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61.
62.
Maria H. Johansson ke Oskarsson Karin Lvqvist Fotini Kiriakidou Pramesh Kapoor 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1053-1055
Both cis‐ and trans‐dichlorobis(diphenyl sulfide)platinum(II), [PtCl2(C12H10S)2], crystallize as mononuclear pseudo‐square‐planar complexes. In the cis compound, the Pt—Cl distances are 2.295 (2) and 2.319 (2) Å, and the Pt—S distances are 2.280 (2) and 2.283 (2) Å. In the trans compound, Pt is located on a centre of inversion and the Pt—Cl and Pt—S distances are 2.2786 (15) and 2.3002 (12) Å, respectively. 相似文献
63.
Implicit–explicit multistep methods for nonlinear parabolic equations were recently analyzed. If the implicit scheme is one of the backward differentiation formulae (BDF) of order up to six, then the corresponding implicit–explicit method of the same order is stable provided the stability constant is less than a specific scheme-dependent constant. Based on BDF, implicit methods are constructed such that the corresponding implicit–explicit scheme of the same order exhibits improved stability properties. 相似文献
64.
Fotini Markopoulou Simone Severini 《Journal of Mathematical Modelling and Algorithms》2009,8(3):335-342
We point out that the total number of trails and the total number of paths of given length, between two vertices of a simple
undirected graph, are obtained as expectation values of specifically engineered quantum mechanical observables. Such observables
are contextual with some background independent theories of gravity and emergent geometry. Thus, we point out yet another
situation in which the mathematical formalism of a physical theory has some computational aspects involving intractable problems. 相似文献
65.
Fotini Viras Kyriakos Viras Carl Campbell Terence A. King Colin Booth 《Journal of Polymer Science.Polymer Physics》1991,29(12):1467-1471
Low-Frequency Raman spectra of odd α,ω-dibromo- and α,ω-dihydroxy-n-alkanes were recorded. The longitudinal acoustic mode (LAM-1) frequencies were assigned by references to the published results for n-alkanes and even α,ω-disubstituted n-alkanes and also by taking account of the effects of end intermolecular forces and end-group masses by use of the chain model of Minoni and Zerbi. 相似文献
66.
For the first time, palladium complexes with salicylaldehyde thiosemicarbazones were applied as catalyst precursors to the Suzuki-Miyaura reaction. These air and moisture stable phosphine-free systems efficiently catalyze the cross-coupling of aryl bromides and chlorides (from electron rich to electron poor) with phenylboronic acid in DMF/H2O at 100 °C for 24 h, using Na2CO3 as base, without addition of free ligand or any promoting additive, and under aerobic conditions no significant homocoupling of phenylboronic acid to unsubstituted biphenyl was observed. 相似文献
67.
The 24Mg(α, p)27 Al nuclear reaction was applied for the determination of the magnesium distribution in near-surface layers of materials.
The cross sections of this reaction were determined in the energy region between 4.5 and 5.5 MeV in steps of 5 to 10 KeV (θlab : 158°) using thin magnesium films. The investigated projectile energy region included five main resonances allowing the
determination of magnesium. The uncertainty of the cross-section determination was of the order of 7%. The applicability of
the technique was tested using Mg-implanted AISI 321 steel samples. Depth resolution of 100 nm and detection limits of the
order of 0.1 ppm were achieved for the determination of magnesium in steel samples using the 4805 keV resonance of the 24Mg(α, p)27 Al nuclear reaction. The shape and height of the magnesium depth-profile in the Mg-implanted steel samples were compared
with corresponding values obtained by X-ray photoelectron spectroscopy.
Received July 15, 1999. Revision March 30, 2000. 相似文献
68.
Constantine D. Georgakopoulos Fotini N. Lamari Ioanna N. Karathanasopoulou Vassiliki S. Gartaganis Nikolaos M. Pharmakakis Nikos K. Karamanos 《Biomedical chromatography : BMC》2010,24(8):852-857
Tears have a significant role in antioxidant defense in ocular tissues and since their collection is quick and noninvasive, their analysis would facilitate monitoring of pathophysiological changes. However, their low volume and low content of antioxidants makes analysis difficult; methods of high sensitivity are needed. In this paper, we present a method for tear analysis of two antioxidant molecules (ascorbic and uric acid) and of a lipid peroxidation indicator (malondialdehyde) with capillary electrophoresis. Tears were collected with Schirmer strips, extracted with a low‐pH phosphate buffer, centrifuged through membrane filters and an antioxidant was added. They were stable at ?70°C for 15 days. After pilot experiments, optimum electrophoretic separation was achieved in a 25 mm borate buffer, pH 10.0, containing 100 mm sodium dodecyl sulfate at 25°C and 20 kV. The developed method has good repeatability (<5% RSD), precision (<15% relative error values) and high sensitivity (LLOQ values of 20, 2.3 and 2.5 μM for ascorbate, urate and malondialdehyde, respectively). It was applied to the analysis of tears from healthy individuals and the antioxidant levels are in agreement with those obtained with other techniques. This method might serve as a tool to clarify the role of endogenous antioxidants in the pathophysiology of ocular diseases. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
69.
Georgios Floros Fotini Agrafioti Alexios Grigoropoulos Patrina Paraskevopoulou Konstantinos Mertis Maria Tseklima Maria Veli Marinos Pitsikalis 《Journal of polymer science. Part A, Polymer chemistry》2013,51(22):4835-4844
Statistical copolymers of norbornene (NBE) with 5‐vinyl‐2‐norbornene (VNBE) were prepared by ring‐opening metathesis polymerization, employing the triply bonded ditungsten complex Na[W2(μ‐Cl)3Cl4(THF)2].(THF)3. NMR measurements revealed that the side vinyl groups of the VNBE monomer remain intact during the copolymerization reaction. The reactivity ratios were estimated using the Finemann–Ross (FR), the inverted FR, and the Kelen–Tüdos graphical methods. Structural parameters of the copolymers were obtained by calculating the dyad sequence fractions, which were derived using the monomer reactivity ratios. The glass transition temperatures, Tg, of the copolymers were measured by differential scanning calorimetry measurements and were examined in the frame of several theoretical equations allowing the prediction of these Tg values. The best fit was obtained using methods that take into account the monomer sequence distribution of the copolymers. Finally, the kinetics of the thermal decomposition of the copolymers was studied by thermogravimetric analysis in the frame of the Ozawa–Flynn–Wall and Kissinger methods. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 4835–4844 相似文献
70.
Basova T Plyashkevich V Petraki F Peisert H Chassé T 《The Journal of chemical physics》2011,134(12):124703
The μ-(oxo)bis[phthalocyaninato] aluminum(III) (AlPc)(2)O films, with the crystallites oriented preferably in one direction, were obtained via chemical transformation of chloroaluminum(III) phthalocyanine AlClPc film upon its annealing in magnetic field. A comparative analysis of the influence of postdeposition annealing without and under applied magnetic field of 1 T on composition and morphology of AlClPc films has been carried out. The chemical transformation of AlClPc to (AlPc)(2)O on the substrate surface is studied by the methods of UV-vis and infrared spectroscopies, Raman, x-ray photoelectron spectroscopy as well as atomic force microscopy. Two interesting effects were observed upon heating the AlClPc films in magnetic field of 1 T. First, the temperature of the chemical transformation of AlClPc to (AlPc)(2)O decreased from 300 °C to 200 °C when magnetic field was applied during postdeposition annealing. Second, the formation of (AlPc)(2)O films with elongated crystallites with a preferential orientation was observed. The heating of (AlPc)(2)O films in a magnetic field at the same conditions did not demonstrate any effect on the structure and morphology of these films. 相似文献