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1.
N. D. Strekal’ I. G. Motevich J. W. Nowicky S. A. Maskevich 《Journal of Applied Spectroscopy》2007,74(1):31-37
We present the IR absorption and surface-enhanced Raman scattering (SERS) spectra of the isoquinoline alkaloid berberine adsorbed
on a silver hydrosol and on the surface of a silver electrode for different potentials. Based on quantum chemical calculations,
for the first time we have assigned the vibrations in the berberine molecule according to vibrational mode. The effect of
the potential of the silver electrode on the geometry of sorption of the molecule on the surface is considered, assuming a
short-range mechanism for enhancement of Raman scattering.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 1, pp. 31–36, January–February, 2007. 相似文献
2.
Silver electrode layers of different porosity on yttrium stabilized zirconia (YSZ) were investigated by X-ray and ultraviolet
photoelectron spectroscopy (XPS and UPS resp.). By applying different potentials in a three electrode arrangement oxygen could
be transported from a gaseous reservoir to the working electrode. The change in the work function of the working electrode
as a function of applied potentials was monitored by UPS. It showed significant different behavior for dense and porous silver
electrodes. On a dense silver electrode a change in work function of up to 0.6 eV was observed at potentials at which a considerable
current passed through the electrolyte. In the UP spectra of the valence band an additional structure appeared at a binding
energy of 3.3 eV. These changes were also reflected in the appearance of oxygen O 1s signals in the XP spectra at 529 eV assigned
to subsurface oxygen. On a porous silver electrode the work function at equilibrium (open circuit) was higher than that of
metallic silver and increased linearly with increasing potential, although yet no current through the electrolyte could be
observed. With the onset of considerable currents at larger anodic potentials the work function increase became stronger.
As reason for the linear increase of the measured work function contributions of the solid electrolyte YSZ are considered.
Paper presented at the 7th Euroconference on Ionics, Calcatoggio, Corsica, France, Oct. 1–7, 2000. 相似文献
3.
O. V. Ovchinnikov E. A. Kosyakova M. S. Smirnov A. B. Evlev V. G. Klyuev A. N. Latyshev A. N. Utekhin 《Journal of Applied Spectroscopy》2007,74(5):681-686
For microcrystals of Zn0.6Cd0.4S with adsorbed molecules of a number of organic dyes, we have observed sensitized anti-Stokes luminescence excited by radiation
with wavelengths in the range 610–750 nm and flux density 1014–1015 photons/cm2·sec. The positions of the bands in the excitation spectra for such luminescence match those of the absorption spectra for
the adsorbed dye molecules, which is evidence in favor of a cooperative mechanism for its appearance. We have shown that enhancement
of the anti-Stokes luminescence is possible when silver atoms and few-atom clusters appear on the Zn0.6Cd0.4S surface in addition to the dye molecules. We hypothesize that its excitation in the latter case occurs as a result of two-photon
optical transitions. These transitions occur sequentially, with transfer of an electron or the electronic excitation energy
from the dye molecules to silver atoms and few-atom clusters adsorbed on the surface of Zn0.6Cd0.4S, creating deep localized states in the bandgap with photoionization energies 1.80–2.00 eV.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 5, pp. 617–621, September–October, 2007. 相似文献
4.
Kaushik Mallick Mike J. Witcomb Mike S. Scurrell 《Journal of nanoparticle research》2007,9(2):323-330
A synthetic route is presented for the preparation of a bimetallic gold–silver film under UV-irradiation. Methoxy polyethylene
glycol, a water soluble polymer, is used as the reducing agent for the gold and silver ions in the presence of a ultra-violet
source that results in the formation of gold and silver bimetallic nanoparticles. During stirring a centrifugal force is generated
at the center of the solution, which results in a coalescence of the nanoparticles and forms a self-assembly of small subunits
that ultimately produces a film-like network. UV–vis spectra and scanning electron microscopy were used to determine, respectively,
the configuration of the gold and the silver in the nanoparticles, a Aucore–Agshell structure, and the thickness of the film. 相似文献
5.
The kinetics of the oxygen exchange reactions at the electrodes of a galvanic cell using yttria-doped zirconia single crystals
(9.5 mole-% Y2O3) as solid electrolyte and Pt or Ag as electrode materials was studied by complex impedance spectroscopy. The electrode resistance
when using silver was found to have negligible values over the temperature range 180 – 900 °C. In agreement with these results,
oxygen sensors were tested successfully at temperatures as low as 200 °C. According to the performance of silver as electrode
material, an electrochemical method was developed to determine the oxygen diffusion coefficient in doped zirconia. The results
obtained, compared to those of conductivity and oxygen tracer diffusion measurements, have allowed us to obtain information
both on the structure of the defects in yttria-doped zirconia and on the correlation factor.
Paper presented at the 4th Euroconference on Solid State Ionics, Renvyle, Galway, Ireland, Sept. 13–19, 1997 相似文献
6.
We have examined the process of redox dispersion of silver, using a solution simultaneously containing an oxidizing agent
(potassium ferricyanide) and a reducing agent (sodium borohydride). We have studied the changes over time in the Raman spectra
of the indicated solution when no silver particles are present and when such particles are added to the solution. We have
established that the silver particles have a catalytic effect on the reaction between potassium ferricyanide and sodium borohydride,
kinetically slowed down in alkaline medium. The original silver particles (1–20 μm) undergo redox dispersion as a result,
and Ag particles are formed with sizes 1–10 nm.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 2, pp. 182–186, March–April, 2006. 相似文献
7.
We have recorded the fluorescence excitation spectra of three heterocyclic compounds with a chain structure [BPO (2-phenyl-5-(4-diphenylyl)oxazole),
POPOP (1,4-di[2-(5-phenyloxazolyl)]benzene, and TOPOT (1,4-di[2-(5-n-tolyloxazolyl)]benzene] and the fluorescence spectra
of POPOP, under conditions where the molecules were cooled in an ultrasonic helium jet. A line structure is observed in the
spectra of POPOP and TOPOT; for the BPO molecules, whose configuration changes considerably during electronic excitation,
vibrational structure is apparent only in the low-frequency region of the excitation spectrum, and a diffuse spectrum is recorded
starting from ν
0
0
+ 200 cm−1. For all the compounds, in the spectra we recorded vibrations with frequencies up to 100 cm−1, arising due to the flexibility of the molecular structure. The rotational contours of the lines for the electronic and vibronic
transitions of the POPOP molecules (Trot = 10.5 K) and TOPOT molecules (Trot = 15 K) are structureless and bell-shaped. The degree of polarization of the fluorescence Pfl for the jet-cooled POPOP molecules for excitation of vibrations along the absorption band up to 2000 cm−1 above ν
0
0
is practically constant (∼8.4%) and matches Pfl for high-temperature vapors.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 6, pp. 728–734, November–December, 2006. 相似文献
8.
I. L. Babich A. N. Veklich L. A. Kryachko R. B. Minakova V. E. Osidach 《Journal of Applied Spectroscopy》2006,73(3):426-431
We have used optical spectroscopy to study the radial temperature profiles for an electric arc plasma between silver electrodes
and electrodes made from composite materials based on silver (Ag-CdO). We studied the structural changes in the working layers
of the electrodes by metallography. We established that the parameters of the arc discharge plasma are determined by the condition
of the electrode surface.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 3, pp. 375–379, May–June, 2006. 相似文献
9.
Two asymmetrical molecules with substituted acetylene as central rigid elongated conjugation are reported as potential chromophores
for two-photon microscopic imaging. These molecules consist of a typical D–π–A structure, have different donors (D), the same
π-conjugated center (π) and the same acceptor (A). Structural characterization and spectroscopic properties, including single-photon
(linear) absorption, quantum yields, single-photon fluorescence, and two-photon absorption spectra, were studied in solvents
with different polarity. These acetylene-substituted molecules were found to have high two-photon absorption cross-sections
(for example, 690 GM for molecule 1 in toluene), which were determined by a two-photon induced fluorescence method using a
femtosecond Ti: sapphire laser as excitation source. Single- and two-photon cellular imaging experiments demonstrate that
the substituted acetylene derivatives could be one kind of promising two-photon fluorescence probes for cellular imaging. 相似文献
10.
We have obtained and analyzed the absorption, fluorescence, and fluorescence excitation spectra of indole vapor, N-acetyl-L-tryptophan
vapor, and 3-indole aldehyde vapor. From analysis of the dependence of the fluorescence spectrum of the free indole molecules
on the wavelength of the exciting radiation λex, it follows that emission of fluorescence occurs when the molecules undergo a transition from the one electronically excited
state 1Lb. The fluorescence spectra of the studied compounds are insignificantly different, suggesting a major role for the indole
chromophore in formation of the compounds. The absorption spectrum of N-acetyl-L-tryptophan, in which the group of atoms is
added to the indole ring through a-C-C bond, is similar to the spectrum of indole, while the spectrum of 3-indole aldehyde
is significantly different from the indole spectrum due to the effect of the C=O group conjugated with the indole ring. The
fluorescence excitation spectra are considerably different from the absorption spectra. This is associated with the strong
dependence of the quantum yield for the free molecules on λex. Qualitatively, they are mirror-symmetric to the fluorescence spectra of the stodied compounds. Analysis of the data obtained
provides a basis for assuming that in the case of free molecules of indole and its derivatives, the 1La absorption in the extreme long-wavelength region of the spectrum does not overlap 1Lb absorption.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 2, pp. 218–222, March–April, 2007. 相似文献
11.
A. N. Latyshev O. V. Ovchinnikov D. A. Minakov M. S. Smirnov 《Journal of Applied Spectroscopy》2006,73(3):377-381
We have used photostimulated flash luminescence to study deep electronic states arising when silver ions Ag+ are deposited under high vacuum onto the surface of a ZnS single crystal, followed by creation of the conditions for neutralization
of the silver ions. The flux density of the silver ion beam was 107 cm−2·sec−1. We have observed the appearance of two types of deep electronic states with photoionization energies 1.60 eV and 1.80 eV,
arising after depositing the silver ions onto the surface of the ZnS single crystal. We have hypothesized that there may be
two different preferred sites for adsorption of silver atoms on the zinc sulfide surface. The corresponding photoionization
spectra of the adsorbed silver atoms have maxima at 775 nm and 690 nm.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 3, pp. 335–338, May–June, 2006. 相似文献
12.
K.-L. Jonas V. von Oeynhausen J. Bansmann K.-H. Meiwes-Broer 《Applied Physics A: Materials Science & Processing》2006,82(1):131-137
Morphology and electronic properties of silver islands and deposited silver clusters on Ge(001) have been studied using scanning tunnelling microscopy (STM) and spectroscopy (STS) at low temperatures. Already the clean surface bears an interesting electronic structure, which is obvious from the STS. The tunnelling spectra exhibit strong peaks associated with dangling bond-derived surface states and an antibonding σ-state of the surface dimer. For silver islands of only few monolayers in height, complex spectra are interpreted to be dominated by metal–semiconductor interface states. These islands show energy gaps which are not observed for larger ones beyond 1 nm in height. Spectra of the larger islands contain a series of distinct peaks originating from lateral and three-dimensional electron confinement, respectively. Silver clusters – preformed in the gas phase using a cluster source – have been fabricated, size selected and deposited onto germanium(001). In tunnelling spectra dips at the Fermi level are accompanied by two maxima. These characteristics seem to be almost independent from the cluster size. Additional weak structures are found at higher bias voltages, which are understood in terms of quantized states. PACS 36.40.Cg; 61.46.+w; 73.20.At 相似文献
13.
We have carried out a comparative analysis of fine-structure fluorescence excitation and fluorescence spectra of naphthalene,
2,6-and 2,7-dimethylnaphthalene, and 2-methylnaphthalene molecules cooled in a supersonic jet. We have shown that both the
frequencies and the intensities of most of the lines in the spectra of these molecules are correlated. Such a correlation
facilitates interpretation of the spectra in the case when it is difficult to calculate the transition intensities and when
lines corresponding to vibrations of different symmetry have close frequencies. For the considered molecules, a preliminary
assignment of the lines in the fine-structure spectra is refined.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 3, pp. 336–340, May–June, 2007. 相似文献
14.
O. V. Ovchinnikov E. A. Kosyakova L. Yu. Leonova M. S. Smirnov A. B. Evlev A. N. Latyshev A. N. Utekhin 《Russian Physics Journal》2008,51(3):244-250
The sensitized anti-Stokes luminescence excited by radiation with wavelengths from 610 to 750 nm and flux densities of 1014–1015 quanta/(cm2·s) is detected for microcrystals of Zn
0.6
Cd
0.4
S solid solutions with adsorbed organic malachite green and methylene blue dye molecules. The position of its excitation spectra
coincides with that of the absorption spectra of adsorbed dye molecules, which suggests the cooperative mechanism of its occurrence.
The possibility of amplification of the anti-Stokes luminescence by means of adsorption of silver atoms and few-atomic silver
clusters, in addition to the dye molecules, on the Zn
0.6
Cd
0.4
S surface is investigated. It is assumed that in the latter case, the anti-Stokes luminescence is excited as a result of two-quantum
optical transitions with electron or electron excitation energy transfer from the dye molecules adsorbed on the Zn
0.6
Cd
0.4
S surface to silver atoms and few-atomic silver clusters creating deep local states with photoionization energies of 1.8–2.0
eV in the gap.
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Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 21–26, March, 2008. 相似文献
15.
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.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 4, pp. 468–472, July–August, 2005. 相似文献
16.
The pH‐dependent surface‐enhanced Raman scattering (SERS) of 1,2,4‐triazole adsorbed on silver electrode and normal Raman (NR) spectra of this compound in the aqueous solutions were investigated. The observed bands in the NR and SERS spectra were assigned with the help of density functional theory calculations for model molecules in the neutral, anionic, and cationic forms and their complexes with silver. The Raman wavenumbers and intensities were computed at the optimized molecular geometry. Vibrational assignments of the SERS and NR spectra are provided by calculated potential energy distributions. The combination of experimental SERS results and density functional theory calculations provide an insight into the molecular structure of adlayers formed by 1,2,4‐triazole on a silver surface at varying pH values and enable the determination of molecular orientation with respect to the surface. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
17.
O. S. Kulakovich N. D. Strekal’ M. V. Artem’ev A. P. Stupak S. A. Maskevich S. V. Gaponenko 《Journal of Applied Spectroscopy》2006,73(6):892-896
We have studied enhancement of the fluorescence of fluorescein isothiocyanate (FITC), bound to albumin and near an annealed
silver island film, as a function of the distance between the protein molecules and the metal. As the intermediate spacer
layer between the albumin and the silver substrate, we used multilayer films based on polyelectrolytes. The maximum nine-fold
enhancement coefficient for the fluorescence of FITC corresponds to a thickness of the intermediate layer of ≈4 nm, or three
layers of the polyelectrolyte. In this case, we observe a significant decrease in the average photoluminescence decay time
for the label near the silver film compared with a dielectric medium.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 6, pp. 797–800, November–December, 2006. 相似文献
18.
We have used valence optical theory to carry out calculation and analysis of in-plane vibrations and intensities of IR spectra
for isolated 5-fluorouracil and 5-bromouracil molecules. We give a complete interpretation of the corresponding bands in the
absorption spectra. We have carried out a quantum mechanical calculations of the relative intensities in the resonant Raman
spectra of 5-fluorouracil and 5-chlorouracil. The calculated spectra for the molecular models obtained agree quantitatively
with the experimental spectra, and reproduce the observed characteristic spectral differences in the series of molecules:
uracil, 5-fluorouracil, 5-chlorouracil, and 5-bromouracil. The models obtained for the molecules can be used for calculation
and analysis of the spectra of other halosubstituted nucleic acid bases.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 4, pp. 437–442, July–August, 2006. 相似文献
19.
N. D. Strekal' V. F. Oskirko G. A. Gachko L. N. Kivach S. A. Maskevich 《Journal of Applied Spectroscopy》1999,66(5):701-707
An investigation of giant RS spectra of a thiamine (vitamin B1) molecule adsorbed on the surface of an anodized silver electrode from weak-concentration aqueous solutions is made. The
dependences of the spectral bands sensitive to the ionic state of the adsorbed molecule on the pH and the electrode potential
are discussed. It is shown that the rate constant of thiamine protonation in the adsorbed layer depends on the electrode potential
and is substantially lower than the corresponding value for the solution. In conformity with the important role of short-range
mechanisms of enhancement of electrochemical GRS in the excitation wavelength range investigated, models of the structural-conformational
states of the molecule in the adsorbed state are constructed and a conclusion is drawn about the possibility of monitoring
the acid-base equilibrium of these states for a molecular layer of thiamine under the conditions of an electrochemical cell.
To whom correspondence should be addressed.
Ya. Kupala Grodno State University, 22, Ozheshko Str., Grodno, 230023, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 66, No. 5, pp. 622–626, September–October, 1999. 相似文献
20.
Using data on the stability of complex forms, electron absorption spectra of copper (I)-, silver (I)-, and gold (I)—thiourea
complexes in an aqueous solution Mituj (Ag: i=1, 2, j=1–3; Cu: j=1, 2; Au: j=2) are calculated from the spectra of solutions of a known analytical composition.
Parameters of particular bands of the absorption spectra of these complexes are given. It is found that the integral intensity
of the spectra of the solutions is proportional to the concentration of thiourea in the solution with high accuracy. The same
is also valid for the spectra in solutions that contain mercury (II) and thiourea. The total intensity of longwave bands in
the spectra of the complexes is proportional to the number of ligands in a molecule of the complex.
Institute of Ionorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, 3, Lavrent’ev Ave., 630090, Novosibirsk-90,
Russia, Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 4, pp. 458–462, July–August, 1997. 相似文献