排序方式: 共有33条查询结果,搜索用时 31 毫秒
1.
V. G. Sister Yu. V. Lugovoi Yu. Yu. Kosivtsov E. M. Sulman E. M. Ivannikova 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2011,85(6):1091-1093
The pyrolysis of polymers with varying composition of the initial polymeric mixture was studied. It was shown that during
the pyrolysis of a polymeric mixture, an increase in the rate and number of volatiles were observed in relation to the pyrolysis
of certain types of polymers. It was determined that introducing cobaltous chloride into the sample composition increases
the effectiveness of the process. 相似文献
2.
3.
S. L. Kotova V. A. Timofeeva N. A. Aksenova V. G. Sister A. B. Solov’eva 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2013,7(5):959-966
The peculiarities of the crystallization of Pluronics from chloroform and aqueous polymer solution on mica surfaces are investigated with the atomic force microscopy method. It is shown that Pluronics in thin films form quasi two-dimensional crystalline structures of 10–12 nm thickness. Pluronic crystallization proceeds predominantly via the mechanism of diffusion-limited aggregation with the formation of dendrites. Three main morphological types of formed structures are identified including two types of dendrites (with 45° and 90° angles between branches) and elongated “needles.” It is shown that the film morphology depends on the polymer concentration, rate of solvent evaporation, and, probably, local gradients of concentration and temperature. Interaction with porphyrins establishes conditions for the local three-dimensional crystallization of Pluronics. 相似文献
4.
Daniilia S Minopoulou E Andrikopoulos KS Karapanagiotis I Kourouklis GA 《Analytica chimica acta》2008,611(2):239-249
The purpose of this study is to clarify important details about a Cumaean Sibyl painting that is preserved in a private collection. This work, bearing neither signature nor date, has never undergone conservation. It was executed after Domenichino's Cumaean Sibyl, a work known to have been used as a model by many 18th century painters.Investigation of the anonymous artist's painting technique and identification of its constituent materials were facilitated by employing optical microscopy (OM), scanning electron microscopy (SEM/EDS), FTIR and microRaman spectroscopies and high performance liquid chromatography with diode array detection (HPLC-DAD). The painter's palette comprised lead white, yellow ochre, lead-antimonate yellow (Naples yellow), cinnabar, cochineal lake, madder lake, haematite, Prussian blue and carbon black.The detection of Prussian blue (synthesized in 1704 and widely used as artist's pigment after 1750) was decisive in establishing the work's authenticity for, as such, it cannot be attributed either to Domenico Zampieri (1581-1641) or to his apprentices. In addition, the identification of Naples yellow, which prevailed in the period from 1750 to 1850, supports this statement. Nevertheless, its elaborate painting technique strongly suggests an artist greatly influenced by the Renaissance masters. A comparison of its stylistic features with those of the Cumaean Sibyl of Angelica Kauffmann (1741-1807), a prolific 18th century artist known to have studied and to have copied Domenichino's Sibyl, reveals significant similarities between the two in composition and palette. The unsigned Sibyl, therefore, could well be by Kauffmann. 相似文献
5.
Zorba T Andrikopoulos KS Paraskevopoulos KM Pavlidou E Popkonstantinov K Kostova R Platnyov V Daniilia S 《Annali di chimica》2007,97(7):491-503
Vibrational spectroscopy is applied on samples obtained from the excavation area of the medieval Monastery (10th century) of Karaach-Teke in Bulgaria. The results of the corresponding study, reveal the type of materials used for the creation of the wall-paintings and give evidence of Byzantine influence, a fact that further supports the well known impact of Byzantium on the technology and thematic-aesthetic features of iconography in Bulgaria during this era. In addition, the complementarity of FTIR and micro-Raman spectroscopies in the identification of pigments is indicated. 相似文献
6.
Bikiaris D Daniilia Sister Sotiropoulou S Katsimbiri O Pavlidou E Moutsatsou AP Chryssoulakis Y 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2000,56(1):3-18
The most widely-used inorganic pigments of Byzantine and post-Byzantine hagiography are earth pigments called ochres such as, red and yellow ochres, limonite, goethite, raw and burnt sienna, caput mortuum and hematite. The present experimental work proposes a technique of differentiation that allows one to distinguish among all the different kinds of iron oxides, thereby providing a better understanding of the painting technique used on portable icons and wall paintings. The ratios between the main spectroscopic peaks, attributable to the major components usually present in ochres, were calculated and compared, one against the another, from the spectra obtained through micro-Raman spectroscopy. Elementary composition is also revealed through a scanning electron microscopy (SEM) analysis. The possibility for detailed study on a particular Byzantine ochre palette can thus be performed based on the small differences in its nature and composition. These differences can first be observed and then measured among all of the natural earth pigments, through microRaman and microFTIR spectroscopies. 相似文献
7.
8.
The crystal structure of phenothiazine-10-propionic acid, C12H8SNC2H4COOH, was determined from three-dimensional X-ray diffraction data collected with a manual diffractomer using MoKα (λ 0.71069 Å) radiation. The space group is P21/c with a = 7.888 (2)Å, b = 8.703 (2)Å, c = 19.700 (8)Å, β = 101.42 (1)°, Z = 4, Dmeas = 1.35(2) g. cm?3 and Dcalc = 1.36 g. cm?3 at 23°. The structure was determined by the direct method and refined with 500 observed reflections by full-matrix least squares to an R of 0.072. The molecule is folded along the S-N axis and the dihedral angle is 136.5°. The C-S-C angle is 98.5(7)° and the average C-S bond is 1.77(2)Å. The shortening of the C-S bond, the small value of the C-S-C angle and the folding of the molecule are typical of the phenothiazine class of compounds and are assumed to be due to sulfur d orbital participation in ring bonding. 相似文献
9.
An analysis of the energy variation of the fission cross section and fragment angular distributions for the 234U (n,f) reaction reveals that the nuclear is reflection assymetric at the inner barrier. 相似文献
10.
R. F. Sisteró 《General Relativity and Gravitation》1976,7(6):487-489
An exact solution of Einstein's field equations of general relativity is given for a plane symmetric zero-rest-mass scalar field in the nonstatic case. The solution generalizes Singh's solution, which itself extends Taub's empty space-time. 相似文献