Yuri A. Pirogov

1H and 13C MAS NMR studies of light alkanes activation over MFI zeolite modified by Zn vapour

The early stages of methane, ethane and propane conversion were studied by in situ (1)H and (13)C MAS NMR techniques over fully exchanged Zn(2+)/MFI catalyst obtained by the reaction with zinc vapour. The in situ techniques revealed strong interaction of alkanes with Zn(2+) cations evidenced by significant shift of the corresponding NMR lines. Besides that, the formation of methyl zinc, ethyl zinc and n-propyl zinc species along with bridging and silanol surface OH-groups was detected already at the ambient temperature. These results pointed to dissociative adsorption of alkanes over (ZO)-Zn(2+)-(OZ) and (ZO)-Zn(2+)-(OSi) active sites of the catalyst. The dissociative adsorption was shown to be a dead-end surface reaction in the case of methane starting reactant, while in the case of ethane and propane, it appeared to be responsible for the initiation of the catalytic cycle leading to alkenes and dihydrogen formation and regeneration of zinc containing catalytic sites.

Radio thermal images of natural objects in 8-mm and 3-mm ranges

This paper describes passive radiovision systems in 8-mm and 3-mm ranges. It contains short description of the systems, data processing algorithms and points out problems specific to multi-ray systems. Image enhancement methods are briefly considered. Several examples of radio thermal images of natural objects are presented herein.

Problem of the radiovision system resolution improvement in millimeter-wave range

At the Faculty of Physics of Moscow State University experimental researches of the working radiovision systems on the base of phased antenna array and radio optical systems with the sensors rules are carried out. Since 1980 the system of Sun radio observation in 3-mm wavelength range created by the specialists of Bauman Moscow State Technical University is exploited. Investigations in the mathematical modeling of image formation systems in wide wavelength range with different receiving schemes and with distortion compensation task solution and super-resolution are conducted by mathematician and physicists.

MRI‐Adaptive Magneto‐Thermo‐Chemotherapy for Improved Cancer Treatment

Dextran‐ferrite (DF) has been synthesized and tested as magnetic resonance imaging (MRI) negative contrast agent for tumors, invasions and metastases. MRI‐adaptive Magneto‐thermo‐chemotherapy (MTCT) by cisplatin (CP), melphalan (MP) and DF led to improved cancer treatment. MTCT by using AC magnetic field (0.88 MHz, 7.3 kA/m and 0.15 kW) was performed at early stages of oncogenesis at +46° C for 30 min using DF at a dose of 60 mg Fe/kg containing CP or MP. MTCT led to regression of adenocarcinoma Ca‐755 tumor ∼45 mm3 before metastases in female mice up to 40% and increasing of life span up to 280%. As for tumor ∼300 mm3 the use of MTCT with slime aspiration and the invasions of cyclophosphamide into metastases led to 200% increased life span.Dextran‐ferrite (DF) has been synthesized and tested as magnetic resonance imaging (MRI) negative contrast agent for tumors, invasions and metastases. MRI‐adaptive Magneto‐thermo‐chemotherapy (MTCT) by cisplatin (CP), melphalan (MP) and DF led to improved cancer treatment. MTCT by using AC magnetic field (0.88 MHz, 7.3 kA/m and 0.15 kW) was performed at early stages of oncogenesis at +46° C for 30 min using DF at a dose of 60 mg Fe/kg containing CP or MP. MTCT led to regression of adenocarcinoma Ca‐755 tumor ∼45 mm3 before metastases in female mice up to 40% and increasing of life span up to 280%. As for tumor ∼300 mm3 the use of MTCT with slime aspiration and the invasions of cyclophosphamide into metastases led to 200% increased life span.

Problems of precise air-spatial monitoring

The designers of modern devices of vision prefer to choose a scanning step of receiving system antenna with some less size than the main lobe of Point Spread Function (PSF). They tell such systems are good constructed. However there is a problem of additional increase of resolution for such well constructed receiving system. This problem is naturally connected with improvement of mathematical models. The report is devoted to development and applications of local-linear method of additional enhancement of resolution for such receiving system in radio vision and optics.

Optimization of radiovision systems in millimeter-wave range

Method of optimization is considered to improve resolution and noise properties of millimeter-wave radio vision system. Conditions of optimal measurements are realized by coincidence of bandwidths both of signals and device.

Discrete mathematical model of a sheet electron beam in a decaying magnetic field

A discrete model of a sheet electron beam is developed in a weakly relativistic approximation. A 3D simulation of the sheet electron beam with cyclotron rotation in an axially symmetric static magnetic field under time-periodic conditions of entry is performed. The velocity spread in the beam and the efficiency of converting the energy stored in the beam into DC power depending on the beam perveance are calculated.

Dynamics of sheet electron beam in cyclotron-wave converter

Dynamics of sheet electron beam was simulated in cyclotron-wave converter with plane-symmetric reverse of magnetic field. High efficient regimes of conversion of microwaves into DC were found. Space charge effects on spatial bunching of sheet electron beam as well as influence of initial entry conditions were studied.

MRI visualization of pathological forms by suppression of normal tissue signals

To improve the visualization and 3D-reconstruction of some pathological formations of the brain, it is offered to use a new method of processing of MR images with suppression of signals from normal tissues. The special attention is offered to be given suppression of signals of fatty tissue, free water and partially bound water of mucous membranes. For such way realization, it is offered to lead two scans with simultaneous suppression of two normal components and to multiply the obtained images. Simultaneous suppression of signals from two normal tissues is realized with the help of pulse sequence twice using inversion-recovery effect. Delays in pulse sequence are selected in accordance with the times of longitudinal relaxation of fat, free water and partially bound water. In comparison with earlier described technique of simultaneous suppression of signals of water and fat, the new method is especially useful at research of pathological formations when the zone of defeat is placed in a zone of nose bosoms. Besides allocation of a zone of defeat, MIP reconstruction becomes simpler. The offered technique well proves at research of tumors and hemorrhages.

Thermo-emission of small-scale rough water surface

The thermal radiation of rough water surface in small-scale approximation is considered. The mathematical model of radiating ability of multiwave perturbation is based on the Kirchhoff law of radiation, Leontovich boundary conditions and small perturbations method. The experimental research of radiating properties of the rough water surface mock-up is carried out. The critical phenomena were revealed as increase of a thermal radiation in the certain allocated spatial directions.