PECULIARITIES OF PHASE TRANSFORMATIONS IN FERRITICMARTENSITIC STAINLESS STEEL

Методами сканирующей электронной микроскопии, включая микрозондовый рентгеноспектральный анализ, установлены структурно-фазовые изменения в нержавеющей стали ферритно-мартенситного класса после термических обработок с различными скоростями охлаждения. В зависимости от скорости охлаждения происходит изменение доли структурных составляющих и перераспределения основных легирующих элементов (Cr, Mo и Mn). Наличие локальных неоднородностей в элементном составе приводит к изменению фазового состава, а именно, к выделению вторых фаз, включающих в себя карбиды на основе Cr и Mo в форме «сеток» по границам ферритных зерен.The methods of scanning electron microscopy, including microprobe X-ray spectral analysis, have established structural and phase changes in stainless steel of ferrite-martensitic class after heat treatment with different cooling rates. Depending on the cooling rate, there is a change in the proportion of structural components and redistribution of the main alloying elements (Cr, Mo and Mn). The presence of local inhomogeneities in the elemental composition leads to a change in the phase composition, namely, to the separation of second phases, including carbides based on Cr and Mo in the form of "meshes" along the boundaries of ferrite grains

INFLUENCE OF COOLING RATE ON THE STRUCTURE OF FERRITE-MARTENSITE CLASS STEEL

Методом сканирующей электронной микроскопии были исследованы образцы из стали ферритно-мартенситного класса, нагретые в печи до температуры 1000 ℃ и охлажденные при различных скоростях. Охлаждение производилось в воду, на воздухе и в печи. Методами сканирующей электронной микроскопии (СЭМ) и дифракции отраженных электронов (EBSD) определялись характеристики структурных составляющих.Using scanning electron microscopy, ferritic-martensitic steel samples heated in a furnace to a temperature of 1000 ℃ and cooled at different speeds were studied. Cooling was carried out in water, in air and in an oven. The characteristics of the structural components were determined using scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD)

Modular Chemical Descriptor Language (MCDL): Stereochemical modules

<p>Abstract</p> <p>Background</p> <p>In our previous papers we introduced the Modular Chemical Descriptor Language (MCDL) for providing a linear representation of chemical information. A subsequent development was the MCDL Java Chemical Structure Editor which is capable of drawing chemical structures from linear representations and generating MCDL descriptors from structures.</p> <p>Results</p> <p>In this paper we present MCDL modules and accompanying software that incorporate unique representation of molecular stereochemistry based on Cahn-Ingold-Prelog and Fischer ideas in constructing stereoisomer descriptors. The paper also contains additional discussions regarding canonical representation of stereochemical isomers, and brief algorithm descriptions of the open source LINDES, Java applet, and Open Babel MCDL processing module software packages.</p> <p>Conclusions</p> <p>Testing of the upgraded MCDL Java Chemical Structure Editor on compounds taken from several large and diverse chemical databases demonstrated satisfactory performance for storage and processing of stereochemical information in MCDL format.</p

Hierarchical Clustering of Large Databases and Classification of Antibiotics at High Noise Levels

A new algorithm for divisive hierarchical clustering of chemical compounds based on 2D structural fragments is suggested. The algorithm is deterministic, and given a random ordering of the input, will always give the same clustering and can process a database up to 2 million records on a standard PC. The algorithm was used for classification of 1,183 antibiotics mixed with 999,994 random chemical structures. Similarity threshold, at which best separation of active and non active compounds took place, was estimated as 0.6. 85.7% of the antibiotics were successfully classified at this threshold with 0.4% of inaccurate compounds. A .sdf file was created with the probe molecules for clustering of external databases

Novel Algorithm of Network Calcium Dynamics Analysis for Studying the Role of Astrocytes in Neuronal Activity in Alzheimer&rsquo;s Disease Models

Accumulated experimental data strongly suggest that astrocytes play an important role in the pathogenesis of neurodegeneration, including Alzheimer&rsquo;s disease (AD). The effect of astrocytes on the calcium activity of neuron&ndash;astroglia networks in AD modelling was the object of the present study. We have expanded and improved our approach&rsquo;s capabilities to analyze calcium activity. We have developed a novel algorithm to construct dynamic directed graphs of both astrocytic and neuronal networks. The proposed algorithm allows us not only to identify functional relationships between cells and determine the presence of network activity, but also to characterize the spread of the calcium signal from cell to cell. Our study showed that Alzheimer&rsquo;s astrocytes can change the functional pattern of the calcium activity of healthy nerve cells. When healthy nerve cells were cocultivated with astrocytes treated with A&beta;42, activation of calcium signaling was found. When healthy nerve cells were cocultivated with 5xFAD astrocytes, inhibition of calcium signaling was observed. In this regard, it seems relevant to further study astrocytic&ndash;neuronal interactions as an important factor in the regulation of the functional activity of brain cells during neurodegenerative processes. The approach to the analysis of streaming imaging data developed by the authors is a promising tool for studying the collective calcium dynamics of nerve cells

Contemporary historiography of civil war in Russia: the results and prospects of research

В статье анализируются итоги и перспективы историографического изучения истории гражданской войны в России. Отмечена результативность использования когнитивно-информационной теории в исторических . The article deals with the results and prospects of historiographical research of Russian civil war history. The affective application of the cognitive in formational theory in historical research is considered

Physicochemical property profile for brain permeability: comparative study by different approaches

<p>A comparative study of classification models of brain penetration by different approaches was carried out on a training set of 1000 chemicals and drugs, and an external test set of 100 drugs. Ten approaches were applied in this work: seven medicinal chemistry approaches (including “rule of 5” and multiparameter optimization) and also three SAR techniques: logistic regression (LR), random forest (RF) and support vector machine (SVM). Forty-one different medicinal chemistry descriptors representing diverse physicochemical properties were used in this work. Medicinal chemistry approaches based on the intuitive estimation of preference zones of CNS or non-CNS chemicals, with different rules and scoring functions, yield unbalanced models with poor classification accuracy. RF and SVM methods yielded 82% and 84% classification accuracy respectively for the external test set. LR was also successful in CNS/non-CNS (denoted in this study as CNS+/CNS−) classification and yielded an overall accuracy equivalent to that of SVM and RF. At the same time, LR is especially valuable for medicinal chemists because of its simplicity and the possibility of clear mechanistic interpretation.</p