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61.
Validation of reducing-difference procedure based on subtracting of non-polarized infrared (IR) spectra of n-component solid mixtures is presented. The accuracy and precision are established. The limits of detection are 3.0, 2.5, 1.5 and 1.0 wt.% for 5-, 4-, 3-and 2-component mixtures, respectively. Smoothing procedures for IR spectral analysis, based on Savitzky-Golay or Fourier methods are applied as well. The mean values and relative standard deviations for peak position (νi) and integral absorbance (Ai) obtained by this data processing approach have been examined using Student's t-test. 相似文献
62.
Michail N. Elinson Sergey K. Feducovich Anatolii N. Vereshchagin 《Tetrahedron》2004,60(51):11743-11749
Electrolysis of arylidenemalononitriles and malononitrile in alcohols in an undivided cell in the presence of sodium bromide as mediator results in the stereoselective formation of (1R,2S,6R)*-6-aryl-2-amino-4,4-dialkoxy-1,5-dicyano-3-azabicyclo[3.1.0]hex-2-enes in 60-80% yields. 相似文献
63.
Irene L. Odinets Natalya M. Vinogradova Konstantin A. Lyssenko Michail Yu. Antipin Pavel V. Petrovskii Tatyana A. Mastryukova 《Heteroatom Chemistry》2002,13(1):1-21
Intramolecular S‐alkylation in a series of ω‐haloalkyl‐substituted thiophosphorylacetonitriles 5–7 presents an effective synthetic route to the hitherto unknown 3‐cyano‐2‐oxo‐1,2‐thiaphospholanes 14 and thiaphosphinanes 15 . The compounds were obtained as a mixture of cis‐ and trans‐isomers that were resolved to individual stereoisomers in most cases. For some of them, X‐ray diffraction analysis has been performed. It was shown that 31P NMR spectroscopy can be used to assign the stereochemistry of 3‐cyano‐2‐oxo‐1,2‐thiaphosphacyclanes. © 2002 John Wiley & Sons, Inc. Heteroatom Chem 13:1–21, 2002; DOI 10.1002/hc.1101 相似文献
64.
Maria Y. Rusanova Michail Grden Andrzej Czerwinski Galina A. Tsirlina Oleg A. Petrii Tatyana Y. Safonova 《Journal of Solid State Electrochemistry》2001,5(3):212-220
Protium and deuterium sorption in the α-phase region is studied for highly defective palladium electrodeposits fabricated
under controllable potentiostatic modes, particularly in the region of concentrated hydride formation. An anomalously high
hydrogen content is observed for these samples in both α- and β-hydrides. On the basis of coulometry in the course of anodic
hydrogen extraction, the non-linear sorption isotherms are plotted and their specific features are considered under an assumption
of simultaneous equilibrium sorption of hydrogen by several types of lattice positions with a certain degree of defectiveness.
Less defective palladium samples deposited in the absence of bulk hydridization are studied for comparison. The approach is
proposed to estimate the fraction of defective regions. The procedure of analyzing the low-pressure limit is used for the
first time for determining the specific values of the isotope effect, and also H and D Sievert's constants. The isotope effect
is demonstrated to be extremely sensitive to the type of defectiveness.
Electronic Publication 相似文献
65.
A new method is proposed for studying the structure and mutual arrangement of selected components in multicomponent particles. Here the difference between the scattering curve of a solution containing two types of structurally identical particles (differing only in the degree of deuteration) and the scattering curve of a solution containing particles of a third type (deuterated to an intermediate degree) is considered. This difference scattering curve differs only by a numerical multiplier from the “vacuum” scattering curve of the particle in which the scattering density is equal to the difference between the scattering densities of the particles of the first and second types. This means that any particle component which is deuterated (protonated) to the same degree in the particles of three different types does not contribute to the difference scattering curve and, consequently, is “invisible” for neutrons. The difference scattering curve depends neither on the isotopic content of the solvent nor on the inter-particle interference and particle association. Possible applications of this method are discussed. 相似文献
66.
Michail N. Elinson Sergey K. Feducovich Anatolii N. Vereshchagin Gennady I. Nikishin 《Tetrahedron》2006,62(17):3989-3996
Electrolysis of malonate and alkylidenecyanoacetates in alcohols in an undivided cell in the presence of NaBr results in stereoselective formation of (E)-3-substituted 2-cyanocyclopropane-1,1,2-tricarboxylates in 75-90% yields. 相似文献
67.
Bojidarka B. Koleva Elena N. Trendafilova Michail G. Arnaudov William S. Sheldrick Heike Mayer-Figge 《Transition Metal Chemistry》2006,31(7):866-873
A new Cu(II)-complex of 3-aminopyridine, [CuCl(3-AP)4][Cu(3-AP)4(H2O)]Cl3 · 2H2O (1), containing two contrasting complex cations has been synthesized and structurally characterized by single crystal X-ray diffraction
and solid-state linear-dichroic infrared (IR-LD) spectral analysis. In both cations four 3-AP molecules coordinate the Cu(II)
atom in a monodentate fashion through their endocyclic (Npy) nitrogens, thereby generating a square-planar coordination geometry for the CuN4 chromophor. Perpendicular to the N4 plane, the metal ion is coordinated by a chloride anion in the first cation and a water ligand in the second cation. One
of three additional water molecules of crystallization occupies the vacant octahedral site of the second cation and participates
in a weak Cu···OH2 interaction. An IR-LD spectral analysis of the samples, oriented as a suspension in a nematic liquid crystal confirmed the
crystallographic data and the retention of the pyridine ring aromatic character after coordination. The presented results
are additionally supported by UV, 1H-NMR, EPR and MS analysis and by thermogravimetric and calorimetric data. 相似文献
68.
This paper establishes polyhedral properties of matroidal structures. Classical problems such as enumeration and classification
of polyhedra matroids, the characterization of face complexes, the metric properties of graphs of polymatroids are considered.
Supported by DAAD and Belarussian Fundamental Science Fund 相似文献
69.
70.
Linear difference equations in a Hilbert space with coefficients depending on the number n of the equation are considered. It is assumed that the coefficients differ from constant ones by a finite sum of exponentially vanishing terms as n → ∞. An asymptotic formula for solutions as n → ∞ is obtained. The coefficients in the asymptotic expansion are expressed as linear functionals on the space of sequences in the terms on the right-hand side. 相似文献