共查询到20条相似文献,搜索用时 31 毫秒
1.
Efficiency of the structure analysis of complex molecules in the gas phase by their optical rotation
V. A. Tolkachev 《Journal of Applied Spectroscopy》1998,65(6):883-890
It was shown in the dipole approximation of optical rotation that in the general case only in orientationally anisotropic
vapors is the rotational force dependent on the intramolecular orientation of both the electric and magnetic dipole moments.
Expressions relating the optical rotational force to the intramolecular orientation of these moments, the orientational distribution
in an anisotropic ensemble, and the configuration of a measurement have been obtained. Calculated dependences of the rotational
force on the intramolecular orientation of the magnetic moment at a fixed electric moment and “rotational force excitation
spectra” obtained for different types of rigid asymmetric top molecules and rotational contours are presented. It is proposed
to measure the intramolecular orientation of the electric and magnetic dipole moments with the use of the rotational force
normalized to that detected in the case of observation at a “magic” angle to the direction of the exciting light electric
vector.
Institute of Molecular and Atomic Physics of the Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 6, pp. 843–849, November–December, 1998. 相似文献
2.
T. D. Ibragimov N. J. Ismailov E. A. Allahverdiyev I. S. Hasanov 《Journal of Applied Spectroscopy》2008,75(6):766-770
The possibility for homogeneous orientation of liquid-crystal (LC) molecules was studied after argon-ion bombardment of substrates
(Si, Ge) transparent in the infrared (IR) spectral region. The orientation of the LC molecules was monitored by IR spectroscopy.
Nematic LC 4-methoxybenzylidene-4′-butylaniline (MBBA) was used to study the molecular orientation. Absorption spectra were
analyzed near the band with maximum at 1630 cm−1 corresponding to − CH=N-group vibrations along the long axis of the MBBA molecule. The type and degree of initial orientation
of the LC molecules were determined from the correlation of the integrated absorptions of this band without and with an applied
electric field (above the threshold voltage for the Fredericksz effect). It has been established that an increased ion fluence
results in a planar orientation of the LC molecules and in a gradual transformation of the planar orientation of the molecules
to a homeotropic one with preliminary argon-ion bombardment of substrates at energies of 250 eV and 1.25 keV, respectively.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 6, pp. 763–767, November–December, 2008. 相似文献
3.
Optimization of the glass cylindrical active element (AE) of a solid-state laser is carried out. Dependences of the optical
quality of a laser medium on scale-geometry parameters of the AE with different-intensity optical pumping are obtained. The
possibility of considerable increasing of the laser efficiency by using an aperture diaphragm is shown.
Baltic State Technical University, 1, 1st. Krasnoarmeiskaya St., St.-Petersburg, 198005, Russia. Translated from Zhurnal Prikladnoi
Spektroskopii, Vol. 64, No. 6, pp. 734–737, November–December, 1997. 相似文献
4.
We present the kinetic and temperature dependences of the optical absorption of thermochromic films of polyvinyl alcohol with
added CoCl2. Based on the data obtained, we have analyzed the possibility that tetrahedral cobalt complexes are formed from octahedral
complexes.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 6, pp. 826–829, November–December, 2007. 相似文献
5.
Yuechun Fu Xuefei Li Yunyun Wang Huan He Xiaoming Shen 《Applied Physics A: Materials Science & Processing》2012,106(4):937-940
Cubic AlN films were successfully deposited on TiN buffered Si (100) substrates by a laser molecular beam epitaxy (LMBE) technique,
and their crystal structure and optical and electrical properties were studied. The results indicate that cubic AlN films
show the NaCl-type structure with a (200) preferred orientation, and the lattice parameter is determined to be 0.4027 nm.
The Fourier transform infrared (FTIR) pattern of the cubic AlN film displays sharp absorption peaks at 668 cm−1 and 951 cm−1, corresponding to the transverse and longitudinal optical vibration modes. Ellipsometric measurements evidence a refractive
index of 1.66–1.71 and an extinction coefficient of about zero for the cubic AlN film in the visible range. Capacitance–voltage
(C–V) traces of the metal–insulator–semiconductor (MIS) device exhibit that the cubic AlN film has a dielectric constant of 8.1,
and hysteresis in the C–V traces indicates a significant number of charge traps in the film. 相似文献
6.
S. N. Polyakov A. T. Rakhimov N. V. Suetin M. A. Timofeev A. A. Pilevskii 《JETP Letters》1997,65(5):434-438
Experiments on growing single-crystal diamond films on silicon crystals with (111) surface orientation have been performed.
Results attesting to the possibility of obtaining thin heteroepitaxial films are presented.
Pis’ma Zh. éksp. Teor. Fiz. 65, No. 5, 414–418 (10 March 1997) 相似文献
7.
The transformation of singular light beams is analyzed theoretically for multiwave interactions on amplitude and phase dynamic
holograms in media with a resonant nonlinearity. The possibility of multiplying topological charge using different diffraction
orders is demonstrated and optimal conditions for parametric energy exchange are determined which ensure retention of the
structure of the wave front of optical vortices.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 76, No. 3, pp. 395–402, May–June, 2009. 相似文献
8.
The laws governing polarization of luminescence in the nanostructure Si/CaF2 upon polarization of the spins of the fluorine nuclei by means of optical excitation of charge carriers are considered theoretically.
The possibility of studying experimentally the properties of nuclear spins in analyzing luminescence is shown. The polarization
of luminescence is most informative in the range of excitation rates of charge carriers from 3⋅107 to 3⋅ 108 sec−1 with the CaF2 layer of thickness from 0.6 to 0.8 nm and optical excitation polarization degree of 0.1.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 4, pp. 524–529, July–August, 2005. 相似文献
9.
We have considered theoretically the characteristic features of optical detection of nuclear magnetization in the Si/CaF2 structure under the conditions of EPR and NMR by measuring luminescence polarization. We show that application of EPR makes
it possible to detect weak nuclear fields, but the time of spin relaxation of electrons imposes its constraint. The application
of NMR is limited by nuclear fields of no less than 15–20 Gs. The possibility of using optical NMR for direct measurement
of the nuclear field from changes in the luminescence polarization spectrum is shown.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 5, pp. 644–649, September–October, 2005. 相似文献
10.
R. I. Dzhioev B. P. Zakharchenya E. L. Ivchenko V. L. Korenev Yu. G. Kusraev N. N. Ledentsov V. M. Ustinov A. E. Zhukov A. F. Tsatsul’nikov 《JETP Letters》1997,65(10):804-809
The experimental results of a study of the fine structure of the levels of excitons localized in InAlAs quantum dots in an
AlGaAs matrix are reported. Transformations from optical orientation to alignment and from alignment to orientation, which
occur due to the exchange splitting of a dipole-active excitonic doublet and are allowed by the low symmetry of a quantum
dot, are observed in a longitudinal magnetic field (Faraday geometry). A comparison of theory with experiment for a self-organized
ensemble of quantum dots enables a determination of the character of the distribution over the dipole orientations for resonance
optical transitions.
Pis’ma Zh. éksp. Teor. Fiz. 65, No. 10, 766–771 (25 May 1997) 相似文献
11.
V. G. Nikiforov G. M. Safiullin A. G. Shmelev A. V. Leontev V. S. Lobkov 《JETP Letters》2007,86(10):666-669
The control of the anisotropy of the orientation of molecules in pure 1,2-dichlorobenzene, C6H4Cl2 at room temperature is demonstrated experimentally. To accomplish the optical control, the medium is exposed to non-resonant
excitation with two successive linearly polarized laser pulses with a duration of 60 fs. The state of transient anisotropy
is probed with the third pulse by detecting the ultrafast optical Kerr effect via optical heterodyne detection and synchronous
demodulation. It is shown that variations in the two parameters, the delay time between two pump pulses, and the angle between
the polarization directions of the pump pulses ensure the control of the anisotropy of the orientation of molecules in the
subpicosecond region.
Original Russian Text ? V.G. Nikiforov, G.M. Safiullin, A.G. Shmelev, A.V. Leont’ev, V.S. Lobkov, 2007, published in Pis’ma
v Zhurnal éksperimental’noĭ i Teoreticheskoĭ Fiziki, 2007, Vol. 86, No. 10, pp. 757–761. 相似文献
12.
The specific features of spectrochemical properties of active silica-gel films in air media with various pH have been studied.
SiO2 films were obtained by acid hydrolysis of tetraethoxysilane. The optical properties were controlled by immobilization of
indicators (bromocresol purple, phenol red). The possibility of using them as optical-fiber sensors is shown.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 4, pp. 503–506, July–August, 2000. 相似文献
13.
V. M. Kotov 《Technical Physics》1999,44(1):120-121
The regime of collinear interaction of bichromatic optical radiation in biaxial crystals is considered. It is shown that the
possibility of the realization of such an interaction is due to dispersion of the optical axes in a biaxial crystal.
Zh. Tekh. Fiz. 69, 131–132 (January 1999) 相似文献
14.
G. L. Bochek V. I. Kulibaba N. I. Maslov V. D. Ovchinnik S. M. Potin 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2011,5(4):650-654
To determine the possibility of technological use of coherent Bremsstrahlung beams the photonuclear transmutation doping of
silicon by aluminum upon γ-quantum irradiation from the aligned single-crystal target was studied. An increase in aluminum
concentration by approximately ten times was obtained upon γ-radiation of silicon from the crystalline target aligned by the
crystallographic axis 〈111〉 along the direction of the electron beam with the energy of 1200 MeV. The orientation effect of
an increase in the yield of γ-radiation from silicon and tungsten crystals in the range of energies of accelerated electrons
of 300–1200 MeV was examined. This result is essential for the estimation of a possible minimum energy of electrons at which
the use of the orientation effect is reasonable. 相似文献
15.
N. A. Davidenko I. I. Davidenko A. N. Popenaka I. A. Savchenko A. N. Shumelyuk 《Journal of Applied Spectroscopy》2007,74(6):926-928
We have studied the possibility of recording holograms in films of the 4-methacroyloxy-(4′-carboxy-3′-hydroxy)-2-chloroazobenzene
polycomplex with cobalt, with parallel and orthogonal orientation of the light beam polarization. We have shown that these
films can be used as recording media for polarization holography. The characteristic features of relaxation of the diffraction
efficiency of the holograms are connected with cistrans isomerization of the azobenzene groups and the characteristic features
of structural rearrangement in the polymer matrix. We hypothesize that the information-related characteristics of the studied
recording media can be controlled by external electric or magnetic fields, due to the presence of magnetic metal ions within
the polymer film.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 6, pp. 830–832, November–December, 2007. 相似文献
16.
Thermal lensing has been studied by a probe beam technique in flashlamp-pumped Nd:KGdW laser rods with rod axes positioned
in the N
p–N
g plane and making different angles with the N
g optical indicatrix axis. It was found that the orientation of principal meridional planes of the astigmatic thermal lens
in Nd:KGdW corresponds to the directions with maximum and minimum values of thermal-expansion coefficient in the plane perpendicular
to the rod axis. The athermal Nd:KGdW laser crystal orientation defined as orientation with weak positive near spherical thermal
lens has been determined to make an angle of 30○–40○ with the N
g axis for light polarization E∥N
m. 相似文献
17.
Polypyrrole (PPy)–indium phosphide (InP) composite material was electrochemically prepared by the incorporation of InP into
a PPy matrix during electrochemical synthesis (cycling) under magnetic stirring from the acetonitrile/LiClO4 electrolyte containing
the Py and InP particles. The PPy–InP composite material was designed to explore new approaches to improve light-collection
efficiency in polymer photovoltaic. The samples were characterised by cyclic voltammetry, impedance spectroscopy measurement,
scanning electron microscopy, energy dispersive X-ray spectroscopy, UV–visible and photoelectrochemical measurements. It was
observed that the photocurrent of the composites was higher than that of the single PPy films and increased with InP concentration.
The study showed that the presence of InP particles in the polymeric film improves the optical and the photovoltaic properties
of PPy and give information on the use possibility of these films for photovoltaic cells' application. 相似文献
18.
T. Asshauer G. Delacrétaz E.D. Jansen A.J. Welch M. Frenz 《Applied physics. B, Lasers and optics》1997,65(4-5):647-657
5 Pa served as tissue phantoms to evaluate such effects. Holmium laser pulses (wavelength: 2.12 μm, duration: 180 μs FWHM),
were delivered through 400 and 600 μm diameter optical fibers inserted into cubes of clear gel. Bubble effects were investigated
using simultaneous flash micro-videography and pressure recording for radiant exposures of 20–382 J/cm2.
Bubble formation and bubble collapse induced pressure transients were observed regardless of phantom stiffness. Bubbles of
up to 4.2 mm in length were observed in gels with a Young’s modulus of 2.9×105 Pa at a pulse energy of 650 mJ. An increase of Young’s modulus (reduction in water content) led to a monotonic reduction
of bubble size. In the softest gels, bubble dimensions exceeded those observed in water. Pressure amplitudes at 3 mm decreased
from 100±14 bars to 17±6 bars with increasing Young’s modulus over the studied range. Theoretical analysis suggested a major
influence on bubble dynamics of the mass and energy transfer through the bubble boundary.
Received: 26 August 1996/Revised version: 10 February 1997 相似文献
19.
The peak-power-density stability and beam-wander precision of a probe laser are important factors affecting the inspection
results in precise thin-film optical measurements. These factors are also key to evaluating a probe laser for in-line long-time
operation of precise thin-film optical measurements. The peak-power density and beam wander of liner helium–neon (He–Ne) lasers,
random He–Ne lasers, and diode lasers as functions of time are investigated experimentally using a beam profiler. It is found
that the linear polarized He–Ne laser is considered to be a promising candidate for a probe laser employed in precise thin-film
optical measurements due to better peak-power-density stability and beam-wander precision. Both the peak-power-density stability
and beam-wander precision of He–Ne lasers are usually better than that of diode lasers, but an adequate warm-up of He–Ne laser
for 30 min is required before thin-film optical measurements are made. After 12 h operation, the linear polarized He–Ne laser
is suitable for precise thin-film optical measurements because both the peak-power-density stability and the beam-wander precision
reach the minimum level. A cost-effective system composed of two linear polarized He–Ne lasers for long-term operation is
proposed. This system can operate for around 0.5–1.2 years in precise thin-film optical measurements under the normal operating
life of a He–Ne laser by switching the probe laser every 18 h. 相似文献
20.
Second harmonic generation and optical parametric amplification in negative-index metamaterials (NIMs) are studied. The opposite
directions of the wave vector and the Poynting vector in NIMs results in a “backward” phase-matching condition, causing significant
changes in the Manley–Rowe relations and spatial distributions of the coupled field intensities. It is shown that absorption
in NIMs can be compensated by backward optical parametric amplification. The possibility of distributed-feedback parametric
oscillation with no cavity has been demonstrated. The feasibility of the generation of entangled pairs of left- and right-handed
counter-propagating photons is discussed.
PACS 78.67.-n; 42.65.Ky; 42.65.Lm 相似文献