Revealing the common sources of commercial explosive-containing articles

A method for identification of explosive-containing commercial articles is suggested. The method is based on chromatographic analysis of petroleum products present in the articles as process admixtures and structural components.     

WITCH: A Penning Trap Retardation Spectrometer Combination for Precision Studies of the Weak Interaction

We present data from three seasons of experimental field work designed to recreate ancient Andean coastal ceramic firing techniques. Based on the recent discovery of two different archaeological ceramic production sites in the La Leche river valley of northern coastal Peru, the opportunity arose to apply Mössbauer spectroscopy and other analytical methods to reconstruct ancient firing procedures. Two sets of firings took place in 1993 and 1997 in Batán Grande using a partially restored Formative kiln from about 800 BC, local hardwood and cow dung as fuel. A third experiment followed in 2000 after the discovery of a Middle Sicán ceramics workshop in use between ca. AD 950 and 1050 at Huaca Sialupe, where an exact replica of an ancient kiln was built from local clay, and fired with local wood and cow dung. Additionally, inverted urns found at Huaca Sialupe were tested for their potential use as furnaces for metal working. Mössbauer spectroscopy was used to compare the physical and chemical state of specimens produced in the field experiments with ancient ceramics and with specimens produced in controlled laboratory experiments.     

Iterative degenerate perturbation theory

A fairly general degenerate perturbation theory has been considered which involves two versions, i.e., the Rayleigh-Schrodinger and Brillouin-Wigner treatments. The simple recursive formulas have been found for effective Hamiltonians which allow one to split the degenerate energy levels in any orders of this theory.     

Kinetics and Mechanism of Monomolecular Heterolysis of Commercial Organohalogen Compounds: XXXIX. Salt Effect of LiClO<Subscript>4</Subscript>in Heterolysis of Ph<Subscript>2</Subscript>CHCl in γ-Butyrolactone

Additions of LiClO₄ accelerate the heterolysis of Ph₂CHCl in γ-butyrolactone; v = k[Ph₂CHCl], SN1 mechanism. The salt effect increases with an increase in the electron-acceptor properties of the verdazyl indicator. A superposition of three salt effects (normal, special, and negative special) is observed.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 1, 2005, pp. 105–110.Original Russian Text Copyright © 2005 by Dvorko, Ponomareva, Golovko, Pervishko.     

Chemical bond in alkali metal sulfates

In the context of the density functional theory of the local electron density the valence and differential density distribution in crystalline sulfates of M₂SO₄ (M is Li, Rb, and Cs) and double sulfates of MLiSO₄ were calculated using the pseudopotential method in the basis set of numerical atomic pseudo-orbitals. It is shown that in lithium sulfate crystallographically inequivalent oxygen atoms are in different charge states and have a different force of chemical bonding with sulfur. Anions are bonded to each other through lithium atoms that form tetrahedral complexes with oxygen. In rubidium sulfates the electron clouds of the anions overlap and chain structures form. Chemical bonding between the anion and the cation has an ionic nature. These features of the electron structure manifest themselves in double sulfates, where LiO₄ complexes that link the anionic chains also form, and heavy metals serve as cations.     

New synthesis of benzo[b][1,6]naphthyridines and pyrido[4,3-b]benz[f]azepines from lactim ethers of 3,4-dihydrocarbostyril and 1H-2,3,4,5-tetrahydrobenz[b]azepin-2-one

Condensation of lactim ethers of 3,4-dihydrocarbostyril and 1H-2,3,4,5-tetrahydrobenz[b]azepin-2-one with malonodinitrile, cyanoacetamide, and ethyl cyanoacetate gave the corresponding 2-methylidene derivatives. Their reactions with dimethylformamide diethyl acetal followed by cyclization into benzo[b][1,6]naphthyridines and pyrido[4,3-b]benz[f ]azepines were studied. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 995–1002, May, 2007.     

Acetals of lactams and acid amides. 67. Polarographic behavior of enamines of the indoles series in anhydrous DMF

The polarographic behavior of derivatives of 2-aminomethyleneindoxyl and 3-aminomethyleneoxindole in anhydrous DMF has been studied and the results compared with data on the polarographic reduction of substituted aminomethyleneacetophenones and of related enaminoketones and eneaminoamides. It is established that the ease of reduction is determined by the nature of the substituent on the enamine and indole nitrogen atoms and also by the presence or absence of an -methyl group in the -position of the eneamines (for noncyclic enaminoketones).For Communication 66, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 642–648, May, 1991.     

Diastereospecific ring cleavage of bornane-2,3-dione in the Bucherer-Bergs reaction

A novel regio- and diastereospecific ring cleavage of bornane-2,3-dione (camphor quinone) under Bucherer-Bergs reaction conditions has been investigated. The simplicity of this transformation provides a novel and straightforward synthetic pathway to enantiopure derivatives of cyclopentane carboxylic acid as well as functionalized hydantoins in just two steps, starting from inexpensive and easily available camphor.     

Specific features of the ferroelectric state in two-layer barium strontium titanate-based heterostructures

The structural properties of one- and two-layer heterostructures based on the barium–strontium titanate of various compositions deposited by the Frank–Van der Merve on a magnesium oxide substrate have been studied. The heterostructures have been prepared by the rf sputtering of the stoichiometric ceramic targets in a Plazma 50 SE deposition system. The principal difference of this method of deposition from known analogs is that the growth of single-crystal films occurs from a disperse oxide phase formed in the plasma of a high-current rf discharge during the ceramic target sputtering at the cluster level. The peculiarities of the manifestation of the ferroelectric state in the two-layer heterostructures when changing the sequence order of the films with various compositions of barium–strontium titanate.     

Superfluidity of a perfect quantum crystal II

This paper continues the work begun in a previous paper [Eur. Phys. J. B 71, 85 (2009)]. To treat the equations that describe a crystal with condensate that can be superfluid, a method termed the Kirkwood approximation is used. Earlier, the method was found to be rather seminal when applied to a classical crystal. In the case of a simple cubic lattice, solutions to the equations under study can be expressed in terms of the well-known Mathieu functions. A more realistic case of the face centered cubic lattice is also considered although in this case the three-dimensional equations cannot be reduced to one-dimensional ones. Condensate crystals without superfluidity are studied first and then the same crystals in a superfluid state. It is shown in particular that a crystal in which the condensate is formed is energetically preferable with respect to the same quantum crystal without condensate at absolute zero of temperature. Therefore, on lowering the temperature there must somewhere occur Bose-Einstein condensation in the crystal. In the concluding section, we discuss various physical aspects of the problem.