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1.
T. G. Adiks A. F. Bunkin V. A. Luk’yanchenko S. M. Pershin 《Physics of Wave Phenomena》2008,16(1):1-6
The contribution of impurity fluorescence was determined in the water Raman spectra excited by the second harmonic (λ = 532 nm) of a pulsed Nd:YAG laser. Water samples prepared by different techniques (tap water (undistilled), distilled water,
Milli-Q water, water for injections, and water subjected to cavitation treatment) were investigated. The Raman (bands at ν
2 ∼ 1550 cm−1 and ν
3 ∼ 3400 cm−1) and fluorescence (Stokes shift 2500 cm−1) signals were separated spectrally and according to the differences in the emission kinetics. It was established that all
investigated samples, including distilled and specially purified water for injections, exhibit afterglow. The highest sensitivity
to the presence of impurities was revealed near ∼ 2500 cm−1. The least contribution to the fluorescence signal was found in the water for injections. 相似文献
2.
C. Reylé P. Bréchignac 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,8(2):205-210
Fluorescence spectra of naphthalene, C10H8, were obtained in the laboratory under conditions which provide an appropriate simulation of the cometary conditions: super-cooled
gas phase molecules in a collision-free environment. Five spectra were recorded, the excitation energies ranging from 1422
to 5293 cm−1 above the first electronic state S1 at 32 020 cm−1. A comparison with previous jet-cooled naphthalene fluorescence spectra obtained by Beck et al. [1] and Hermine [2] shows that the former results are not consistent with the present ones. Spectra obtained by Beck et al. show weaker intensities at greater wavelengths compared to those obtained by Hermine and ourselves. We also measured the
fluorescence lifetimes by recording the fluorescence decay as a function of time after the excitation of the molecules by
monochromatic lasers and deduced the fluorescence quantum yields. A synthetic emission spectrum under solar irradiation is
obtained for astrophysical implications. 相似文献
3.
R. H. Compton K. T. V. Grattan T. Morrow 《Applied Physics A: Materials Science & Processing》1980,22(3):307-311
The fundamental photophysical parameters of the organic scintillators, anthracene, 9, 10 dimethyl antracene (DMA), 9, 10 diphenyl
anthracene (DPA), 2-(1-napthyl)-5-phenyloxazole (α-NPO) and 2, 2′-p-phenyl bis (5-phenyloxazole) (POPOP), were investigated
in the liquid and vapour phases. Their ground state, triplet-triplet and fluorescence spectra were determined and accurate
extinction coefficients obtained. Photodecomposition of POPOP vapour under 337 nm excitation was investigated in detail and
a photodecomposition quantum yield of 1.1×10−2 obtained at 568 K. The POPOP triplet state in the vapour phase is quenched by the addition of 1, 3, 5, 7 cyclo-octatetraene
and a quenching rate constant of 2.9×1010 M−1 s−1 was determined. 相似文献
4.
The effect of deuteration of the central NH groups on the quasi-linear fluorescence and fluorescence excitation (with selective
monitoring) spectra for triazatetrabenzoporphine, a close analog of phthalocyanine, has been investigated at 77K in n-nonane.
Vibrational analysis of the spectra was carried out. The normal mode frequencies were determined for the electronic states
S0 (from fluorescence spectra) and S1 (for fluorescence excitation spectra). It has been established that N-deuteration lowers the frequency of a vibration involving
inplane NH bending down to ∼990 cm−1 and leads to resonant vibrational-electronic (vibronic) interaction of Fermi-type resonance between the zero level of the
S2 state and the vibronic level of the S1 state upon excitation of this mode. Thereby the possibility of the “vibronic analog of Fermi resonance” (a term coined by
G. Herzberg) occurring in a simple (two-component) variant of phthalocyanine-type molecules has been shown.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 6, pp. 796–803, November–December, 2008. 相似文献
5.
The infrared spectrum of D2O from 2400 to 3000 cm−1 has been analysed at a resolution better than 0·02 cm−1. It was recorded at the Fourier transform spectrometer of the Kitt Peak National Observatory, Tucson. Ground state constants
of the reduced Watson-Hamiltonian, ground state energies and transition for theν
1 andν
3 bands are reported. The effect of strong Coriolis resonances on the spectra is discussed.
Work done at the Jet Propulsion Laboratory, Division of Stratospheric and Planetary Research California Institute of Technology,
Pasadena, Ca (U.S.A.) 相似文献
6.
Summary The fluorescence excitation spectrum of SO2 in the 32 200–33 300 cm−1 energy region was recorded, at very low rotational temperature, in a pulsed supersonic jet. The band centres and relative
intensities of about 60 well-resolved vibronic bands were determined in this region, which extends the previously available
data by 800 cm−1. Single vibronic level fluorescence spectra of two neighbouring vibronic bands in theD-band region along with a few filtered excitation spectra are also presented as an example of the resolution for the listed
bands.
The authors of this paper have agreed to not receive the proofs for correction. 相似文献
7.
Coherent Stokes Raman spectra of the ν1 and ν3 bands of CH4 have been recorded in mixing two pulsed lasers (ruby and dye) of very good spectral and spatial quality. The results show
a resolution of about 0.010 cm−1 for a 10 Torr pressure, corresponding in great part to Doppler broadening. 相似文献
8.
Polarization of the fluorescence of the vapors of anthracene, perylene, 1,4-di(2,5-phenyloxazolyl)benzene (POPOP), and 2-phenyl-5-(4-biphenylyl)oxazole (BPO) upon excitation by a beam of monokinetic electrons with energy varying in the 5–300-eV range has been found. The electrical vector of radiation has a higher value in the direction perpendicular to the direction of the electron beam. For the substances studied, maxima of fluorescence polarization are observed that approximately coincide in position with the maxima of the excitation function. The maximum value of the fluorescence polarization degree of POPOP does not exceed 3.8%. 相似文献
9.
V. N. Bocharov A. P. Burtsev E. V. Dubrovskaya T. D. Kolomiitsova D. N. Shchepkin 《Optics and Spectroscopy》2010,108(4):533-543
IR spectra of the solution of SF6 molecules in liquid NF3 at 84 K have been recorded. In a solvent transmission window of 1500–1750 cm−1, two wide absorption bands with pronounced peaks in the high-frequency part are observed. The profile of these bands is explained
by the influence of the resonance dipole-dipole (RDD) interaction of the states of the simultaneous transition ν1(SF6) + ν3(NF3) and ν2(SF6) + ν3(NF3) with the states (ν1 + ν3) and (ν2 + ν3) of the SF6 molecules, respectively. The use of three isotopic modifications 32SF6, 33SF6, and 34SF6 has allowed us to vary the resonance detuning and thus to change the strength of the RDD interaction. With the liquid near
the melting point being represented as a close-packed cubic crystal, the profile was calculated and its spectral characteristics
were determined. The frequencies of the main peaks coincide with the experimental values accurate to the error. 相似文献
10.
N. A. Borisevich D. K. Buslov V. A. Khripach V. N. Zhabinsky 《Journal of Applied Spectroscopy》2008,75(5):637-643
Comparative analysis of IR spectra of S-and R-isomers differing in the configuration of OH groups in the side chain of biologically
active 24-epi-and 28-homocastasterones and 24-epi-and 28-homobrassinolides is carried out. Stretching vibration frequencies
of H-bonded OH groups of isomers of corresponding brassinosteroids practically coincide. The optical density in maxima of
these bands is higher in spectra of the R-isomers. Alteration in the configuration of the OH groups weakly influences also
the band intensities of CH3, CH2, and CH groups. Band intensities of stretching vibrations of associated C=O groups of S-and R-isomers also neglibibly differ
from each other. Their frequency characteristics do not experience substantial changes. These features differ considerably
in IR spectra of castasterones and brassinolides. For castasterones, the difference in frequencies of band maxima of free
and bound C=O groups amounts to ∼15 cm−1; for brassinolides, 23 cm−1. Intensities of both bands are approximately equal in spectra of castasterones. The band intensity of free C=O groups of
brassinolides is considerably lower than that of H-bonded ones. The above spectral differences can be used to identify these
brassinosteroids. Frequencies of both symmetric and antisymmetric deformation vibrations of CH3 and CH2 groups are close in spectra of all brassinosteroids studied. The frequency of CH2 in a CH2-OC group belongs only to brassinolides; of deformation vibrations of CH in a CH-C=O group, to castasterones. The frequency
of stretching vibrations of C-O-C and C-O groups is observed only in spectra of brassinolides. In the region 1130–900 cm−1 of IR spectra of brassinosteroids, stretching vibrations of CC, CCH, and C-OH groups are predominantly observed. In the frequency
range 1130–995 cm−1, the optical density of band maxima of S-isomers is higher than that of R-isomers, which can be used to identify isomers.
At the same time frequencies of corresponding bands of isomers practically coincide. Differences in the structure of the side
chain of brassinosteroids do not influence essentially the frequency characteristics of the IR spectra. The exception is the
band related to stretching vibrations ν(C23-OH) of the side chain which features a considerable frequency νmax ≈ 983 cm−1 only in spectra of R-isomers of homocastasterone and brassinolide.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 5, pp. 623–630, September–October, 2008. 相似文献
11.
N. A. Borisevich G. G. Dyachenko V. A. Petukhov D. I. Polishchuk M. A. Semenov 《Optics and Spectroscopy》2011,110(5):686-693
We measured the fluorescence and fluorescence excitation spectra of supersonic jet-cooled 1,2-benzanthracene. Using the MO/M8ST
method, we calculated the frequencies of in-plane vibrations in the ground and first excited singlet electronic states, and,
in the Franck-Condon approximation, we calculated the intensities of transitions between them. Experimental spectra are interpreted
based on these data. In the fluorescence excitation spectrum, the position of the line of the 0–0 transition (26535 ± 1 cm−1), which is the most intense, is determined. 相似文献
12.
Resonant responses of Mandelshtam-Brillouin scattering from longitudinal and transverse acoustic waves at frequencies of ν
LS
= ±1.15 cm−1 and ν
TS
= ±0.7 cm−1, respectively, and at frequency of ν
SS
= ν
TS
$
\sqrt 3
$
\sqrt 3
= ±0.43 cm−1 were detected in K8 optical glass at room temperature using four-photon spectroscopy. We attribute this effect to the induced
generation of a second sound wave (coherent thermal phonons). The mechanisms of generation and the possibility of practical
application of the observed effect for express diagnostics of the quality of transparent materials are discussed. 相似文献
13.
V. I. Tomin 《Optics and Spectroscopy》2010,108(4):544-552
The dual fluorescence spectra of 3-hydroxyflavone molecules excited by electromagnetic radiation in the region of the S
1 and S
2 absorption bands in the temperature region of 20–80°C are studied using the dynamic quenching of the excited state. An analysis
of the fluorescence parameters shows that heating the solution from room temperature to 60°C increases the proton transfer
rate by a factor of 1.24 in the case of standard excitation into the main absorption band and even stronger (by a factor of
6.9) in the case of excitation into the second absorption band. The presence of a quencher reduces the yield of the two emission
bands and noticeably increases the proton transfer rate, by a factor of 1.16 at room temperature and by a factor of 1.25 at
80°C. Upon excitation into the second singlet band, the transfer rate increases even more (especially at higher temperatures),
by a factors of 1.24 and 3.5 for the same temperatures. The temperature dependences of the transfer rate constant allowed
us to estimate the activation energies of the proton transfer reaction under different physical conditions and reach conclusions
about the mechanism by which this reaction proceeds. It is found that the proton transfer activation energy decreases from
500 to 360 cm−1 when measured in temperature ranges of 20–40 and 20–60°C. The introduction of a quencher with a concentration of 5 × 10−3 M increases the activation barrier to 534 and 471 cm−1 in the same temperature ranges. 相似文献
14.
The Raman spectra of the single crystal of K2Zn(SO4)2·6H2O belonging toC
2h
5
space group in the 40–1200 cm−1 region in different scattering geometries and their spectra ofthe microcrystalline salt in the 1500-50 cm−1 region have been reported. The dynamics of the crystal has been described in terms of 186 phonon modes under the unit cell
approximation. The weak bands in the region 400–900 cm−1 have been assigned to the libratory modes of H2O molecules in contradiction to the assignments reported by Ananthanarayanan. The ambiguities existing in the literature about
the assignments ofν
2
c
andν
5
c
modes of [Zn(H2O)6]2+ have also been removed. The translatory and libratory modes of different units of the crystal have been identified and assignments
are made using farir and Raman data on various isomorphous tutton salts.
It has been inferred that both SO
4
2−
tetrahedron and [Zn(H2O)6]2+ octahedron undergo linear as well as angular distortions from their free state symmetries in the crystal. 相似文献
15.
Quasiline fluoresence and fluorescence excitation spectra of NH-isomers of 2,2,7,7,12,13,17,18-octamethylisobacteriochlorin
(cis- and trans-) in polycrystalline matrices in n-hexane and n-octane at 4.2 K are obtained. A vibration analysis of the
spectra in combination with the data of quasiline spectra of cyano-substituted octaethylisobacteriochlorin and octamethylporphin
permitted a qualitative interpretation of the vibronic spectra of NH-isomers. It is inferred that for a trans-isomer, the
0–0 transition S2⇃S0 is localized in the region of electron-vibrational S1⇃S0 transitions; the interval S2-S1 has a magnitude of about 1300 cm−1.
Reported at the VIIIth International Conference on the Spectroscopy and Chemsitry of Poprhyrins and Their Analogs, Belarus,
Minsk, September 22–26, 1998.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 1, pp. 79–85, January–February, 2000. 相似文献
16.
Fourier transform infrared spectroscopy studies have been conducted to investigate the interaction among components in a system
of high molecular weight polyvinylchloride (PVC)–lithium trifluoromethanesulfonate (LiCF3SO3) incorporated with different type of plasticizers, namely, ethylene carbonate (EC), propylene carbonate (PC), and dibutylphthalate
(DBP). Interaction between PVC and LiCF3SO3 was confirmed by C–H rocking mode at 1,255 cm−1 for PVC shift to 1,252 cm−1 in PVC–LiCF3SO3. The plasticizers’ carbonyl (C=O) oxygen atom which carries lone pair electrons interact with Li+ of LiCF3SO3 and methine hydrogen of PVC in LiCF3SO3–plasticizer system and PVC–plasticizer system, respectively. Changes in peaks assigned to 1,264 cm−1 (ν
as(SO3)), 1,033 cm−1 (ν
s(SO3)), 1,181 cm−1 (ν
as(CF3)), 1,230 cm−1 (ν
s(CF3)), 765 cm−1 (δ
s(CF3)), 644 cm−1 (δ
s(SO3)), 578 cm−1 (δ
as(CF3)), and 519 cm−1 (δ
as(SO3)) indicate the occurrence of complexation in the PVC–LiCF3SO3 system, LiCF3SO3–plasticizer system, and PVC–LiCF3SO3–plasticizer system. 相似文献
17.
N.?A.?Borisevich A.?L.?Ivanov S.?M.?Kazakov A.?V.?Kukhto A.?I.?Mit'kovets D.?V.?Murtazaliev V.?A.?Povedailo O.?V.?Khristoforov 《Journal of Applied Spectroscopy》2005,72(4):503-508
The electron energy loss spectra (EELS) of indole, 3-indolyl propionic acid, 3-indolealdehyde, 3-dimethylaminomethylindole,
tryptophan, and N-acetyl-L-tryptophan in the gas phase upon excitation by monokinetic electrons with an energy of E0 = 11–50 eV are obtained. The structure of EELS is determined in the main by the indole chromophore; the side groups, except
for the C=O group of 3-indolealdehyde, exert an insignificant influence. The energy of the lower triplet level 3La is 3.3 eV for indole and its derivatives and 3.2 eV for tryptophan and N-acetyl-L-tryptophan. Four singlet transitions in
the region of 4.4–7.2 eV have been identified. The molecules studied, except for tryptophan, fluoresce in the gas phase on
excitation by electrons. At low values of E0 (10–25 eV), the fluorescence spectra are similar and are due to the indole fluorophore. Just as in the case of optical excitation,
fluorescence on excitation by electrons is associated with the 1Lb-S0 transitions. An increase in the energy E0 up to 60–80 eV leads to dissociation of a portion of the indole molecules and to the appearance of additional bands in the
fluorescence spectrum.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 4, pp. 468–472, July–August, 2005. 相似文献
18.
R. M. Vlasova N. V. Drichko O. O. Drozdova R. N. Lyubovskaya 《Physics of the Solid State》1997,39(8):1165-1170
The reflection spectra and optical conductivity spectra of the new organic conductor ϰ-(ET)2[Hg(SCN)2Cl] with a metal-insulator transition in the spectral regions 700–5500 and 9000–40 000 cm−1 have been studied in polarized light at 300 K. A comparisonis made between the spectra obtained and the corresponding spectra
of related isostructural conductors based on the ET molecule, and also the properties of the crystal structure of the investigated
compounds. An electronic transition between the ET molecules of the dimer (ET)
2
+
in the spectral region 700–5500 cm−1 has been identified, as have the features of the electronic-vibrational structure arising as a consequence of the interaction
of this transition with the completely symmetric intramolecular vibrations of the ET molecule. It is found that the conductor
with the stronger dimer interaction between the ET molecules has the higher the transition temperature.
Fiz. Tverd. Tela (St. Petersburg) 39, 1313–1319 (August 1997) 相似文献
19.
N. A. Nemkovich W. Baumann Yu. V. Kruchenok G. I. Kurilo V. G. Pivovarenko A. N. Rubinov 《Optics and Spectroscopy》2011,110(4):541-549
Using spectroscopy of the molecular Stark effect and fluorescence spectroscopy, we study the characteristics of diflavonol
3,7-dihydroxy-2,8-di(4-dimethylaminophenyl)-4H,6H-pyrano[3,2-g]chromene-4,6-dione (DFME), which demonstrates intramolecular charge and proton phototransfer. In the ground state, this dye
has only one form and, in the excited state, it has two forms, i.e., normal and phototautomeric. We found that, for the normal
form of DFME, the transition dipole moment that is responsible for the absorption (m
a
), the dipole moment in the equilibrium ground state (μ
g
), and the change of the dipole moment upon transition of the molecule in the excited Franck-Condon state (Δ
a
μ) are parallel. In the ground equilibrium state, the dipole moments in 1,4-dioxane and cyclohexane are equal to μg = 12.2 × 10−30 C m and μ
g
= 11.0 × 10−30 C m, respectively. Upon excitation, they increase by Δ
a
μ = 61 × 10−30 C m and Δ
a
μ = 50.2 × 10−30 C m in these solvents. We study the spectral characteristics of DFME in organic solvents and erythrocyte membranes. A spectral
inhomogeneity of DFME in erythrocyte ghosts is found. The inhomogeneous broadening of fluorescence spectra is manifested as
a long-wavelength shift of the band of the normal form of DFME by 1640 cm−1 upon excitation at the red edge of the absorption spectrum. 相似文献
20.
The methods of selective laser spectroscopy applied at 1.8–10 K to a glass-forming tetrahydrofuran-toluene (3∶1) mixture have
revealed that in the dimers of tetrapyrrole compounds (ethane-bis-octaethylporphyrins, ethane-bis-Zn-octaethylchlorins, heterodimers
of Zn-cyclopentane porphyrins) the exciton interactions (V12≈118 cm−1) and S-S-transfer of energy (of probability F≈11 sec−1) are implemented under conditions of substantial inhomogeneous broadening (δF1/2≈50 cm−1). Upon excitation of a donor component in the dimers, one observes a strong quenching of its emission, the disappearance
of the fine structure in the fluorescence spectra, a decrease in the efficiency of spectral hole burning by, approximately,
an order of magnitude, and a 12-fold increase in their halfwidth.
To whom correspondence should be addressed.
Reported at the VIIIth International Conference on Spectroscopy of Porphyrins and Their Analogs, Minsk, September 22–26, 1998.
Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 4, pp. 500–504, July–August, 1999. 相似文献