A thermochemical study of acid-base interactions in aqueous solutions of citric acid

The heat effects of interaction of a solution of citric acid with HNO₃ and KOH were measured calorimetrically at 298.15 K and ionic strengths of 0.5, 1.0, and 1.5 (KNO₃). The heat effects of acid dissociation were calculated using the universal HEAT program. The standard thermodynamic characteristics of step dissociation of citric acid were determined.     

Synthesis of New Phosphorylated 1,2,4-Triazole-3-thiones. N,S-Functionalization Methods

New phosphorylated 1,2,4-triazole-3-thiones have been synthesized, and the possibility of their N,Sfunctionalization has been demonstrated. The direction of alkylation of 1,2,4-triazole-3-thiones with ethyl acrylate has been shown to depend on the substituent on the N⁴ atom.     

Humin-like substances formed under the conditions of industrial hydrolysis of wood

Pathways of formation of humin-like substances from carbohydrates and furan compounds under the conditions of acid hydrolysis of wood were studied.     

Problems of solubility of hydrolysis lignin

Interaction of hydrolysis lignin with polyacrylonitrile in water-dimethyl sulfoxide solution in the presence of an activator was studied, and the properties of the products were examined.     

Extraction of the neutron charge form factor G<Superscript>n</Superscript><Subscript>E</Subscript>(Q<Superscript>2</Superscript>) from the charge form factor of deuteron G<Superscript>d</Superscript><Subscript>C</Subscript>(Q<Superscript>2</Superscript>)

We extract the neutron charge form factor G ⁿ _E(Q ²) from the charge form factor of deuteron G ^d _C(Q ²) obtained from T ₂₀(Q ²) data at 0≤Q ²≤ 1.717 (GeV/c)². The extraction is based on the relativistic impulse approximation in the instant form of the relativistic Hamiltonian dynamics. Our results (12 new points) are compatible with existing values of the neutron charge form factor of other authors. We propose a fit for the whole set (36 points) taking into account the data for the slope of the form factor at Q ² = 0. Received: 26 July 2002 / Accepted: 18 September 2002 / Published online: 4 February 2003 RID="a" ID="a"e-mail: krutov@ssu.samara.ru RID="b" ID="b"e-mail: troitsky@theory.sinp.msu.ru Communicated by V.V. Anisovich     

Semileptonic decays of Pseudoscalar mesons in the instant form of relativistic Hamiltonian dynamics

A formalism for describing semileptonic decays of pseudoscalar mesons is developed on the basis of the instant form of relativistic Hamiltonian dynamics. By way of example, this formalism is applied to the decay process $K^ - \to \pi ^0 + \mu ^ - + \bar \nu _\mu $ . Relevant calculations are performed with wave functions that correspond to various models of constituent-quark interactions in mesons. Free parameters that appear in these models are determined from a fit to the root-mean-square radii of the kaons and pions. The results of the calculations agree well with experimental data.     

Fine structure of the muonic <Superscript>4</Superscript>He ion

On the basis of quasi-potential approach to the bound state problem in QED we calculate the vacuum polarization, recoil and structure corrections of orders α⁵ and α⁶ to the fine splitting interval ΔE ^fs = E(2P _3/2) − E(2P _1/2) in muonic ₂⁴He ion. The resulting value ΔE ^fs = 146180.68 μeV provides reliable guideline in performing a comparison with the relevant experimental data.     

Analytic continuation of the pion form factor from the spacelike to the timelike domain

We solve the problem of analytically continuing the electromagnetic pion form factor into the complex domain of transferred momenta. We treat the pion as a composite quark-antiquark system. We demonstrate that the analytic properties of the form factor calculated in the framework of relativistic quantum mechanics with direct interaction agree with the analytic properties following from the general principles of quantum field theory.     

Environmental problems of wood biomass processing. Waste processing lignin

in this paper the ecological problems of wood biomass processing are analyzed. The strongest attention is drawn to the problem of recycling and processing waste materials containing lignin with the help of high temperature self-propagating synthesis.     

Formation of concentric rings of antiparallel domains in the nonlinear-optical ferroelectrics in the presence of an HF field

The formation of cylindrical antiparallel domains is predicted for ferroelectrics in the presence of an HF field at a constant bias. The reorientation of the domains on the temperature lattice induced by the HF field whose amplitude is described with the zero-order Bessel function is considered. The quasi-period of the antiparallel domains is estimated for LiNbO₃, LiTaO₃, and Ba_0.5Sr_0.5Nb₂O₆ crystals. The phenomenon can be used to create photonic crystals, in particular, for the spatial selection of optical signals based on the controlled electrooptical reflection.