Вещественный состав метеорита Северный Колчим

New data on the material composition of the Severny Kolchim meteorite, found in the Perm region territory in 1965, is presented. It is established that the cosmic substance is composed of forsterite, enstatite, diopside, plagioclase (oligoclase, bitovnite), glass, chromite, magnetite, ilmenite, rutile, iron and nickel metals (kamasite, taenite and tetrataenite), sulphides (troilite, pentlandite), chlorapatite and merrillite. Some minerals, namely the diopside, tetrataenite, chlorapatite and merrillite, were determined in the Severny Kolchim meteorite first time. The data on the chemical composition of minerals and the trace element composition are given. It was verified that this meteorite is a nonequilibrium stone chondrite and belongs to the petrological type H3.Приведены современные данные о вещественном составе метеорита Северный Колчим, найденного на территории Пермского края в 1965 г. Установлено, что космическое вещество сложено форстеритом, энстатитом, диопсидом, плагиоклазами (олигоклазом, битовнитом), стеклом, хромитом, магнетитом, ильменитом, рутилом, металлами железа и никеля (камаситом, тэнитом и тетратэнитом), сульфидами (троилитом, пентландитом), хлорапатитом и мерриллитом. При этом диопсид, тетратэнит, хлорапатит и мерриллит определены в метеорите Северный Колчим впервые. Приведены данные о химическом составе минералов и микроэлементном составе породы. Сам метеорит является неравновесным каменным хондритом и относится к петрологическому типу H3

The Boltzmann equation for colourless plasmons in hot QCD plasma. Semiclassical approximation

Within the framework of the semiclassical approximation, we derive the Boltzmann equation describing the dynamics of colorless plasmons in a hot QCD plasma. The probability of the plasmon-plasmon scattering at the leading order in the coupling constant is obtained. This probability is gauge-independent at least in the class of the covariant and temporal gauges. It is noted that the structure of the scattering kernel possesses important qualitative difference from the corresponding one in the Abelian plasma, in spite of the fact that we focused our study on the colorless soft excitations. It is shown that four-plasmon decay is suppressed by the power of $g$ relative to the process of nonlinear scattering of plasmons by thermal particles at the soft momentum scale. It is stated that the former process becomes important in going to the ultrasoft region of the momentum scale.Comment: 41, LaTeX, minor changes, identical to published versio

The significance of retained austenite in the high strength and plasticity of medium carbon Q&P steel

The Fe-0.44%C-1.8%Si-1.3%Mn-0.82%Cr-0.28%Mo steel treated by the quenching-partitioning partitioning process showed a product of strength and elongation of 30 GPa % with yield stress of 1350 MPa. Such a combination of high ultimate tensile strength and good ductility is attributed to a high portion of retained austenite (≥20%) transforming to martensite under tension. The high yield stress is provided by carbon supersaturation of austenite and a high dislocation density in this phas

Studies of Biofilm Formation in Non-Pigmented and Plasmid-Deprived Mutants of <I>Yersinia pestis</I> on Biotic Surfaces, <I>in vivo</I> and <I>in vitro</I> Conditions

In non-pigmented and plasmid-deprived mutants – isogenic variants of highly virulent Yersinia pestis 231 strain – studied is the mechanism of biofilm formation on biotic surfaces, both in vitro (on the laboratory model of nematode Caenorhabdiitis elegans) and in vivo (inside the alimentary tract of Nosopsyllus laeviceps flea). It is determined that spontaneous loss of ability to form biofilms and generate pigmented colonies in the mutants is probably caused not only by the deletion of the whole chromosome pigmentation fragment, but also by a point(single base) mutation in structural hms operon. It is demonstrated that the absence of pCad, pFra or pPst plasmids does not have an impact on the ability of plasmid-deprived mutants to form biofilm on the cuticle of nematode C. elegans

Двухдиапазонная отражательная антенная решетка Ka/Q-диапазонов частот

Introduction. Duplex satellite communication is commonly arranged using two spaced frequency bands, with one band receiving and the other band transmitting signals to a satellite. The main task of a communications satellite antenna system consists in providing an identical coverage area across all involved frequency bands, which is often a challenging task for conventional parabolic reflector antennas. Reflectarrays allow an independent control of the reradiated wave phase in spaced frequency bands, which can be used to create efficient multi-band antenna systems for modern communication satellites.Aim. To develop a Ka/Q-frequency range phase-correcting element and to create on its basis a dual-band reflectarray for operation with orthogonal circular polarizations and identical gains in a given sector of angles in significantly spaced frequency ranges.Materials and methods. Numerical studies were carried out using the finite element analysis method. Radiation patterns were measured using the near field scanning method.Results. A single-layer dual-band phase-correcting reflectarray element was developed for operation with orthogonal circular polarizations with low losses and a weak dependence of the relative position of the elements on the phase characteristic. On the basis of the proposed element, a reflectarray consisting of 24 465 two-frequency elements was synthesized and manufactured. The developed prototype of a single-layer dual-band reflectarray demonstrated good characteristics, with the efficiency reaching 56 and 36 % in the Ka- and Q-frequency ranges, respectively, and an almost identical minimum gain in the ±0.75° angle sector.Conclusion. The research results confirm the potential of the developed reflectarray to successfully replace conventional parabolic reflectors installed both on modern communication satellites and as part of ground-based satellite terminals in the millimeter wavelength range.Введение. Для организации дуплексной спутниковой связи, как правило, используются два разнесенных диапазона частот: один – для приема, второй – для передачи сигнала на спутник. Основной задачей антенной системы спутника связи является обеспечение идентичной зоны покрытия во всех задействованных диапазонах частот, что зачастую затруднительно с использованием традиционных параболических зеркальных антенн. Отражательные антенные решетки (ОАР) позволяют осуществлять независимое управление фазой переизлученной волны в разнесенных диапазонах частот, что может быть использовано для создания эффективных многодиапазонных антенных систем современной спутниковой связи.Цель работы. Разработка фазокорректирующего элемента Ka/Q-диапазонов частот и создание на его основе двухдиапазонной ОАР для работы с ортогональными круговыми поляризациями, обладающей идентичными коэффициентами усиления (КУ) в заданном секторе углов в значительно разнесенных диапазонах частот.Материалы и методы. Численные исследования проведены методом конечных элементов. Характеристики направленности измерялись методом сканирования в ближнем поле антенны.Результаты. Разработан однослойный двухдиапазонный фазокорректирующий элемент ОАР для работы с ортогональными круговыми поляризациями с малыми потерями и слабой зависимостью фазовой характеристики от взаимного расположения элементов. На основе предложенного элемента синтезирована и изготовлена ОАР, состоящая из 24 465 двухчастотных элементов. Разработанный макет однослойной двухдиапазонной ОАР продемонстрировал хорошую эффективность, коэффициент использования поверхности достигает 56 и 36 %, соответственно, в Ka- и Q-диапазонах частот при практически идентичном минимальном КУ в секторе углов ±0.75°.Заключение. Результаты исследований показывают возможность ОАР с успехом замещать традиционные параболические рефлекторы как на современных спутниках связи, так и в составе наземных спутниковых терминалов в миллиметровом диапазоне длин волн

The pathological anatomy of alcoholic disease

The problem of alcohol abuse is high on the agenda for the whole world both medically and socially. However, the fight against this disease is less than effective, mostly due to the fact that its solution has been left to psychiatrists and experts in narcology. They are making attempts to treat alcoholism, a disease which results from long-term, chronic alcohol intoxication and alcohol dependence. What is missed here is a long period of excessive use of hard drinks characterized by alcohol cravings with no alcohol dependence; this period is called “excessive alcohol consumption”. Based on the results of 1113 autopsies of patients aged 18 to 73 years who died at home or in a hospital, the authors propose the concept of the alcohol disease, whose pathogenesis consists of 3 stages: stage 1, episodic alcohol intoxication, stage 2, excessive alcohol drinking, and stage 3, alcoholism and its complications. The article describes the changes over time that can be found in the liver, vessels and other organs. The authors emphasize that the formation of Mallory bodies (auto-antigens), mainly in the stage of alcoholism, triggers an irreversible autoimmune inflammatory reaction explaining an extremely poor effect of alcoholism treatment. In this regard, excessive alcohol drinking is being suggested as a separate stage, which should be treated by internists

The inclusion of grothite in the zircon from granitoids of the crystalline basement of the Southern Yamal Peninsula

Grothite – rare F-Al-rich type of titanite – has been found in accessory zircon from the granitoids of the pre-Jurassic basement of the Verkhnerechensky oil-gas area (in the southern part of the Yamal Peninsula) as a result of the study. Titanite forms rare inclusions (so-called minerals-prisoners) in the central parts of zircon crystals; in our sample of 35 individuals only two grains of titanite have been discovered. The measurement of the chemical composition of the mineral has been carried out on an electron-probe microanalyzer CAMECA SX 100, equipped with five wave spectrometers (IGG UrB RAS, Ekaterinburg). According to the microprobe analysis, the mineral has an unusual chemical composition, it shows the presence of significant concentrations of alumina (Al2O3 to 8.5 wt.%), rare earths elements (REE to 4.3 wt.%), and fluorine (F to 2 wt.%). This grothite is dramatically different in chemical composition from the accessory titanite of the matrix granitoid (monzoleicogranite), which is characterized by values close to the reference sphene. Overall, grothite is an intermediate connection between the two extreme members CaTiSiO4O (titanite) – CaAlSiO4F (synthesized Al-F-titanite), and the Verkhnerechensky mineral content of a hypothetical Al-F-titanite achieves a high level of 24–26 %. Unfortunately, grothite is crystallized in a wide range of temperatures and pressures which does not allow its use in thermodynamic reconstructions. The existence of grothite (or Al-F-titanite) is apparently determined not so much on the PT-conditions of rocks' formation, but most likely on the chemistry of the environment. So it is obvious that the Verkhnerechensky titanite was formed in the melt with an increased concentration of fluorine. It is the first record of grothite in the form of inclusions in accessory zircon

AGE AND COMPOSITION OF GRANITOIDS FROM THE BASEMENT OF KRASNOLENINSKY OIL AND GAS REGION (WESTERN SIBERIA)

The relevance of the study consists in the insufficient level of scrutiny of the crystalline basement of the West Siberian megabasin. The purpose of this research is to study the material composition and age of granitoids from the pre-Jurassic basement of Krasnoleninsky oil and gas region in the Ural part of the West Siberian megabasin. Research methodology: a detailed study of mineralogy, petrochemistry, geochemistry and age (different isotope systems using K–Ar, Rb–Sr and U– Pb methods of dating) of the granites in the Krasnoleninsky area. Results. The mineralogy and petrogeochemical of the Krasnoleninsky region granites are studied in detail. It was found that rocks are composed of quartz, plagioclase (albite and oligoclase), potassic feldspar (microcline and orthoclase) and mica (annite). The accessory mineralization in the form of rutile, apatite, magnetite, titanite, monazite, zircon and cassiterite is added. Granites are subject to propylitization, which is expressed in the development of secondary carbonate, chlorite, sericite and albite. The sulfide (chalcopyrite, galena) and native (gold, silver) mineralization is also added to it. On petrogeochemical characteristics of rocks belong to granitoids of S-type, the source of substance for them was mainly sedimentary rocks. Granites are of early Permian age, which, apparently, reflects the process of raising granites to the level of the upper crust during riftogenesis and stretching of the entire region. Summary. The granites of the Kamennaya petroleum exploration area are an integral part of the regional Shaimsky-Kuznetsovsky anticlinorium. Thetime of magmatic introduction and crystallization of granites of the Krasnoleninsky area is estimated at 300 million years, as well as of the granitoids of the nearby Shaimsky oil and gas area. The difference between U–Pb (297.9 ± 3.8 million years) and Rb–Sr (291.8 2.1 million years) granite ages is likely to result from the gradual cooling of the granite massif. This happened because the uranium-lead isotope system closes at a higher temperature than the rubidium-strontium one. We interpret the “Mesozoic” numerals obtained by the K–Ar method as the time of the last tectonic-thermal events, most likely expressed in the form of granites propylitization