288 research outputs found
"CSTC T-PPR": ARCHITECTURAL AND HISTORICAL DEVELOPMENT OF ODESSA IN ХІХ ... THE BEGINNING OF THE XX-th CENTURIES
It is offered to create in the city of Odessa "the Corporate scientific and technical complex town-planning power reconstruction "CSTC T-PPR", as innovative organizational structure which uses in practice the saved up scientific and technical potential for reconstruction of buildings of historical building of Odessa under standards power efficiency. It is executed researches of historically-style development which is characterized by the big scope of civil work and presence of various styles. Superstructures were carried out in a city practically during all history its development. The mansard floor is an effective variant a superstructure buildings of background building. Пропонується створити у місті Одесі "Корпоративний науково-технічний комплекс містобудівної енергореконструкції "КНТК МЕРек", як інноваційну організаційну структуру, яка використовує на практиці накопичений науково-технічний потенціал для реконструкції будівель історичної забудови Одеси за стандартами енергоефективності. Виконано дослідження історично-стильового розвитку Одеси в ХІХ … на початку ХХ століть, який характеризується великим розмахом будівельних робіт та наявністю різноманітних стилів (класицизм, бароко, романтизм, конструктивізм). Враховуючи, що розташування нового будинку в щільному ряду історичної забудови заборонено, то виходом з такої ситуації є надбудова будівлі новим об'ємом. Надбудови виконувалися в місті практично в ході всієї історії його розвитку. Ефективним варіантом надбудови будівель фонової забудови є мансардний поверх.
"CSTC T-PPR": USING CONSTRUCTION–HEAT-INSULATING AN AUTOCLAVE FOAM-CONCRETE
It is offered to create in the city of Odessa "the Corporate scientific and technical complex town-planning power reconstruction "CSTC T-PPR", as innovative organizational structure which uses in practice the saved up scientific and technical potential for reconstruction of buildings of historical building of Odessa under standards power efficiency. It was experimentally substantiated that the strength and carrying capacity of wall elements from construction–heat-insulating an autoclave foam-concrete depend on the amount of filler and its dispersion, and vary within fairly wide limits, which allows using this material as an effective material for external walls.Key words: a corporate scientific and technical complex, town-planning power reconstruction, external walls, construction–heat-insulating an autoclave foam-concrete, buildings of historical building
Maximally-localized Wannier Functions in Antiferromagnetic MnO within the FLAPW Formalism
We have calculated the maximally-localized Wannier functions of MnO in its
antiferromagnetic (AFM) rhombohedral unit cell, which contains two formula
units. Electron Bloch functions are obtained with the linearized augmented
plane-wave method within both the LSD and the LSD+U schemes. The thirteen
uppermost occupied spin-up bands correspond in a pure ionic scheme to the five
Mn 3d orbitals at the Mn_1 (spin-up) site, and the four O 2s/2p orbitals at
each of the O_1 and O_2 sites. Maximal localization identifies uniquely four
Wannier functions for each O, which are trigonally-distorted sp^3-like
orbitals. They display a weak covalent bonding between O 2s/2p states and
minority-spin d states of Mn_2, which is absent in a fully ionic picture. This
bonding is the fingerprint of the interaction responsible for the AFM ordering,
and its strength depends on the one-electron scheme being used. The five Mn
Wannier functions are centered on the Mn_1 site, and are atomic orbitals
modified by the crystal field. They are not uniquely defined by the criterion
of maximal localization and we choose them as the linear combinations which
diagonalize the r^2 operator, so that they display the D_3d symmetry of the
Mn_1 site.Comment: 11 pages, 6 PostScript figures. Uses Revtex4. Hi-res figures
available from the author
The issues of weed infestation with environmentally hazardous plants and methods of their control
The authors analyze expansion of segetal and ruderal vegetation on agricultural lands in Leningrad and Tomsk oblasts, typical for the European and Asian parts of Russia. The spreading conditions, composition of species, biological features and ecological requirements of the most aggressive species are identified. Some effective ways of weed control are suggested
Dynamical mean-field theory using Wannier functions: A flexible route to electronic structure calculations of strongly correlated materials
International audienceA versatile method for combining density functional theory in the local density approximation with dynamical mean-field theory (DMFT) is presented. Starting from a general basis-independent formulation, we use Wannier functions as an interface between the two theories. These functions are used for the physical purpose of identifying the correlated orbitals in a specific material, and also for the more technical purpose of interfacing DMFT with different kinds of band-structure methods (with three different techniques being used in the present work). We explore and compare two distinct Wannier schemes, namely the maximally localized Wannier function and the Nth order muffin-tin-orbital methods. Two correlated materials with different degrees of structural and electronic complexity, SrV O3 and BaV S3, are investigated as case studies. SrV O3 belongs to the canonical class of correlated transition-metal oxides, and is chosen here as a test case in view of its simple structure and physical properties. In contrast, the sulfide BaV S3 is known for its rich and complex physics, associated with strong correlation effects and low-dimensional characteristics. Insights into the physics associated with the metal-insulator transition of this compound are provided, particularly regarding correlation-induced modifications of its Fermi surface. Additionally, the necessary formalism for implementing self-consistency over the electronic charge density in a Wannier basis is discussed. © 2006 The American Physical Society
Spontaneous polarization and piezoelectric constants of III-V nitrides
The spontaneous polarization, dynamical Born charges, and piezoelectric
constants of the III-V nitrides AlN, GaN, and InN are studied ab initio using
the Berry phase approach to polarization in solids. The piezoelectric constants
are found to be up 10 times larger than in conventional III-V's and II-VI's,
and comparable to those of ZnO. Further properties at variance with those of
conventional III-V compounds are the sign of the piezoelectric constants
(positive as in II-VI's) and the very large spontaneous polarization.Comment: RevTeX 4 pages, improved upon revie
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