Temperature independent diffuse scattering and elastic lattice deformations in relaxor PbMg1/3Nb2/3O3

The results of diffuse neutron scattering experiment on PbMg1/3Nb2/3O3 single crystal above the Burns temperature are reported. It is shown that the high temperature elastic diffuse component is highly anisotropic in low-symmetry Brillouin zones and this anisotropy can be described using Huang scattering formalism assuming that the scattering originates from mesoscopic lattice deformations due to elastic defects. The qualitative agreement between this model and the experimental data is achieved with simple isotropic defects. It is demonstrated that weak satellite maxima near the Bragg reflections can be interpreted as the finite resolution effect.Comment: 7 pages, 7 figure

Structural heterogeneity and diffuse scattering in morphotropic lead zirconate-titanate single crystals

Complementary diffuse and inelastic synchrotron X-ray scattering measurements of lead zirconate-titanate single crystals with composition near the morphotropic phase boundary (x=0.475) are reported. In the temperature range 293 K < T < 400 K a highly anisotropic quasielastic diffuse scattering is observed. Above 400 K this scattering disappears. Its main features can be reproduced by model of inhomogeneous lattice deformations caused by inclusions of a tetragonal phase into a rhombohedral or monoclinic phase. This observation supports the idea that PZT at its morphotropic phase boundary is essentially structurally inhomogeneous.Comment: 4 pages, 4 figure

BERNAS ION SOURCE DISCHARGE SIMULATION

The joint research and development program is continued to develop steady-state ion source of decaborane beam for ion implantation industry. Bemas ion source is the wide used ion source for ion implantation industry. The new simulation code was developed for the Bemas ion source discharge simulation. We present first results of the simulation for several materials interested in semiconductors. As well the comparison of results obtained with experimental data obtained at the ITEP ion source test-bench is presented

Ion Sources for Energy Extremes of Ion Implantation.

For the past four years a joint research and development effort designed to develop steady state, intense ion sources has been in progress with the ultimate goal to develop ion sources and techniques, which meet the two energy extreme range needs of mega-electron-volt and 100's of electron-volt ion implanters. This endeavor has already resulted in record steady state output currents of high charge state of Antimony and Phosphorous ions: P{sup 2+} (8.6 pmA), P{sup 3+} (1.9 pmA), and P{sup 4+} (0.12 pmA) and 16.2, 7.6, 3.3, and 2.2 pmA of Sb{sup 3+} Sb{sup 4+}, Sb{sup 5+}, and Sb{sup 6+} respectively. For low energy ion implantation our efforts involve molecular ions and a novel plasmaless/gasless deceleration method. To date, 1 emA of positive Decaborane ions were extracted at 10 keV and smaller currents of negative Decaborane ions were also extracted. Additionally, Boron current fraction of over 70% was extracted from a Bemas-Calutron ion source, which represents a factor of 3.5 improvement over currently employed ion sources

GENERAL PROFESSIONAL COMPETENCE OF A MODERN RUSSIAN ENGINEER

The National Presidential Council for professional competence coordinates development of new professional standards and modernization of existing ones. A task was set to prepare and update Educational Standards on the basis of revised Professional Standards. 158 Federal State Educational Standards on Engineering and Industrial Technology Sciences have been developed so far. It is suggested to use this massive data to formulate a generalized competence-based model of an engineer with a particular educational degree in a particular field of education. To develop the model a standardization of wording for all general professional competences similar for all engineering majors had to be completed. The results of the survey described in this article will be the basis for recommendations of Coordination Board in Engineering and Industrial Technology Sciences. A project of general professional competences unified for the field of education is presented in the summary of the article

Ways to Reduce Risks When Building the Digital Economy in Russia. Educational Aspect

А group of authors of Peter the Great St. Petersburg Polytechnic University, working within the framework of the activity of Coordination Council for the Federal Educational and Methodical Associations on education in the field of “Engineering, Technology and Technical Sciences” have undertaken a comprehensive study dedicated to the processes of the digital economy formation. More than two hundred primary sources of reference have been analyzed. Several main groups of risks associated with the transition to global digitalization have been defined and classified. Further research results described in this article allow to characterize the specific features of the occurrence of risks in the Russian Federation and to determine the ways of reducing these risks.In addition to the six groups of risks which are currently possible to arise and which are characteristic of the entire world space, the authors have revealed a number of several additional risks typical only of Russia. One of the key areas in Russia that poses a whole range of various risks is the education system. The authors have analyzed and classified the policies and moves suggested by the researchers and politicians to reduce the likelihood of these specific risks occurrence.The qualitative leap of the educational process in Russia is possible only by means of the formation of some new competence profiles of educational institutions graduates with reference to the digital economy development conditions. The authors have defined seven types of competencies that are relevant for the transition of Russia to the digital economy and developed twelve pilot educational modules necessary for their formation

Conditions for Production of Composite Material Based on Aluminum and Carbon Nanofibers and Its Physic-Mechanical Properties

Aluminum-based metallic matrix composites reinforced by carbon nanofibers (CNFs) are important precursors for development of new light and ultralight materials with enhanced properties and high specific characteristics. In the present work, powder metallurgy technique was applied for production of composites based on reinforcement of aluminum matrices by CNFs of different concentrations (0~2.5 wt%). CNFs were produced by chemical vapor deposition (CVD) and mechanical activation. We determined that in situ synthesis of carbon nanostructures with subsequent mechanic activation provides satisfactory distribution of nanofibers and homogeneous composite microstructure. Introduction of 1 vol% of flux (0.25 NaCl + 0.25 KCl + 0.5 CaF2) during mechanic activation helps to reduce the strength of the contacts between the particles. Additionally, better reinforcement of alumina particles and strengthening the bond between CNFs and aluminum are observed due to alumina film removal. Introduction of pure aluminum into mechanically alloyed powder provides the possibility to control composite durability, plasticity and thermal conductivity