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31.
32.
A. Anastassov Yu. P. Gangrsky B. K. Kul'djanov K. P. Marinova B. N. Markov S. G. Zemlyanoi 《Zeitschrift für Physik A Hadrons and Nuclei》1994,348(3):177-181
Isotope shifts and hyperfine structures in three optical transitions of HfI are investigated. Magnetic dipole coupling constant A and electric quadrupole coupling constant B of four atomic levels for both stable odd-even isotopes177Hf and179Hf are determined. Nuclear charge radii changesδ〈r 2〉 of the stable Hf isotopes and182 Hf (T 1/2=9×106 y) are extracted using the standard semiempirical procedure. Strong deviation from muonic atom data onδ〈r 2〉 is observed. The course of theδ〈r 2〉 dependence on mass number indicates changes in nuclear deformation at A=174 and influence of higher order deformations on nuclear shape in this region. 相似文献
33.
Romanus K Van Neer W Marinova E Verbeke K Luypaerts A Accardo S Hermans I Jacobs P De Vos D Waelkens M 《Analytical and bioanalytical chemistry》2008,390(2):783-793
Burned greasy deposits were found inside shells of the large Nile bivalve Chambardia rubens, excavated in an eight- to tenth- century AD church of the Coptic monastery of Bawit, Egypt, and supposedly used as oil lamps.
The residues were subjected to a combination of chromatographic residue analysis techniques. The rather high concentrations
of unsaturated fatty acids, as analysed by gas chromatography (GC) in the methylated extract, suggest the presence of a vegetal
oil. Analysis of the stable carbon isotopes (δ
13C values) of the methyl esters also favoured plants over animals as the lipid source. In the search for biomarkers by GC coupled
to mass spectrometry on a silylated extract, a range of diacids together with high concentrations of 13,14-dihydroxydocosanoate
and 11,12-dihydroxyeicosanoate were found. These compounds are oxidation products of erucic acid and gondoic acid, which are
abundantly present in seeds of Brassicaceae plants. Liquid chromatography coupled to mass spectrometry analysis showed low
concentrations of unaltered triglycerides, but revealed sizeable amounts of triglycerides with at least one dihydroxylated
acyl chain. The unusual preservation of dihydroxylated triglycerides and α,ω-dicarboxylic acids can be related to the dry preservation conditions. Analysis of the stereoisomers of the dihydroxylated
fatty acids allows one to determine whether oxidation took place during burning of the fuel or afterwards. The results prove
that the oil of rapeseed (Brassica napus L.) or radish (Raphanus sativus L.) was used as illuminant in early Islamic Egypt, and that not only ceramic lamps but also mollusk shells were used as fuel
containers. 相似文献
34.
Marinova P. Marinov M. Kazakova M. Feodorova Y. Blazheva D. Slavchev A. Sbirkova-Dimitrova H. Sarafian V. Stoyanov N. 《Russian Journal of General Chemistry》2021,91(5):939-946
Russian Journal of General Chemistry - The presented study is devoted to the structural and biological properties of four derivatives of fluorenylspirohydantoin based on experimental data. The... 相似文献
35.
M. Sendova-Vassileva D. Dimova-Malinovska M. Kamenova A. Kakanakova-Georgieva Ts. Marinova 《Journal of luminescence》1998,80(1-4):179-182
Porous silicon (PS) is studied by stepwise peeling of the surface layer to clarify the non-uniformity in the photoluminescence (PL) and correlate it with the in-depth chemical bonding and structure of the 30 μm thick layer. The PL intensity grows by an order of magnitude after the peeling off of the first 10 μm and decreases five times in the next 5 μm while the peak maximum position shifts from 730 to 800 nm. X-ray photoelectron spectroscopy (XPS) measurements show that Si–Si and Si–O bonds are present both on the surface and below, and the preferential oxidation state of silicon changes from 3+ and 4+ on the surface to 1+ and 2+ below 10 μm. Using Raman spectroscopy silicon nanocrystals are shown to exist. Their mean size can be estimated at about 3 nm. These results show that the strongest PL comes from a region in the PS layer where silicon nanocrystallites are surrounded by oxides with a low level of oxidation and not from the strongly oxidized surface layer. 相似文献
36.
Gagana Karkada G Arun Maiya Praveen Arany Mohandas Rao KG Shalini Adiga Shobha U. Kamath 《Photochemistry and photobiology》2023,99(4):1172-1180
Individuals with diabetic foot ulcers have overlapped the inflammatory, proliferative and remodeling phase, making the tissue vulnerable to delayed healing responses. We aimed to establish the dose–response relationship of photobiomodulation therapy of different doses and matrix metalloproteinases in the healing dynamics of diabetic neuropathic ulcers. Diabetes was induced in 126 Albino Wistar rats, and neuropathy was induced to the hind paw by a sciatic nerve injury method. An excisional wound was created on the neuropathy-induced leg. Photobiomodulation therapy of dosages 4, 6, 8, 10, 12 and 15 J cm−2 and wavelength 655 nm and 808 nm was irradiated. Photobiomodulation therapy of dosages 4, 6 and 8 J cm−2 showed better wound healing properties with optimized levels of matrix metalloproteinases-1 and 8. We observed a strong dose response in the experimental group treated with 6 and 8 J cm−2. The findings from the present study conclude that photobiomodulation therapy of dosages 4, 6 and 8 J cm−2 is suggestive of usefulness in diabetic neuropathic ulcer healing. Markers like matrix metalloproteinases may give a clear direction on response to the therapy. Based on the findings from the present study, we recommend to validate the findings for safety and efficacy in future through human prospective randomized controlled clinical trials. 相似文献
37.
Yu. M. Gledenov J. Kvitek S. Marinova Yu. P. Popov J. Rigol V. I. Salatski 《Zeitschrift für Physik A Hadrons and Nuclei》1982,306(1):57-61
TheK-internal conversion coefficient of the 205 keV (7/2+→5/2+) transition in107Cd was determined. From the measured value α K =0.0552±0.0009 and the known value of theE2/M1 mixing ratio δ2 a value of 6.3±1.5 was deduced for the penetration parameterλ. Information derived on effective gyromagnetic ratios in the frame of an extreme single particle model is briefly discussed. 相似文献
38.
39.
Evelina Marinova 《Nuclear Physics B - Proceedings Supplements》2011,215(1):125-127
40.
Anife Ahmedova Vasil Atanasov Petja Marinova Neyko Stoyanov Mariana Mitewa 《Central European Journal of Chemistry》2009,7(3):429-438
New 2-acyl-1,3-indandione derivatives, compounds 1–4, were obtained by condensation of 2-acetyl-1,3-indandione with benzaldehyde,
thiophene-2-aldehyde, thiophene-3-aldehyde and furane-2-aldehyde, respectively. The structures of the newly synthesized 2-substituted
1,3-indandiones were characterized by means of spectroscopic methods (FT-IR, 1H and 13C NMR, UV-Vis and MS). Based on the obtained results it is suggested that the compounds exist in the exocyclic enolic form.
Mass spectral fragmentation paths are also proposed. In order to verify the possibility for tautomerization processes of the
newly synthesized compounds their absorption spectra were recorded in various solvents. Furthermore, the complexation properties
of the compounds with metal(II) ions were also studied. A series of non-charged complexes with Cu(II), Cd(II), Zn(II), Co(II)
and Ni(II) was isolated and analyzed by elemental analyses and IR. The paramagnetic Cu(II) complexes were studied by EPR and
distorted, flattened tetrahedral structures are predicted. The other metal complexes show the presence of water molecules,
most probably coordinated to the metal ion, thus forming octahedral geometry. Ultimately, the studied properties of the newly
synthesized compounds, 1–4, suggest that they may find application as extracting agents for metal ions, rather than as optical
sensors.
相似文献