Reaction of 4-oxocarboxylic acids and 5-substituted 3<Emphasis Type="Italic">H</Emphasis>-furan-2-ones with 1,2-binucleophiles of aromatic and alicyclic series

Based on reactions of 5-substituted 3H-furan-2-ones or 4-oxocarboxylic acids with 1,2-binucleophiles of aromatic and aliphatic series methods were developed for the synthesis of tricyclic structures containing a pyrrolidine fragment fused with imidazolidine or oxazolidine ring. The pathways of the reactions are considered. It was demonstrated that the nature of the substrate did not affect the reaction direction, but changed the scheme of the interaction. The structures of compounds obtained for the first time were proved using IR and ¹H NMR spectra.     

Reactions of Triarylbismuth Bis(arenesulfonates)

Reactions of triphenylbismuth with sodium salts, acids, alkalies, and zinc are studied. In the first three cases Bi-O bond cleavage takes place, while zinc reduces the starting bismuth compounds to triphenylbismuth.     

Structure of tetragonal martensite in the In<Subscript>95.42</Subscript>Cd<Subscript>4.58</Subscript> cast alloy

The structure of martensite in the In_95.42Cd_4.58 alloy has been studied by metallography, X-ray diffraction, dilatometry, and transmission electron microscopy. It has been shown that a massive structure built of colonies of tetragonal lamellar plates divided by a twin boundary {101}FCT is formed in the alloy under cooling below the martensite FCC → FCT transition temperature. The alloy recrystallizes after a cycle of FCT → FCC → FCT transitions with a decrease in the grain size by several times compared with the initial structure such fashion that the size of massifs and individual martensite lamella in the massif correlates with the change in the size of the alloy grain. Using thermal cycling, it has been revealed that the alloy tends to stabilize the high-temperature phase.     

Thermochemistry of Compounds of the MI I(PUO6)2·nH2O Series

The standard enthalpies of formation of uranophosphates M^{I I}(PUO₆)₂·nH₂O (M^{I I} = Mn, Fe, Co, Ni, Cu, Zn, Cd) are determined. The standard enthalpies of the synthesis and dehydration of these compounds are calculated and analyzed.     

Muscle spindles are concentrated in the superior vocalis subcompartment of the human thyroarytenoid muscle

It is hypothesized that different parts of the thyroarytenoid muscle (TA) are functionally specialized. Specifically, the TA is divided into a lateral muscularis compartment and a medial vocalis compartment. This study examined the distribution of muscle spindles throughout the human TA as an indicator of these functional differences. Histological cross-sections from the anterior, middle, and posterior regions of five human membranous vocal folds were examined for the number and location of muscle spindles. There was an average of 6.1 muscle spindles in sections from each region with no significant variation between the different regions (p < .05). However, in sections from all three regions, the muscle spindles were always found to be concentrated in the superior medial quadrant of the TA (mean 85.9%, p < .01). The inferior medial, superior lateral, and inferior lateral quadrants of the TA contained 11.96%, 2.17%, and 0%, respectively, of the total muscle spindles. Within the superior medial quadrant, most of the muscle spindles were localized in the most superficial part of the muscle.The results of this study demonstrate that the majority of TA muscle spindlesare concentrated in its superior medial quadrant, an area we have termed the superior vocalis subcompartment (SC. This finding suggests that the superior vocalis SC is functionally distinct from the remainder of the TA. It is hypothesized that tension in the superior vocalis SC can be controlled independently from the remainder of the TA, and this capability is used to effect the biomechanics of vocal fold vibration during phonation.     

Enumeration of trees by inversions

Mallows and Riordan “The Inversion Enumerator for Labeled Trees,” Bulletin of the American Mathematics Society, vol. 74 [1968] pp. 92-94) first defined the inversion polynomial, J_n(q) for trees with n vertices and found its generating function. In the present work, we define inversion polynomials for ordered, plane, and cyclic trees, and find their values at q = 0, ± 1. Our techniques involve the use of generating functions (including Lagrange inversion), hypergeometric series, and binomial coefficient identities, induction, and bijections. We also derive asymptotic formulae for those results for which we do not have a closed form. © 1995 John Wiley & Sons, Inc.     

Absence of Quantum States Corresponding to Unstable Classical Channels

We develop a general theory of absence of quantum states corresponding to unstable classical scattering channels. We treat in detail Hamiltonians arising from symbols of degree zero in x and outline a generalization in an Appendix. E. Skibsted is (partially) supported by MaPhySto – A Network in Mathematical Physics and Stochastics, funded by The Danish National Research Foundation. Submitted: September 18, 2007. Accepted: January 14, 2008.     

Supersonic Laminar-Turbulent Gas Flow Past a Circular Cylinder

The flow past a circular cylinder with an isothermal surface at Mach numbers M=2 and 5 and Reynolds numbers ranging from 10⁴ to 10⁸ is investigated on the basis of the Reynolds equations using a differential two-equation turbulence model. The effect of flow turbulization on the separation point displacement, the separation zone length, the maximum velocity reduction in the separation zone, and the increase in the heat flux at the rear stagnation point is determined.     

3, 6-Di(tert-butyl)-o-benzoquinone fluoroalkylated derivatives

Russian Chemical Bulletin - A reaction of perfluoroalkyltrimethylsilanes with 3, 6-di(tert-butyl)-o-benzoquinone was used to obtain new perfluoroalkyl-substituted sterically hindered...