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1.
The spatial inhomogeneity of pulsed atmospheric pressure discharge in argon is investigated using the electron number density Ne diagnostics procedure applied to asymmetrically broadened Ar I lines. A dedicated fitting procedure is used for describing Ar I 703.0 nm line shape recorded from argon gas discharge and H I (at 486.13 and 656.28 nm) lines recorded from Ar-H2 gas mixture discharge. The results revealed the change in Ne in both axial and radial directions. The additional Ar I lines at 614.5, 710.7, 731.2, and 731.6 nm, recorded from integral spatial radiation, are analysed as well to confirm the results from the plasma column region. The possibility of using AlO (B2∑+–X2∑+) and CN (B2∑+–X2∑+) molecular bands for gas temperature Tg measurements in this type of gas discharge source is demonstrated and Tg used as an input parameter for the Ne diagnostics procedure. For the proper identification of molecular band spectral lines, the Fortrat parabolas are constructed. The results obtained from Ar I 703.0 nm line indicate three different Ne values, with Ne1 ≈ 0.6 × 1016 cm−3, Ne2 ≈ 3.6 × 1016 cm−3, and Ne3 ≈ 19 × 1016 cm−3 measured from the plasma column. These Ne values increase in the cathode and anode region. 相似文献
2.
Triangulated categories coming from cyclic posets were originally introduced by the authors in a previous paper as a generalization of the constructions of various triangulated categories with cluster structures.We give an overview, and then analyze "triangulation clusters" which are those corresponding to topological triangulations of the 2-disk. Locally finite nontriangulation clusters give topological triangulations of the "cactus space" associated to the "cactus cyclic poset". 相似文献
3.
Marija argonja Darko Mekterovi Paula
urga Jagoda Ravli‐Gulan Iva Bogdanovi Radovi Gordana
auhar 《X射线光谱测定》2021,50(1):68-79
During metal welding and cutting, large amounts of particulate matter (PM) are produced that might represent a significant health risk for the exposed workers. In the present pilot study, we performed an elemental analysis of fine PM collected in a metal workshop. Also, elemental analysis of the hair and nail samples collected from workers exposed to the workshop dust and control group was done. Concentrations of 15 elements in PM were measured with X‐Ray Fluorescence (XRF) and Particle Induced X‐ray Emission (PIXE), whereas inductively coupled plasma mass spectrometry (ICP‐MS) was used to determine 12 elements in hair and nail samples. Mean 8‐hr concentrations of PM2.5, Fe, and Mn in the vicinity of welders were up to 1803, 860, and 30 μg/m3, respectively, whereas in the nearby city, daily PM2.5 concentrations are on average 11 μg/m3. We found that several elements, especially Fe and Mn, had substantially higher concentrations in hair and nail samples of exposed workers than in the control group, which indicates the accumulation of metals in workers' tissues, although limit values were not exceeded. 相似文献
4.
5.
Dusan Miljković Nada Vukojević DuŜAn Minie Pavle Hadzcircć Gordana Hajduković 《Journal of carbohydrate chemistry》2013,32(3):501-508
Abstract 1,2-O-Cyclohexylidene-α-d-xylofuranuronic acid (2) has been converted into its 3-O-acetyl derivative and consecutively to the corresponding acid chloride and ethyl ester. Direct reaction of 2 with ethanol in the presence of p-to-luene sulphonic acid gave the ethyl ester. Reaction of 2 with phosphorus pentachloride in dry ether gave the acid chloride of 1,2-O-cyclohexylidene-3-O-dichlorophosphoryl–α-d-xylofuranuronic acid. Conformational data have been obtained from 1H and 13C NMR measurements. 相似文献
6.
Associated with a finite-dimensional algebra of global dimension at most 2, a generalized cluster category was introduced in Amiot (2009) [1]. It was shown to be triangulated, and 2-Calabi–Yau when it is Hom-finite. By definition, the cluster categories of Buan et al. (2006) [4] are a special case. In this paper we show that a large class of 2-Calabi–Yau triangulated categories, including those associated with elements in Coxeter groups from Buan et al. (2009) [7], are triangle equivalent to generalized cluster categories. This was already shown for some special elements in Amiot (2009) [1]. 相似文献
7.
JPC – Journal of Planar Chromatography – Modern TLC - The behavior of 5,5-disubstituted hydantoin derivatives has been studied using four chromatographic systems, two normal-phase... 相似文献
8.
Milena Simic Predrag Jovanovic Milos Petkovic Gordana Tasic Milos Jovanovic Vladimir Savic 《Journal of heterocyclic chemistry》2021,58(8):1665-1674
Octahydro-dipyrroloquinoline skeleton is the building component of a very few naturally occurring compounds. Nevertheless, these natural products have been attractive synthetic targets, and their study commanded development of efficient synthesis of this core. While the reported methods are based on the dimerization procedure of N-arylpyrrolidines of N-arylhomopropargyl amines, our approach relay on dipolar cycloaddition/amination sequence. This strategic approach allows sequential introduction of aromatic moieties increasing the product diversity and hence may be useful in further exploration of incargranine B or seneciobipyrrolidine derivatives. 相似文献
9.
Luljeta Raka Andrea Sorrentino Gordana Bogoeva‐Gaceva 《Journal of Polymer Science.Polymer Physics》2010,48(17):1927-1938
The effect of organo‐modified clay (Cloisite 93A) on the crystal structure and isothermal crystallization behavior of isotactic polypropylene (iPP) in iPP/clay nanocomposites prepared by latex technology was investigated by wide angle X‐ray diffraction, differential scanning calorimetry and polarized optical microscopy. The X‐ray diffraction results indicated that the higher clay loading promotes the formation of the β‐phase crystallites, as evidenced by the appearance of a new peak corresponding to the (300) reflection of β‐iPP. Analysis of the isothermal crystallization showed that the PP nanocomposite (1% C93A) exhibited higher crystallization rates than the neat PP. The unfilled iPP matrix and nanocomposites clearly shows double melting behavior; the shape of the melting transition progressively changes toward single melting with increasing crystallization temperature. The fold surface free energy (σe) of polymer chains in the nanocomposites was lower than that in the PP latex (PPL). It should be reasonable to treat C93A as a good nucleating agent for the crystallization of PPL, which plays a determinant effect on the reduction in σe during the isothermal crystallization of the nanocomposites. The activation energy, ΔEa, decreased with the incorporation of clay nanoparticles into the matrix, which in turn indicates that the nucleation process is facilitated by the presence of clay. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1927–1938, 2010 相似文献
10.
Gordana iri‐Marjanovi Miroslava Trchov Jaroslav Stejskal 《Journal of Raman spectroscopy : JRS》2008,39(10):1375-1387
The structural changes of aniline oligomers and polyaniline, associated with oxidation of aniline with ammonium peroxydisulfate in aqueous solutions without any added acid, were studied. The reaction was quenched at various times and the films deposited on silicon windows have been studied in detail by Raman spectroscopy, at excitation wavelengths 633 and 514 nm. The presence of substituted phenazine structural units, in addition to ordinary benzenoid, quinonoid, and semiquinonoid structures, has been proved by the appearance of characteristic Raman bands at 1645–1630, 1420–1400, 1380–1365, ∼575, and ∼415 cm−1. The remarkable differences of the Raman spectra of oligoanilines, precipitated in the first phase of oxidative polymerization, and polyaniline nanotubes and nanorods, formed in the second stage of reaction, are discussed. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献