Consolidation of aluminum oxide and hydroxide powders, and also compositions of them with commercial alumina powders is studied. Compaction is carried out by static pressing followed by high-temperature sintering. Introduction of nanostructured boehmite into a mix of commercial Al 2 O 3 powder slows down ceramic recrystallization and makes it possible to improve ceramic K 1c to 5.8 MPa·m 1/2 . The ceramic obtained is promising for use as ceramic armor. Ceramic composites are prepared.

Formation and sintering of nanostructured Al2O3 and boehmite powders prepared by hydrothermal synthesis from aluminum powder are studied. Formation of workpieces (green bodies) is performed by extrusion, static and explosive pressing followed by high-temperature sintering. Use of explosive pressing increases raw material density, reduces the temperature for α-Al2O3 formation, activates sintering, and improves ceramic operating properties.

A light-emitting diode (LED) monitoring system of the PHOS photon spectrometer in the ALICE experiment on the CERN large hadron collider is described. The spectrometer includes three modules in the form of 64 × 56 matrices consisting of plumbum tungstate (PWO) crystals. As test light signal sources, Kingbright L934SCC superbright green light-emitting diodes with an individual instrumental regulation of light flash intensities in each channel of the spectrometer are used. The system ensures adjustment and monitoring of the electronics at the stage of preparing for the physical trigger of the PHOS modules and is intended to perform special test measurements with the spectrometer without using high-energy particles. In addition, in the course of the experiment, it allows one to promptly monitor each channel of the spectrometer and keep track of temperature variations of the light yield of the PWO crystals. In this case, the long-term relative channel monitoring stability is ensured at a 1.2 × 10−3 level.

A method for correcting the nonlinearity of the electromagnetic calorimeter response is described. This method is based on minimizing the deviation of the measured mass of a neutral π0 meson decaying into two photons, depending on their energy. This method has been developed for the LGD2 electromagnetic calorimeter and used in the Hyperon-M experiment at the U-70 accelerator of the Institute for High Energy Physics. The proposed correction technique has made it possible to substantially reduce variations of the reconstructed π0 and η meson masses in accordance with their minimum energies.

A structure of the multicomputer data acquisition complex for the Hyperon-M experiment at the U-70 accelerator (Protvino, Russia) is described. This complex has been designed to collect and merge data from several particle detectors, the electronic systems of which are made either to the MISS or SUMMA standard. The MISS system is autonomously operated under control of a special ЛЭ-74 controller that collects information in its internal buffer storage during a beam spill. The data acquired are combined with the information from the SUMMA electronics and are copied to an external storage device (a hard disk of a computer) in intervals between spills. On the contrary, software control is needed for the SUMMA electronics to read data on each event. Software-and hardware-based methods are used to provide joint operation of the electronic systems made to diverse standards and guarantee that the streams of incoming data are correctly merged. The problems of net interactions between different parts of the multicomputer system and monitoring of this system are analyzed.

Based on the reaction of 8-R-4,5-dihydro-4,4-dimethyl[1,2]dithiolo[3,4-c]quinoline-1-thiones with oxalyl chloride followed by the reactions of 1,3-dipolar cycloaddition and diene synthesis with participation of acetylenedicarboxylic acid dimethyl ester, we have developed approaches to synthesis of novel polycondensed heterocyclic systems: [1,2]dithiolo[3,4-c]pyrrolo[3,2,1-ij]quinoline-4,5-dione, 6-(1,3-dithiol-2-ylidene)-1,2-dioxo-5-thioxo-7H-pyrrolo[3,2,1-ij]quinoline and 4,5-dioxospiro(pyrrolo)-[3,2,1-ij]thiopyrano[2,3-c]quinoline-11,2′-[1,3]dithiole.

The structure of the fast data acquisition system collecting data from multichannel particle detectors for experiments on an accelerator, which is based on MISS electronics, is described. A special feature of the architecture used is the ЛЭ-74 specialized controller that independently reads data from the detectors into the internal memory buffer on a real-time scale in the course of the beam spilling into the target. The stored information is rewritten from the internal buffer on the hard disk of the computer. The data are further transmitted via the local network in intervals between spills. This scheme allows one to avoid accessing slow peripherals in the course of the beam spill and, thus, to attain a speed that is only limited by the response speed of the used circuitry components. In tests conducted as part of the Hyperon-M experiment on the U-70 accelerator, an experimental data collection speed of up to 9 Mbyte/s was attained, which is comparable with the data transmission speed in existing local communication networks.

The scintillation characteristics of CsI-based inorganic scintillators subjected to a severe plastic deformation were studied. Nanosecond decay times were observed in some samples of severely deformed scintillators. The mechanisms of variations in the characteristics of severely deformed scintillators upon relaxation of their internal stresses were investigated.

New synthetic approaches to 6(7)-R-4-methyl-2-sulfanylquinazolines are developed and certain transformations of the products are studied.

The results from studies of the scintillation characteristics of new multicomponent composite scintillators are described. These scintillators were developed on the basis of inorganic matrices, a set of heavy inorganic and organic scintillating fillers, and activators based on luminescent additives. The characteristics of some of the produced composite scintillators turned out to be nonadditive with respect to the characteristics of their components. Studies of the scintillation processes in dynamically changing media were resumed. The equations obtained allow the description of the scintillation process for a wide class of multicomponent media in both static and dynamically changing states.

AbstractFor Abstract see ChemInform Abstract in Full Text.

The scintillation properties of new composite scintillators based on both organic and inorganic matrices with inorganic scintillating fillers have been investigated. For some of these composite scintillators, their characteristics are not additive with respect to the characteristics of their components. The laws responsible for changes in the scintillation process in dynamically changing media are investigated.

8-R-1-Aryl-4,4,6-trimethyl-4H-pyrrolo[3,2,1-ij]quinolines have been synthesized by the Bischler-Melau reaction in the series of 6-R-2,2,4-trimethylhydroquinolines.

We synthesized 2-(6-R-4-methyl-2-quinazolyl)amino-1,4-dihydropyrimid-4-ones by reaction of 6-R-4-methyl-2-quinazolylguanidines with acylacetic esters.

4,6,6-Trimethyl-1,4-dihydropyrimidines have been synthesized by condensation of 2-quinazolylguanidines with mesityl oxide. The analogous reaction with benzalacetone leads to unstable 4-methyl-6-phenyl-1,4-dihydropyrimidines, which are oxidized to the corresponding 4-methyl-6-phenylpyrimidines.

The scintillation process in dynamically changing media was studied. Noticeable changes in the laws that govern the scintillation process in such media were observed in comparison with their particular forms in the same media in the static equilibrium state. A method is proposed for determining the properties of materials by transferring them to dynamically changing states, using the scintillation process for probing.

The scintillation, optical, and other characteristics of a new block and molded scintillators based on polystyrene and hybrid glasses were studied. The cross-linked scintillators polymerized in block were produced. The light yield in some of these scintillators reached 70% of that in anthracene. Boron- and lithium-containing scintillators were manufactured by bulk polymerization and tested for the detection of thermal neutrons. We obtained samples of polystyrene-based hybrid glasses and low-melting inorganic fillers with the scintillation decay times highly sensitive to the ionization density of detected particles.

The interaction of ethyl propiolate with 4,4-dimethyl-4,5-dihydro-2,3-dithiolo[3,4-c]quinoline-1-thiones leads to 1,3-dithiol-2-ylidenes, 1,6,6a(l4)-trithiapentalene, or thiino[2,3-c]quinolines depending on the conditions.