Ionic liquid matrices for MALDI mass spectrometry of lignin

Analytical and Bioanalytical Chemistry - The use of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry for the study of lignin is still extremely limited due to its low...     

Numerical simulation of the field distribution produced by the SP-40 magnet of the MARUSYA setup and comparison of simulation results with experimental data

In terms of the magnetostatic problem in the differential statement, a mathematical simulation of the 3D distribution of the magnetic field generated by the SP-40 magnet of the MARUSYA experimental setup (Laboratory of High Energies, Joint Institute for Nuclear Research, Dubna) is carried out. The mathematical statement of the direct magnetostatic problem is given. Computational procedures and field calculation algorithms with one vector and two scalar potentials are described. The simulated magnetic field distribution is compared with experimental data for the field of the modified SP-40 magnet with a pole spacing of 0.207 m. The results of this work are used in experimental data processing and are also helpful in simulation of magnetooptic systems.     

New chalcones containing carbazole and 3,4-ethylenedioxythiophene fragments

Russian Journal of Organic Chemistry - Acylation of 9-(2-ethylhexyl)carbazole with acetyl bromide in the presence of tin(IV) chloride gave 3-acetyl- and 3,6-diacetyl-9-(2-ethylhexyl)carbazoles...     

Depolymerization of Alkaline Lignin in the Medium of Supercritical 2-Propanol

Russian Journal of Applied Chemistry - The results of optimizing the conditions of alkaline lignin depolymerization in a medium of supercritical 2-propanol in order to obtain low molecular weight...     

Calculations of the field distribution of a spectrometric magnet

The design and construction of magnetic systems of electrophysical installations require preliminary mathematical modeling. Mathematical modeling is necessary in the process of adjustment and subsequent operation of an installation. Calculations of fields of magnetic systems, although performed on the basis of the solution of direct magnetostatic problems, are related to the class of inverse magnetostatic problems, since they actually include the search for optimal design of current elements and an iron yoke for a given magnetic field distribution. In this work, the method of numerical solution of the magnetostatic problem for domains with boundaries containing cusps is proposed. Using this numerical method, magnetic systems of rectangular configuration were modeled with high accuracy. In particular, the calculations of several modifications of the magnetic system SP-94 used in certain experimental installations are presented.     

Synthesis and Optical Properties of New Chalcones Containing a 3,4-Ethylenedioxythiophene Fragment

Russian Journal of Organic Chemistry - A new series of chalcones bearing two or more 3,4-ethylenedioxythiophene fragments were synthesized, and their optical properties were studied. The Stokes...     

Study of the sedge (Cárex) lignin by high-resolution mass spectrometry and NMR spectroscopy

Russian Chemical Bulletin - A combination of high-resolution mass spectrometry based on an orbital ion trap and 2D NMR spectroscopy was first applied to the characterization of the structure of...     

Computer simulation of spectrometer magnets for some experimental installations

The significance of numerical simulation in the research of magnetic systems is determined by not only known advantages of the computing experiment, but also by the fact that the measurement of a magnetic field is a labour-consuming and expensive problem. Mathematical simulation allows one to investigate those parts of the magnet’s design where the measurements of the magnetic field are extremely complicated or even impossible. This work is aimed to generalize experience of the mathematical simulation of magnetic systems of various-type physical and electromechanical installations and to work out some recommendations of the optimal use of some software products for the numerical modeling of magnetostatic problems. This work also presents some results of a numerical analysis of the magnetic systems of the JINR’s physical installation MARUSYA with the purpose of studying an opportunity of designing magnetic systems with predetermined characteristics of the magnetic field. The article is published in the original.     

Synthesis of Pyrrolo[2,1-a][1,4]oxazine-1,6,7-triones by the Reaction of 3-Methylenemorpholin-2-ones with Oxalyl Chloride

Russian Journal of Organic Chemistry - 8-Aroyl-3,4-dihydropyrrolo[2,1-a][1,4]oxazine-1,6,7(1H)-triones were synthesized by the reactions of 3-(2-aryl-2-oxoethylidene)morpholin-2-ones with oxalyl...