158 research outputs found
A screened independent atom model for the description of ion collisions from atomic and molecular clusters
We apply a recently introduced model for an independent-atom-like calculation
of ion-impact electron transfer and ionization cross sections to proton
collisions from water, neon, and carbon clusters. The model is based on a
geometrical interpretation of the cluster cross section as an effective area
composed of overlapping circular disks that are representative of the atomic
contributions. The latter are calculated using a time-dependent
density-functional-theory-based single-particle description with accurate
exchange-only ground-state potentials. We find that the net capture and
ionization cross sections in p-X collisions are proportional to
with . For capture from water clusters at 100 keV impact
energy is close to one, which is substantially different from the
value predicted by a previous theoretical work based on the
simplest-level electron nuclear dynamics method. For ionization at 100 keV and
for capture at lower energies we find smaller values than for capture
at 100 keV. This can be understood by considering the magnitude of the atomic
cross sections and the resulting overlaps of the circular disks that make up
the cluster cross section in our model. Results for neon and carbon clusters
confirm these trends. Simple parametrizations are found which fit the cross
sections remarkably well and suggest that they depend on the relevant bond
lengths.Comment: 13 pages, 12 figure
Исследование влияния типа грунта на напряженно-деформированное состояние стенки магистрального трубопровода
В магистерской диссертации проведено исследование влияния типа грунта на напряжённо- деформированное состояние магистрального трубопровода. В качестве объекта исследования был выбран участок трубопроводной системы "Восточная Сибирь- Тихий Океан", находящийся в зоне распространения многолетнемёрзлых грунтов. Рассматриваемый участок был смоделирован в программе 3D Frost и оценено тепловое влияние нефтепровода на многолетнемёрзлые грунты. Рассчитана осадка нефтепровода и в программном комплексе ANSYS смоделирована деформация и рассмотрены напряжения стенки нефтепровода.In the Master's dissertation, the influence of the soil type on the stress-strain state of the main pipeline was investigated. The site of the pipeline system "Eastern Siberia-Pacific Ocean", located in the zone of distribution of permafrost soils, was chosen as the object of the study. The considered site was modeled in the 3D Frost program and the thermal influence of the oil pipeline on the permafrost was estimated. The sediment of the oil pipeline was calculated and deformation was modeled in the ANSYS software complex and the pipeline wall stresses were considered
Учет материально-производственных запасов в Российской Федерации и Республике Узбекистан
Цель данной работы является всесторонний анализ теоретических и практических основ организации учета материально-производственных запасов путем изучения и сравнения учета материально-производственных запасов в Российской Федерации и Республике Узбекистан, на примере АО "Алмалыкский ГМК", и разработать предложения по их усовершенствованию.
Объект исследования – предприятие АО "Алмалыкский ГМК" в Республике Узбекистан.The purpose of this work is a comprehensive analysis of the theoretical and practical foundations of the organization of accounting of inventories by studying and comparing the accounting of inventories in the Russian Federation and the Republic of Uzbekistan, using the example of JSC Almalyk MMC, and develop proposals for their improvement.
The object of the study is an enterprise of "Almalyk GMK" in the Republic of Uzbekistan
Molecular Level in Silico Studies for Oncology. Direct Models Review
The combination of therapy and diagnostics in one process "theranostics" is a trend in a modern medicine, especially in oncology. Such an approach requires development and usage of multifunctional hybrid nanoparticles with a hierarchical structure. Numerical methods and mathematical models play a significant role in the design of the hierarchical nanoparticles and allow looking inside the nanoscale mechanisms of agent-cell interactions. The current position of in silico approach in biomedicine and oncology is discussed. The review of the molecular level in silico studies in oncology, which are using the direct models, is presented
Оценка состояния протяженных выработок с длительным сроком службы шахт Центрального Донбасса на примере Шахтоуправления «Покровское»
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