ВЕРОЯТНОСТНО-СТАТИСТИЧЕСКАЯ ОЦЕНКА ШЕРОХОВАТОСТИ ПОВЕРХНОСТИ ЭЛЕКТРОИМПУЛЬСНО ПОЛИРОВАННЫХ ДЕТАЛЕЙ

The paper presents methodology and results of investigations pertaining to profilograms of specimen surfaces being polished using electric pulse method and being made of steel 10 и 20Х13 with the help of correlative transformation. It has been established that in the process of polishing topography formation is initiated due to simultaneous surfacing of micro- and sub-micro-irregularities with equal probability and equal intensity. The obtained mechanism for topography formation is justified by the fact that break-down of gas-vapor shell takes place with equal probability as on the micro-profile top so in its cavities on the polished surface in the zones of accidental  non-homogeneity of electric field.Приведены методика и результаты исследования профилограмм электроимпульсно полированных поверхностей образцов из сталей 10 и 20Х13 с помощью корреляционного преобразования. Установлено, что в процессе полирования формирование топографии поверхности происходит за счет одновременного с равной вероятностью и равной интенсивностью сглаживания микро- и субмикронеровностей поверхности. Выявленный механизм формирования топографии обусловлен тем, что пробой парогазовой оболочки происходит с равной вероятностью как на вершинах, так и во впадинах микропрофиля обрабатываемой поверхности в областях случайных неоднородностей электрического поля.

ВЛИЯНИЕ ТЕХНОЛОГИЧЕСКИХ ПРИМЕСЕЙ НА ВОЛЬТ-АМПЕРНЫЕ ХАРАКТЕРИСТИКИ БИПОЛЯРНОГО n–p–n-ТРАНЗИСТОРА

Contamination of the monocrystal silicon with technological impurities in the devices fabrication process exerts a considerable influence on the electro-physical characteristics of the bipolar n–p–n-transistors. Revelation of the causes of the labile reproducibility of the basic characteristics of the bipolar planar n–p–n-transistors is vital for the purpose of establishing the factors, determining reliability and stability of the operational parameters of the integrated circuits. There were investigated I–V characteristics of the various lots of the bipolar n–p–n-transistors, fabricated under the epitaxialplanar technology as per the similar process charts with the identical used technological materials, however, at different times. It is established that the electro-physical characteristics of the bipolar n–p–n-transistors substantially depend on the contents of the technological impurities in the substrate material. Availability of the high concentration of the generation-recombination centers, related to the metallic impurities, results both in increase of the reverse current of the collector – base junction of the transistors and the significant reduction of the breakdown voltage of the collector junction. The most probable cause of deterioration of the electro-physical parameters of the bipolar n–p–n-transistors is the material contamination with the technological impurities (such, as Fe, Cl, Ca, Cu, Zn and others) during the production process of the devices fabrication. The sources of impurity may be both the components and sub-assemblies of the technological units and the materials and reagents under usage.Загрязнение монокристаллического кремния технологическими примесями в процессе изготов- ления приборов оказывает существенное влияние на электрофизические характеристики биполярных n–p–n-тран- зисторов. Выявление причин лабильной воспроизводимости основных характеристик биполярных планарных n–p–n-транзисторов является актуальным с целью установления факторов, определяющих надежность и стабильность эксплуатационных параметров интегральных микросхем. Исследованы вольт-амперные характеристики различных партий биполярных n–p–n-транзисторов, изготовленных по эпитаксиально-планарной технологии по аналогичным технологическим маршрутам, при идентичных используемых технологических материалах, однако в различное время. Установлено, что электрофизические характеристики биполярных n–p–n-транзисторов существенным образом зависят от содержания технологических примесей в материале подложки. Наличие высокой концентрации генерационно-рекомбинационных центров, связанных с металлическими примесями, приводит как к увеличению обратного тока через переход коллектор–база транзисторов, так и к существенному снижению напряжения пробоя коллек- торного перехода. Наиболее вероятной причиной ухудшения электрофизических параметров биполярных n–p–nтранзисторов является загрязнение материала технологическими примесями (такими, как Fe, Cl, Ca, Cu, Zn и др.) во время производственного процесса изготовления приборов. Источниками загрязнений могут служить как детали и узлы технологических установок, так и используемые материалы и реактивы

Network analysis of human glaucomatous optic nerve head astrocytes

<p>Abstract</p> <p>Background</p> <p>Astrocyte activation is a characteristic response to injury in the central nervous system, and can be either neurotoxic or neuroprotective, while the regulation of both roles remains elusive.</p> <p>Methods</p> <p>To decipher the regulatory elements controlling astrocyte-mediated neurotoxicity in glaucoma, we conducted a systems-level functional analysis of gene expression, proteomic and genetic data associated with reactive optic nerve head astrocytes (ONHAs).</p> <p>Results</p> <p>Our reconstruction of the molecular interactions affected by glaucoma revealed multi-domain biological networks controlling activation of ONHAs at the level of intercellular stimuli, intracellular signaling and core effectors. The analysis revealed that synergistic action of the transcription factors AP-1, vitamin D receptor and Nuclear Factor-kappaB in cross-activation of multiple pathways, including inflammatory cytokines, complement, clusterin, ephrins, and multiple metabolic pathways. We found that the products of over two thirds of genes linked to glaucoma by genetic analysis can be functionally interconnected into one epistatic network via experimentally-validated interactions. Finally, we built and analyzed an integrative disease pathology network from a combined set of genes revealed in genetic studies, genes differentially expressed in glaucoma and closely connected genes/proteins in the interactome.</p> <p>Conclusion</p> <p>Our results suggest several key biological network modules that are involved in regulating neurotoxicity of reactive astrocytes in glaucoma, and comprise potential targets for cell-based therapy.</p

Model of daytime emissions of electronically-vibrationally excited products of O₃ and O₂ photolysis: application to ozone retrieval

The traditional kinetics of electronically excited products of O3 and O2 photolysis is supplemented with the processes of the energy transfer between electronically-vibrationally excited levels O2(a1&Delta;g, v) and O2(b1&Sigma;+g, v), excited atomic oxygen O(1D), and the O2 molecules in the ground electronic state O2(X3&Sigma;g&minus;, v). In contrast to the previous models of kinetics of O2(a1&Delta;g) and O2 (b1&Sigma;+g), our model takes into consideration the following basic facts: first, photolysis of O3 and O2 and the processes of energy exchange between the metastable products of photolysis involve generation of oxygen molecules on highly excited vibrational levels in all considered electronic states &ndash; b1&Sigma;+g, a1&Delta;g and X3&Sigma;g&minus;; second, the absorption of solar radiation not only leads to populating the electronic states on vibrational levels with vibrational quantum number v equal to 0 &ndash; O2(b1&Sigma;+g, v=0) (at 762 nm) and O2(a1&Delta;g, v=0) (at 1.27 &micro;m), but also leads to populating the excited electronic&ndash;vibrational states O2(b1&Sigma;+g, v=1) and O2(b1&Sigma;+g, v=2) (at 689 nm and 629 nm). The proposed model allows one to calculate not only the vertical profiles of the O2(a1&Delta;g, v=0) and O2(b1&Sigma;g, v=0) concentrations, but also the profiles of [O2(a1&Delta;g, v&le;5)], [O2 (b1&Sigma;+g , v=1, 2)] and O2(X3&Sigma;g&minus;, v=1&ndash;35). In the altitude range 60&ndash;125 km, consideration of the electronic-vibrational kinetics significantly changes the calculated concentrations of the metastable oxygen molecules and reduces the discrepancy between the altitude profiles of ozone concentrations retrieved from the 762-nm and 1.27-&micro;m emissions measured simultaneously

Research of Mechanical Treatment Influence on Rheological Properties of Coal-Water Fuel Based on Low-Grade 3B Coal

Experimental study of mechanical treatment effect of rotary flow modulation device on coal-water fuel rheological properties were conducted. The slurry was prepared on the basis of low-grade 3B coal from Balakhtinskoe deposit