Morphology and Optical Investigations of InAs-QD/GaAs Heterostructures Obtained by Ion-Beam Sputtering

A new ion-beam sputtering technique for obtaining self-assembled InAs quantum dots on GaAs (001) substrates is proposed. The current paper demonstrates that a temperature increase in a range from 450 to 550°C at ion current of 120 μA and energy of 150 eV leads to an expansion of average sizes of InAs hut-quantum dots. According to atomic force and electron microscopy, photoluminescence, and capacity-voltage measurements it was found that an increase of ion-beam current from 60 to 120 μA at a temperature of 500°C and energy of 150 eV slightly enlarges the average sizes of quantum dots from 15 nm to 18 nm while their dispersion is about 30%. At a current of 180 μA a surface density is 1.3·1011 cm−2, but under these conditions there is a very high dispersion of quantum dots up to 50%

Covariant Quantum Dynamical Semigroups: Unbounded generators

A survey of the probabilistic approaches to quantum dynamical semigroups with unbounded generators is given. An emphasis is made upon recent advances in the structural theory of covariant Markovian master equations. The relations with the classical Levy-Khinchin formula are elucidated. As an example, a complete characterizations of the Galilean covariant irreversible quantum Markovian evolutions is given in terms of the corresponding quantum master and Langevin equations. Important topics for future investigation are outlined.Comment: 14 pages,Latex, no figures, submitted to the Semigroup Volume, Group 21, Goslar 199

Local Magnetohydrodynamic Characteristics of the Plasma Stream generated by MPC

This paper investigates the spatial distributions of electrical current which flows inside the plasma stream generated by a magnetoplasma compressor (MPC). Two different modes of MPC operation with different gas supply scenarios have been applied in the experiments presented here. The first is the operation mode with a pulse injection of xenon into the interelectrode space, and the second is the operation mode with residual helium in the chamber and local injection of xenon directly into the compression zone. The maximum value of the electric current observed outside the MPC channel is 15 ÷ 20% of the total discharge current. Electric current vortices were discovered in the plasma stream. The amplitude of the current in the vortices reaches 50% of the total discharge current. The maximum EUV radiation power was measured in the mode of MPC operation with local xenon injection. Power in the wave range 12.2 ÷ 15.8 nm achieves up to 16 ÷ 18 kW

Local Magnetohydrodynamic Characteristics of the Plasma Stream generated by MPC

This paper investigates the spatial distributions of electrical current which flows inside the plasma stream generated by a magnetoplasma compressor (MPC). Two different modes of MPC operation with different gas supply scenarios have been applied in the experiments presented here. The first is the operation mode with a pulse injection of xenon into the interelectrode space, and the second is the operation mode with residual helium in the chamber and local injection of xenon directly into the compression zone. The maximum value of the electric current observed outside the MPC channel is 15 ÷ 20% of the total discharge current. Electric current vortices were discovered in the plasma stream. The amplitude of the current in the vortices reaches 50% of the total discharge current. The maximum EUV radiation power was measured in the mode of MPC operation with local xenon injection. Power in the wave range 12.2 ÷ 15.8 nm achieves up to 16 ÷ 18 kW

УСТРАНЕНИЕ ДЕФЕКТОВ ОСНОВАНИЯ ЧЕРЕПА И СРЕДНЕЙ ЗОНЫ ЛИЦА ПОСЛЕ ХИРУРГИЧЕСКОГО ЛЕЧЕНИЯ РАСПРОСТРАНЕННЫХ КРАНИОМАКСИЛЛЯРНЫХ ОПУХОЛЕЙ

Introduction. Performance the radical surgical treatment in patients with widespread cranio-maxillary tumors is followed by appearance of extensive defects.Objective. To explore the possibility of the applying the basic methods of eliminating defects cranio-maxillary localization after surgical treatment of tumors and their impact on quality of life and survival.Material and methods. The results of surgical treatment of 94 patients with the widespread cranio-maxillary tumors, depending on the performed type of the surgery and method of eliminating postoperative defects were analyzed.Results. Efficiency of different methods of reconstruction of defects of the midface and anterior skull base and their impact on quality of life and survival after the surgery were estimated. The use of general oncological methods in combination with the methods of the primary effectively correction of formed defects allows to achieve better results in the treatment of patients with widespread cranio-maxillary tumors. .Введение. Выполнение радикального оперативного пособия у пациентов с распространенными краниомаксиллярными опухолями сопровождается возникновением обширных дефектов.Цель исследования – изучить возможности применения основных методик устранения дефектов краниомаксиллярной локализации после хирургического лечения опухолей, их влияние на качество жизни и выживаемость.Материал и методы. Проанализированы результаты хирургического лечения 94 больных с распространенными краниомаксиллярными опухолями в зависимости от характера выполненного оперативного вмешательства, применяемой методики устранения послеоперационных дефектов.Результаты. Выполнена оценка эффективности использования различных методов в реконструкции дефектов средней зоны лица и основания черепа после хирургического лечения, их влияния на качество жизни и выживаемость. Применение онкологических методик в сочетании с первичным устранением образовавшихся дефектов позволяет добиться более высоких результатов лечения краниомаксиллярных опухолей

Predicting Missing Links via Local Information

Missing link prediction of networks is of both theoretical interest and practical significance in modern science. In this paper, we empirically investigate a simple framework of link prediction on the basis of node similarity. We compare nine well-known local similarity measures on six real networks. The results indicate that the simplest measure, namely common neighbors, has the best overall performance, and the Adamic-Adar index performs the second best. A new similarity measure, motivated by the resource allocation process taking place on networks, is proposed and shown to have higher prediction accuracy than common neighbors. It is found that many links are assigned same scores if only the information of the nearest neighbors is used. We therefore design another new measure exploited information of the next nearest neighbors, which can remarkably enhance the prediction accuracy.Comment: For International Workshop: "The Physics Approach To Risk: Agent-Based Models and Networks", http://intern.sg.ethz.ch/cost-p10

Characterization of the Row Geometric Mean Ranking with a Group Consensus Axiom

An axiomatic approach is applied to the problem of extracting a ranking of the alternatives from a pairwise comparison ratio matrix. The ordering induced by row geometric mean method is proved to be uniquely determined by three independent axioms, anonymity (independence of the labelling of alternatives), responsiveness (a kind of monotonicity property) and aggregation invariance, which requires the preservation of group consensus, that is, the pairwise ranking between two alternatives should remain unchanged if unanimous individual preferences are combined by geometric mean.Comment: 17 pages, 2 figure