2\varSigma g+)^{2}\varSigma _{\mathrm{g}}^{+})
, N2(C3
Π
u–B3
Π
g), N
2+(_{2}^{+}(
D2
Π
g–A2
Π
u) and OH(A2
Σ
+–X2
Π). Excitation temperatures of 23400±700 K and 26600±1400 K were estimated by means of N+ and O+ ionic lines, respectively. Electron number densities of the order of (0.5–2.4)×1017 cm−3 and (0.6–7.5)×1017 cm−3 were deduced from the Stark broadening of several ionic N+ and O+ lines, respectively. Estimates of vibrational and rotational temperatures of N
2+_{2}^{+}
electronically excited species are reported. The characteristics of the spectral emission intensities from different species
have been investigated as functions of the air pressure and laser irradiance. Optical breakdown threshold intensities in air
at 10.591 μm have been measured. 相似文献
10.
Jarmila Kodymová Otomar Špalek Vít Jirásek Miroslav Čenský 《Czechoslovak Journal of Physics》2004,54(5):561-574
Results of three problems investigated on a Chemical Oxygen-Iodine Laser (COIL) in our laboratory are presented in connection with the advanced COIL development in the world. These problems concern: i) A gain modulation on the laser transition in iodine atom, I(2P1/2) - (2P3/2), by external magnetic field, and its utilization for a COIL output power stabilization, ii) An evaluation of the Einstein A-coefficient of singlet oxygen, O2(1 g), and its utilization in advanced diagnostics for O2(1 g) determination in COIL operation, iii) A chemically driven iodine atom delivery system for advanced COIL. 相似文献
11.
V. M. Svistunov V. Yu. Tarenkov A. I. D’yachenko R. Aoku H. Murakami M. Shirai 《Journal of Experimental and Theoretical Physics》1998,86(4):763-770
We study the energy spectrum of Bi2223 (Bi1.6Pb0.4Sr1.8Ca2.2Cu3Ox) at high hydrostatic pressures by Andreev-and tunneling-spectroscopy methods. We determine the gap anisotropy in the basal
ab plane and find the following values for the parameters Δ(ϕ): Δmax=42 mV, and Δmin=19.5 mV (T
c
=110 K and dT
c
/dP=0.16 K/kbar). We detect an increase in the ratio R=2Δmax/kT
c
with pressure P; for Bi2223 cuprate, dR/dP≈0.017 kbar−1. In the phonon-frequency region we detect a “softening,” due to pressure, of the high-frequency part of the phonon spectrum
corresponding to “breathing” modes of oxygen, as well as other optical modes of Cu-O. The characteristic frequencies of the
spectrum for ℏΩ>60 mV are found to decrease, with increasing pressure, at a rate d ln(ℏΩ)/dP≈−6.5±0.5×10−3 kbar−1. This result explains the observed increase in the ratio 2Δ/kT
c
(P) in the model of strong electron-phonon interaction.
Zh. éksp. Teor. Fiz. 113, 1397–1410 (April 1998) 相似文献
12.
I. Horn A. V. Anisovich G. Anton R. Bantes O. Bartholomy R. Beck Y. Beloglazov R. Bogendörfer R. Castelijns V. Credé A. Ehmanns J. Ernst I. Fabry H. Flemming A. Fösel M. Fuchs Ch. Funke R. Gothe A. Gridnev E. Gutz S. Höffgen J. Hößl J. Junkersfeld H. Kalinowsky F. Klein E. Klempt H. Koch M. Konrad B. Kopf B. Krusche J. Langheinrich H. Löhner I. Lopatin J. Lotz H. Matthäy D. Menze J. Messchendorp V. Metag V. A. Nikonov D. Novinski M. Ostrick H. van Pee A. V. Sarantsev C. Schmidt H. Schmieden B. Schoch G. Suft V. Sumachev T. Szczepanek U. Thoma D. Walther Ch. Weinheimer 《The European Physical Journal A - Hadrons and Nuclei》2008,38(2):173-186
The reaction γp → pπ0η has been studied with the CBELSA detector at the tagged photon beam of the Bonn electron stretcher facility. The reaction
shows contributions from Δ+(1232)η , N(1535)+π0 and pa
0(980) as intermediate states. A partial-wave analysis suggests that the reaction proceeds via formation of six Δ -resonances,
Δ(1600)P
33 , Δ(1920)P
33 , Δ(1700)D
33 , Δ(1940)D
33 , Δ(1905)F
35 , Δ(2360)D
33 , and two nucleon resonances N(1880)P
11 and N(2200)P
13 , for which pole positions and decay branching ratios are given. 相似文献
13.
We present the results of an investigation of a short-wavelength radiation source (Δλ = 130–350 nm) with excitation by a transverse
high-frequency (f = 1.76 MHz) discharge based on a mixture of argon and chlorine (p = 100–500 Pa). We have studied the spectral
characteristics of the plasma, the oscilloscope traces of the voltage, the current and emission of the discharge, the dependence
of the power of the emission on the electrical power of the discharge, and also the pressure and partial composition of the
Ar/Cl2 mixture. The UV-VUV source emits in a system of broadened and overlapping ArCl(B/X), Cl2(D′/A′), and Cl**2 molecular bands.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 5, pp. 648–651, September–October, 2007. 相似文献
14.
Using the EPR- and IR-spectroscopy methods, we studied the conditions of formation of stable ion-radicals in the structure
of calcium sulfite and determined the limits of their stability. We detected and identified the ion-radicals SO
2
−
with g(iso) = 2.0055 in the initial substances, two types of thermally induced SO
2
−
(with g1 = 2.0093, g2 = 2.0045, and g3 = 2.0020, and g1 = 2.0104, g2 = 2.0049, and g3 = 2.0018) when the substance was heated, and three types of mechanically induced SO
3
−
(with g⊥ = 2.0036 and g‖ = 2.0022, with g(iso) = 2.0033 and ΔH = 0.1 mT and with g(iso) = 2.0031 and ΔH = 0.33 mT) when the substance was ground up.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 3, pp. 391–396, May–June, 2005. 相似文献
15.
A. K. Shuaibov 《Technical Physics》2000,45(10):1346-1348
Results are presented from a study of UV and VUV emission from the plasma of a transverse volume discharge in chlorine and a He/Cl2 mixture. In the wavelength range Δλ=140–300 nm, the Cl2(D′-A′) band with an edge at 258 nm and the Cl 2 * band with edge at λ=195 nm are found to be dominant. It is shown that, in the pressure range [Cl2]=0.1–2.0 kPa, the intensity of emission with λ≤195 nm is higher than the intensity of the Cl2(D′-A′) band. At [Cl2]≥2 kPa, emission in the 258-nm band is dominant. 相似文献
16.
A. K. Shuaibov 《Journal of Applied Spectroscopy》1999,66(2):256-262
Survey emission spectra in the region of 190–600 nm and time and service-life characteristics of a transverse nanosecond discharge
in He/Ar/CF2Cl2(CCl4) mixtures at a pressure of 10–100 kPa are investigated. In the emission spectra, excited products of the decomposition of
freons—C2(A−X), CN(B−X), Cl
2
*
, C*, Cl*, and Cl+*— and the emission of ArF at λ=193 nm are revealed. The emissions of Cl
2
*
at λ=258 nm and ArF at λ=193 nm were the most intense. The discharge in the He/Ar/CF2Cl2 mixture is a multiwave emission source with λ=258 nm Cl
2
*
193 nm ArF, and probably, 175 nm Arcl. It is of interest for applications in UV-VUV-range pulse photometry. The duration
of the emission on Cl
2
*
, ArF, ArI, ClI, and ClII transitions in the discharge in the Ar/CF2Cl2 mixture (P=10–20 kPa) was 200–300 nsec. With adding He and increasing pressure to 100 kPa the duration of the emission decreased
by a factor of 1.5–2. The basic mechanisms of the formation of Cl2, ArF, and CN(B) molecules in the transverse-discharge plasma are considered.
Uzhgorod State University, 46, Pidgirna Str., Uzhgorod, 294000, Ukraine. Translated from Zhurnal. Prikladnoi Spektroskopii,
Vol. 66, No. 2, pp. 241–246, March–April, 1999. 相似文献
17.
The influence of the oxygen partial pressure P
O
2 in the growth atmosphere on the coefficient of chromium distribution between the crystal and the melt of forsterite, the
Cr3+ and Cr4+ ion contents in crystals, and the concentration of color centers induced by irradiation has been investigated. It has been
established that the crystals grown at low oxygen partial pressures P
O
2 (0.01–0.05 kPa) are characterized by low concentrations of Cr4+ ions and color centers. A change in the oxygen partial pressure to P
O
2 ∼ 0.85 kPa leads to an increase in the Cr4+ center concentration by a factor of ∼10 and in the color center concentration by a factor of ∼5. A further increase in the
oxygen partial pressure to P
O
2 to 12 kPa remains the concentration of these centers almost unchanged. A model has been proposed according to which the intrinsic
defects formed under conditions of a relative excess of oxygen leads to both the self-oxidation of chromium and the formation
of color centers in the forsterite crystals under irradiation. 相似文献
18.
In this review, we have focused on the oxidation reactions of single dye molecules by reactive oxygen species (ROS). The methodologies
for the single-molecule detection of ROS, such as hydroxyl radical (HO•), singlet oxygen (O2(a1Δg)), and hydrogen peroxide (H2O2), have been introduced together with examples. In particular, a successful application using the single-molecule fluorescence
technique for the investigation of the TiO2 photocatalytic oxidation reactions is demonstrated in detail. 相似文献
19.
E. Glickman D. Fuks N. Frage S. Barzilai N. Froumin 《Applied Physics A: Materials Science & Processing》2012,106(1):181-189
The experiments show that the alloying liquid In with only (0.1–0.5) at% Ti dramatically reduces the equilibrium contact angle
Θ
∞ formed by In on the surface of CaF2. The aim of this paper is to clarify whether this practically important and conceptually challenging effect can be explained
solely by Ti adsorption at the F-terminated solid–liquid interface without resorting to any other Ti-induced effect. The combination
of ab initio calculations and regular solution approximation was proposed for finding the binding energy, ΔE
Ti of Ti adatom with the interface “CaF2/liquid solutions In–Ti.” With thus obtained ΔE
Ti=1.16 eV, we calculated from the Shishkovsky isotherm the reduction in the solid–liquid interface energy, Δγ
SL induced by Ti adsorption from liquid In with various Ti concentration, C. It was found that Δγ
SL(C) dependence demonstrated close inverse correspondence with Θ
∞(C) and that the theory fitted very well all available experimental data on the concentration and temperature dependence of
Δγ
SL. It was concluded that the Ti adsorption effect is large enough to account for the observed wetting improvement. The proposed
multiscale modeling approach to the role of adsorption in wetting can be applied also to other nonreactive systems “liquid
metal–ceramics” where the substrate determines the surface density of the adsorption sites for the active element. 相似文献
20.
Infrared (IR) and UV spectra of ternary Li2O–CuO–P2O5 glasses in two series Li2O(65−X)%–CuO(X%)–P2O5(35%), X = 20, 30, 40 and Li2O(55−X)%–CuO(X%)–P2O5(45%), X = (10, 20, 30) were studied. Infrared (IR) investigations showed the metaphosphate and pyrophosphate structures and with
increase of CuO content in metaphosphate glass, the skeleton of metaphosphate chains is gradually broken into short phosphate
groups such as pyrophosphate. IR spectra showed one band at about 1,220 and 1,260 cm−1 for P2O5(35%) and P2O5(45%) series, respectively, assigned to P=O bonds. For CuO additions ≤20 mol%, the glasses exhibit two bands in the frequency
range 780–720 cm−1 which are attributed to the presence of two P–O–P bridges in metaphosphate chain. But for CuO addition ≥30 mol%, the glasses
exhibit only a single band at 760 cm−1 which is assigned to the P–O–P linkage in pyrophosphate group. In optical investigations, absorption coefficient versus photon
energy showed three regions: low energy side, Urbach absorption, and high energy side. In Urbach’s region, absorption coefficient
depends exponentially on the photon energy. At high energy region, optical gap was calculated and investigations showed indirect
transition in compounds and decreases in optical gap with increases of copper oxides contents that is because of electronic
transitions and increasing of nonbridging oxygen content. 相似文献