p t -Multiplicity correlations in a multi-pomeron-exchange model with string collective effects

The 〈p _t 〉N _ch - N _ch correlations experimentally observed in the central rapidity region in pp and p collisions, in a wide energy range from the ISR to Tevatron, are described in the framework of a multi-Pomeron exchange model in which string collectivity has been included in an effective way. Three parameters are obtained from the fit to data: the string tension, the average number of particles per string, and a parameter which effectively introduces string collective effects. The model successfully reproduces the rise of 〈p _t 〉 of charged particles, the flattening with growing rapidity density of charged particles and with the collision energy, and the negative p _t -N _ch correlation at low energies. The string tension and the average number of particles per string are energy independent, while the parameter that includes effectively string collective effects shows a smooth increasing behavior with energy. The text was submitted by the authors in English.     

Damage of Dusty Optical Elements in the Field of Continuous-Wave Laser Radiation

The structure and properties of high-pressure phases of iron nitrides Fe₇N₃ in the pressure range of 50–150 GPa have been studied with ab initio calculations within the electron density functional theory. A new phase Amm2-Fe₇N₃, which is the most energetically favorable in the pressure range of 43–128 GPa, has been found using the USPEX (Universal Structure Predictor: Evolutionary Xtallography) algorithms. It has been thermodynamically shown that another high-pressure phase β-Fe₇N₃ is isostructural to a similar phase of iron carbide. The elastic properties have been calculated for all modifications ε-, β-, and Amm2-Fe₇N₃ stable at high pressures.     

Synthesis of new derivatives of 2,4-dihydroxybenzoic acid and aldehyde and the study of the spectral-luminescent properties of their lanthanide complexes

4-Acylated derivatives of 2,4-dihydroxybenzoic acid and aldehyde were synthesized. It was found that 2-hydroxy-4-[(4-decyloxy)benzoyloxy]benzaldehyde coordinates to Eu(III) ion, and when the aldehyde group is replaced by the carboxy group, a complex with Tb(III) ions is formed. The photoluminescent properties of the resulting complexes in solution were studied.     

NEW SCANNING MILLIMETER WAVEBAND ESR-MICROSCOPE WITH LOCALIZED MAGNETIC FIELD

The design of the new scanning ESR-microscope, which is able to detect magnetic particles smaller than 0.015×3×0.025 mm³ by the method of Electron Spin Resonance in 30–45 GHz frequency band is presented. The static magnetic field in the working zone of the microscope is created by the use of the special magnetic field concentrator unit. Mechanical shifting of the specimen provides the scanning of the static magnetic field on its surface. The first experimental data, which demonstrate the efficiency of the device operation, are presented and analyzed. The possibility of the ESR-microscope design for the frequency band up to 140 GHz is discussed.     

High-Frequency Magnetoresonance and Magnetoimpedance in Co/Cu Multilayers with Variable Interlayer Thickness

The paper is devoted to the investigation of high frequency magnetic features of multilayered metallic structures (Co/Cu) demonstrating the Giant Magnetic Resistance effect (GMR-effect) and Giant Magnetic Impedance effect (GMI-effect). Dynamic features have been investigated in dependence on the distance between magnetic Co-layers and analyzed in comparison with static magnetic features. Ferromagnetic resonance response as well as non-resonance magnetoimpedance at small applied static magnetic field have been studied. Experiments were carried out at room temperatures in frequency band 20-37GHz for the ferromagnetic resonance technique and in frequency band 30-140GHz for study the low field non-resonance magnetoimpedance effects.     

Acetylspectabiflaside fromStachys atherocalyx

From the herbage ofStachys atherocalyx C. Koch, a new flavonoid glycoside has been isolated — acetylspectabiflaside, with mp 237–242°C. On the basis of acetylation, the formation of a hydroxamic acid, alkaline, and enzymatic hydrolysis, and oxidative degradation, and also the results of UV, IR, and PMR spectroscopy, the structure of 4,5,7,8-tetrahydroxy-3-methoxyflavone 7-O-{acetyl-[O--D-glucopyranosyl-(12)--D-mannopyranoside]} has been proposed for acetylspectrabiflaside.Khar'kov Scientific-Research Institute of Pharmaceutical Chemistry. Institute for the Advanced Training of Doctors, Minsk. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 187–189, March–April, 1982.