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1.
We demonstrate the stimulated Raman scattering (SRS) of a binary solution of toluene and m-xylene at different volume concentrations
in liquid-core optical fiber (LCOF). The results show that SRS of three vibration modes of 1002 cm−1,2920 cm−1 and 3058 cm−1 bands are simultaneously generated at some volume concentrations. The 2920 cm−1 band and the 3058 cm−1 band are generated at one time, the SRS thresholds of the first-order Stokes of the 2920 cm−1 and 3058 cm−1 bands are lower compared with the second-order Stokes threshold of the 1002 cm−1 band and the main peak of the 2920 cm−1 and 3058 cm−1 bands changes from the 2920 cm−1 band to the 3058 cm−1 band as the volume concentrations are changed. We assume that these phenomena are attributed to the intermolecular Fermi
resonance. Raman scattering cross section (RSCS) theory is used to explain this assumption. 相似文献
2.
We further discuss possible sgoldstino interpretation of the observation, reported by the HyperCP collaboration, of three
Σ+ → pμ+μ− decay events with the dimuon invariant mass 214.3 MeV within the detector resolution. With a sgoldstino mass equal to 214.3
MeV, this interpretation can be verified at existing and future B and ϕ factories. We find that the most natural values of the branching ratios of two-body B and D meson decays to sgoldstino P and vector meson V are about 10−6−10−7. The branching ratios of ϕ meson decay ϕ → Pγ are estimated to be in the range 1.8 × 10−13−1.6 × 10−7, depending on the hierarchy of supersymmetry-breaking soft terms. Similar branching ratios for ρ and ω mesons are in the
range 10−14−3.4 × 10−7.
The text was submitted by the authors in English. 相似文献
3.
A. V. Besnosov S. Yu. Savinov O. O. Novozhilova M. A. Antonenkov 《Physics of Atomic Nuclei》2011,74(14):1930-1936
Presented are the results of experimental research of temperature and velocity fields for lead and lead-bismuth coolant flows
in channels having circular and annular cross sections under varying oxygen content in the coolant and varying characteristics
of insulating coatings. Tests are performed under the following operating conditions: (1) lead-bismuth eutectic—temperature
T = 400−520°C, thermodynamic oxygen activity a = 10−5–100, average flow velocity of the coolant w = 0.12−1.84 m/s, value of magnetic induction B = 0−0.85 T, Reynolds number Re = (0.24–3.5) × 105, Hartmann number Ha = 0−500, and Peclet number Pe = 320−4600; (2) lead coolant-T = 400−550°C, a = 10−5−100, w = 0.1−1.5 m/s, Re = (2.36−2.99) × 105, and Pe = 500−7000. 相似文献
4.
Indoor radon has been recognized as one of the health hazards for mankind. Building materials constitute the second most important
source of radon in dwellings. The common building materials used in the construction of dwellings are studied for radon exhalation
rate. The ‘Can’ technique using LR-115 type-II solid-state nuclear track detector has been used for these measurements. The
radon exhalation rate in these samples varies from 4.75 m Bq m−2 h−1 (0.14 m Bq kg−1 h−1) for limestone to 506.76 m Bq m−2 h−1 (15.24 m Bq kg−1 h−1) for soil. 相似文献
5.
Ganesh Prasad Yogesh Prasad G. S. Gusain Manjari Badoni J. M. S. Rana R. C. Ramola 《Indian Journal of Physics》2009,83(6):887-892
Radon was measured in soil-gas and groundwater in the Budhakedar area of Tehri Garhwal, India in summer and winter to obtain
the seasonal variation and its correlation with radon exhalation rate. The environmental surface gamma dose rate was also
measured in the same area. The radon exhalation rate in the soil sample collected from different geological unit of Budhakedar
area was measured using plastic track detector (LR-115 type II) technique. The variation in the radon concentration in soil-gas
was found to vary from 1098 to 31,776 Bq.m−3 with an average of 7456 Bq.m−3 in summer season and 3501 to 42883 Bq.m−3 with an average of 17148 Bq.m−3 in winter season. In groundwater, it was found to vary from 8 to 3047 Bq.l−1 with an average value 510 Bq.l−1 in summer and 26 to 2311 Bq.l−1 with an average value 433 Bq.L−1 in winter. Surface gamma dose rate in the study area varied from 32.4 to 83.6 μR.h−1 with an overall mean of 58.7 μ-R.h−1 in summer and 34.6 to 79.3 μR.h−1 with an average value 58.2 μR.h−1 in winter. Radon exhalation rate from collected soil samples was found to vary from 0.1 × 10−5 to 5.7 × 10−5 Bq.kg−1.h−1 with an average of 1.5 × 10−5 Bq.kg−1.h−1 in summer season and 1.7 × 10−5 to 9.6 × 10−5 Bq.kg−1.h−1 with an average of 5.5 × 10−5 Bq.kg−1.h−1. A weak negative correlation was observed between radon exhalation rate from soil and radon concentration in the soil. Radon
exhalation rate from the soil was also not found to be correlated with the gamma dose rate, while it shows a positive correlation
with radon concentration in water in summer season. Inter-correlations among various parameters are discussed in detail.
相似文献
6.
T R Seshadri 《Pramana》1999,53(6):989-993
We have carried out a multi-fractal analysis of the distribution of galaxies in the three Northern slices of the Las Campanas
redshift survey. In this analysis we have studied the scaling properties of the distribution of galaxies on length scales
from 20 h−1 Mpc to 200 h−1 Mpc. Our main results are: (1) The distribution of galaxies exhibits a multi-fractal scaling behaviour over the scales 20
h−1 Mpc to 80 h−1 Mpc, and, (2) the distribution is consistent with homogeneity on the scales 80 h−1 Mpc to 200 h−1 Mpc. We conclude that our results are consistent with the Universe being homogeneous at large scales and the transition to
homogeneity occurs somewhere in the range 80 h−1 Mpc to 100 h−1 Mpc. 相似文献
7.
Transparent conducting Zn−Sn−O films were deposited on Polypropylene adipate thin-film substrates at low temperature by r.
f. magnetron sputtering. The structural, electrical and optical properties of the deposited films were investigated. All the
obtained films are of amorphous structure and have a very good adhesion to the substrates. The resistivity, carrier concentration
and Hall mobility of the film are 1.3×10−2 Ω·cm, 4.1×1019 cm−3 and 12.4 cm2· V−1· s−1, respectively. The transmittance of the film reaches 82%. 相似文献
8.
Three sensitive and selective new alternatives for fluorometric determination of cerium(III) are described in this study.
Ce(III) is highly fluorescent in sodium pyrophosphate, sodium trimetaphosphate, and sodium tetrametaphosphate solutions. For
these reagents, the maximum excitation/emission wavelengths are 300/350, 297/340, and 299/352 nm, respectively. Maximum fluorescence
intensities are obtained by irradiating Ce(III) dissolved in 0.033 g L−1 sodium pyrophosphate, 41.4 g L−1 sodium trimetaphosphate, and 0.96 g L−1 sodium tetrametaphosphate at room temperature. The fluorescence intensities are linear over the range 0.001–30, 0.001–75,
and 0.001–70 μg ml−1. The detection limits are calculated as 9.5 × 10−3, 1.1/10−3, and 3.8 × 10-3 μg ml−1 Ce(III), respectively. The relative standard deviations for 15/0.05 Μg ml−1 Ce(III) are 1.1/1.2, 1/1.1, and 1.2/1.3%, respectively. Quenching effects of other lanthanides and some inorganic anions
were investigated. The methods have been applied to rare earth mixtures with a good accuracy. 相似文献
9.
It is found that silver nanoparticles (AgNPs) can further enhance the fluorescence intensity of curcumin (CU) - cetyltrimethylammonium
bromide (CTAB) – nucleic acids and improve its anti-photobleaching activity. Under optimum conditions, the enhanced fluorescence
intensity is proportion to the concentration of nucleic acids in the range of 2.0 × 10−8–1.0 × 10−6 g mL−1 for fish sperm DNA (fsDNA), 2.0 × 10−8–1.0 × 10−6 g mL−1 for calf thymus DNA (ctDNA), 1.0 × 10−8–1.0 × 10−6 g mL−1 for yeast RNA (yRNA), and their detection limits (S/N = 3) are 8.0 ng mL−1, 10.5 ng mL−1 and 5.8 ng mL−1, respectively. This method is used for determining the concentration of DNA in actual sample with satisfactory results. The
interaction mechanism is also studied. 相似文献
10.
A novel, simple, sensitive and selective spectrofluorimetric method was developed for the determination of trace amounts of
chlorzoxazone and Ibuprofen in pharmaceutical tablets using optical sensor Eu-Tetracycline HCl doped in sol–gel matrix. The
chlorzoxazone or Ibuprofen can remarkably enhance the luminescence intensity of Eu-Tetracycline HCl complex doped in a sol–gel
matrix in dimethylformamide (DMF) at pH 9.7 and 6.3, respectively, λex = 400 nm. The enhancing of luminescence intensity peak of Eu-Tetracycline HCl complex at 617 nm is proportional to the concentration
of chlorzoxazone or Ibuprofen a result that suggested profitable application as a simple optical sensor for chlorzoxazone
or Ibuprofen assessment. The dynamic ranges found for the determination of chlorzoxazone and Ibuprofen concentration are 5 × 10−9–1 × 10−4 and 1 × 10−8–7 × 10−5 mol L−1, and the limit of detection (LOD) and quantitation limit of detection (LOQ) are 3.1 × 10−10 , 9.6 × 10−10 and 5.6 × 10−10, 1.7 × 10−9 mol L−1, respectively. 相似文献
11.
The electromagnetic mass splittings of heavier hadrons are estimated in the framework of gauge theory model where ligher quarks
are taken to behave relativistically and the spatial wave functions are described by the spin-spin interaction affected relative
distances between quarks. The predictions for (Ξ−-Ξ0), (Σ*0−Σ*+), (Ξ*−-Ξ*0), (D
c
+−D
c
0) and (D
c
*+
−D
c
*0
) are in fair agreement with the experimental data available whereas those for (D
b
−
−D
b
0
) and (D
b
*−
−D
b
*0
) are in qualitative agreement with other theoretical estimates. 相似文献
12.
Water-soluble Mn2+-doped ZnS quantum dots (QDs) were prepared using mercaptoacetic acid as the stabilizer. The optical properties and structure
features were characterized by X-Ray, absorption spectrum, IR spectrum and fluorescence spectrum. In pH 7.8 Tris-HCl buffer,
the QDs emitted strong fluorescence peaked at 590 nm with excitation wavelength at 300 nm. The presence of sulfide anion resulted
in the quenching of fluorescence and the intensity decrease was proportional to the S2− concentration. The linear range was from 2.5 × 10−6 to 3.8 × 10−5 mol L−1 with detection limit as 1.5 × 10−7 mol L−1. Most anions such as F−, Cl−, Br−, I−, CH3CO2
−, ClO4
−, CO3
2−, NO2
−, NO3
−, S2O3
2−, SO3
2− and SO4
2− did not interfere with the determination. Thus a highly selective assay was proposed and applied to the determination of
S2− in discharged water with the recovery of ca. 103%. 相似文献
13.
14.
V. M. Andrianov 《Journal of Applied Spectroscopy》2007,74(1):1-12
A theoretical conformational analysis has been carried out for the side substituents of a fragment of the molecule for 2,6-carboxymethyl
cellulose (a water-soluble cellulose ether), and the frequencies and the potential energy distribution of the normal vibrations
have been calculated for the most stable conformers of the ether groups of this fragment in the approximation of the molecular
mechanics method. It has been shown that the most stable conformers are those that have the conformations gg, t, g−, g−, g−-for the groups of atoms on the bonds C5-C6, C6-O6, C13-O6, C10-C13, C10-O9 and the conformations g+g−, g+, g−, g−; g+g−, g−, g−, g−; g+g−, g−, g+, t for the groups of atoms on the bonds C2-O2, C11-O2, C7-C11, C7-O8. Comparative analysis of the calculated frequencies
and the potential energy distribution of the normal vibrations for 13 of the most stable conformers showed, as in the case
of the 2,6-hydroxyethyl cellulose molecule, that the frequencies and modes of the normal vibrations are highly sensitive to
conformational transitions in the analyzed spectral region (800–1500 cm−1). The characteristic patterns for the change in the frequencies and modes of the normal vibrations have been established
in connection with conformational transitions within both side substituents. The observed conformational lability of the bulky
substituents in the cellulose ether molecules and its manifestations in the vibrational spectrum provide a basis for hypothesizing
that one of the major mechanisms for the process of their thermal gelation in aqueous solutions is conformational transitions
within these substituents.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 1, pp. 5–15, January–February, 2007. 相似文献
15.
The activity concentrations of the natural radionuclides namely 238Ra, 232Th and 40K are measured for soil samples collected from different locations of Faridkot and Mansa districts of Punjab. HPGe detector,
based on high-resolution gamma spectrometry system is used for the measurement of activity concentration. The range of activity
concentrations of 226Ra, 232Th and 40K in the soil from the studied areas varies from 21.42 Bq kg−1 to 40.23 Bq kg−1, 61.01 Bq kg−1 to 142.34 Bq kg−1 and 227.11 Bq kg−1 to 357.13 Bq kg−1 with overall mean values of 27.17 Bq kg−1, 95.22 Bq kg−1 and 312.76 Bq kg−1, respectively. Radium equivalent activities are calculated for the analyzed samples to assess the radiation hazards arising
due to the use of these soil samples in the construction of dwellings. The absorbed dose rate calculated from activity concentration
of 226Ra, 232Th and 40K ranges between 9.87 and 18.55, 38.01 and 88.68 and 9.40 and 14.79 nGy h−1, respectively. The total absorbed dose in the study area ranges from 61.10 nGy h−1 to 112.86 nGy h−1 with an average value of 84.80 nGy h−1. The calculated values of external hazard index (H
ex) for the soil samples of the study area range from 0.36 to 0.68. Since these values are lower than unity, according to the
Radiation Protection 112 (European Commission, 1999) report, soil from these regions is safe and can be used as construction
material without posing any significant radiological threat to population. The corresponding average annual effective dose
for indoor and outdoor measured in the study area are 0.42 mSv and 0.10 mSv respectively.
相似文献
16.
Total (elastic+inelastic) cross sections fore
−-O,e
−-O2 ande
−-O3 scattering have been calculated at sample energies between 100 and 1000eV. The basice
−-O atom scattering amplitudes are obtained from the partial wave analysis with a complex optical potential. Thee
−-O2 ande
−-O3 cross-sections are obtained through the independent atom model. Oure
−-O2 cross-sections reproduce the experimental data quite well. Adequate comparisons are made in all the three cases. 相似文献
17.
N. P. Baran V. M. Maksimenko V. V. Teslenko A. A. Bugay 《Journal of Applied Spectroscopy》2008,75(1):15-20
EPR spectra of barium dithionate hydrate single crystals γ-irradiated at low (80 Gy) and high (10 kGy) doses are studied.
Four lines, the strongest of which is due to the SO3− radical, are observed in the EPR spectrum of the low-irradiated samples. Another line seems to belong to SO2−. The strong line and weak lines with hyperfine structure and lines for pairs of closely spaced SO3− centers with a strong angular dependence are observed at high irradiation doses. The main values of the SO3− hyperfine coupling tensor and the dipole-dipole coupling constants of the SO3− pairs are determined. A quantum-chemical calculation of the electronic structure of isolated SO3− and SO2− radicals is performed. Values of the g tensors and hyperfine couplings are calculated.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 1, pp. 18–22, January–February, 2008. 相似文献
18.
In terms of chemical enhancement in Surface Enhanced Raman Scattering (SERS), we investigated the effect of halide and other
anions to rhodamine 6G (R6G) adsorbed Ag particles that were immobilized on the substrates. The residual species on chemically
prepared Ag particles such as citrate or a-carbon were thoroughly substituted by various anions, e.g., Cl−, Br−, I−, SCN−, CN−, or S2O3
2− anions, whose adsorption features are elucidated by the formation constants for AgX2
(m−1)−, here X denotes the above anions. In particular, Cl−, Br−, or SCN− ions activated SERS of R6G via intrinsic electronic interaction with Ag, whereas CN−, S2O3
2−, or I− anions quenched it due to their exclusive adsorption onto the Ag surfaces. We found that the activation process with the
anions commonly yields a marked blue-shift of the coupled plasmon peak from ca. 650–700 to 500–550 nm in elastic scattering.
It is rationalized by slight increase of the gap size between adjacent Ag nanoparticles by only ca. 1 nm based on theoretical
simulations. This is probably caused by slight dissolution, oxidative etching, of the particles according to large formation
constants of the complexes. Consequently, partly remaining negative charges on the Ag surface, and a slight increase in the
gap size, providing huge electric field, facilitated R6G cations to adsorb on the nanoparticles, especially at the junction. 相似文献
19.
B. M. Forster J. M. Bailey G. A. Beer J. L. Beveridge J. H. Brewer W. N. Hardy T. M. Huber K. R. Kendall A. R. Kunselman J. A. Macdonald G. M. Marshall G. R. Mason A. Olin M. Senba J. B. Warren 《Hyperfine Interactions》1991,65(1-4):1007-1013
Muonic hydrogen isotopes (μ− p, μ− d, and μ−t) are simple quantum mechanical systems ideally suited for studies of numerous fundamental phenomena in electroweak and strong
interactions as well as in applied areas such as muon chemistry or muon catalyzed fusion.
Emission of muonic hydrogen isotopes into vacuum helps to overcome the limitations which are normally imposed on conventional
investigations with gaseous and liquid targets. A proof of principle experiment for this new technique was performed at TRIUMF
last year. Negative muons with 30 MeV/c momentum were stopped in a thin film of solid hydrogen and produced very low energy μ−d in vacuum. The distribution center of the normal velocity components of emitted μ−d atoms was measured to be ∼1 cm/μs. The yield of μ−d in vacuum is an increasing function of H2 film thickness δ up to a value of δ≥1 mm. 相似文献
20.
J. R. Kempton R. F. Marzke D. G. Fleming A. C. Gonzalez S. K. Leung J. J. Pan P. W. Percival M. Senba A. Tempelmann 《Hyperfine Interactions》1991,65(1-4):811-817
Results of the first μSR studies using Merck FO Optipur silica powder, which contains paramagnetic impurities at the ppb level
and has a surface area of 610±20 m2/g. are reported. Above 20 K, the transverse field muonium relaxation rate is roughly constant at 0.5 μs−1. Upon the addition of oxygen at ppm levels, the relaxation rate increases linearly with O2 concentration in the temperature range from 40–100 K yielding two-dimensional depolarization rate constants on the order
of 10−4 cm2 molecule−1 s−1. As the temperature is increased further, both oxygen and muonium desorb from the surface yielding a three-dimensional rate
constants at 300 K of 3.1(3)×10–10−10 cm3 molecule−1 s−1, in agreement with the gas phase value. Longitudinal field measurements suggest that MuO2 is formed and is able to spin exchange with other oxygen molecules. 相似文献